1. Field of the Invention
The present invention relates to an electro-optic component obtainable from a foil. The present invention further relates to a method of manufacturing the electro-optic component.
2. Related Art
For large area OLED lighting on flexible plastic substrates, a large current is required to drive the system. The present thin film materials used for the anode (e.g. ITO) and cathode (e.g. Ba/Al) have a large resistivity and the large currents give rise to a substantial voltage drop, which determine inhomogeneous light emission. For producing large area flexible OLED devices on plastic substrates there is a need for an additional metallization structure of the plastic substrate. For reducing the manufacturing costs, such structured metallization coatings will preferably be applied on rolls of plastic foil using an inline roll-to-roll web coating process. Accordingly, for electro-optic devices, such as light emitting devices, electro-chromic devices, and photo-voltaic products there is a need for a metallization structure that on the one hand has a good electrical conductivity, while on the other hand has a high transmission for radiation.
WO2010016763 describes an electric transport component that comprises a substrate provided with a barrier structure with a first inorganic layer, an organic decoupling layer and a second inorganic layer. At least one electrically conductive structure, for example a mesh, is accommodated in trenches in the organic decoupling layer. In the electric transport component the walls of the trenches support the mesh. Therewith the aspect ratio of the elements in the mesh can be relatively high. The aspect ratio is defined here as the height of the mesh, divided by the smallest dimension of said structure within the plane of the organic decoupling layer. The mesh is accommodated in the organic decoupling layer of the barrier structure. Therewith the organic decoupling layer serves a dual purpose and in manufacturing of the component only a single step is necessary to provide the organic decoupling layer that decouples the inorganic layers and that accommodates the mesh. Organic electro-optic devices often comprise materials that are sensitive to moisture. The known electric transport component provides for an electric signal or power transport function, as well as for a protection of the device against moisture.
In an embodiment of the known electric transport component the at least one trench extends over the full depth of the organic decoupling layer. This makes it possible to separate the electric transfer component, or an electro-optic device comprising the electric transfer component into parts. The electrically conductive structure embedded in the organic decoupling layer prevents a lateral distribution of moisture via the organic decoupling layer towards the electro-optic device.
In the case of most common electronic device designs on foil, OLEDs or OPVs, there is the need to define two electrode contacts for connecting the electrodes to a respective external electrical conductor, i.e. a contact for the bottom electrode of the device and a contact for the top electrode of the device.
The bottom electrode is herein defined as the one of the electrodes that is arranged closest to the mesh. The bottom electrode of the device is electrically contacted through the mesh at the sides of the device. The mesh provides a uniform current distribution to the device but in between the metal tracks of the mesh a current spreading layer is applied to provide a uniform power distribution. This can be a transparent organic conductor with sufficient conductivity. Depending on the application the mesh may have openings in the order of a mm to a few cm. The top electrode requires a separate electric contact. The necessity to separately provide this contact complicates the manufacturing of the electro-optic component.
US2011/0084624 pertains to a light emitting device comprising a first common electrode, a structured conducting layer, forming a set of electrode pads electrically isolated from each other, a dielectric layer, interposed between the first common electrode layer and the structured conducting layer, a second common electrode, and a plurality of light emitting elements. Each light emitting element is electrically connected between one of the electrode pads and the second common electrode, so as to be connected in series with a capacitor comprising one of the electrode pads, the dielectric layer, and the first common electrode. When an alternating voltage is applied between the first and second common electrodes, the light emitting elements will be powered through a capacitive coupling, also providing current limitation. During operation of the light emitting device, a shorts circuit failure in one light emitting element will affect only light emitting elements connected to the same capacitor. Further, the short circuit current will be limited by this capacitor.
It is an object of the present invention to provide an electro-optic component that can be manufactured with a foil.
It is a further object of the present invention to provide a method of manufacturing an electro-optic component from a foil.
A foil can be used to manufacture electro-optic products. The foil has an electrically conductive structure with a mesh and a plurality of mutually insulated electrically conductive elements that are laterally enclosed by the mesh in mutually separate zones. Therein respective ones of the mutually insulated electrically conductive elements are arranged. In an embodiment the electrically conductive elements are laterally separated parts of the mesh.
According to a first aspect of the present invention an electro-optic component is provided as claimed in claim 1.
According to a second aspect of the invention a method is provided as claimed in claim 8, for manufacturing an electro-optic component from a foil.
