WO2010080561A1

WO2010080561A1 - Lighting assembly

Info

Publication number: WO2010080561A1
Application number: PCT/US2009/068615
Authority: WO
Inventors: Michael J. Alloway; Robert H. Miller
Original assignee: 3M Innovative Properties Company
Priority date: 2008-12-19
Filing date: 2009-12-18
Publication date: 2010-07-15
Also published as: CN202905786U

Abstract

Flexible lighting assemblies having a flexible cable, a light emitting diode(s), and a heat sink. The lighting assemblies are useful, for example in vehicles (e.g., automobile, trucks, etc.), as well as task lighting, accent lighting, merchandise display lighting, and back lighting applications.

Description

LIGHTING ASSEMBLY Background

[001] Light-emitting diodes ("LEDs") are widely used in a variety of sign, message board, and light source applications. The relatively high efficacy of LEDs (in lumens per watt) is typically the primary reason for their use. Large power savings are possible when LED signals are used to replace traditional incandescent signals of similar luminous output. One aspect of LED technology that has not been satisfactorily resolved is the efficient management and removal of waste heat, especially for high optical power LEDs, requiring increased electrical power. The waste heat typically results in excessive junction temperatures, degrading performance, and reducing device life. LED lamps typically exhibit substantial light output sensitivity to temperature, and can be permanently degraded by excessive temperature. For example, the maximum recommended operating temperature for LEDs that incorporate indium in their compositions is typically in a range from 85⁰C to about 100⁰C. These devices can exhibit typical (half brightness) lives on the order of 50,000 to 100,000 hours at about 25⁰C. However, degradation above about 9O⁰C is rapid as the LEDs degrade exponentially with increases in temperature.

[002] Permanent thermal degradation of LEDs may also occur during array fabrication if care is not taken, when the LEDs are soldered to the supporting and/or interconnecting circuit board. For example, typical soldering temperatures can exceed 25O⁰C and seriously affect the performance of the LEDs even before they are put into service, if the LEDs remain at or near such high temperatures for an extended period of time. Therefore, it is very advantageous to remove heat rapidly from the vicinity of LEDs whether such heat is generated by the LEDs during normal use or applied during the assembly or manufacturing process.

[003] One common method for dissipating heat generated from LEDs that are mounted on an insulating printed circuit board (TCB'), such as the commonly available FR-4 fiber composite circuit board, is to form a plurality of vias under each LED through the thickness of the PCB. The vias are filled with a metal or alloy having high thermal conductivity and connected to a heat sink attached to the PCB opposite to the LED. However, the formation of such vias adds to the cost of manufacturing the PCB. In addition, the rate of heat dissipation is limited by the rate of heat conduction through the vias because of their typical small cross section.

[004] Another approach is to provide thermally conductive substrates on which electronic components are mounted. These substrates generally perform a function of mechanical support, also provide for electrical interconnection to and between components, and assist in the extraction and dissipation of heat generated by the electronic components. These substrates often are costly or require complicated multi-step manufacturing processes. For example, substrates have been made of thermally conductive ceramics or metals coated or laminated with dielectric materials. Thermally conductive ceramic substrates are costly compared to metals and are, therefore, more appropriately reserved for high temperature applications or for devices the price of which is a secondary concern. These substrates are typically thick and bulky and greatly decrease the flexibility of the lighting assembly. When coated or laminated metallic substrates are used, the electrical insulating property of the coating is important. Puncture voltage and dielectric dissipation of the insulating coating directly depend on film thickness, but the rate of heat dissipation inversely depends on the film thickness. Thus, a compromise must be accepted which often results in a less efficient overall device.

[005] Therefore, there exists a continued need to provide a simple, cost effective way to rapidly dissipate heat from LEDs. In addition, it is also desirable to provide a flexible LED light assembly.

Summary

[006] In one aspect, the present disclosure describes a flexible lighting assembly comprising: a flexible cable having a width and thickness, and comprising electrical conductors to provide electrical circuit paths; a light emitting diode electrically connected to electrical conductors of the flexible cable, wherein the light emitting diode(s) comprises leads placed against a first exterior side of the flexible cable; and a flexible heat sink sheet material having a thermal conductivity of at least 25 W/m-K (in some embodiments, at least 50, 100, 150, 200, 250, 300, 350, 400, 450, or even at least 500 W/m-K; in arrange, for example, from 25 to 500, 200 to 500, or even 200 to 450 W/m-K) thermally attached to a second side of the flexible cable generally opposite the light emitting diode connected to the flexible cable and not in direct physical contact (wherein direct physical contact includes soldering or adhering the heat sink directly to the light emitting diode) with any light emitting diode connected to the flexible cable.

