GB2530307A

GB2530307A - LED lighting assembly

Info

Publication number: GB2530307A
Application number: GB1416549.2A
Authority: GB
Inventors: Kenneth Senior Arthur
Original assignee: Johnson Electric SA
Current assignee: Johnson Electric SA
Priority date: 2014-09-19
Filing date: 2014-09-19
Publication date: 2016-03-23
Also published as: GB201416549D0

Abstract

Preferably the light emitting diode assembly provides a flexible array of LEDs that can then be mounted to a contour of a motorised vehicle to provide a headlight, brake light etc. Each LED is heat-sinked through the assembly. The LED lighting assembly 10, 110 has a base 14 able to provide heatsinking, and which preferably can be flexed, possibly by providing portions 116 between heatsink portions 114. A thermal adhesive 22 (having no metal) fixes conductor 16 to the base 10. An LED 46 is mounted over an interruption 30 in the conductor. A dielectric layer 18 is fixed to the conductor layer via adhesive 28. The dielectric layer has a recess (through hole) to accept the LED and The conductor and dielectric layers 16, 28, 18 may comprise a flexible PCB 12 that is glued to the heatsink base.

Description

LED Lighting Assembly The present invention relates to an LED lighting assembly. and in particular to a flexible assembly which is suitable for a light cluster of a motorised vehicle. The invention further relates to a method of forming such a lighting assembly. a method of installing such an assembly into a motorised vehicle, and to a motorised vehicle having such an LED lighting assembly installed.

LED lighting is becoming more and more common, being a considerably more energy efficient means of providing illumination when compared with incandescent bulbs.

Modern vehicles, such as cars, often utilise LED headlights, side lights, tail lights and brake lights for use when on the road.

Although far less thermal energy is generated using LED lighting in comparison with incandescent, halogen or discharge lighting, it is still important to dissipate any excess thermal energy in an LED lighting assembly in order to prevent damage to other components, since the LEDs will be in close communication with the circuit board to which they are attached. Common problems involve degradation of solder and/or adhesive components within the assembly.

As such, LED lighting assemblies are typically provided in communication with heatsink elements, being metallic components through which thermal energy can he readily dissipated. This leads to rigid, heavy assemblies which can be difficult to integrate into motor vehicles in an aesthetically pleasing manner.

To circumvent this problem. it has been known to construct a plurality of individual LED lights, each having a heatsink. and then wiring them up to one another in order to accommodate three-dimensional forms. Whilst this permits the assembly to be moulded to a particular shape, the wiring is typically brittle and easily damaged.

Flexible LED lighting assemblies are known, but these involve the creation of a bespoke contoured heatsink element, to which a flexible printed circuit can be attached, and then the heatsink element can he attached to the motor vehicle. Such bespoke creation of heatsink elements increases the cost associated with construction of the assembly.

Additionally, such lighting assembhes often include a dielectric substrate positioned between the electrically conductive portion of the flexible printed circuit and the heatsink element, which substantially retards the thermal dissipation from the assembly to the heatsink element.

It is an object of the present invention to provide s&utions to or at least substantially obviate the aforementioned problems.

According to a first aspect of the invention, there is provided an LED lighting assembly comprising: a base layer; a heatsink element forming at least in part the base layer; an electrically conductive layer overlying and affixed to the base layer using a thermally sensitive adhesive without metal loading, the electrically conductive layer including at least one electrical interruption; a dielectric layer overlying and affixed to the electrically conductive layer, a recess through the dielectric layer being positioned over the or each electrical interruption; am! at least one LED light element in electrical communication with the electrically conductive layer, and positioned in a recess of the dielectric layer so as to bridge an electrical interruption of the electrically conductive lighting assembly; wherein thermal energy generated by the light emitted by the in use LED is dissipated at least in part into heatsink dement through the electrically conductive layer and the thermally sensitive adhesive.

The present invention seeks to improve upon LED lighting assemblies utibsed in the automotive industry, by providing a more reliable and cost-effective flexible lighting assembly. Existing flexible assemblies comprise a number of rigid lighting assemblies which are interlinked by connective conductive wires. However, these are easily damaged, particularly over time in the harsh working environment.

Alternatively, flexible assemblies are produced having upper and lower dielectric layers.

which are then applied to the base layer. The present invention only utilises a single dielectric layer, which allows for straightforward thermal exchange between the LED light element and the heatsink element via the thermally sensitive adhesive.