In the method according to the second aspect of the invention a first, translucent electrically conductive layer, an electro-optic layer and a second electrically conductive layer are applied over said electro-optic layer, therewith forming an electro-optic element. The second electrically conductive layer extends beyond the electro-optic layer over one or more enclosed electrically conductive elements. The enclosed electrically conductive elements can serve as an electric contact for the second electrically conductive layer. Although the enclosing mesh serves as a power distribution grid for the first electrically conductive layer, the latter may also cover one ore more enclosed electrically conductive elements provided that these are not the same that are covered by the second electrically conductive layer.
Subsequently a barrier layer is provided over the electro-optic component. Therein the barrier layer and the embedded mesh in the foil encapsulate the electro-optic component to form an encapsulated electro-optic component. In a subsequent step the encapsulated electro-optic component is separated from the remainder.
Therewith an encapsulated electro-optic component according to the first aspect of the invention is obtained as claimed in claim 1.
The foil used to manufacture the electro-optic component allows for an easy application of the electric contact of both electrically conductive layers, without restricting the dimensions of the encapsulated electro-optic component to be manufactured therewith to a predetermined size. Relatively small sized components may be manufactured, wherein a single one of the electrically conductive elements, for example a laterally separated portion of the mesh is used to contact. But also larger components can be manufactured, wherein the electro-optic component extends over a larger area with a plurality of mutually electrically insulated elements. It is therewith no objection that the first, transparent electrical conductive layer overlaps also electrically conductive elements of the mesh, provided that these do not serve as contact points for the second electrical conductive layer. In this case the first, transparent electrical conductive layer reconnects the electrically conductive elements with the mesh, and therewith provides for a current distribution in the enclosed zone in cooperation with the electrically conductive element in the enclosed zone.
In an embodiment the mutually insulated electrically conductive elements have a bounding box with a smallest dimension in a range between 0.5 and 3 times the square root of the average area of openings enclosed by the mesh. A substantially smaller dimension, e.g. less than 0.1 times the square root of the average area of openings would make it difficult to obtain an adequate electrical connection between the second electrically conductive layer and the insulated electrically conductive element. A substantially larger smallest dimension, e.g. more than 5 times the square root of the average area of openings, would not further improve the electrical connection with the second electrically conductive layer. Hence, when it is used to provide the electrical contact for the second electrically conductive layer, it would occupy an unnecessary large space which can not be used for depositing the first electrically conductive layer.
In embodiments the bounding box has a largest dimension in the range between 1.5 and 10 times its smallest dimension. A largest dimension substantially greater than 10 times the smallest dimension, e.g. 50 times the smallest dimension would too much restrict the number of ways in which the foil can be partitioned in the process of manufacturing an electro-optic component. A largest dimension less than 1.5 times would result in an unnecessarily fine partitioning of the mesh which would impede the conductivity of the electrically conductive element.
In an embodiment the shortest distance between an insulated electrically conductive element and the enclosing mesh portion is in the range between 1 and 5 times the width of the mesh elements. A substantially smaller distance, e.g. less than 0.5 times the width of the mesh elements would necessitate small production tolerances, to prevent that the insulated electrically conductive element and the enclosing mesh portion contact each other. In areas wherein the insulated electrically conductive element is covered by the first, transparent electrically conductive layer, electrical conduction over this distance is only possible via this transparent layer. In this case a distance, substantially larger than the 5 times the width of the mesh elements, e.g. larger than 10 times the width of the mesh elements, would result in a too inhomogeneous distribution of the current.
These and other aspects are described in more detail with reference to the drawings, wherein:
Therein
In the following detailed description numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be understood by one skilled in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, and components have not been described in detail so as not to obscure aspects of the present invention.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof
Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
The invention is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity.
It will be understood that when an element or layer is referred to as being “on”, “connected to” or “coupled to” another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to” or “directly coupled to” another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.
Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures.
It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
Embodiments of the invention are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
As can be seen in
The inorganic layers may be any translucent ceramic including but not limited to metal oxide, silicon oxide (SiO2), aluminum oxide (Al2O3), titanium oxide (TiO2), silicon nitride (SiN), silicon oxynitride (SiON) and combinations thereof.
The inorganic layers have a water vapour transmission rate of at most 10−4 g·m−2·day−1.
The inorganic layers are in practice substantially thinner than the organic layers. The inorganic layers should have a thickness in the range of 10 to 1000 nm, preferably in the range of 100 to 300 nm.
