Patent Publication Number: US-2019186841-A1

Title: Thermal management devices and methods of making the same

Description:
PRIORITY 
     This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 62/336,040, filed on May 13, 2016, the benefit of priority of each of which is claimed hereby, and each of which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     Thermal management is critical in extending the life of various electrical and electronic devices. The life span and performance of the electronic devices can be partially dependent on efficiently dissipating generated heat. For example, a life span of a light-emitting diode (LED) can depend on the junction temperature. The life span of the LED can decrease exponentially with increase in junction temperature of the LED, LEDs, and other electronic devices, can produce a considerable amount of heat. If the heat is not efficiently dissipated and accumulates, the electrical and electronic devices can overheat and significantly reduce the work efficiency and cause the lifespan to decrease or cause terminal failure. Additionally, as the electronic devices, such as LEDs, are made smaller and the use of high density semiconductor circuits is increased, the difficulty of efficiently removing the heat can increase. 
     SUMMARY OF THE INVENTION 
     The present disclosure is directed to thermal management devices and methods of making the thermal management devices. In various embodiments, the thermal management devices and methods can include a hybrid heat sink having a body formed from a thermally conductive plastic with metal thermal wicks formed on the external surface of the body by a selective metallization process. The thermal management devices and methods can include a cooling structure integrally formed with a heat sink body and/or a lens cap for an LED and include one or more channels configured to hold a medium (e.g., a heat transport medium) that can transport heat generated by a heat source away from the heat source. The devices and methods of the present disclosure can be used to efficiently dissipate heat generated by an electric device. As discussed herein, the present disclosure can increase heat dissipation while decreasing the cost of manufacture. 
     The present inventors have recognized, among other things, that existing devices and methods for thermal management can be improved. For example, with increased miniaturization of devices and use of high density semiconductor circuits there is significant heat that has to be dissipated from the system that would otherwise lead to premature failure of devices. The present subject matter described herein can provide a solution to this problem, such as by providing hybrid heat sinks with metal thermal wicks and cooling structures. 
     Traditionally, heat sinks can be made of aluminum and are usually extruded or machined from blocks. In the recent times with the advent of thermally conductive plastics, previous approaches have replaced aluminum heat sinks with heat sinks formed from thermally conductive plastics. Beyond certain wattage, previous approaches have overmolded aluminum inserts with thermally conductive plastics. In such cases, the aluminum insert has to be shaped typically through metal stamping and insert molded using injection molding process, leading to an increase in costs, use of many processes, and limits design of the heat sink. 
     In various embodiments, the present subject matter provides a heat sink where the use of metal is minimized and is deposited on the outer surface of the plastic part, forming a highly preferred conductive path between the heat source and the outside ambient air. The thermal wicks that are deposited on the external surface of the heat sink allow for three-dimensional forms and design of heat sinks, which would be more costly for the other heat sinks that incorporate the overmolded aluminum inserts. Thus, the present subject matter allows for design freedom with light weight and low cost solutions for thermal management. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. 
         FIG. 1  illustrates a perspective view of a heat sink system, in accordance with various embodiments. 
         FIG. 2  illustrates a perspective view of a main body of a heat sink, in accordance with various embodiments. 
         FIG. 3  illustrates another perspective view of the main body shown  FIG. 2 . 
         FIG. 4  illustrates a perspective view of a heat sink, in accordance with various embodiments. 
         FIG. 5  illustrates a cross-sectional view of a heat sink including an LED chip, in accordance with various embodiments. 
         FIG. 6  illustrates a cross-sectional view of a heat sink including an LED chip, in accordance with various embodiments. 
         FIG. 7  illustrates a cross-sectional view of a heat sink including an LED chip, in accordance with various embodiments. 
         FIG. 8  illustrates a top down view of a heat sink, in accordance with various embodiments. 
         FIG. 9  illustrates a top down view of a heat sink, in accordance with various embodiments. 
         FIG. 10  illustrates a perspective view of a heat sink, in accordance with various embodiments. 
         FIG. 11  illustrates a cross-sectional view of a heat sink including a heat source, in accordance with various embodiments. 
         FIG. 12  illustrates a cross-sectional view of a heat sink system, in accordance with various embodiments. 
         FIG. 13  illustrates a cross-sectional view of a heat sink system, in accordance with various embodiments. 
         FIG. 14  illustrates a cross-sectional view of a heat sink system, in accordance with various embodiments. 
         FIG. 15  illustrates a cross-sectional view of a heat sink system, in accordance with various embodiments. 
         FIG. 16  illustrates a cross-sectional view of a heat sink system, in accordance with various embodiments. 
         FIG. 17  illustrates a perspective view of a heat sink system, in accordance with various embodiments. 
         FIG. 18  illustrates a cross-sectional view of a heat sink system, in accordance with various embodiments. 
         FIG. 19  illustrates a cross-sectional view of a heat sink system, in accordance with various embodiments. 
         FIG. 20  illustrates a cross-sectional view of a heat sink system, in accordance with various embodiments. 
         FIG. 21  illustrates a perspective view of a heat sink, in accordance with various embodiments. 
         FIG. 22  illustrates a cross-sectional view of a heat sink system, in accordance with various embodiments. 
         FIG. 23  illustrates another cross-sectional view of the heat sink system in  FIG. 22 , in accordance with various embodiments. 
         FIG. 24  illustrates a cross-sectional view a heat sink system, in accordance with various embodiments. 
         FIG. 25  illustrates a flow of a heat transport medium through a heat sink, in accordance with various embodiments. 
         FIG. 26  illustrates a cross-sectional view of a heat sink system, in accordance with various embodiments. 
         FIG. 27  illustrates a representation of Examples 1-5. 
         FIG. 28  illustrates a representation of Example 6. 
         FIG. 29  illustrates a representation of Comparative Example B. 
         FIG. 30  is a graph illustrating the maximum temperature for the temperature sensors in Example 6 and Comparative Example B. 
         FIG. 31  is a graph illustrating a temperature profile for each of the temperature sensors for Comparative Example B. 
         FIG. 32  is a graph illustrating a temperature profile for each of the temperature sensors for Example 6. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to certain embodiments of the disclosed subject matter, examples of which are illustrated in part in the accompanying drawings. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter. 
     Heat Sink Including Thermal Wicks 
       FIG. 1  illustrates a perspective view of a heat sink system  10 . In various embodiments, the heat sink system  10  can include a heat sink  12  and a conductive insert  20 . The heat sink system  10  can be used to efficiently transport heat away from a heat source  22 , e.g., an LED chip. The heat sink  12  includes a main body  14  including heat dissipation elements (e.g., fins  16 ). The main body  14  can have various designs including different shapes, sizes, and heat dissipation elements. As seen in  FIG. 1 , the heat sink  12  includes thermal wicks  18  extending along the main body  14 . As discussed herein, the main body  14  is formed from plastic, which can reduce manufacturing costs and increase design flexibility. The thermal wicks  18  are disposed along the main body  14  to increase the heat dissipation of the heat sink  12  while minimizing the amount of material used to form the thermal wicks  18  thereby further reducing the cost of manufacture. 
       FIGS. 2 and 3  illustrate perspective views of the main body  14  of the heat sink  12 . The main body  14  is formed from a plastic. For example, the main body  14  can be formed from thermally conductive plastics or non-thermally conductive plastics. The main body  14  includes a first end  26 , a second end  28 , and a plurality of heat dissipation elements (e.g., fins  16 ) extending therebetween. As shown in  FIG. 2 , the first end  26  includes an interior ridge  34  and an exterior ridge  36  that define a space  24  therebetween. The space  24  can be configured to receive and couple with, for example, a plastic lens cap, when the heat source  22  (shown in  FIG. 1 ) is a LED chip. The main body  14  can define an opening  32  extending from the first end  26  to the second end  28 . The main body can also include a flange  30  extending into the opening  32 . The main body  14  can include an internal surface  40  and an external surface  44 . 
     The design of the main body  14  can be dependent upon the particular application and heat transfer needed. The main body  14  can have a round or polygonal cross-sectional geometry. The main body  14  can also include various heat dissipation elements. Referring to  FIGS. 2 and 3 , fins  16  are shown as the heat dissipation elements.  FIG. 10  illustrates another heat dissipation element design wherein fins  72  extend outward, e,g, laterally. Any design and suitable spacing of the heat dissipation elements are possible. The heat dissipation elements can increase the surface area of the heat sink to enhance heat dissipation away from the heat source. 
     Referring to  FIG. 3 , the main body  14  can include a base portion  38  where the heat dissipation elements, e.g., fins  16 , are disposed radially around and extending outward from the base  38 . The fins  16  can include a first surface  33  and a second surface  35 , opposite the first surface  33 , and a face  37  extending between the first and second surfaces  33 ,  35 . Between adjacent fins  16  is a wall  42  of the base portion  38  connecting adjacent fins  16 . The spacing between adjacent fins  16  can be same between all fins  16  or can vary. While the main body  14 , as shown, includes heat dissipation elements, the thermal wicks of the present disclosure can be used on a main body  14  that does not include thermal dissipation elements (e.g., fins  16 ). 
     In one embodiment, the main body  14  can be formed by injection molding a flowable composition of the plastic (e.g., a thermally conductive plastic or a non-thermally conductive plastic). As used herein, the term “injection molding” refers to a process for producing a molded part or form by injecting a composition including one or more polymers that are thermoplastic, thermosetting, or a combination thereof, into a mold cavity, where the composition cools and hardens to the configuration of the cavity. Injection molding can include the use of heating via sources such as steam, induction, cartridge heater, or laser treatment to heat the mold prior to injection, and the use of cooling sources such as water to cool the mold after injection, allowing faster mold cycling and higher quality molded parts or forms. 