[007] In another aspect, the present disclosure describes a flexible lighting assembly comprising: a flexible cable having a width and thickness, and comprising electrical conductors to provide electrical circuit paths; a light emitting diode(s) electrically connected to electrical conductors of the flexible cable, wherein the light emitting diode(s) comprises leads placed against a first exterior side of the flexible cable; and a first discrete heat sink having a thermal conductivity of at least 25 W/m-K (in some embodiments, at least 50, 100, 150, 200, 250, 300, 350, 400, 450, or even at least 500 W/m-K; in arrange, for example, from 25 to 500, 200 to 500, or even 200 to 450 W/m-K) thermally attached to a second side of the flex cable generally opposite the light emitting diode connected to the flexible cable, and not in direct physical contact with any light emitting diode connected to the flexible cable wherein the first discrete heat sink has a thickness not greater than 0.5 cm and a width not greater than the width of the flexible cable. Optionally, the light assembly further comprises an additional discrete heat sink(s) (including a plurality of discrete heat sinks) having a thermal conductivity of at least 25 W/m-K (in some embodiments, at least 50, 100, 150, 200, 250, 300, 350, 400, 450, or even at least 500 W/m-K; in arrange, for example, from 25 to 500, 200 to 500, or even 200 to 450 W/m-K) thermally each attached to a second side of the flexible cable generally opposite a light emitting diode connected to the flexible cable and not in direct physical contact with any light emitting diode connected to the flexible cable. For example, the light assembly may further comprise a second, third, fourth, fifth, sixth, seven, eighth, ninth, and/or tenth, etc. discrete heats sink(s). Each additional discrete heat sink typically has a thickness not greater than 0.5 cm and a width not greater than the diameter of the flexible cable.

[008] In this application: [009] "Flexible" means the lighting assembly, cable, or continuous heat sink sheet material except at the point where an LED or discrete heat sink is located, as applicable, can be wrapped around a 5 mm diameter rod without breaking or damaging the lighting function of the lighting assembly, heat sink, or cable, as applicable.

[0010] In some embodiments, the addition of heat sink material allows input power levels to be held constant while achieving lower light emitting diode pin temperatures and thus longer lumen maintenance life with some corresponding increase in light output due to lower temperature degradation. In some embodiments, the addition of heat sink material allows input power levels to be increased while achieving lower light emitting diode pin temperatures and thus increasing light output and maintaining lumen maintenance life.

[0011] In some embodiments, and typically desirably, the light emitting diodes, when energized have a uniform lumens output. In some embodiments, lighting assemblies described herein have a total power usage of up to 1 watt, 0.75 watt, or even 0.5 watt, wherein lower wattages are typically more desirable.

[0012] Light assemblies described herein are useful, for example, in vehicles (e.g., automobile, trucks, etc.), as well as, task lighting, accent lighting, merchandise display lighting, and back lighting applications. Useful embodiments of light assemblies described herein for vehicles include as a brake center light.

Brief Description of the Drawings

[0013] FIG. IA is a cut away side view of an exemplary flexible lighting assemblies described here.

[0014] FIG. IB is a cross-sectional end view of the flexible cable shown in FIG. 1.

[0015] FIG. 2 is a cut away side view of another exemplary flexible lighting assemblies described here.

Detailed Description

[0016] Referring to FIG. IA and IB, exemplary flexible lighting assembly 99 has flexible cable 100 with electrical conductor 102, 104, 106 and punchouts 111, 112, 113, 114, 211, 212, 213 to provide electrical circuit paths. Flexible lighting assembly 99 includes first and second electrical groups 109 and 209, respectively. Light emitting diodes 151, 152, 153, 251, 252, 253 are electrically connected to electrical conductors 102 of the flexible cable 100 via leads connected to first exterior side 191 of flexible cable 100. Flexible heat sink sheet material 141, 142, 143, 241, 242, 243 is thermally attached to second side 192 of flexible cable 100 via thermally conductive adhesive 181, 182, 182, 281, 282, 283.