Preferably, a plurality of LED light elements may be provided.

Construction of the LED lighting assembly is facilitated by providing multiple LED light elements on a single assemily. This allows a light duster for a vehicle to he assembled in one piece. should multiple illunilnation sources be required.

Preferably, the heatsink element is associated with each of the LED light elements.

Individual heatsink elements advantageously allow for independent thermal pathways to form from each LED light element, ensuring that one overheated element does not have a deleterious eflect on the thermal dissipation associated with adjacent LED light elements.

Preferably. the base layer may include at least one flexion portion. and more preferably, the flexion portion may accommodate flexing of the base layer. Most preferably. the flexion portion may accommodate flexing of the base layer in at least two directions simultaneously.

By providing a flexible base layer. it is beneficially possible to mould the LED lighting assembly to whatever shape is desired. As such, bespoke mounting elements do not need to be provided in order to integrate with the shape or design of the vehicle or item to which the lighting assembly is being mounted. Advantageously, this greatly reduces the cost associated with instaflation of lighting assemblies.

Thermal dissipation may occur either side of the electrical interruption, and preferably thermal energy dissipation may occur symmetrically about the LED light element.

By providing thermal pathways either side of the electrical interruption, there are multiple routes for thermal energy to be dissipated through to the heatsink element. By providing these symmetrically about the LED light element, the risk of loca' overheating is minimised.

Prcferahly, the thermally sensitive adhesive may substantially maintain its adhesive properties over the temperature range of at least -SOt to +125 C. The typical operating temperature of vehicular headlights is in the range -50 t to +125 C, and it is therefore beneficial to ensure that the thermally sensitive adhesive will not become viscous or lose its adhesive properties in this range. A particular issue with epoxy-based adhesives is that the particulate matter in the resin which enables the thermal conduction will move under gravity if the resin is heated, which further retards the thermal conductivity of the adhesive.

Preferably, a further adhesive layer may he provided to bond the dielectric layer to the electrically conductive layer.

The simplest manner in which the protective dielectric layer may be installed onto the flexible printed circuit is by adhering it to the electrically conductive layer.

Preferably, the electrically conductive layer may be formed from copper.

Copper is a highly electrically and thermally conductive metal, and it is therefore advantageous in both regards to utilise it in the present lighting assembly. Additionally, it is readily etched, which is advantageous during the manufacturing process.

Preferably, the or each LED light element may be directly soldered via a base of the or each LED light element to the electrically conductive layer.

One issue with prior LED lighting assemblies is that to protect the electrical interruption of the circuit, thereby avoiding short-circuit behaviour, the interruption is sealed underneath the dielectric layer. In such arrangements, the LED light clement does not directly bridge the electrically conductive layer, but further includes a wire projecting from an upper surface of the LED light element which does bridge the interruption, tunnelling through the dielectric layer. Such a wire is easily damaged, and therefore it is beneficial to provide a directly connected LED light element to the electrically conductive layer.

Preferably, the assembly may further comprise a plurality of vias through the thermally sensitive adhesive to allow for direct thermal communication between the electrically conductive layer and the or each heatsink dement of the base layer.

Such vias allow for direct conductive communication between the electrically conductive layer and die heatsink element, which advantageously can aflow the manufacturer to direct the thermal exchange along predefined channels, since the metal of the electrically conductive layer will he a more efficient conductor of thermal energy than the thermally sensitive adhesive.

Preferably, the dielectric layer may be formed from a polyimide.

Advantageously, poyimides are capable of protecting an electrically conductive layer thereunder without inhibiting the electrical conductance of the layer.

According to a second aspect of the invention, there is provided a method of installing an LED lighting assembly in accordance with the first aspect of the invention into a motorised vehicle, comprising the steps of: a] flexing the LED lighting assembly to match a desired contour of the motorised vehicle; and b] affixing the LED lighting assembly to a portion of the niotorised vehicle having said contour.

As previously mentioned, it is advantageous to install a flexible lighting assembly to a motorised vehicle without needing to first form a bespoke mounting unit, since the base layer can be easily contoured to the curves of the portion of the motor vehicle to which is to he attached. This reduces the complexity of the construction of the lighting units of the motorised vehicle.

According to a third aspect of the invention, there is provided a motorised vehicle including an LED lighting assembly as installed in accordance with the third aspect of the invention. Said assembly may preferably form at least part of a headlight unit, a side light unit, a tafl light unit, and/or a brake light unit of the motorised vehicle.