     The thermally conductive plastics can also be electrically insulating, e.g., having an electrical resistivity greater than or equal to 10 13  Ohms per square (Ohm/sq). The thermally conductive plastic can include an organic polymer and a filler composition comprising graphite and boron nitride. For example, the thermally conductive plastic can have a bulk surface resistivity greater than or equal to 10 13  Ohm/sq, while displaying a thermal conductivity greater than or equal to 2 W/m-K. The melt flow index can be 1 to 30 grams per 10 minutes at a temperature of 280 degrees Celsius (° C.) and a load of 16 kilograms force per square centimeter (kg-f/cm 2 ). Exemplary thermally conductive plastics are disclosed in commonly assigned U.S. Pat. No. 8,741,998, U.S. Pat. No. 8,552,101, and U.S. patent application Ser. No. 11/689,228. 
     The organic polymer used in the thermally conductive plastic can be selected from a wide variety of thermoplastic resins, blend of thermoplastic resins, thermosetting resins, or blends of thermoplastic resins with thermosetting resins, as well as combinations comprising at least one of the foregoing. The organic polymer may also be a blend of polymers, copolymers, terpolymers, or combinations comprising at least one of the foregoing. The organic polymer can also be an oligomer, a homopolymer, a copolymer, a block copolymer, an alternating block copolymer, a random polymer, a random copolymer, a random block copolymer, a graft copolymer, a star block copolymer, a dendrimer, or the like, or a combination comprising at least one of the foregoing. Examples of the organic polymer include polyacetals, polyolefins, polyacrylics, poly(arylene ether) polycarbonates, polystyrenes, polyesters cycloaliphatic polyester, high molecular weight polymeric glycol terephthalates or isophthalates, and so forth), polyamides (e.g., semi-aromatic polyamid such as PA4.T, PA6.T, PA9.T, and so forth), polyamideimides, polyarylates, polyarylsulfones, polyethersulfones, polyphenylene sulfides, polyvinyl chlorides, polysulfones, polyimides, polyetherimides, polytetrafluoroethylenes, polyetherketones, polyether etherketones, polyether ketone ketones, polybenzoxazoles, polyphthalides, polyacetals, polyanhydrides, polyvinyl ethers, polyvinyl thioethers, polyvinyl alcohols, polyvinyl ketones, polyvinyl halides, polyvinyl nitriles, polyvinyl esters, polysulfonates, polysulfides, polythioesters, polysulfones, polysulfonamides, polyureas, polyphosphazenes, polysilazanes, styrene acrylonitrile, acrylonitrile-butadiene-styrene (ABS), polyethylene terephthalate, polybutylene terephthalate, polyurethane, ethylene propylene diene rubber (EPR), polytetrafluoroethylene, fluorinated ethylene propylene, perfluoroalkoxyethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, or the like, or a combination comprising at least one of the foregoing organic polymers. Examples of polyolefins include polyethylene (PE), including high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), mid-density polyethylene (MDPE), glycidyl methacrylate modified polyethylene, maleic anhydride functionalized polyethylene, maleic anhydride functionalized elastomeric ethylene copolymers (like EXXELOR VA1801 and VA1803 from ExxonMobil), ethylene-butene copolymers, ethylene-octene copolymers, ethylene-acrylate copolymers, such as ethylene-methyl acrylate, ethylene-ethyl acrylate, and ethylene butyl acrylate copolymers, glycidyl methacrylate functionalized ethylene-acrylate terpolymers, anhydride functionalized ethylene-acrylate polymers, anhydride functionalized ethylene-octene and anhydride functionalized ethylene-butene copolymers, polypropylene (PP), maleic anhydride functionalized polypropylene, glycidyl methacrylate modified polypropylene, and a combination comprising at least one of the foregoing organic polymers. 
     In the context of this application a ‘semi-aromatic polyamide’ is understood to be a polyamide homo- or copolymer that contains aromatic or semi-aromatic units derived from an aromatic dicarboxylic acid, an aromatic diamine or an aromatic aminocarboxylic acid, the content of said units being at least 50 mole percent (mol %). In some cases these semi-aromatic polyamides are blended with small amounts of aliphatic polyamides for better proccessability. They are available commercially e.g. DuPont, Wilmington, Del., USA under the Tradename ZYTEL HTN, Solvay Advanced Polymers under the Tradename AMODEL or from DSM, Sittard, The Netherlands under the Tradename STANYL FOR TII. 
     Examples of blends of thermoplastic resins include acrylonitrile-butadiene-styrene/nylon, polycarbonate/acrylonitrile-butadiene-styrene, acrylonitrile butadiene styrene/polyvinyl chloride, polyphenylene ether/polystyrene, polyphenylene ether/nylon, polysulfone/acrylonitrile-butadiene-styrene, polycarbonate/thermoplastic urethane, polycarbonate/polyethylene terephthalate, polycarbonate/polybutylene terephthalate, thermoplastic elastomer alloys, nylon/elastomers, polyester/elastomers, polyethylene terephthalate/polybutylene terephthalate, acetal/elastomer, styrene-maleicanhydride/acrylonitrile-butadiene-styrene, polyether etherketone/polyethersulfone, polyether etherketone/polyetherimide polyethylene/nylon, polyethylene/polyacetal, or the like. 
     Examples of thermosetting resins include polyurethane, natural rubber, synthetic rubber, epoxy, phenolic, polyesters, polyamides, silicones, or the like, or a combination comprising at least one of the foregoing thermosetting resins. Blends of thermoset resins as well as blends of thermoplastic resins with thermosets can be utilized. 
     In one embodiment, an organic polymer that can be used in the conductive composition is a polyarylene ether. The term poly(arylene ether) polymer includes polyphenylene ether (PPE) and poly(arylene ether) copolymers; graft copolymers; poly(arylene ether) ionomers; and block copolymers of alkenyl aromatic compounds with poly(arylene ether)s, vinyl aromatic compounds, and poly(arylene ether), and the like; and combinations including at least one of the foregoing. 
     The organic polymer can be used in amounts of 1 to 85 weight percent (wt %), specifically, 33 to 80 wt %, more specifically 35 wt % to 75 wt %, and yet more specifically 40 wt % to 70 wt %, of the total weight of the moldable composition. 
     The filler composition used in the moldable composition comprises graphite and boron nitride. It is desirable to use graphite having average particle sizes of 1 to 5,000 micrometers. Within this range graphite particles having sizes of greater than or equal to 3, specifically greater than or equal to 5 micrometers may be advantageously used. Also desirable are graphite particles having sizes of less than or equal to 4,000, specifically less than or equal to 3,000, and more specifically less than or equal to 2,000 micrometers. 2.5 Graphite is generally flake like with an aspect ratio greater than or equal to 2, specifically greater than or equal to 5, more specifically greater than or equal to 10, and even more specifically greater than or equal to 50. In one aspect, the graphite is flake graphite, wherein the flake graphite is typically found as discrete flakes having a size of 10 micrometers to 800 micrometers in diameter (as measured along a major axis) and 1 micrometers to 150 micrometers thick, e.g., with purities ranging from 80-99.9% carbon. In another aspect the graphite is spherical. “Aspect ratio” as used herein referred to the ratio of average diameters of the flakes to the average thickness of the flake. 
     Graphite is generally used in amounts of greater than or equal to 10 wt % to 30 wt specifically, 13 wt % to 28 wt %, more specifically 14 wt % to 26 wt %, and yet snore specifically 15 wt % to 25 wt %, of the total weight of the moldable composition. 
     Boron nitride may be cubic boron nitride, hexagonal boron nitride, amorphous boron nitride, rhombohedral boron nitride, or another allotrope. It may be used as powder, agglomerates, fibers, or the like, or a combination comprising at least one of the foregoing. 
     Boron nitride has an average particle size of 1 to 5,000 micrometers. Within this range boron nitride particles having sizes of greater than or equal to 3, specifically greater than or equal to 5 micrometers may be advantageously used. Also desirable are boron nitride particles having sizes of less than or equal to 4,000, specifically less than or equal to 3,000, and more specifically less than or equal to 2,000 micrometers. Boron nitride is generally flake like with an aspect ratio greater than or equal to  2 , specifically greater than or equal to 5, more specifically greater than or equal to 10, and even more specifically greater than or equal to 50. An exemplary particle size is 125 to 300 micrometers with a crystal size of 10 to 15 micrometers. The boron nitride particles can exist in the form of agglomerates or as individual particles or as combinations of individual particles and agglomerates. Exemplary boron nitrides are PT350, PT360 or PT 370, commercially available from General Electric Advanced Materials. 
     Boron nitride (BN) is generally used in amounts of 5 wt % to 60 wt %, specifically, 8 wt % to 55 wt %, more specifically 10 wt % to 50 wt %, and yet more specifically 12 wt % to 45 wt %, of the total weight of the moldable composition. An exemplary amount of boron nitride is 15 to 40 wt % of the total weight of the thermally conductive plastic. In one aspect, the BN has a BN purity of 95% to 99.8%. In one aspect, a large single crystal sized flake BN with an average size of 3 to 50 micrometer and a BN purity of over 98% is used. The particle size indicated here means the single BN particle or its agglomerate at any of their dimensions. 
