WO2010091742A1

WO2010091742A1 - Panel of laminated substrates with barrier layer

Info

Publication number: WO2010091742A1
Application number: PCT/EP2009/056718
Authority: WO
Inventors: Antoine Luijkx; Pierre Boulanger
Original assignee: Agc Glass Europe
Priority date: 2009-02-12
Filing date: 2009-06-02
Publication date: 2010-08-19

Abstract

15 Abstract PANEL OF LAMINATED SUBSTRATES WITH BARRIER LAYER The invention relates to a panel (10) of laminated substrates, comprising a first substrate (12), a conductive layer (14), wherein the conductive layer (14) is provided on the first substrate (12), a second substrate (22), wherein the first substrate (12) and the second substrate (22) are laminated together via a plastics interlayer (20), a light emitting diode (16) inserted between the first substrate (12) and the second substrate 5 (22) being in contact with the conductive layer (14), and a barrier layer (18) preventing a migration of particles from the plastics interlayer (20) to the light emitting diode (16). (Fig. 1)

Description

PANEL OF LAMINATED SUBSTRATES WITH BARRIER LAYER

The invention relates to a panel of laminated substrates with a first substrate, a second substrate and an electronic component as well as a method of making and operating such a panel.

Technical Background

Laminating of two substrates together is often used in the glass panel manufacturing.

Laminated glass is a type of safety glass that holds together when shattered. In the event of breaking, it is held in place by a plastics interlayer, typically of

Polyvinylbutyral (PVB), placed between its two or more layers of glass substrates. The plastics interlayer keeps the layers of glass substrates bonded even when broken, and its high strength prevents the glass substrates from breaking-up into large sharp pieces.

Methods for manufacturing laminated glass are well-known in the window industry since decades. A so-called sandwich of the first glass substrate, the plastics interlayer and the second glass substrate is laminated in an automated laminating line by using the procedure of calendaring and autoclaving. Calendaring means the pre-gluing of the sandwich under the action of a pressure imposed by two rolls applied on either side of the glass substrates. The final gluing of the glass substrates by a vacuum/heating cycle, which combines pressure and temperatures, takes place during the step of autoclaving, which removes air between the plastics interlayer and the glass substrates.

In the automotive, aviation and other industries, panels of laminated glass with integrated electronic components, such as light emitting diodes (LED), are often used, e. g. for displaying information or for lighting purposes. For these application areas, the manufacturing of a panel of laminated glass with electronic components typically comprises the steps of depositing a conductive layer on the first layer of glass substrate, realization of electronic circuits in the conductive layer and depositing of electronic components on the conductive layer, connected to the electronic circuits. The plastics interlayer is then deposited on the conductive layer. The sandwich is obtained by the application of the second layer of glass on the plastics interlayer, which is then laminated as outlined before.

EP 1 437 215 describes such a panel of laminated glass with at least two glass substrates and one or more plastic interlayers, such as PVB, in which the light emitting diode as well as their connecting circuits are inserted between the two glass substrates, wherein the connecting circuits are formed from at least one conductive layer.

Because of adding more and more functionality and increasing light fluxes, the electric power used in those panels has increased. Typically, the current passing through a LED has increased from 10 mA to 70 mA. Due to the higher current passing through the LED the strain for the LED has been increased, too. It has been found that for some basic panels of laminated glass embedding LEDs as described in EP 1 437 215 it can occur that an abnormal decrease of the light flux of 50 % to 80 % is observed after 5000 hours of operation with a power supply set at 70 mA.

Summary of the invention

It is an object of the invention to provide a panel of laminated substrates and to provide a method for manufacturing a panel of laminated substrates with a light source such as an LED. An advantage of embodiments of the present invention is that the emitted light flux is stable over a long period of time and for a high current power supply of the light source, e.g. LED.

This object is addressed by a panel of laminated substrates comprising a first substrate, a conductive layer, wherein the conductive layer is provided on the first substrate, a second substrate, wherein the first substrate and the second substrate are laminated together via a plastics interlayer, a light source, e.g. light emitting diode inserted between the first substrate and the second substrate being in contact with the conductive layer, and a barrier layer preventing a migration of particles from the plastics interlayer to the light source, e.g. light emitting diode.