A vehicle, such as a car. utilising a lighting assembly in accordance with the present invention can firstly be built without requiring a specific mounting unit for the assembly.

since the assembly can be contoured to a specific shape, and secondly can much more easily comply with regulations regarding the photometry of its fights. since the accuracy of the positioning of the LED light elements, particularly in relation to the other optical components of the unit in which it is accommodated, is much improved over prior devices.

The invention will now be more particularly described, by way of example only, with reierence to the accompanying drawings, in which: Figure 1 shows a cross-sectional representation through a Iirst embodiment 01 an LED lighting assembly. in accordance with the first aspect of the invention; Figure 2a shows a cross-sectional representation through a second embodiment of an LED lighting assembly, in accordance with the first aspect of the invention; Figure 2b shows the LED lighting assembly of Figure 2a in a bent or flexed con hguration; Figure 3 shows an exploded perspective representation of a third embodiment of an LED lighting assembly, in accordance with the first aspect of the invention; and Figure 4 shows a perspective representation of a fourth embodiment of an LED lighting assembly, in accordance with the first aspect of the invention.

Referring firstly to Figure 1. there is shown a first embodiment of an LED lighting assembly, indicated globally at 10. The assembly 10 is a layered device, and comprises two main portions: a Ilexible printed circuit 12 and a base ayer 14, the flexible printed circuit 12 being positioned on top of the base layer 14.

The flexible printed circuit 12 comprises an electrically conductive layer 16, forming the circuitry of the assembly 10, over which is laid a protective, electrically insulative dielectric layer 18. acting as a substrate. The base layer 14 is primarily a heatsink clement 20 for the dissipation of thermal energy frotn the assembly 10. This heatsink element 20 comprises the entirety of the base layer 14 in this embodiment, and is substantially formed as a thick sheet of aluminium. However, any appropriately thermally conductive material may he utilised, such as hut not limited to stainless steel and/or copper.

To interconnect the flexihie printed circuit 12 and the base ayer 14, there is provided a, preferably thermally sensitive, adhesive 22 between an upper surface 24 of the base layer 14 and a lower surface 26 of the electrically conductive layer 16. In the present embodiment, there is a further adhesive layer 28 which binds the dielectric layer 18 to the electrically conductive ayer 16.

Working upwards from the bottom of the assemlly ID. the base layer 14 is a, preferably solid metal. heatsink element 20 covered by the thermally sensitive adhesive 22. The thermally sensitive adhesive 22 is typically an acrylic solution rather than an epoxy-based resin, since this will have a greater resistance to variations in temperature over the thermal cycle of the lighting assembly 10. An example of such an adhesive wouM he the DuPont Pyralux RTM LF Sheet adhesive manufactured by DuPont Electronic Technologies. 14 T. W. Alexander Drive, Research Triangle Park, North Carolina 27709. USA.

The electrically conductive layer 16 on top of the thermally sensitive adhesive 22 is a printed circuit, typically formed from copper, and is not formed as a contiguous layer.

There is at least one electrical interruption 30 positioned in the circuit, which prevents electrical current flow between separated portions 32a, 32b of the electrically conductive layer 16.

In this embodiment, the further adhesive layer 28 is laid on top of the eleetneally conductive layer 16. However, the further adhesive layer 28 does not fully coat an upper surface 34 of the electrically conductive layer 16; there is a gap. centred on and wider than the electrical interruption 30. which defines a recess 36 in an upper surface 38 of the assembly 10. The dielectric layer 18 is similarly overlain on the further adhesive layer 28, further defining the recess 36; disparate portions 40a. 4Db of the dielectric layer 18 defining an upper rim 42 of the recess 36.

The upper suitace 38 of the assembly 10 is therefore formed by the dielectric layer 18, with the exception of the recess 36. wherein access to the electrically conductive layer 16 is viable. Therefore, there is defined an exposed portion 44 of the electrically conductive layer 16.

Onto the exposed portion 44 of the electrically conductive layer 16 is fixed an LED light element 46. The LED light element 46 comprises a main body 48, a light-emitting portion 50. and first and second terminals 52, 54.

In the present embodiment, there is an electrical contact pad 56 positioned on each of the separated portions 32a, 32h of the electricaIy conductive layer 16, to which are respectively connected the first and second terminals 52, 54 of the LED light element 46, typically using solder 58. but alternatively using any type of conductive bonding means.