     One or more low thermal conductivity fillers can be used. The low thermal conductivity, electrically insulative filler has an intrinsic thermal conductivity of from 10 to 30 W/mK, specifically, 15 to 30 W/mK, and more specifically, 15 to 20 W/mK. The resistivity can be greater than or equal to 10 5  Ohm·cm. Examples of the low thermal conductivity filler include, but are not limited to, ZnS (zinc sulfide), CaO (calcium oxide), MgO (magnesium oxide), ZnO (zinc oxide), TiO 2  (titanium dioxide), or a combination comprising at least one of the foregoing. 
     One or more high thermal conductivity, electrically insulative fillers can be used. The high thermal conductivity filler has an intrinsic thermal conductivity greater than or equal to 50 W/mK, specifically, greater than or equal to 100 W/mK, more specifically, greater than or equal to 150 W/mK. The resistivity can be greater than or equal to 10 5  Ohm·cm. Examples of the high thermal conductivity, electrically insulative filler include, but are not limited to, AlN (aluminum nitride), BN (boron nitride), MgSiN 2  (magnesium silicon nitride), SiC (silicon carbide), ceramic-coated graphite, or a combination comprising at least one of the foregoing. 
     One or more high thermal conductivity, electrically conductive fillers can be used. The high thermal conductivity, electrically conductive filler has an intrinsic thermal conductivity greater than or equal to 50 W/mK, specifically, greater than or equal to 100 W/mK, more specifically, greater than or equal to 150 W/mK. The resistivity can be less than or equal to 1 Ohm·cm. Examples of the high thermal conductivity, electrically conductive filler include, but are not limited to, graphite, expanded graphite, graphene, carbon fiber, carbon nanotubes (CNT), graphitized carbon black, or a combination comprising at least one of the foregoing. 
     Additionally, the thermally conductive plastic can optionally also contain additives such as antioxidants, such as, for example, organophosphites, for example, tris(nonyl-phenyl)phosphite, tris(2,4-di-t-butylphenyl)phosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite or distearyl pentaerythritol diphosphite, alkylated monophenols, polyphenols and alkylated reaction products of polyphenols with dienes, such as, for example, tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)]methane, 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, octadecyl 2,4-di-tert-butylphenyl phosphite, butylated reaction products of para-cresol and dicyclopentadiene, alkylated hydroquinones, hydroxylated thiodiphenyl ethers, alkylidene-bisphenols, benzyl compounds, esters of beta-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid with monohydric or polyhydric alcohols, esters of beta-(5-tert-butyl-4-hydroxy-3-methylphenyl)-propionic acid with monohydric or polyhydric alcohols; esters of thioalkyl or thioaryl compounds, such as, for example, distearylthiopropionate, dilaurylthiopropionate, ditridecylthiodipropionate, amides of beta-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid; fillers and reinforcing agents, such as, for example, silicates, titanium dioxide (TiO 2 ), calcium carbonate, talc, mica and other additives such as, for example, mold release agents, ultraviolet absorbers, stabilizers such as light stabilizers and others, lubricants, plasticizers, pigments, dyes, colorants, anti-static agents, blowing agents, flame retardants, impact modifiers, among others, as well as combinations comprising at least one of the foregoing additives. 
     The thermally conductive plastics can comprise a random distribution of graphite and boron nitride and can have a thermal conductivity of greater than 2 Watts per meter-Kelvin (W/mK). The thermally conductive plastic can have a thermal conductivity of 2 to 6 W/mK, specifically, 2.2 W/mK to 4.0 W/mK, more specifically 2.3 W/mK to 3.9 W/mK, and yet more specifically 2.4 W/mK to 3.8 W/mK. 
     In various embodiments, the thermally conductive plastic can comprise: 35 volume percent (vol %) to 80 vol of a thermoplastic polymer; 5 vol to 45 vol of a thermally insulative filler with an intrinsic thermal conductivity less than or equal to 10 W/mK; and 5 vol % to 15 vol % of a thermally conductive filler with an intrinsic thermal conductivity greater than or equal to 50 W/mK. The thermally conductive plastic can have a thermal conductivity of at least 1.0 W/mK, a thermal conductivity of at least 7 times the total filler volume fraction times the thermal conductivity of the pure thermoplastic polymer; and/or a volume resistivity of at least 10 7  Ohm-centimeter (Ohm·cm). In various embodiments, the thermally conductive filler can comprise AlN, BN, MgSiN 2 , SiC, graphite, ceramic-coated graphite, expanded graphite, graphene, a carbon fiber, a carbon nanotube, graphitized carbon black, or a combination comprising at least one of the foregoing thermally conductive fillers. In one embodiment, the thermoplastic polymer comprises a polyamide, polyester, polyethylene and ethylene based copolymer, polypropylene, polyphenylene sulfide, or a combination comprising at least one of the foregoing; the thermally insulative filler comprises talc, CaCO 3 , Mg(OH) 2 , or a combination comprising at least one of the foregoing; and the thermally conductive filler comprises graphite. 
     In various embodiments, the thermally conductive plastic the composition) can comprise: 35 vol % to 80 vol of a thermoplastic polymer; 5 vol % to 45 vol % of a low thermal conductivity, electrically insulative filler with an intrinsic thermal conductivity of 10 W/mK to 30 W/mK; 2 vol % to 15 vol % of a high thermal conductivity, electrically insulative filler with an intrinsic thermal conductivity greater than or equal to 50 W/mK; and 2 vol % to 15 vol % of a high thermal conductivity, electrically conductive filler with an intrinsic thermal conductivity greater than or equal to 50 W/mK. The composition can have a thermal conductivity of at least 1.0 W/mK and/or a volume resistivity of at least 10 7  Ohm·cm. 
     An example of a thermally conductive plastic is Konduit* thermally conductive plastic commercially available from SABIC Innovative Plastics, Pittsfield, Mass., including, but not limited to, grades PX08321, PX08322, PX09322, PX10321, PX10322, PX10323, and PX10324. In one example, the main body  14  is formed from Konduit*. 
     As discussed herein, non-thermally conductive plastics can be used to form the main body  14 . In various embodiments, the non-thermally conductive plastics can include any of the fillers or additives discussed herein. In various embodiments, the non-thermally conductive plastics can be a blend of polymers such as, but not limited to, polycarbonate and acrylonitrile-butadiene-styrene. 
       FIG. 4  illustrates a perspective view of the heat sink  12 . The heat sink  12  includes the thermal wicks  18  deposited on the main body  14 . For example, the thermal wicks  18  are deposited along the internal surface  40  and the external surface  44 . The heat sink  12  also includes a wick connector  46  formed on the internal surface  40  and thermally connects all of the thermal wicks  18 . As discussed herein, the wick connector  46  and thermal wicks  18  form a conductive path that is thermally connected to the heat source. The thermal wicks  18  can have a first end thermally connected to the heat source located toward the first end  26  of the main body  14  and extend away from the heat source toward the second end  28  of the main body  14 . The thermal wicks  18  can be exposed to air to remove heat generated from the heat source. The wick connector  46 , thermally coupling the thermal wicks  18 , can be thermally connected to a heat source  22  (as shown in  FIG. 1 ) at the first end  26  of the main body  14  and the thermal wicks  18  can extend from the wick connector  46  and along the main body  14  toward the second end  28 . 
     The number and placement of the thermal wicks  18  can depend on the particular application and heat transfer needs. As shown in  FIG. 4 , the thermal wicks  18  extend from the wick connector  46 , along a portion of the internal surface  40  and along the external surface  44 , toward the second end  28 . The heat sink  12  can include thermal wicks  18 - 1  that extend along the wall portion  42  between two adjacent fins  16  and thermal wicks  18 - 2  that extends along the face  37  of the fin  16 . 
     In various embodiments, the conductive path including the wick connector  46  and the thermal wicks  18  can be formed on the main body  14  by selective metallization processes. In various embodiments, the conductive path is formed by laser direct structuring (LDS). In that instance, the main body  14  can be formed from a plastic that reacts to laser direct structuring. A laser can write the course of the determined conductive path on the main body  14 . Wherever the laser hits the plastic, the surface becomes activated and metal can be deposited precisely on the tracks of the laser via an electroless metal deposition process. In various embodiments, the wick connector  46  and the thermal wicks  18  can be formed from copper. For example, after activation, the main body  14  can be taken up for electroless copper plating, where copper gets deposited on the activated surfaces of the main body  14  forming the conductive path. This method provides a thermal conducting three-dimensional path. Other metals besides copper can also be used. For example, silver and aluminum, among others, can be used. In various embodiments, the wick connector  46  and the thermal wicks  18  can have a thickness of about 0.2 millimeters and have a width of about 4.0 mm. However, the thickness and width can vary depending on the main body  14  design and particular application and heat transfer needs. As discussed herein, the heat sink  12  including the thermal wicks  18  can provide increased, heat dissipation, while minimizing costs and simplifying manufacturing methods. 