[0017] Referring to FIG. 2, exemplary flexible lighting assembly 199 has flexible cable 1100 with electrical conductor 1102 (two other electrical conductors shown as 102 and 106 not shown) and punchouts 1111, 1112, 1113, 1114, 1211, 1212, 1213 to provide electrical circuit paths. Flexible lighting assembly 199 includes first and second electrical groups 1109 and 1209, respectively. Light emitting diodes 1151, 1152, 1153, 1251, 1252, 1253 are electrically connected to electrical conductors 1102 of the flexible cable 1100 via leads connected to first exterior side 1191 of flexible cable 1100. Flexible heat sink sheet material 1141 is thermally attached to second side 1192 of flexible cable 1100 via thermally conductive adhesive 1181.

[0018] Exemplary widths of the flexible cable range from 10 mm to 30 mm. Exemplary thicknesses of the flexible cable range from 0.4 mm to 0.7 mm.

[0019] Suitable flexible cables are known in the art, and include those marketed by Parlex USA, Methuen; Leoni AG, Nuremburg, Germany; and Axon' Cable S.A.S., Montmirail, France.

[0020] The flexible heat sink sheet material and discrete heat sink sheet materials can be made of metal (e.g., at least one of silver, copper, aluminum, lead, or an alloy thereof).

[0021] In some embodiments, the flexible heat sink sheet material and/or discrete heat sink sheet material has a thickness not greater than 0.45 mm, 0.4 mm, 0.35 mm, 0.3 mm, 0.25 mm, 0.2 mm, 0.15 mm, or even not greater than 0.1 mm). It is within the scope of the present disclosure to combine both the flexible heat sink sheet material and the discrete heat sink features in one light assembly. In some embodiments, the exposed surface area of the flexible heat sink sheet material is in a range from 350 mm² to 1600 mm². In some embodiments, the exposed surface area of the flexible heat sink sheet material is in a range from 45 percent to 100 percent of the outer surface area of the flexible cable. In some embodiments, the exposed surface area of the discrete heat sink features is in a range from 100 mm² to 450 mm². In some embodiments, the surface area of the discrete heat sink features is in a range from 5 percent to 45 percent of the area of the flexible cable.

[0022] The heat sink materials can be attached to the cable using, for example, thermally conductive adhesives which are known in the art.

[0023] Suitable light emitting diodes are known in the art, and commercially available. LEDs are available in a variety of power usage ratings, including those ranging from less than 0.1 to 5 watts (e.g., power usage ratings up to 0.1, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 4, or even up to 5 watts) per LED. LEDs are available in colors ranging range from violet (about 410 nm) to deep red (about 700 nm). A variety of LED colors are available, including white, blue, green, red, amber, etc.

[0024] In some embodiments of light assemblies described herein, the distance between LEDs may be at least 50 mm, 100mm, 150 mm, 200 mm, or even at least 250 mm or more.

[0025] In some embodiments of light assemblies described herein have at least 2, 3, 4, or even at least 5, light emitting diodes per length of, for example, per 300 mm.

[0026] Suitable light assembly configurations can be designed and assembled using known techniques by one skilled in the art after reviewing the instant disclosure.

[0027] Light assemblies described herein are useful, for example, in vehicles (e.g., automobile, trucks, etc.), as well as, task lighting, accent lighting, merchandise display lighting, and back lighting applications. Useful embodiments of light assemblies described herein for vehicles include as a brake center light.

[0028] Advantages and embodiments of this invention are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this invention. All parts and percentages are by weight unless otherwise indicated.

Example 1

[0029] An exemplary lighting assembly as generally shown in FIG. 2 was constructed, except four LED's were in each electrical group rather than just three. A flat flexible cable was made be conventional techniques by drawing three rectangular copper conductors side-by-side through a pull-through die and encapsulating the three conductors with a TPE-E type insulation having a Shore D hardness of 72. The resulting flat flexible cable was 13.5 mm in width with the conductors arranged as shown in FIG. 2. The two outer conductors (0.1 mm thick by 1.5 mm in width) were each located 0.9 mm from each edge of the cable. A center conductor (0.1 mm thick by 6.6 mm in width) was positioned between the two outer conductors with a separation of 1 mm from the two outer conductors. The total thickness of the cable was 0.55 mm.