Positioning the LED light element 46 via its base 60 therefore allows for direct electrical communication between the LED light element 46 and the electrically conductive layer 16, rather than utilising a separate conductive wire which projects from an upper portion of the LED light element, a configuration which is known in the prior art awl is easily damaged.

When operational, electrical current is able to flow through the electrically conductive layer 16 to the first separated portion 32a, through the first terminal 52 of the LED light element 46, then through the second terminal 54 and into the second separated portion 32b of the electrically conductive layer 16. The electrical circuit is therefore complete.

and the light-emitting portion 50 of the LED light element 46 is illuminated.

As the light-emitting portion 50 is illuminated, the LED light element 46 becomes heated. Thermal dissipation is able to occur via the first and second terminals 52, 54 and through the electrical contact pads 56, following a path through the electrically conductive layer 16. the thermally sensitive adl esive 22, and into the heatsink element of the base layer 14.

Furthermore, by preferably utilising a dry-film adhesive 22, one which is a thermally sensitive adhesive rather than a pressure sensitive adhesive. along with the adhesive 22 not being metal loaded, delamination in the high temperature working environment of the lighting unit is prevented or at least limited.

Ordinarily, the above-mentioned flexible printed circuit would he formed separately of its heatsink, having protective didectric ayers on both sides ol the electrically conductive layer. This means that the flexibility of the flexible printed circuit is maintained before fixation to the heatsink, but whilst retarding heat transfer from the LED light element to the heatsink.

In the present embodiment of the invention, there is no such inhibiting further dielectric layer between the electrically conductive layer 16 and the heatsink element 20, only the thermally sensitive adhesive 22. Therefore, thermal dissipation is highly effective, obviating the deleterious effects of heating.

The preferred use of an acrylic solution rather than an epoxy-based resin means that the thermally sensitive adhesive 22 is also resistant to heating effects; ordinary epoxy usually utiliscs metallic particles suspended in its resinous structure, which, upon heating of the adhesive, leads to gravitational diffusion of said particles as the resin becomes less viscous with elevated temperature. This inhibits the thermal conductivity of such adhesives over time, and can also lead to electric shorting issucs.

Although not shown in the present embodiment, it is possible to provide via holes through the thermally sensitive adhesive 22, allowing the material of the electrically conductive layer 16 to be extended into direct thernml communication with the heatsink element 20, in order to further facilitate thermal dissipation.

Thermal dissipation occurs downwardly through from the base 60 of the LED light element 46. Dissipation can occur through either side 32a. 32b of the electrical interruption 30, allowing independent thermal cxchLmgc from each terminal 52, 54 of the LED light element 46. Since the LED light element 46 is centred on the electrical interruption 30, thermal dissipation will advantageous'y occur symmetrically from the LED light element 46, thereby avoiding local heat pockets.

Whflst it may he advantageous to provide an assembly 10 as detailed above, thereby removing the need for an additional interstitial dielectric layer. it may be preferable to form an assembly wherein the underlying base layer is flexible as well. A second embodiment of the invention is therefore shown in Figures 2a and 2b, indicated generally at 110. Similar or identical references refer to similar or identical parts to those described above, and therefore further detailed description is omitted for brevity.

In the second embodiment, the flexible printed circuit 112 is largely identical to that of the first embodiment, albeit with a plurality of recesses 136 integrated into its upper surface 138 defining a plurality of exposed portions 144 of the electrically conductive layer 116. There is therefore a plurality of LED light elements 146 associated with this particular assembly 110.

However, die base layer 114 in this embodiment is lormed as a single heatsink element having a flexible body portion 162 interconnecting a plurality of heatsink contact surfaces 164, each heatsink contact surface 164 being associated with a respective LED light element 146. Within (he flexible body portion 162 is provided a plurality of flexion portions 166 between each heatsink contact surface 164.

The flexion portion 166 is a void or opening in this embodiment, hut may he formed from an elastomeric or similarly flexible material, so as to allow contouring of the assembly 110 without causing stresses in either the base layer 114 or the flexible printed circuit 112.

Whilst the heatsii* contact surfaces 164 are described as being integrally formed with or part of the flexible body portion 162 in the present embodiment, it will he apparent that the heatsink contact surfaces 164 could be provided as separate heatsink elements.