     In various embodiments, the conductive path including the wick connector  46  and the thermal wicks  18  can be formed, by a selective masking approach. For example, after the main body  14  is formed, the main body  14  is covered with a masking ink (e.g., wax, lacquer, paint, etc.). After the main body  14  is covered with the masking ink, the masking ink is removed, along the course of the determined conductive path. For example, a LASER, heat source, machine, or other device is used to write the course of the determined conductive path on the main body  14  including the masking ink. As the LASER, or other device, hits the masking ink on the main body  14  including the masking ink, the masking ink melts, gets diffused, or is otherwise removed. The plastic underneath is now exposed and all other regions remain covered by the masking ink. An electroplating/metallization process is performed to deposit the metal that will form the conductive path. During the electroplating/metallization process, the metal will get deposited only where the plastic is exposed. Once the metal is deposited, the masking ink can be washed-off to obtain the heat sink  12  including the thermal wicks  18  and wick connector  46 . 
     In using the LDS approach, the main body  14  is formed from LDS compatible thermoplastics. Examples of LDS compatible thermoplastics can include, but are not limited to, LNP* THERMOCOMP NX10302, NX11302, NX07354P, NX07354 are LDS from SABIC Innovative Plastics, Pittsfield, Mass. In using the selective masking approach, any type of plastic can be used. 
       FIG. 5  illustrates a cross-sectional view of the heat sink  12  including an LED chip  48 . The cross-sectional view in  FIG. 5  is along the wall portion  42  between two adjacent fins  16  (as shown in  FIG. 4 ).  FIGS. 5-8  illustrate a simplified architecture of a LED chip  48  including a substrate  50  and LEDs  52 . The LEDs  52  can be mounted on the substrate  50  using various techniques, such as soldering. The substrate  40  has a wiring for supplying a drive current to the LEDs  52 . Further, the substrate  50  can include a terminal for supplying the drive current to the LEDs  52 . The wiring can be made of, for example, copper or a copper-base metal material, and the LEDs  52  mounted on the substrate  50  are electrically connected to the wiring  30 . 
     Optionally, the LED chip can comprise a substrate  50  (without a circuit) supporting the LED  52  and a printed circuit. LED chip can comprise a COB (chip on board) and/or COHC (chip on heat sink). Hence, in the various embodiments disclosed herein, COBs and/or COHCs can be used in addition or alternative to the LED. 
     The wick connector  46  is positioned along a portion of the interior surface  40 . The LED chip  48  is mounted to an aluminum insert  54  using a thermally conductive adhesive  56 . The aluminum insert  54  is located and held in a positive matter in the designated place either by an interference fit or through other means of locking it in place. As seen in  FIG. 5 , the aluminum insert  54  is placed in opening  32  of the main body  14  at the first end  26  and in contact with the flange  30 . The thermal wicks  18  extend from the wick connector  46 , along a portion of the internal surface  40  and along an external surface  44  toward the second end  28 . As shown in  FIG. 5 , the thermal wicks  18  extend along the wall portion  42  between two adjacent fins  16  (as shown as thermal wicks  18 - 1  in  FIG. 4 ), 
       FIG. 6  illustrates a cross-sectional view of the heat sink  12  including the LED chip  48 . The cross-sectional view in  FIG. 6  is along the fins  16  (as shown in  FIG. 4 ). The thermal wicks  18  extend from the wick connector  46 , along a portion of the internal surface  40  and along an external surface  44  toward the second end  28 . As shown in  FIG. 6 , the thermal wicks  18  extend along the face  37  of the fins  16  (as shown as thermal wicks  18 - 2  in  FIG. 4 ). As shown in  FIGS. 4-6 , the wick connector  46  is deposited on the internal surface  40 . However, the wick connector  46  can also be deposited on the flange  30 . 
       FIG. 7  illustrates a cross-sectional view of a heat sink  60  including the LED chip  48 . The hybrid heat sink  60  shown in  FIG. 7  is similar to the heat sink  12 , except that instead of the flange  30 , the main body  62  includes a ledge  64  that extends across the opening  32 . In the embodiment shown in  FIG. 7 , the aluminum insert  54  (shown in  FIG. 5 ) is not used. However, in some embodiments, the aluminum insert  54  can be used with the heat sink  60 . In various embodiments, the wick connector  46  can be deposited on the ledge  64  and/or portions of the internal surface  40 . The substrate  50  of the LED chip  48  can be mounted to the ledge  64  on the wick connector  46  via a thermally conductive adhesive  56 . 
     As shown in  FIG. 7 , the wick connector  46  extends across the entire portion of the ledge  64  and a portion of the internal surface  40  and the thermal wicks  18  begin similar to where the thermal wicks  18 , shown n  FIGS. 4-6 , begin.  FIG. 8  illustrates a top down view of the heat sink  60 . As seen in  FIG. 8 , the wick connector  46  is deposited across the entire surface of the ledge  64  (as shown in  FIG. 7 ). The thermal wicks  18  extend from the wick connector  46 , as descried herein. However, the wick connector  46  can also be deposited on a portion of the ledge  64  that is slightly larger than an area of the LED chip  48  and the thermal wicks  18  can begin on a portion of the ledge  64 , as shown in  FIG. 9 . For example, the wick connector  46  can be deposited on a portion of the ledge  64  and the thermal wicks  18  begin from the wick connector  46  and extend along a portion of the ledge  64 . 
       FIG. 10  illustrates a perspective view of a heat sink  66 . The heat sink  66  shown in  FIG. 10  includes a main body  68  having a first end  67  and a second end  69 . The main body  68  can be planar and the first end  67  can receive the heat source  76 . The main body  68  includes heat dissipation elements (e.g., fins  72 ) extending outward, e.g., laterally from a base portion  70 . The heat sink  66  can include a wick connector  74  deposited on a top surface of the base portion  70  and have thermal wicks  75  extending from the wick connector  74  toward, the second end  69 . For example, the thermal wicks  75  can extend, from the wick connector  74 , along a top surface of the base portion  70 , along a side surface of the base portion  70 , along a bottom surface of the base portion  70 , and along a side surface of the fin  72  and/or a front and/or back surface of the fin  72 . 
     As discussed herein, the heat sinks  12 ,  60 ,  66  can allow for design freedom while providing enhanced heat dissipation and minimizes the cost by reducing the amount of metal used and the number of processes used, as compared to previous approaches. 
     Heat Sinks Including Cooling Structures 
     As discussed herein, heat management can be controlled through the use of heat sinks with large surface areas including heat dissipation elements, e.g., fins. The heat transfer of the heat sinks is partly reliant on thermal conductivity values of the material(s) used to create the heat sink, the surface area, and any secondary cooling equipment (e.g., fans). While solid aluminum or copper heat sinks, for example, both have excellent thermal conductivity, these articles typically are expensive to manufacture and are not lightweight. As discussed herein, previous approaches have utilized plastics for heat sinks to minimize cost. However, as compared to metal, plastics have lower thermal conductivity. Therefore, to increase the thermal conductivity to be comparable to metals, thermally conductive fillers are added to increase the thermal conductivity coefficient. 
     The present disclosure provides a heat sink having increased thermal conductivity. The heat sinks of the present disclosure include a cooling structure including one or more channels disposed within the heat sink. The one or more channels are configured to receive a thermal transport medium. The one or more channels can have a configuration that increases the thermal conductivity. The cooling structure of the present disclosure can be incorporated into any scenario where heat sinks are utilized and can further improve heat transfer, thereby, increasing part performance. The cooling structure can be incorporated into metal heat sinks, plastic heat sinks, and hybrid heat sinks (heat sinks including metal and plastic) to improve the heat transfer. The cooling structure can be incorporated into any article, e.g., heat sinks, to decrease heat-spots, improve heat transfer, and improve the heat transfer coefficient of the entire system, for the purpose of improving part lifetime and performance. 
       FIG. 11  illustrates a cross-sectional view of a heat sink  80  including a heat source  84  such as a LED chip. The heat sink  80  includes a main body  82  having a first end  92  and a second end  94 . The first end  92  can define a recess  90  that can receive the heat source  84 . As shown in  FIG. 11 , the heat source  86  is coupled to the main body  14  within the recess  90  via a thermally conductive adhesive  86 . Other coupling mechanisms can be used as well, such as mechanical means. The heat sink  80  can be formed from metals, plastics, and combinations thereof. The heat sink  80  includes a cooling structure  102  including at least one channel  100  disposed within the main body  82  of the heat sink  80 . In various embodiments, a surface  104  defining the recess  90  can include at least one outlet opening  96  and at least one inlet opening  98 , where the channel  100  extends between the outlet opening  96  and the inlet opening  98 . Thus, each channel  100  can extend between an outlet opening  96  and an inlet opening  98 . 
       FIG. 12  illustrates a cross-sectional view of a heat sink system  116 . The heat sink system  116  includes the heat sink  80 , a seal  108  and the thermal transport medium  107 . In various embodiments, the seal  108  can be coupled to the first end  92  of the heat sink  80  to form a chamber  106 . The thermal transport medium  107  can be introduced into the channels  100  and the recess  90 , under vacuum, to fill the channels  100  and the chamber  106  with the thermal transport medium  106 . In an example, the heat source  84  can be a LED chip, e.g., LED chip  48  as shown in  FIGS. 5-7 , and is submerged within the thermal transport medium  107 . While illustrated with simplified architecture, the wiring for the LED chip can extend from the chamber  106  by being positioned between the seal  108  and the main body  82  of the heat sink  80 . 