[0030] A Class IV, CO₂ laser was used to make cutouts and remove insulation from the flat flexible cable make, and thereby facilitate proper electrical contact for the resistors and LEDs. A series of three electrically parallel groups of resistors and LEDs were surface mounted onto the cable and electrically connected to the conductor where insulation was removed via conventional soldering. Each group consisted of a 2 ohms resistor (obtained under the trade designation "CRCW2512"e from Vishay, Malvern, PA), four LED' s (maximum rating of 7 watts; operated nominally at 1 watt; obtained under the trade designation "LCW W5AP" from Osram-Sylvania, Danvers, MA) followed by another resistor ("CRCW2512"). The resistors and LED's were hand soldered to the cable using a conventional tin-lead solder paste. The first resistor in each group was positioned to bridge the outer conductor (power supply) and the center conductor of the cable. The first LED within a group was positioned with its anode electrically connected to the first resistor. The second, third, and fourth LEDs were positioned with their anodes biased to the higher potential. The second resistor in a group was positioned to bridge the center conductor and the outer conductor (ground potential), and was electrically connected to the cathode of the fourth LED.

[0031] The spacing between the first resistor and first LED in each group was about 61 mm. The spacing between each LED within a group was about 65 mm. The spacing between the last LED in the group and the second resistor was about 34 mm. An additional punchout through the center conductor was provided after the second resistor of each group, using a conventional punch tool in a hand operated press, to interrupt electrical current flow and provide parallel-series electrical circuits in the flat flexible cable. To provide power to the lighting assembly, one of the outer conductors was connected to a positive power supply potential and the other outer conductor connected to a ground potential.

[0032] To dissipate the heat generated from the LEDs mounted on to the flat flexible cable, flexible heat sink material was added. The continuous heat sink material was a 0.13 mm thick by 16 mm wide aluminum foil, and was attached to the bottom side of the cable using a thermally conductive adhesive transfer tape (available from 3M Company, St. Paul, MN, under the trade designation "3M 8810"). Excess width of the foil (i.e., foil that extended beyond the width of the cable) was trimmed by hand using a scalpel. The insulation was not removed in the attachment region.

[0033] The resulting lighting assembly, except at the point where an LED is located, if (including the cable and continuous heat sink material) wrapped around a 5 mm diameter rod would not break or damage the lighting function of the lighting assembly, heat sink, or cable.

Example 2

[0034] An exemplary lighting assembly as generally shown in FIGS. IA and IB was constructed except only two light emitting diodes were used and only one electrical group. A flat flexible cable was made and insulation removed as described in Example 1.

[0035] Two resistors and two light emitting diodes were surface mounted onto the cable in series to form one electrical group. The group consisted of a 6.19 ohm resistor ("CRCW2512"), two light emitting diodes (maximum rating 4 watts; operated nominally at 1 watt; obtained under the trade designation "LW W5 AM" from obtained from Osram- Sylvania), followed by another 6.19 ohm resistor ("CRCW2512"). The resistors and light emitting diode were hand soldered to the cable using conventional tin-lead solder. Light emitting diode bias as given in previous example.

[0036] The spacing between the first resistor and first light emitting diode was about 50 mm. The spacing between the two light emitting diodes was about 350 mm. The spacing between the second light emitting diode and the second resistor was about 50 mm. One discrete wire lead was attached to each of the outer conductors to facilitate energizing of the lighting assembly. [0037] Aluminum heat sinks 20 mm length, 13.5 mm wide, 1.6 mm thickness were attached to the cable with thermal transfer tape ("8810") as shown in FIG IA.

[0038] The resulting lighting assembly, except at the point where an LED and discrete heat sink are located, if wrapped around a 5 mm diameter rod would not break or damage the lighting function of the lighting assembly or cable.

Illustrative Example

[0039] A light assembly was constructed as described for Examplel, except no heat sinks were attached or used.

Test Method

[0040] The thermal management of the lighting assembly was determined using the following technique. Conventional horizontal and vertical grids were constructed, wherein the horizontal grid was 1219 mm by 764.5 mm, with 152.4 mm by 152.4 mm measurement zones, and the vertical grid was 1219 mm by 457.2 mm, with 152.4 mm by 76.2 mm measurement zones. This allowed for 40 measurement zones in the horizontal grid and 40 measurement zones in the vertical grid. The horizontal grid was placed on a horizontal measuring surface and the vertical grid was placed on a vertical surface at an approximate right angle to the horizontal surface.