For example, the dashed portion shown in Figures 2a and 2b could be provided as individual heatsink elements 1 14a which could be assembled with or provided subsequent to the formation or as part of the flexible body portion 162, thereby forming a composite or multi-part base layer.

The flexion portions 166 are typically affanged in a lattice in the plane of the flexible printed circuit 112. This enables muhi-dimensional flexibility of the assembly 110, as opposed to flexibility purely along a single axis.

The flexibility conferred by the flexion portion 166 of the base layer 114, as shown in Figure 2b, allows the assembly 110 as a whole to be moulded to the curvature of a support to which it is being mounted, without requiring the creation of a bespoke mounting unit so'ely br the assembly 110.

A critical feature of lighting assemblies, in particular for motorised vehicle headlights, is that the lights must be correctly aligned with both reflectors and lenses of the headlights in order to avoid dazzling oncoming traffic. Similar care needs to be undertaken for the rear lighting units also. It is therefore important that the u1exihe printed circuit and base layer are correctly oriented with one another when forming said assemhly, iii preparation Icr the base hyer to then he received in a correct tolerance alignment in the lighting housing.

A third embodiment of the invention, indicated globally at 210. is shown in Figure 3, showing the arrangement of the flexible printed circuit 212 and base layer 214 relative to one another. The flexible printed circuit 212 is overlain onto the base layer 214 such that individual circuit areas 268 of the flexible printed circuit 212 arc in alignment with the flexion portions 266 of the heatsink element 220.

In this embodiment, the flexible printed circuit 212 is applied as a whole panel, being preferably bonded to the base layer 214. hidividual circuit areas 268 can be punched out of or formed from this panel as required. One advantage of applying the flexible printed circuit 212 thus so is that afl of the individual circuit areas 268 can he aligned with the flexion portions 266 simultaneously.

An alternative fourth embodiment is shown in Figure 4. indicated generally at 310. The base layer 314 is substantially identical to that of the third embodiment; however, rather than a single contiguous flexible printed circuit, a plurality of flexible pnnted circuits 312 arc provided, each corresponding to a particular circuit area 368.

Similar alignment holes may be formed through each flexible pnnted circuit 312, and in this embodiment., the LED light elements 346 are shown either side of the flexion portions 366, with the individual flexible printed circuits 312 retained in alignment with the base layer 314. The individual flexible printed circuits 312 can then he punched from the base layer 314, as appropriate.

The lighting assemblies 210, 310 shown in the third and fourth embodiments of the invention are formed by affixing the dielectric layer 218, 318 to the electrically conductive ayer 216, 316 to form the flexible printed circuit 212, 312, and then aligning the base layer 214. 314 and the flexible printed circuit 212. 312. such that the heatsink element 220,320 and LED light elements 346 are correctly aligned.

At this point, the thermally sensitive adhesive is in an unadhered condition. The etched targets 270 in the Ilexilie printed circuit 212, 312 may then he used to secure the flexible printed circuit 212, 312 and base layer 214, 314 together, and the thermally sensitive adhesive is then cured to adhere the electrica'ly conductive layer 216 to the base Iayer2l4, 314.

This curing may occur either by using an elevated temperature or pressure. so as to sufficiently set the thermally sensitive adhesive 22 into a fully adhered state, whilst being resistant to moderate operating temperatures, that is, those in the range of at least -SOt to +l25t.

As stated, the primary use of this invention is in the automobile industry, for use with a motorised vehicle in a lighting unit, and more particularly in a headlight unit, side light unit, tail light unit and/or brake light unit. Such vehicles typically have highly contoured cavities, particularly in relation to head light units, in which the lighting assemblies are to he installed, making the installation of rigid lighting assemblies problematic.

Utilising a hghting assemhly as constructed in accordance with the present invention, it is possible to flex the assembly in two or three dimensions to the match a desired contour of the motorised vehicle, such as the interior of a lighting cavity of the vehicle, and the assembly may then be affixed to the portion of the motorised vehicle having said contour. In this manncr. the construction of a bespoke mounting for the lighting assembly along with daisy-chaining rigidly formed mountings is avoided.

It will be apparent that, although the flexible printed circuit. is described above as being formed of a plurality of layers, not all of the byers may he strictly necessary in order to create a hghting assembly in accordance with the present invention. In particular, the further adhesive layer. between the upper dielectric layer and the electrically conductive layer could be any form of bonding or fastening. For example, the dielectric layer could feasibly be laser ablated onto the electrically conductive layer.