     Overall, the heat sink  80  including the seal  108  and the thermal transport medium  107  allows for a circulating cooling structure, which is driven by heat generation within the heat source  84 . For example, as the thermal transport medium  107  closest to the heat source  84  becomes heated, the thermal transport medium  107  can rise according to the similar fluid-mechanics observed for Thiele Tube circulation. This thermal transport medium  107  can then be directed through the channel  100  framework, so the heat sink material, e.g., a thermally conductive polymer, can dissipate the heat. After the thermal transport fluid transfers heat into the main body  82  of the heat sink  80 , with the proper channel  100  design, the cooled thermal transport medium  107  is then directed back towards the heat source  84  for a second heating/cooling cycle. For example, the thermal transport medium  107  that is heated can exit the chamber  106  and enter the channel  100  via the outlet opening  96 . The thermal transport medium  107  can follow the channel  100  path within the main body  82  and transfer heat to the main body  82  as the channel  100  brings the thermal transport fluid  107  away from the heat source  84  toward the second end  94  of the heat sink  80 . The channel  100  design eventually returns the thermal transport medium  107  that has been cooled, as compared to the thermal transport medium  107  leaving the chamber  107 , back to the chamber  106 . For example, the thermal transport medium  107  can enter the chamber  107  via the inlet opening  98 . The heat sink  80  including the cooling structure  102  can increase the heat transfer and can improve the lifetime of the heat source, e.g., LED chip. 
     The main body  82  of the heat sink  80  can be formed using a variety of methods depending on the complexity and design of the channels  100 . In various embodiments, the main body  82  can be formed using additive manufacturing techniques. For example, various three dimensional printing techniques can be used to form the main body  82  including the cooling structure  102 . In various examples, three-dimensional printing techniques include, but are not limited to, extrusion methods such as fused deposition modeling (FDM) or fused filament fabrication (FFF) and powder bed methods such as powder bed and inject head 3D printing (3DP), electron-beam melting (EBM), selective heat sintering (SHS), selective laser melting (SLM), direct metal laser sintering (DMLS). 
     In various embodiments, the main body  82  can be formed by other methods including machining and injection molding. For example, depending on the channel design, the channels  100  can be machined into the main body  82  of the heat sink  80 . Any access holes, e.g., access points from an external surface to a channel, that was used for forming the channels  100  can be plugged or sealed. In various examples, portions (e,g., halves) of the main body  82  can be formed via injection molding and subsequently bonded together to form the main body  80  including the cooling structure  102 . 
     In various examples, the thermal transport medium  107  can be a liquid or gas. For example, the liquid can be a heat-conductive, electrically insulative, transparent fluid such as, but not limited to, mineral oil, silicone oils, nanofluids, fluorinated hydrocarbons, among other liquids that aid in the dissipation of heat and cooperate with the particular system in which it is being used. The nanofluids can include nanomaterials formed from metals such that the nanomaterials can increase the heat transfer of the thermal transport medium  107 . In various embodiments, the thermal transport medium  107  can include gases such as, but not limited to, nitrogen, argon, helium, neon, and other gases that aid in the dissipation of heat and cooperate with the particular system in which it is being used. 
     In various embodiments, the thermal transport medium  107  can include various additives. The additives can include, but are not limited to, flame retardant additives, heat-transfer additives, colorants, pigments, dyes, flow modifiers, and combinations thereof. The additives can improve product aesthetics while maintaining or improving overall product performance. 
     In various embodiments, dyes such as soluble phosphor dyes can be added to the thermal transport medium  107  so that the LED light output can be tuned to the desired light wavelengths. Examples of soluble dyes include, but are not limited to, fluorescent dyes, non-fluorescent dyes, and thermochromic dyes, among others. The dyes can interact with the light output of the LED and the incorporation of the dyes can alter the overall light output such that wavelengths in the visible spectra are tailored to the observer&#39;s preferences. 
     In various embodiments, the seal  108  can be formed from transparent films. For example, the seal  108  can be formed thermoplastic film and glass, among others. Thermoplastic films can include, but are not limited to, those commercially available from the Sabic Innovative Plastics, Inc. under the trade name Lexan. In various examples, the seal  108  can be formed from diffuser films to initially refract/direct the light form the LED chip evenly in all directions. Examples of films that can be used as the seal  108  are described in U.S. Pat. No. 7,991,257 B1, filed Sep. 12, 2008, the entire disclosure of which is hereby incorporated by reference herein. 
     The seal  108  can be coupled to the main body  82  of the heat sink  80  by any bonding technology. In various embodiments, the seal  108  is coupled to the main body  82  by bonding technology including, but not limited to, heat-press, laser welding, among others. 
     The channel  100  design can depend on the particular application and heat transfer needed. The size, shape, patterning, direction, and flow design of the channels  100  can vary. For example, the channels  100  can have a cross-section shape including, but not limited to, circular, square, triangular, and octagonal, among others. As shown in  FIG. 12 , the heat sink  80  includes four channels that are in fluid communication with each other via the chamber  106 . Moreover, the channel design can include, but is not limited to, linear, curved, helix, and double helix configurations, among others. 
       FIG. 13  illustrates a cross-sectional view of a heat sink system  120  including heat sink  81 , the seal  108 , and the thermal transport medium  107 . The heat sink  81  is similar to the heat sink  80  in  FIG. 12 , except that the heat sink  81  includes cooling structure  110 . The cooling structure  110  differs from cooling structure  102  by having a reservoir  118  located toward the second end  94  of the main body  82 . The cooling structure  110  includes channels  100  that are in fluid communication with each other. The channels  100  are in fluid communication with each other via the chamber  106  formed by the recess  90  and the seal  108  and the reservoir  118 . Each channel  100  can extend between the recess  90  and the reservoir  118 . As the thermal transport medium  107  absorbs heat and beings to circulate within the heat sink  81 , the thermal transport medium  107  can exit the chamber  106  through the outlet openings  96  and travel from the chamber  106  to the reservoir  118  via channels  100 -A. Channels  100 -A are the channels  100  that extend between the outlet opening  96  and the reservoir  118 . As circulation continues, the thermal transport medium  107  can travel back to the chamber  106  via the channels  100 -B and enter the chamber  106  via the inlet openings  98 . Channels  100 -B are the channels  100  that extend between the reservoir  118  and the inlet openings  98 . However, the circulation of the thermal transport medium  107  within the channels  100  can vary depending on the design of the channels  100  and placement of the heat source  84 . 
     Some thermal transport medium  107  can expand when heated. For example, a volume of the thermal transport medium  107 , at a first temperature, can be less than a volume of the thermal transport medium  107 , at a second temperature, greater than the first temperature. To account for the expansion of the thermal transport medium  107 , the volume of the thermal transport medium  107  introduced into the system (under vacuum) can be less than a volume of the chamber  106 , the channels, and in some embodiments, and the reservoir  118  combined. In other embodiments, the seal  108  can be flexible to account for any changes in volume of the thermal transport medium  107  as the thermal transport medium  107  becomes heated. 
     In various embodiments, the thermal transport medium  107  can be introduced at the second temperature and then the seal can be bonded to the heat sink. Thus, the final pressure is adequate during normal operating temperatures at the second temperature. Further, the pressure generated froth any expansion can be utilized by the channel design to create pressure flows. For example, if a smaller pipe section has an increase in pressure, and the channel opens inot a larger diameter, the pressure would in addition to convetion, aid in forcing fluid flow. 
       FIG. 14  illustrates a cross-sectional view of a heat sink system  122  including a heat sink  83 , the seal  108 , and the thermal transport medium  107 . The heat sink  81  is similar to the heat sinks  80 ,  81  but includes cooling structure  124  instead of cooling structures  102  and  110 . The cooling structure  124  differs from cooling structures  102  and  110  by having an expansion chamber  126 . The expansion chamber  126  is in fluid communication with the reservoir  118 , channels  100 , and the chamber  106 The expansion chamber  126  can be used to receive a portion of the thermal transport medium  107  if, while in use, a temperature increase from the first temperature to a second temperature results in thermal expansion of the thermal transport medium  107 . The size of the expansion chamber  126  can vary and can depend, in part, on the coefficient of thermal expansion of the thermal transport medium  107  and the expected temperature change, among other factors. 
     In various embodiments, a volume of the thermal transport medium  107 , at the first temperature, can be less than a volume of the reservoir  118 , channels  100 , chamber  106 , and the expansion chamber  126  combined. For example, the volume of the thermal transport medium  107 , at the first temperature, can substantially equal the volume of the channels  100 , chamber  106 , and the reservoir  118 . In other embodiments, the volume of the thermal transport medium  107 , at the first temperature, can be greater than the volume of the channels  100 , the chamber  106 , and the reservoir  118  but less than the volume of the channels  100 , the chamber  106 , the reservoir  118  and the expansion chamber  126 . In various embodiments, the volume of the thermal transport medium  107 , at the second temperature, can be greater than the volume of the channels  100 , the chamber  106 , and the reservoir  118  or substantially equal to or slightly less than the volume of the channels  100 , the chamber  106 , the reservoir  118 , and the expansion chamber  126 . 
     In various embodiments, the expansion chamber  126  can be in unrestricted communication with the reservoir  118 . Meaning, the thermal transport medium  107  at the first temperature can flow unrestricted between the expansion chamber  126  and the reservoir  118 . In various embodiments, the expansion chamber  126  can be in restricted communication with the reservoir  118 . For example, the cooling structure  124  can include a valve  128  such as a pinch point that can allow the thermal transport medium  107  to enter the expansion chamber  126  when the thermal transport medium  107  is at the second temperature and has a volume greater than the volume of the chamber  106 , the channels  100 , and the reservoir  118 . 