[0041] The light assembly to be tested was mounted on an upper horizontal surface made of wood (which has a relatively very low thermal conductivity) using tape (available from 3M Company, St. Paul, MN, under the trade designation "3M VHB"). The upper horizontal surface was opposite the horizontal measurement surface, and generally parallel to the horizontal measurement surface. K-type thermocouples were soldered to the anodic pin of each of LED. The distance between the horizontal measuring surface and the horizontal light assembly mounting surface was 46 cm. The distance from the mounted light assembly to the vertical surface was 30 cm.

[0042] The mounted light assembly being tested was powered with a conventional voltage sourced laboratory power supply. Temperatures were measured at the anodic pin of each LED, and were monitored with a temperature electronic chart recorder system. Voltage levels were increased to a level were the highest anode pin temperature was stable at 81⁰C, 30 minutes was then allowed for thermal stabilization prior to the light readings being taken. 81⁰C was used because it is the temperature which corresponds to 35000 hour L70 lumen maintenance for the LED's which were used. A dark room was used to take illuminance measurements in each grid measurement zone using a chromameter (obtained from Konica-Minolta, Tokyo, Japan, under the trade designation "KONICA-MINOLTA CL-200 CHROMA METER").

[0043] The average (based on 40 measurements) illuminance for the vertical and horizontal surfaces, total flux reaching the combined measurement surfaces, and electrical test parameters measured are listed in the Table, below.

Exemplary Flexible Lighting Assembly Embodiments

Flexible Lighting Assembly Embodiment 1

A flexible lighting assembly comprising: a flexible cable having a width and thickness, and comprising electrical conductors to provide electrical circuit paths; a light emitting diode electrically connected to electrical conductors of the flexible cable, wherein the light emitting diode comprises leads placed against a first exterior side of the flexible cable; and a flexible heat sink sheet material having a thermal conductivity of at least 25 W/m-K thermally attached to a second side of the flexible cable generally opposite the light emitting diode connected to the flexible cable, and not in direct physical contact with any light emitting diode connected to the flexible cable. Flexible Lighting Assembly Embodiment 2

The flexible lighting assembly according to flexible lighting assembly embodiment 1 having two light emitting diodes electrically connected to electrical conductors of the flexible cable. Flexible Lighting Assembly Embodiment 3

The flexible lighting assembly according to flexible lighting assembly embodiment 1 having three light emitting diodes electrically connected to electrical conductors of the flexible cable. Flexible Lighting Assembly Embodiment 4

The flexible lighting assembly according to flexible lighting assembly embodiment 1 having at least four light emitting diodes electrically connected to electrical conductors of the flexible cable. Flexible Lighting Assembly Embodiment 5

The flexible lighting assembly according to any preceding flexible lighting assembly embodiment, wherein the flexible cable has a width in a range from 10 mm to 30 mm. Flexible Lighting Assembly Embodiment 6

The flexible lighting assembly according to any preceding flexible lighting assembly embodiment, wherein the flexible cable has a thickness in a range from 0.4 mm to 0.7 mm. Flexible Lighting Assembly Embodiment 7

The flexible lighting assembly according to any preceding flexible lighting assembly embodiment, wherein the flexible heat sink sheet material has a thickness not greater than 0.5 mm. Flexible Lighting Assembly Embodiment 8

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 6, wherein the flexible heat sink sheet material has a thickness not greater than 0.45 mm. Flexible Lighting Assembly Embodiment 9

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 6, wherein the flexible heat sink sheet material has a thickness not greater than 0.4 mm. Flexible Lighting Assembly Embodiment 10

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 6, wherein the flexible heat sink sheet material has a thickness not greater than 0.35 mm. Flexible Lighting Assembly Embodiment 11

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 6, wherein the flexible heat sink sheet material has a thickness not greater than 0.3 mm. Flexible Lighting Assembly Embodiment 12

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 6, wherein the flexible heat sink sheet material has a thickness not greater than 0.25 mm. Flexible Lighting Assembly Embodiment 13

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 6, wherein the flexible heat sink sheet material has a thickness not greater than 0.2 mm. Flexible Lighting Assembly Embodiment 14

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 6, wherein the flexible heat sink sheet material has a thickness not greater than 0.15 mm. Flexible Lighting Assembly Embodiment 15

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 6, wherein the flexible heat sink sheet material has a thickness not greater than 0.1 mm. Flexible Lighting Assembly Embodiment 16