The thermally sensitive adhesive has been described above as an acrylic scñution hut it could feasibly be any bonding adhesive with the appropriate thermal and dielectric properties. For instance, it could be a laminated temperature-sensitive-adhesive film, screen printed or pressure-sensitive-adhesive film.

It is therefore possible to provide an LED lighting assembly which not only comprises fewer components than prior assemblies, comprising only an upper dielectric layer. an electrically conductive layer to which at least one LED light clement is affixed, a thermally sensitive adhesive, and a heatsiiik layer, but which is also capable of flexion.

Such a flexible lighting assembly may be contoured to the curves of a particular motor vehicle, thereby avoiding the construction of a bespoke mounting support in order to retain the assembly in the vehide.

The words comprises/comprising' and the words having/including' when used herein with reference to the present irn'ention are used to specify the presence of stated features, integers, steps or components. but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments. may a'so he provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment. may also be provided separately or in any suitable sub-combination.

The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled hi the field without departhig from the scope of the invention as defined herein.

Claims

Claims 1. An LED lighting assembly comprising: a base layer; a heatsink element forming at least in part the base layer; an electrically conductive layer overlying and affixed to the base ayer using a thermally sensitive adhesive without metal loading, the electrically conductive layer including at least one electncal interruption; a dielectric layer overlying and affixed to the electrically conductive layer, a recess through the dielectric layer being positioned over the or each electrical interruption; and at least one LED light element in electrical communication with the electrically conductive layer, and positioned in a recess of the dielectric layer so as to bridge an electrical interruption of the electrically conductive lighting assembly; wherein thermal energy generated by the light emitted by the in use LED is dissipated at least in part into the heatsink element through the electrically conductive layer and the thermally sensitive adhesive.
2. An LED lighting assembly as claimed in claim 1, wherein there is provided a plurality of LED light elements.
3. An LED lighting assembly as claimed in claim 2. wherein the heatsink element is associated with each of the LED light elements.
4. An LED lighting assembly as claimed in claim 3, wherein the base layer includes at least one flexion portion.
5. An LED lighting assembly as claimed in claim 4, wherein the flexion portion accommodates flexing of the base layer.
6. An LED lighting assembly as claimed in claim 5, wherein the flexion portion accommodates Ilexing ol the base layer in at east two directions simultaneously.
7. An LED lighting assembly as daimed in any one of the preceding daims.wherein thermal energy dissipation occurs either side of the electrical interruption.
8. An LED lighting assembly as claimed in claim 7, wherein thermal energy dissipation occurs symmetrically about the LED light element.
9. An LED lighting assembly as claimed in any one of the preceding claims, wherein the thermafly sensitive adhesive substantially maintains its adhesive properties over a temperature range of at least -50°C to +125°C.
10. An LED lighting assembly as claimed in any onc of thc prcccding claims.wherein a further adhesive layer is provided to bond the dielectric layer to the electrically conductive layer.
11. An LED lighting assembly as claimed in any one of the preceding claims, wherein the electrically conductive layer is formed from copper.
12. An LED lighting assembly as daimed in any one ol the preceding claims, wherein the or each LED light element is directly soldered via a base of the or each LED light element to the electrically conductive layer.
13. An LED lighting assembly as claimed in any one of the preceding claims, further comprising a plurality ol vias through the thermally sensitive adhesive to allow for direct thermal communication between the electrically conductive layer and the or each heatsink element of the base layer.
14. An LED lighting assembly as claimed in any one of the preceding claims.wherein the dielectric layer is formed from a polyimide.
15. An LED lighting assembly substantially as hereinhefore described, with reference to Figures 1 to 4 of the accompanying drawings.
16. A method of installing an LED lighting assembly as claimed in any one of claims I to 15 into a motorised vehicle, comprising the steps of: a] flexing the LED lighting assembly to match a desired contour of the motorised vehicle: and hI affixing the LED lighting assembly to a portion of the motorised vehicle having said contour.
17. A motorised vehicle including an LED lighting assembly as installed according to the method of daim 16.
18. A motorised vehicle as daimed in claim 17, wherein the LED lighting assembly forms at Icast in part any onc of a headlight unit, a side light unit, a tail light unit, and/or a brake light unit of the motorised vehicle.