     As seen in  FIGS. 12, 13, and 14 , the channels  100  are in fluid communication with each other and the heat source  84  is submerged within the thermal transport medium  107 . However, in certain instances, there may be limitations on liquid submerged electronics or circuitry, or other instances where the heat source cannot be submerged within a thermal transport medium. 
       FIGS. 15 and 16  illustrate heat sinks systems  130 ,  160  including a heat source  150  that is not submerged within the thermal transport medium  107 . As shown in  FIG. 15 , the heat sink system  130  includes a heat sink  85  including a main body  136  extending from a first end  138  to a second end  140 . The heat sink  85  includes cooling structure  132  including a chamber  142 , one or more channels  134 , and the thermal transport medium  107 . As compared to heat sinks  80 ,  81 , and  83  where the chamber  106  was formed by the recess  90  and the seal  108  (shown in  FIGS. 12-14 ), a chamber  142  in  FIG. 15  is formed within the main body  136  of the heat sink  85 . As the thermal transport medium  107  starts to circulate within the cooling structure  132  as the thermal transport medium  107  absorbs heat from the heat sink  150 , the thermal transport medium  107  can exit the chamber  142  via a first opening and enter the channel  134  via a second opening. For example, the thermal transport medium  107  can exit the chamber  142  via an outlet opening  146 , travel through the channel  134 , and enter the chamber  143  via the inlet opening  148 . As seen in  FIG. 15 , the cooling structure  132  can include one or more distinct channels  134  in fluid communication with another channel via the chamber  142 . However, other designs can be used. For example, the reservoir  118  and the expansion chamber  126 , as discussed with respect to  FIGS. 13 and 14  can be incorporated into the cooling structure  132 . 
       FIG. 16  illustrates the heat sink system  160  including heat sink  87  including cooling structure  162 , and the heat source  150 . The heat sink  87  in  FIG. 16  is similar to the heat sink  83  but does not include the chamber  142 , as shown in  FIG. 15 . The cooling structure  162  includes two discrete channels  164  that are not in fluid communication with each other. Each channel  164  can include the thermal transport medium  107 . In various embodiments, each channel  164  can also include an expansion reservoir such as expansion reservoir  126  in  FIG. 14 . 
     The cooling structures  102 ,  110 ,  132 , and  162  can be incorporated into any heat sink or article where heat dissipations is needed. The shape of the heat sinks  80 ,  81 ,  83 ,  85 , and  87  and the location of the cooling structures  102 ,  110 ,  124 ,  132  and  162  can vary depending on particular application, materials used, and heat dissipation needed. For example, the cooling structures can be incorporated into heat sinks shown in  FIGS. 1-10  and include various heat dissipation elements such as fins  16 . 
       FIGS. 17-20  illustrate heat sink systems  170 ,  171 , and  173  include heat sinks  190 ,  192 , and  194 , respectively,and a heat source  172 . The heat sinks  190 ,  192 , and  194  have a planar base  174  with a plurality of heat dissipation elements  176  extending laterally from the planar base  174 . As shown in  FIG. 17 , a top surface  173  of the planar base  174  can be coupled to the heat source  172 .  FIGS. 17 and 18  illustrate a cooling structure  175  including one or more channels  178  and the thermal transport medium  107  incorporated into one or more of the heat dissipation elements  176 . Each heat dissipation element  178  can include one or more channels  178  winding through the respective heat dissipation elements  176  such that, as the thermal transport medium  107  absorbs heat, the heat transport medium  107  can circulate within the channel  178 . In the embodiment shown in  FIGS. 17 and 18 , each channel  178  is distinct and not in fluid communication with other channels  178 . That is, the cooling structure  175  includes one or more discrete channels  178  disposed, within each heat dissipation element  176 . A portion of the discrete channel  178  can be positioned adjacent to the heat source  172  such that the thermal transport medium  107  can absorb heat and circulate within the channel  178 . 
       FIG. 19  illustrates heat sink  192  having a cooling structure  177  that includes a chamber  180  positioned within the planar base  174 . The chamber  180  is in fluid communication with the channel  178 . For example, the chamber  180  can include an outlet opening  182  and an inlet opening  184  such that when circulation of the thermal transport medium  107  begins, the thermal transport medium  107  can exit the chamber  180  via the outlet opening  182 , flow along the channel  178  and enter the chamber  180  via inlet opening  184 . The placement of the outlet opening  182  and the inlet opening  184  can vary and can be arranged to maximize circulation of the thermal transport medium  107 . For example, the outlet opening  182  can be positioned at a location that is closer to a maximum temperature location  183  as compared to the inlet opening  184 . 
     In various embodiments, each heat dissipation element  176  of the heat sink  192  can include a chamber  108  such that a chamber and channel of a first heat dissipation element are not in fluid communication with another chamber and channel of a second heat dissipation element. In other embodiments, the chamber  108  can be fluid communication with one or more channels located in two different heat dissipation elements. In that instance, the channels extending through two different heat dissipation elements are in fluid communication with each other via the chamber  180 .  FIGS. 17-19  illustrate embodiments where the heat source is not submerged within the thermal transport medium  107 . 
       FIG. 20  illustrates heat sink  194  having cooling structure  177  that includes a chamber  190  formed from a recess  186  in the planar base  174  and a seal  188 . The seal  188  can be formed from materials as described herein with reference to seal  108 . As shown in  FIG. 20 , the heat source  172  is submerged within the thermal transport medium  107 . The chamber  190  can be in fluid communication each channel  178  formed in the one or more heat dissipation elements  176 . For example, the chamber  190  can include an outlet opening  182  and an inlet opening  184  for each channel  178 . Thus, the number of outlet openings  182  and the number of inlet openings  184  can be equal to the number of channels  178 . For example, if the heat sink  173  includes three heat dissipation elements  176  that each include one channel  178 , the chamber  190  can include three outlet openings  182  and three inlet openings  184 . 
     Overall, the cooling structures described herein can provide for a circulating cooling system in scenarios where heat dissipation is desired and improve the thermal conductivity of heat sinks, such that the overall heat management is improved. By natural convection and principles of fluid-mechanics, the thermal transport medium can be directed through the channel framework, depending on application needs. Proper channel design can optimize flow as well as heat-transfer. After the warmed thermal transport medium transfers thermal energy into the heatsink, the channel design will re-direct the thermal transport medium back towards the heat source for additional heating/cooling cycles. The increased heat transfer will improve the lifetime of the part. The cooling structures described herein can be used in applications including, but not limited to, Head-Up displays, LED&#39;s, computer processors, radiators, medical and office equipment, aerospace devices, and telecom technologies, etc. 
     Hybrid Heat Sinks Including Thermal Wicks and Cooling Structures 
     The present disclosure provides a heat sink including the thermal wicks and a cooling structure. The heat sinks including the thermal wicks and the cooling structure can increase the thermal conductivity of a heat sink while allowing use of cheaper materials and less manufacturing processes. Any of the hybrid heat sinks shown in  FIGS. 1-10  can be combined with any of the cooling structures shown in  FIGS. 11-20 . 
       FIGS. 21-23  illustrate an example of a heat sink including thermal wicks and a cooling structure. For example,  FIG. 21  illustrates heat sink  200  including a main body  201  extending from a first end  202  to a second end  204 . The heat sink  200  can be similar to the heat sink  12  shown in  FIG. 4 . The difference between the heat sink  200  and the heat sink  12  is that the heat sink  200  does not include the flange  30 , but instead includes a ledge  230 . Also, the heat sink  200  includes a cooling structure  205 . 
     As shown in  FIG. 21 , the first end  202  includes an interior ridge  216  and an exterior ridge  218  that define a space  220 . The space  220  can be configured to receive and couple with a plastic lens cap. The main body  201  includes heat dissipation elements (e.g., fins  206 ). The fins  206  can include a first surface  208  and a second surface  210  opposite the first surface  208  and a face  212  extending between the first and second surfaces  208 ,  210 . A wall surface  228  can be disposed between two adjacent fins  206 . As discussed herein, thermal wicks  214  and a wick connector  226  can be disposed on the surface of the main body  201  to form the heat sink  200 . The main body  201  and the thermal wicks  214  and the wick connector  226  can be formed by methods discussed herein with respect to  FIGS. 140 . The wick connector  226  can be deposited on the main body  201  such that it thermally connects all of the thermal wicks  214  and forms a conductive path extending from the first end  202  toward, the second end  204 . The thermal wicks  214  can extend from the wick connector  225  toward the second end  204  of the main body  201  along either the wall surface  228  or along a surface of the fins  206  along the face  212  of the fins  206 ). The first end  202  of the main body  201  can define a recess  217  and the wick connector  226  and a portion of the thermal wicks  214  can be positioned along the recess  217 . 
     The cooling structure  205  can include outlet opening  224  and inlet openings  222 . For example, the outlet openings  224  and the inlet openings  222  can be formed along the recess  217 . In various embodiments, the outlet openings  224  are positioned on a side wall  207  of the recess where the inlet openings  222  are positioned on the ledge  230 . In various embodiments, the thermal wicks  214  and the outlet openings  224  do not overlap. However, in other embodiments, the thermal wicks  214  and the outlet openings  224  can overlap. In that instance, the outlet openings  224  should not break the conductive path of the thermal wick  214 . That is, a width of the outlet opening  224  should be less than the width of the thermal wick  214 . 