The flexible lighting assembly according to any preceding flexible lighting assembly embodiment, wherein the light emitting diode has a power usage rating up to 2 watts. Flexible Lighting Assembly Embodiment 17

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 15, wherein the light emitting diode has a power usage rating up to 1.5 watt. Flexible Lighting Assembly Embodiment 18

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 15, wherein the light emitting d diode has a power usage rating up to 1.25 watt. Flexible Lighting Assembly Embodiment 19

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 15, wherein the light emitting diode has a power usage rating up to 1.1 watt. Flexible Lighting Assembly Embodiment 20

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 15, wherein the light emitting diode has a power usage rating up to 1 watt. Flexible Lighting Assembly Embodiment 21

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 15, wherein the light emitting diode has a power usage rating up to 0.75 watt. Flexible Lighting Assembly Embodiment 22

The flexible lighting assembly according to any of flexible lighting assembly embodiments 1 to 15, wherein the light emitting diode has a power usage rating up to 0.5 watt. Flexible Lighting Assembly Embodiment 23

The flexible lighting assembly according to any preceding flexible lighting assembly embodiment having at least 2 light emitting diodes per length of at least 300 mm. Flexible Lighting Assembly Embodiment 24

The flexible lighting assembly according to any preceding flexible lighting assembly embodiment wherein the flexible heat sink sheet material is made of metal. Flexible Lighting Assembly Embodiment 25 The flexible lighting assembly according to flexible lighting assembly embodiment 24, wherein the metal is at least one of aluminum, copper, or an alloy thereof. Flexible Lighting Assembly Embodiment 26

The flexible lighting assembly according to any of the flexible lighting assembly embodiments 1 to 25, which is task lighting. Flexible Lighting Assembly Embodiment 27

A flexible lighting assembly comprising: a flexible cable having a width and thickness, and comprising electrical conductors to control electrical circuit paths; a light emitting diode electrically connected to electrical conductors of the flexible cable, wherein the light emitting diode comprises leads placed against a first exterior side of the flexible cable; and a first discrete heat sink having a thermal conductivity of at least 25 W/m-K thermally attached to a second side of the flexible cable generally opposite the light emitting diode connected to the flexible cable, and not in direct physical contact with any light emitting diode connected to the flexible cable, wherein the first discrete heat sink has a thickness not greater than 0.5 cm and a width not greater than the width of the flexible cable.

Flexible Lighting Assembly Embodiment 28

The flexible lighting assembly according to flexible lighting assembly embodiment 27 having two light emitting diodes electrically connected to electrical conductors of the flexible cable. Flexible Lighting Assembly Embodiment 29

The flexible lighting assembly according to flexible lighting assembly embodiment 27 having three light emitting diodes electrically connected to electrical conductors of the flexible cable. Flexible Lighting Assembly Embodiment 30

The flexible lighting assembly according to flexible lighting assembly embodiment 27 having at least four light emitting diodes electrically connected to electrical conductors of the flexible cable. Flexible Lighting Assembly Embodiment 31 The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 30 wherein the flexible cable has a width in a range from 10 mm to 30 mm. Flexible Lighting Assembly Embodiment 32

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 30 wherein the flexible cable has a thickness in a range from 0.4 mm to 0.7 mm. Flexible Lighting Assembly Embodiment 33

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 30, wherein the first discrete heat sink has a thickness not greater than 0.45 cm. Flexible Lighting Assembly Embodiment 34

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 30, wherein the first discrete heat sink has a thickness not greater than 0.4 cm. Flexible Lighting Assembly Embodiment 35

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 30, wherein the first discrete heat sink has a thickness not greater than 0.35 cm. Flexible Lighting Assembly Embodiment 36

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 30, wherein the first discrete heat sink has a thickness not greater than 0.3 cm. Flexible Lighting Assembly Embodiment 37

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 30, wherein the first discrete heat sink has a thickness not greater than 0.25 cm. Flexible Lighting Assembly Embodiment 38

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 30, wherein the first discrete heat sink has a thickness not greater than 0.2 cm. Flexible Lighting Assembly Embodiment 39 The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 30, wherein the first discrete heat sink has a thickness not greater than 0.15 cm. Flexible Lighting Assembly Embodiment 40

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 30, wherein the first discrete heat sink has a thickness not greater than 0.1 cm. Flexible Lighting Assembly Embodiment 41