According to a first embodiment of the present invention the first and second substrates are glass substrates. According to a second embodiment of the present invention, the substrates are metal based substrates (e.g. aluminium or inox or iron or any other metal or alloy of metals substrates) or, according to a third embodiment, one of the first and the second substrates is a glass substrate and the other substrate is a metal substrate. More generally, each one of the first substrate and the second substrate can be made with any material suitable (e.g. glass, metal, Plexiglas, plastics, ceramics,

By adding a barrier layer to the panel of laminated substrates and in particular, but not exclusively, in the case of a panel of laminated glass it is possible to provide a stable light flux over a long period of time and for a high current power supply of the light source, e.g. LED. The increase in electrical power supplied to the light source, e.g. LED generates a local temperature increase at the light source, e.g. LED. The local increase in temperature causes interactions between the materials of the different elements of the panel. Especially strong interactions are observed between LEDs and the plastics interlayer in which the LEDs are embedded. Particles originated from the plastics interlayer, especially particles identified by infrared spectroscopy to be molecular fragments of the type of molecules or ions based on carbonyl C=O groups and resulting from the deterioration of the plastics interlayer and/or from additives added to the plastics interlayer during the production process, are diffusing into the LEDs and causing a decrease of the luminous performance of the LEDs over time.

The barrier layer is a protection layer for the light sources, e.g. LEDs embedded in the plastics interlayer by preventing a migration of particles from the plastics interlayer to the light source, e.g. LED. The barrier layer, especially arranged between the light source, e.g. LED and the plastics interlayer, avoids the diffusion of particles of the plastics interlayer into the light source, e.g. LED to maintain the luminous properties of the light source, e.g. LED over a long time without a decrease of the light flux.

According to a preferred embodiment of the invention, the barrier layer is provided as a film being applied over the whole area of the panel. After applying a conductive layer to the first substrate and contacting one or more light sources, e.g.

LEDs with the conductive layer the barrier layer is deposited as a film over the light sources, e.g. LEDs and the conductive layer. Afterwards the plastics interlayer is deposited on the barrier layer. Thus, the barrier layer covers the light sources, e.g. LEDs and the conductive layer. According to another preferred embodiment of the invention, the barrier layer is provided as a film covering the light source, e.g. light emitting diode and at least partly the conductive layer. Thus, there are spaces between the light sources, e.g. LEDs where the plastics interlayer is in direct contact with the conductive layer. This encourages the adhesion between the first substrate and the second substrate by the plastics interlayer.

Furthermore, it is a preferred embodiment of the invention that the barrier layer is provided as a film being arranged at the surface of the light source, e.g. light emitting diode, whereas the film provides the same size as the surface of the light source, e.g. light emitting diode adjoining the plastics interlayer. The barrier layer is preferably only arranged around the light sources, e.g. LEDs. The conductive layer may be not covered by the barrier layer. Thus, the conductive layer is in direct contact with the plastics interlayer so that the adhesion forces of the plastics interlayer for laminating the first substrate with the second substrate are not affected by the barrier layer.

The film can be applied to the light source, e.g. LED and/or the conductive layer for example by gluing.

According to another preferred embodiment of the invention, the barrier layer is provided as a liquid being applied on the surface of the light source, e.g. light emitting diode. Thus, the barrier layer need only be provided to the light source, e.g. LED before embedding the light source, e.g. LED in the plastics interlayer. By using a liquid for applying the barrier layer it is possible to apply a very thin barrier layer to the light source, e.g. LED. The barrier layer may be applied to the light source, e.g. LED as a solution so that it is easy to apply the barrier layer on each light source, e.g. LED for example by a dispenser or by a spray. The light source, e.g. LED may comprise a chip, e.g. a LED chip and a transparent resin package enclosing the light source, e.g. LED chip. The liquid used for the barrier layer should be able of wetting any hydrophobic surface of the resin package enclosing the light source, e.g. LED chip and having a boiling point below 100 ⁰C.

It is further preferred, that the barrier layer is provided as a solid deposited on the surface of the light source, e.g. light emitting diode. For depositing the barrier layer as a solid to the light source, e.g. LED it is preferred to use Plasma Assisted Chemical Vapour (PACVD) or Plasma Enhanced Chemical Vapour Deposition (PECVD). By these processes it is possible to deposit an insulating layer, e.g. an oxide layer such as a silicon oxide (SiOx) layer at low temperatures.

Moreover, according to a preferred embodiment of the invention, the barrier layer is provided as a layer of monomers polymerised under ultraviolet light beam on the surface of the light source, e.g. light emitting diode. An UVEKOL resin, commercialised by the company CYTEC, may be used as monomer(s). Preferably, a thin layer of a liquid resin is applied on the surface of the light source, e.g. LED, especially on the surface of the resin package enclosing the chip, e.g. LED chip, and after depositing the liquid resin the resin may be polymerized.

Preferably, the barrier layer comprises at least one of the following materials: Polyethylene terephthalate (PET), Polyvinylidene chloride (PVDC), Polyacrylonitrile (PAN), Ethylene vinyl alcohol (EVOH), Polyvinyl alcohol (PVOH), Parylene, Polyethylene naphthalate (PEN), Liquid crystal polymers (LCP).