       FIG. 22  illustrates a cross-sectional view of a heat sink system  250 . The heat sink system  250  includes the heat sink  200 , the LED chip  48 , a seal  232 , and the thermal transport medium  107 . The LED chip  48  can include the substrate  50  and LEDs  52 , as discussed herein. The heat sink  200  can have the cooling structure  205  including a chamber  234  formed from the seal  232  coupled to the first end  202  of the main body  201 . For example, the chamber  234  is defined by the seal  232  and the recess  217 . The cooling structure  205  can further include one or more channels  246  extending through the main body  201 . As shown in  FIG. 22 , the fins  206  each include a channel  246 . As discussed herein, the chamber  234  can include an outlet opening  224  and an inlet opening  222  such that the channel  246  extends from the owlet opening  224  to the inlet opening  22 . The channels  246  can extend through the increased surface area of the fins  206  thereby increasing the heat dissipation of the heat sink  200 . The wick connector  226  is deposited along a surface of the recess  217 . For example, the wick connector  226  is deposited along the ledge  230  and a portion of the side wall  206  surface defining the recess  217 . The thermal wicks  214  extend from the wick connector  226  toward the second end  204  of the main body  201 . 
     The cross-sectional view of  FIG. 22  is along the fins  206 .  FIG. 23  illustrates a cross-sectional view of the heat sink system  250  including the heat sink  200  having the thermal wicks  214  and the cooling structure  205 . The cross-sectional view in  FIG. 23  is along the wall surface  228  of a base  242  of the main body  201  between two adjacent fins  206  (as shown in  FIG. 21 ). The thermal wicks  214  extend from the wick connector  226  toward the second end  201  of the main body  201 . As shown in  FIG. 23 , the base  242  does not include channels (e.g., channels  246  in  FIG. 22 ). 
       FIG. 24  illustrates a cross-sectional view of a heat sink system  252  including a heat sink  253 , a heat source such as a LED chip  48 , thermal wicks  214 , and a cooling structure  254 . The heat sink  253  is similar to heat sink  200  in  FIG. 22 , except that instead of having a plurality of channels, heat sink  253  include a single channel  246  winding through the main body  201 . 
     The chamber  234  is formed from the recess  217  and the seal  232  and includes one outlet opening  224  and one inlet opening  222 . The single channel  246  extends from the outlet opening  224  to the inlet opening  22 . The single channel  246  can wind through the main body  201 , in various configurations, to increase heat transfer from the thermal transport medium  107  to the main body  201 . For example, the channel  246  can extend from the outlet opening  224  of the chamber  234  at the top of a first fin  206  and extend toward the bottom of the first fin  206  and into the base  242 , where the channel  246  extends within the base  242  and advances until it reaches a second fin. Once the channel  246  reaches the second fin, the channel  246  can extend from the bottom of the second fin toward the top of the second fin and into the base  242 , where the channel  246  extends within the base  242  and advances until it reaches a third fin. The channel  246  can continue to extend up and down fins and between adjacent fins via the base  242  until the channel reaches the inlet opening  22 . As seen in  FIG. 24 , the outlet opening  224  is along the recess  217  and the inlet opening  222  is along the ledge  230 . Thus, one the channel  246  reaches the last fin, the channel  246  can extend toward the inlet opening  222  along the base  242 . 
       FIG. 25  illustrates the flow of the heat transport medium  107  (shown in  FIG. 24 ) through the heat sink  253 . That is,  FIG. 25  illustrates the route of the channel  246  in  FIG. 24  extending through the main body  201 . The channel  246  can begin at the outlet opening  224  and end at the inlet opening  222 . The channel  246  can move from top to bottom and bottom to top through the fins  206 - 1 ,  206 - 2 ,  206 - 3 ,  206 - 4 ,  206 - 5 ,  206 - 6 ,  206 - 7 , and  206 - 8 . The outlet opening  224  enters fin  206 - 1 , and the channel  246  leaves fin  206 - 8  and extends to the inlet opening  222 . The channel  246  can enter and exit the first fin  206 - 1  by moving from top to bottom. The channel  246  can then move along the base and enter and exit the second fin  206 - 2  by moving bottom to top. The channel  246  can continue this pattern through each fin (e.g., fins  206 - 3  through  206 - 7 ). Once the channel  246  enters tin  206 - 8  the channel will extend from the bottom to the top of fin  206 - 8  and terminate at the inlet opening  222 . 
     Various embodiments also include the combination of heat sinks  190 ,  192 , and  194  (shown in  FIGS. 17-20 ) including thermal wicks, such as thermal wicks  75 , as shown in  FIG. 10 , 
     LED Lens Cap Including a Cooling Structure 
     The present disclosure provides a heat sink including a cooling structure and/or thermal wicks and a lens cap that includes a cooling structure. The cooling structure of the heat sink can include channels that can transport the thermal transport medium through the heat sink to dissipate heat. However, the cooling structure of the heat sink can also include a channel that is configured to align with a channel formed in the lens cap such that the thermal transport medium can further dissipate heat through the lens cap. The heat sink system including the heat sink and the lens cap with the cooling structures can increase the thermal conductivity of a heat sink. Any of the hybrid, heat sinks described herein can be combined with the lens cap to further increase heat dissipation. 
       FIG. 26  illustrates a cross-sectional view of a heat sink system  300  including a heat sink  312 , a heat source  318 , and a lens cap  301 . The heat sink  312  and the lens cap  301  can include cooling structures  313  and  315 , respectively. The cooling structure  313  can include channels  322 ,  324  and a chamber  320  formed by coupling a seal  316  to the main body  314  such that the seal  316  covers a recess  319  formed, in the main body. While the seal  316  is shown in  FIG. 26  as forming the chamber  320 , in some embodiments, the seal  316  does not need to be used and the lends cap  301  can serve to couple to the main body  314  and form the chamber  320 . 
     The thermal transport medium is not shown in  FIG. 26 , however, as discussed herein, the thermal transport medium can be introduced into the chamber and channels of the cooling structure. The cooling structure  314  includes a channel  324  extending from a chamber outlet opening  317  to a heat sink outlet  326  and a channel  327  extending from a heat sink inlet  328  to a chamber inlet opening  321 . In various embodiments, the cooling structure  315  can also include channels  322  that extend from a chamber outlet opening  317  to a chamber inlet opening  321 . 
     The cooling structure  315  of the lens cap  301  can include a channel  306  winding through the lens cap that extends from a lens cap inlet  308  to a lens cap outlet  310 . The cooling structures  313  and  315  are designed to work together to move the thermal transport medium through the heat sink  312  and the lens cap  301  to increase heat dissipation. For example, the heat sink outlet  326  is configured to align with the lens cap inlet  308  and the heat sink inlet  328  is configured to align with the lens cap outlet  310 . The flow of the thermal transport medium is depicted with the arrows. While  FIG. 26  illustrates just one channel extending through the lens cap  301 , more than one channel can be formed. Further, the configurations of the channels formed within the heat sink  312  can have any configuration disclosed herein, including, but not limited to, the reservoir, and the expansion chamber. Moreover, the thermal wicks described herein can also be incorporated into the embodiment shown in  FIG. 26 . 
     The lens cap  301  can be formed via the same methods as described herein with the heat sinks including channels. For example, three-dimensional printing techniques, like fused deposition modelling (FDM) can be used. The channel  306  in the lens cap  301  can be designed such that the optical qualities are optimized. For example, the refractive index (RI) can be tuned such that the light diffusion is optimized by modifying the additives, formulations, viscosity, or other properties of the thermal transport medium such that an optimal balance of RI is obtained for increased transmissivity and diffusion. As discussed herein, pigments such as diffusor pigments and phosphors that improve overall optical appearance of light transmitted through the LED lens cap can be added to the thermal transport medium. 
     EXAMPLES 
     Various embodiments of the present invention can be better understood by reference to the following Examples which are offered by way of illustration. The present invention is not limited to the Examples given herein. 
     Maximum Temperature Evaluation Through Thermal Simulation 
     Thermal Simulation was carried out for various heat sink models with fixed amount of heat supplied to the heat sink. Steady state maximum temperatures at different heat sinks were recorded. 
     Comparative Example A 
     Thermal Simulation 
     Comparative Example A was a plastic square sample (Konduit) having dimensions of 100 min×100 mm×3 mm without any thermal wicks. The maximum temperature of Comparative Example A was 137.5 degrees Celsius (° C.). This was derived using heat conduction simulation in ABAQUS™. 
     Example 1 
     Example 1 was a plastic square sample (Konduit) having dimensions of 100 mm×100 mm×3 min with thermal wicks of copper deposited onto the surface of the sample. The thickness of the thermal wicks was 0.2 mm Heat conduction simulation showed that the maximum temperature of Example 1 was 80.3° C., which is a 41.6 percent % decrease over Comparative Example A.  FIG. 27  illustrates the plastic square heat conduction simulation sample  400  including the thermal wicks  402  and a wick connector  404  for Examples 1-5. The heat source is placed in contact with the wick connector  404 . 
     Example 2 
     Example 2 was a plastic square sample (generic amorphous polymer e.g polycarbonate, PEI) having dimensions of 100 mm×100 mm×3 mm with thermal wicks of copper deposited onto the surface of the sample via LDS or selective metallization. The thickness of the thermal wicks was 0.2 mm. The maximum temperature of Example 2 was 118.2° C., which is a 14% decrease over Comparative Example A. 