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 40, further comprising a second discrete heat sink having a thermal conductivity of at least 25 W/m-K thermally attached to a second side of the flex cable generally opposite a second of the light emitting diodes connected to the flexible cable and not in direct physical contact with any light emitting diode connected to the flexible cable, wherein the second discrete heat sink has a thickness not greater than 0.5 cm and a width not greater than the diameter of the flexible cable. Flexible Lighting Assembly Embodiment 42

The flexible lighting assembly according to flexible lighting assembly embodiment 41, wherein the second discrete heat sink has a thickness not greater than 0.45 cm. Flexible Lighting Assembly Embodiment 43

The flexible lighting assembly according to flexible lighting assembly embodiment 41, wherein the second discrete heat sink has a thickness not greater than 0.4 cm. Flexible Lighting Assembly Embodiment 44

The flexible lighting assembly according to flexible lighting assembly embodiment 41, wherein the second discrete heat sink has a thickness not greater than 0.35 cm. Flexible Lighting Assembly Embodiment 45

The flexible lighting assembly according to flexible lighting assembly embodiment 41, wherein the second discrete heat sink has a thickness not greater than 0.3 cm. Flexible Lighting Assembly Embodiment 46

The flexible lighting assembly according to flexible lighting assembly embodiment 41, wherein the second discrete heat sink has a thickness not greater than 0.25 cm. Flexible Lighting Assembly Embodiment 47 The flexible lighting assembly according to flexible lighting assembly embodiment 41, wherein the second discrete heat sink has a thickness not greater than 0.2 cm. Flexible Lighting Assembly Embodiment 48

The flexible lighting assembly according to flexible lighting assembly embodiment 41, wherein the second discrete heat sink has a thickness not greater than 0.15 cm. Flexible Lighting Assembly Embodiment 49

The flexible lighting assembly according to flexible lighting assembly embodiment 41, wherein the second discrete heat sink has a thickness not greater than 0.1 cm. Flexible Lighting Assembly Embodiment 50

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 40 further comprising a plurality of discrete heat sinks having a thermal conductivity of at least 25 W/m-K, wherein each of the light emitting diodes has thermally attached to a second side of generally opposite each respective light emitting diode, at least one of the discrete heat sinks and not in direct physical contact with any light emitting diode connected to the flexible cable, wherein the discrete heat sinks each have a thickness not greater than 0.5 cm and a width not greater than the diameter of the flex cable.

Flexible Lighting Assembly Embodiment 51

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 50, wherein the light emitting diode has a power usage rating up to 2 watts. Flexible Lighting Assembly Embodiment 52

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 50, wherein the light emitting diode has a power usage rating up to 1.5 watt. Flexible Lighting Assembly Embodiment 53

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 50, wherein the light emitting diode has a power usage rating up to 1.25 watt. Flexible Lighting Assembly Embodiment 54 The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 50, wherein the light emitting diode has a power usage rating up to 1.1 watt. Flexible Lighting Assembly Embodiment 55

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 50, wherein the light emitting diode has a power usage rating up to 1 watt. Flexible Lighting Assembly Embodiment 56

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 50, wherein the light emitting diode has a power usage rating up to 0.75 watt. Flexible Lighting Assembly Embodiment 57

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 50 wherein the light emitting diode has a power usage rating up to 0.5 watt. Flexible Lighting Assembly Embodiment 58

The flexible lighting assembly according to any of flexible lighting assembly embodiments 21 to 51 having at least 3 light emitting diodes per length of at least 300 cm. Flexible Lighting Assembly Embodiment 59

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 58, wherein the discrete heat sink sheet material is made of metal. Flexible Lighting Assembly Embodiment 60

The flexible lighting assembly according to flexible lighting assembly embodiment 59, wherein the metal is at least one of aluminum, copper, or an alloy thereof. Flexible Lighting Assembly Embodiment 61

A vehicle comprising the flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 60. Flexible Lighting Assembly Embodiment 62

The vehicle according to flexible lighting assembly embodiment 61, wherein the flexible lighting assembly is a brake center light. Flexible Lighting Assembly Embodiment 63 The vehicle according to any of flexible lighting assembly embodiments 61 or 62, which is an automobile. Flexible Lighting Assembly Embodiment 64

The vehicle according to any of flexible lighting assembly embodiments 61 or 62, which is a truck. Flexible Lighting Assembly Embodiment 65

The flexible lighting assembly according to any of flexible lighting assembly embodiments 27 to 60, which is task lighting.