The object of the invention is further addressed to a method for manufacturing a panel laminated substrates, the method comprising the steps of providing a first substrate, applying a conductive layer on the first substrate, contacting a light source, e.g. light emitting diode with the conductive layer, applying a plastics interlayer covering the conductive layer and the light source, e.g. light emitting diode, applying a barrier layer for preventing a migration of particles from the plastics interlayer to the light source, e.g. light emitting diode, and applying a second substrate on top of the thermoplastic interlayer. The skilled person will readily realize the features of the method according to the present invention when studying the disclosure of the panel of laminated according to the present invention above.

According to at least one embodiment of the invention, the step of applying a barrier layer is performed before the step of applying a plastics interlayer. According to at least another embodiment of the present invention, the step of applying a plastics interlayer is performed before the step of applying a barrier layer.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

Brief description of the drawings

In the drawings:

Fig. 1 depicts a schematic sectional view of a panel of laminated glass according to a first embodiment of the invention,

Fig. 2 depicts a schematic sectional view a panel of laminated glass according to a second embodiment of the invention, and

Fig. 3 depicts a schematic sectional view a panel of laminated glass according to a third embodiment of the invention.

Detailed Description of the detailed embodiments

The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Where the term "comprising" is used in the present description and claims, it does not exclude other elements or steps. Where an indefinite or definite article is used when referring to a singular noun e.g. "a" or "an", "the", this includes a plural of that noun unless something else is specifically stated.

The term "comprising", used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. Thus, the scope of the expression "a device comprising means A and B" should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.

It is to be noticed that the term "comprising", used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a device comprising means A and B" should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

Similarly it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

In the description provided herein, numerous specific details are set forth.

However, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

The invention will now be described by a detailed description of several embodiments of the invention. It is clear that other embodiments of the invention can be configured according to the knowledge of persons skilled in the art without departing from the technical teaching of the invention, the invention being limited only by the terms of the appended claims. As used herein and in the appended claims, the term "solid state light source" includes any light source that is made from semiconductor material such as an LED, a semiconductor laser diode, etc. A solid state light source can be in the form of a chip - an electronic component including a substrate that is typically a semiconductor substrate.

As used herein and in the appended claims, the term "light-emitting diode" or "LED" includes LEDs of all types, such as light-emitting polymers, semiconductor dies that produce light in response to current, organic LEDs, electro-luminescent strips, silicon-based structures that emit light, etc. The term "light-emitting diode" or "LED" may also refer to a single LED package having multiple semiconductor dies that are either individually or collectively controlled. In addition, the term "light-emitting diode" or "LED" may refer to packaged or non-packaged LED's, surface-mount LED's, chip on board LED's, etc. Moreover, the term "light-emitting diode" or "LED" may refer to LEDs packaged or associated with phosphor wherein the phosphor may convert energy from the LED to a different wavelength. Furthermore, the term "light-emitting diode" or "LED" may refer to a LED comprising a LED chip and a transparent resin package enclosing the LED chip.

Fig. 1 shows a sectional view of a first embodiment of a panel 10 of laminated glass. The panel comprises a first glass substrate 12 and a conductive layer 14 applied on top of the first glass substrate 12. The conductive layer 14 is in contact with one or more light sources, e.g. LEDs 16. The light sources, e.g. LEDs 16 and the conductive layer 14 are completely covered by a barrier layer 18. The barrier layer 18 is preferably formed as a film. On top of the barrier layer 18 a plastics interlayer 20, especially of PVB, is applied. The plastics interlayer 20 laminates the first glass substrate 12 with a second glass substrate 22. The conductive layer 14 and the light sources, e.g. LEDs 16 are covered by the barrier layer 20. The barrier layer 20 prevents a migration of particles from the plastics interlayer 20 to the light sources, e.g. LEDs 16 or other solid state light sources.

Fig. 2 shows a second embodiment of a panel 10 of laminated glass where the barrier layer 18 covers the light sources, e.g. LEDs 16 and at least partly the conductive layer 14. Thus, there are spaces between the light sources, e.g. LEDs 16 where the plastics interlay er 20 is in direct contact with the conductive layer 12.

Fig. 3 shows a third embodiment of a panel 10 of laminated glass where the barrier layer 18 is only applied to the light sources, e.g. LEDs 16, especially at the surfaces of the light sources, e.g. LEDs 16 where the light sources, e.g. LEDs 16 are directly joined to the plastics interlayer 20. The barrier layer 18 provides the same size as the surface of the light source, e.g. LED 16 adjoining the plastics interlayer 20.