     Example 3 
     Example 3 was a plastic square sample (generic semi-crystalline resin e. g polypropylene, polyamides having dimensions of 100 mm×100 mm×3 mm with thermal wicks of copper deposited onto the surface of the sample via LDS or selective metallization. The thickness of the thermal wicks was 0.2 mm. The maximum temperature of Example 3 was 115° C., which is a 16.3% decrease over Comparative Example A. 
     Example 4 
     Example 4 was a plastic square sample (generic amorphous polymer e.g. polycarbonate, PEI) having dimensions of 100 mm×100 mm×3 mm with thermal wicks of silver deposited onto the surface of the sample via LDS or selective metallization. The thickness of the thermal wicks was 0.2 mm. The maximum temperature of Example 4 was 81° C., which is a 41.1% decrease over Comparative Example A. 
     Example 5 
     Example 5 was a plastic square sample (Konduit) having dimensions of 100 mm×100 mm×3 mm with thermal wicks of copper deposited onto the surface of the sample via LDS. The thickness of the thermal wicks was 0.2 mm. The surface area in contact with the thermal wicks was increased as compared to Examples 1-4. That is, the area of the wick connector  404  in  FIG. 27  was increased. The maximum temperature of Example 4 was 70.7° C., which is a 48.5% increase over Comparative Example A. Profile Temperature Through Thermal Experiments 
     Two samples of an example heat sink (one including thermal wicks and one not including thermal wicks) were formed and heat source was placed on the heat sinks. Temperature sensors (J-type thermocouples) were places in various locations on the surface of the sample and temperature at these locations were recorded with time until it reached steady state. 
     Example 6 
     Example 6 was a plastic square sample (CYCOLOY™ a blend of polycarbonate and ABS) having dimensions of 100 mm×100 mm×3 mm with thermal wicks made from copper tape adhesively bonded with the surface of the sample. The thickness of the thermal wicks was 0.1 mm.  FIG. 28  illustrates Example 6 and the location of the temperature sensors.  FIG. 28  illustrates the plastic sample  506  including a wick connector  501  and a plurality of thermal wicks  501 . The heat source  500  was placed on the wick connector  501 . Temperature sensors were placed at locations “ 1 ”, “ 2 ”, “ 3 ”, “ 4 ”, “ 5 ”, “ 6 ”, “ 7 ”, “ 8 ”, “ 9 ”, and “ 10 ”. Position “ 8 ” is on the opposite surface directly behind “ 1 ” and location “ 6 ” is on the opposite surface directly behind location “ 4 .” 
     Comparative Example B 
     Comparative Example B was a plastic square sample CYCOLOY™ having dimensions of 100 mm×100 mm×3 mm with no thermal wicks.  FIG. 29  illustrates Comparative Example B and the locations of the temperature sensors. The locations of the sensors “ 1 ”, “ 2 ”, “ 3 ”, “ 4 ”, “ 5 ”, “ 6 ”, “ 7 ”, “ 8 ”, “ 9 ”, and “ 10 ” are the same as in  FIG. 28 . 
     Results of Example 6 and Comparative Example B 
       FIGS. 30-32  illustrate the results of Example 6 and Comparative Example B.  FIG. 30  is a graph illustrating the maximum temperature for each of the temperature sensors in Example 6 and Comparative Example B. In locations “ 1 ”, “ 2 ”, and “ 8 ”, which are the locations closest to the heat source  500  (as shown in  FIGS. 28 and 29 ), the temperature of Example 6 had a lower maximum temperature. In locations “ 3 ”, “ 4 ”, “ 9 ”, and “ 10 ”, the temperature of Example 6 had a higher maximum temperature.  FIGS. 31 and 32  are graphs illustrating the temperature profile for each of the locations for 70 minutes. Thus, Example 6 (including the thermal wicks) has improved heat dissipation by removing more heat from the heat source and spreading it through the heat sink. 
     Additional Embodiments 
     The following exemplary embodiments are provided, the numbering of which is not to be construed as designating levels of importance: 
     Embodiment 1 provides a heat sink system, comprising: a heat sink formed from a plastic, the heat sink including: a main body extending from a first end toward a second end, the first end configured to couple with a heat source; at least one thermal wick extending from the first end toward the second end, the at least one thermal wick formed from a metal; and a cooling structure including at least one channel extending through the main body, the at least one channel configured to receive a thermal transport medium. 
     Embodiment 2. provides the heat sink system of claim  1 , wherein the first end of the main body defines a recess configured to receive the heat source. 
     Embodiment 3 provides the heat sink system of any one of Embodiments 1-2, wherein the cooling structure further includes:a seal coupled to the first end of the main body to form a chamber, the chamber including an outlet opening and an inlet opening, and wherein the at least one channel extends from the outlet opening to the inlet opening. 
     Embodiment 4 provides the heat sink system of any one of Embodiments 1-3, wherein the heat source is coupled to the heat sink within the chamber such that the heat source is configures to be submerged within the thermal transport medium. 
     Embodiment 5 provides the heat sink system of any one of Embodiments 1-4, wherein the seal is selected from plastics, structured diffuser films, glass, and thermoplastic films. 
     Embodiment 6 provides the heat sink system of any one of Embodiments 1-5, wherein the at least one channel is a plurality of channels, and wherein the plurality of channels are discrete channels not in fluid communication with each other. 
     Embodiment 7 provides the heat sink system of any one of Embodiments 1-6, wherein the at least one channel is a plurality of channels, and wherein the plurality of channels are in fluid communication with each other via a chamber formed by a seal coupled to the first end of the main body. 
     Embodiment 8 provides the heat sink system of any one of Embodiments 1-7, wherein the cooling structure further includes: a chamber formed within the main body of the heat sink, wherein the chamber has at least one inlet opening and at least one outlet opening, wherein the at least one channel extends from the at least one outlet opening to the at least one inlet opening. 
     Embodiment 9 provides the heat sink system of any one of Embodiments 1-8, wherein the thermal wick is formed from copper, silver, gold, aluminum and all the metals and alloys of high thermal conductivity. 
     Embodiment 10 provides the heat sink system of any one of Embodiments 1-9, wherein the at least one thermal wick is a plurality of thermal wicks, and wherein the plurality of thermal wicks are thermally coupled via a wick connector. 
     Embodiment 11 provides the heat sink system of any one of Embodiments 1-10, wherein the wick connector is configured to be thermally coupled to the heat source. 
     Embodiment 12 provides the heat sink system of any one of Embodiments 1-11, wherein the thermal transport material includes at least one of mineral oil, silicone oil, nanofluids, and fluorinated hydrocarbons. 
     Embodiment 13 provides a heat sink system, comprising: a heat sink formed from a plastic, the heat sink including: a main body extending from a first end toward a second end, the first end configured to couple with a heat source, the first end defining recess; at least one thermal wick extending from the first end toward the second end, the at least one thermal wick formed from a metal; and a cooling structure, including: a seal coupled to the first end of the main body to form a chamber, the chamber including at least one outlet opening and at least one inlet opening; at least one channel extending from the at least one outlet opening, through the main body, and to the at least one inlet opening; and a thermal transport material positioned within the chamber and the at least one channel; and a heat source coupled to the main body within the chamber and submerged within the thermal transport material. 
     Embodiment 14 provides the heat sink system of Embodiment 13, wherein the at least one channel includes a plurality of channels, and further including: a reservoir positioned at the second end of the main body, the reservoir in fluid communication with the plurality of channels and the chamber. 
     Embodiment  15  provides the heat sink system of any one of Embodiments 13-14 further including: an expansion chamber in fluid communication with the at least one channel and the chamber, wherein a volume of the expansion chamber, the at least one channel, and the chamber is greater than a volume of the thermal transport material. 
     Embodiment 16 provides the heat sink system of any one of Embodiments 13-15, wherein the main body includes a plurality of heat dissipation fins, and wherein the thermal wicks extend along a face of the fins. 
     Embodiment 17 provides the heat sink system of any one of Embodiments 13-16 wherein the main body includes a plurality of heat dissipation fins, wherein the at least one channel extends within the heat dissipation fin. 
     Embodiment 18 provides a method of forming a heat sink system, the method comprising: providing or obtaining a heat sink formed from a plastic, the heat sink including a main body extending from a first end to a second end, the first end defining a recess, and the main body including at least one channel extending from an inlet opening along the recess to an outlet opening along the recess; forming at least one thermal wick along the main body extending from the first end toward the second end; coupling a heat source to the main body within the recess; introducing a thermal transport material into the recess and the at least one channel; and coupling a seal to the first end of the main body forming a chamber including the heat source and the thermal transport material. 
     Embodiment 19 provides the heat sink system of any one of Embodiments 13-18, wherein forming the thermal wick along the main body includes forming the thermal wick using a selective metallization process. 
     Embodiment 20 provides the heat sink system of any one of Embodiments 13-19, wherein the selective metallization process is one of laser direct structuring and selective masking. 
     Embodiment 21 provides the method of any me or any combination of Embodiments 1-20 optionally configured such that all elements or options recited are available to use or select from. 
     Additional Notes 
     The above Detailed Description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more elements thereof) can be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. Also, various features or elements can be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter can lie in less than all features of a particular disclosed embodiment. Thus, the following clams are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. 
     In the event of inconsistent usages between this document and any document so incorporated by reference, the usage in this document controls. 
     In this document, the terms “a” or “an” are used to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the phrase “varus/valgus angle” is used to refer to a varus angle only, a valgus angle only, or both a varus angle and a valgus angle. 
     In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” The terms “including” and “comprising” are open-ended, that is, a system or method that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. 
     The Abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.