Exemplary Vehicle Embodiments

Vehicle Embodiment 1

A vehicle comprising the flexible lighting assembly according to any preceding flexible lighting assembly embodiment. Vehicle Embodiment 2

The vehicle according to vehicle embodiment 1 , wherein the flexible lighting assembly is a brake center light. Vehicle Embodiment 3

The vehicle according to any of vehicle embodiments 1 or 2, which is an automobile. Vehicle Embodiment 4

The vehicle according to any of vehicle embodiments 1 to 3, which is a truck.

[0044] Foreseeable modifications and alterations of this invention will be apparent to those skilled in the art without departing from the scope and spirit of this invention. This invention should not be restricted to the embodiments that are set forth in this application for illustrative purposes.

Claims

What is claimed is:

1. A flexible lighting assembly comprising: a flexible cable having a width and thickness, and comprising electrical conductors to provide electrical circuit paths; a light emitting diode electrically connected to electrical conductors of the flexible cable, wherein the light emitting diode comprises leads placed against a first exterior side of the flexible cable; and a flexible heat sink sheet material having a thermal conductivity of at least 25 W/m-K thermally attached to a second side of the flexible cable generally opposite the light emitting diode connected to the flexible cable, and not in direct physical contact with any light emitting diode connected to the flexible cable.

2. The flexible lighting assembly according to claim 1, wherein the flexible heat sink sheet material has a thickness not greater than 0.5 mm.

3. A flexible lighting assembly comprising: a flexible cable having a width and thickness, and comprising electrical conductors to control electrical circuit paths; a light emitting diode electrically connected to electrical conductors of the flexible cable, wherein the light emitting diode comprises leads placed against a first exterior side of the flexible cable; and a first discrete heat sink having a thermal conductivity of at least 25 W/m-K thermally attached to a second side of the flexible cable generally opposite the light emitting diode connected to the flexible cable, and not in direct physical contact with any light emitting diode connected to the flexible cable, wherein the first discrete heat sink has a thickness not greater than 0.5 cm and a width not greater than the width of the flexible cable.

4. The flexible lighting assembly according to any of claims 1 to 3 having a plurality of light emitting diodes electrically connected to electrical conductors of the flexible cable.

5. The flexible lighting assembly according to any of claims 1 to 4 wherein the flexible cable has a width in a range from 10 mm to 30 mm.

6. The flexible lighting assembly according to any of claims 3 to 5 wherein the flexible cable has a thickness in a range from 0.4 mm to 0.7 mm.

7. The flexible lighting assembly according to any of claims 3 to 5, wherein the first discrete heat sink has a thickness not greater than 0.45 cm.

8. The flexible lighting assembly according to any of claims 3 to 7, further comprising a second discrete heat sink having a thermal conductivity of at least 25 W/m-K thermally attached to a second side of the flex cable generally opposite a second of the light emitting diodes connected to the flexible cable and not in direct physical contact with any light emitting diode connected to the flexible cable, wherein the second discrete heat sink has a thickness not greater than 0.5 cm and a width not greater than the diameter of the flexible cable.

9. The flexible lighting assembly according to claim 8, wherein the second discrete heat sink has a thickness not greater than 0.45 cm.

10. The flexible lighting assembly according to any of claims 3 to 7 further comprising a plurality of discrete heat sinks having a thermal conductivity of at least 25 W/m-K, wherein each of the light emitting diodes has thermally attached to a second side of generally opposite each respective light emitting diode, at least one of the discrete heat sinks and not in direct physical contact with any light emitting diode connected to the flexible cable, wherein the discrete heat sinks each have a thickness not greater than 0.5 cm and a width not greater than the diameter of the flex cable.

11. The flexible lighting assembly according to any of claims 1 to 10, wherein the light emitting diode has a power usage rating up to 2 watts.

12. The flexible lighting assembly according to any of claims 1 to 11 having at least 3 light emitting diodes per length of at least 300 cm.

13. A vehicle comprising the flexible lighting assembly according to any of claims 1 to 12.

14. The vehicle according to claim 13, wherein the flexible lighting assembly is a brake center light.

15. The flexible lighting assembly according to any of claims 1 to 12, which is task lighting.