According to all three embodiments, the barrier layer 18 can be formed as a film, as a liquid, as a solid or as a layer of monomers polymerised under ultraviolet light beam.

Using a liquid as barrier layer 18 it is preferred to use a solution of EVOH in a mixture of water and isopropanol. A droplet, for example 0.05 ml, of this solution may be applied on the surface of the light source, e.g. LED, especially on the resin package enclosing a chip such as an LED chip. After an evaporation of the solvent of the solution, a residue of the EVOH polymer may be deposited on the outer edges of the resin packing enclosing the chip, e.g. LED chip, e.g. because of the hydrophobic character of the resin packing enclosing the chip, e.g. LED chip.

Furthermore, it is preferred using a solution of PET dissolved in a mixture of phenol and methyl enechlorde. A droplet of this solution may be deposited on the resin package enclosing the chip, e.g. LED chip. After evaporation of the light solvent the precipitated PET polymer and the phenol may remain on the surface of the the resin package enclosing the chip, e.g. LED chip.

Moreover, it is preferred using a solution of PVDC for applying a barrier layer 18.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. Panel ( 10) of laminated substrates, comprising

a first substrate (12), a conductive layer (14), wherein the conductive layer (14) is provided on the first substrate (12), a second substrate (22), wherein the first substrate (12) and the second substrate (22) are laminated together via a plastics interlayer (20), a light source (16) inserted between the first substrate (12) and the second substrate (22) being in contact with the conductive layer (14), and a barrier layer (18) preventing a migration of particles from the plastics interlayer (20) to the light source (16).

2. Panel (10) of laminated substrates according to claim 1 , wherein the barrier layer (18) is provided as a film being applied over the whole area of the panel (10).

3. Panel (10) of laminated substrates according to claim 1 , wherein the barrier layer (18) is provided as a film covering the light source (16) and at least partly the conductive layer (14).

4. Panel (10) of laminated substrates according to claim 1 , wherein the barrier layer (18) is provided as a film being arranged at the surface of the light source (16), whereas the film provides the same size as the surface of the light source (16) adjoining the plastics interlayer (20).

5. Panel (10) of laminated substrates according to claim 1 , wherein the barrier layer (18) is provided as a liquid being applied on the surface of the light source (16).

6. Panel (10) of laminated substrates according to claim 1 , wherein the barrier layer (18) is provided as a solid deposited on the surface of the light source (16).

7. Panel (10) of laminated substrates according to claim 1 , wherein the barrier layer (18) is provided as a layer of monomers polymerised under ultraviolet light beam on the surface of the light source (16).

8. Panel (10) of laminated substrates according to anyone of claims 1 to 7, wherein the barrier layer (18) comprises at least one of the following materials:

Polyethylene terephthalate, Polyvinylidene chloride, Polyacrylonitrile, Ethylene Vinyl Alcohol, Polyvinyl alcohol, Parylene, Polyethylene naphthalate, Liquid crystal polymers.

9. Panel (10) of laminated substrates according to anyone of the previous claims, wherein the light source is a light emitting diode.

10. Panel (10) of laminated substrates according to anyone of the previous claims, wherein the light source is a solid state light source.

11. Method for manufacturing a panel (10) laminated substrates, the method comprising the steps of:

providing a first substrate (12), applying a conductive layer (14) on the first substrate (12), contacting a light source (16) with the conductive layer (14), applying a plastics interlayer (20) covering the conductive layer (14) and the light source (16), applying a barrier layer (18) for preventing a migration of particles from the plastics interlayer (20) to the light source (16), and applying a second substrate (22) on top of the thermoplastic interlayer (20).

12. Method according to claim 11, further comprising providing the barrier layer (18) as a film being applied over the whole area of the panel (10), or providing the barrier layer (18) as a film covering the light source (16) and at least partly the conductive layer (14), or providing the barrier layer (18) as a film being arranged at the surface of the light source (16), whereas the film provides the same size as the surface of the light source (16) adjoining the plastics interlayer (20), or providing the barrier layer (18) as a liquid being applied on the surface of the light source (16), or providing the barrier layer (18) as a solid deposited on the surface of the light source (16), or providing the barrier layer (18) as a layer of monomers polymerised under ultraviolet light beam on the surface of the light source (16).

13. Method of claim 11 or 12, wherein the barrier layer (18) comprises at least one of the following materials: Polyethylene terephthalate, Polyvinylidene chloride, Polyacrylonitrile, Ethylene Vinyl Alcohol, Polyvinyl alcohol, Parylene, Polyethylene naphthalate, Liquid crystal polymers.

14. Method of any of claims 11 to 13, wherein the light source is a light emitting diode.

15. Method of any of claims 11 to 13, wherein the light source is a solid state light source.