In the embodiment shown, the mesh 24 is formed as a regular grid with square openings. In other embodiments the mesh 24 may have hexagonal openings as shown in
In the embodiment shown in
In the embodiment shown in
In the embodiment shown in
It can also be verified that in each of the embodiments shown in
In the embodiments shown the shortest distance between an insulated electrically conductive element 22a, 22b and the enclosing mesh 24 is in the range between 1 and 5 times the width w of the mesh elements.
In the embodiments shown in
By way of example,
In order to improve electric conductivity between the mutually insulated electrically conductive elements 22a and 22b on the one hand and the enclosing mesh 24 on the other hand, the mutually insulated elements, also denoted as enclosed portions 22a, 22b may be provided with a ring conductor 28b as shown in
In the embodiment shown in
Although the mutually insulated portions typically are arranged in a rectangular zone within the enclosing mesh 24, also other embodiments may be considered as shown in
Several options are possible for the arrangement of the inorganic layers in the barrier layer structure 30 wherein the electrically conductive structure 20 is embedded.
As in
providing a substrate 10,
providing the substrate with a barrier layer structure 30 with an embedded electrically conductive structure 20, the barrier layer structure 30 comprising a first inorganic layer 32, a second inorganic layer 34 and an organic layer 36 between said inorganic layers, said organic layer being partitioned by the mesh, into organic layer portions 36a, the electrically conductive structure 20 comprising an enclosing mesh 24 and a plurality of mutually insulated electrically conductive elements 22a, 22b, wherein the enclosing mesh encloses mutually separate zones 26a, 26b wherein respective ones of the mutually insulated electrically conductive elements 22a, 22b are arranged.
A method for manufacturing a foil as described in general terms above, can be carried out in various ways of which some are described now in more detail.
In a first step S1 shown in
In a subsequent step S2 (as shown in
In further subsequent steps S3 (See
An alternative method is described with reference to
In the embodiment shown, the substrate 10 is provided, upon which in subsequent steps S10 and S11 a first inorganic layer 32 and an organic layer 36 is deposited. The result of these steps is shown in
In order to form the trenches in the organic decoupling layer for example soft lithography (embossing PDMS rubber stamp into a partially reacted organic layer) may be applied. In this way trenches are formed that can have an aspect ratio of up to 10.
Further the organic decoupling layer is fully cured after imprinting e.g. by polymerization using a heat-treatment or UV-radiation.
Alternatively, the organic layer 36 and the pattern of tranches may be formed in a single step, e.g. by printing the organic layer in a pattern complementary to the pattern of trenches 37.
The trenches 37 are treated such that no organics remain in bottom of the trench on top of the first inorganic barrier layer 32. A plasma etch might be used for this cleaning. Remaining organic material could form a diffusion path for moisture.
As shown in
In a further step an electrically conductive material that is to form the electrically conductive structure 22a, 24 is deposited in the trenches 37. Therewith the semi-finished product shown in
To mitigate that the conductive material spreads out at the surface, the top surface is made hydrophobic and the trenches are made hydrophilic. The trenches may be filled in a single step, for example by sputtering, or by vapor deposition, such as MOCVD, and combining this with the step of polishing or etching. Preferably the trenches are filled with a two-stage process. For example the trenches can be filled with an evaporated metal (e.g. Al like in publication EP 1 693 481 A1) or with solution based metals (e.g. Ag, Au, Cu) and an extra baking step (below 150 C). The next process is to fill completely the trenches in order to compensate for shrinkage of the material in the trenches. The electrically conductive material applied during the second step may be the same, but may alternatively be a different material. In that case, suitable metals for the first layer M1, having a relatively high conductivity are for example Ag, Au, Cu and Al. Suitable materials for the second layer M2, having relatively high reflectivity, are for example Cr, Ni and Al. See
An inline vacuum or air based roll-to-roll web coating system known as such may be used to apply the organic and inorganic layers. The coating system consists of multiple sections combining an unwind, a rewind and in between a multiple of process chambers dedicated for example to pre-treat a substrate surface, or coat a substrate surface with an inorganic layer, or coat a substrate surface with an organic layer, or coat a substrate surface with a patterned organic layer, or cure an organic coated surface.
The inorganic layers may be applied by all kinds of physical vapor deposition methods such as thermal evaporation, e-beam evaporation, sputtering, magnetron sputtering, reactive sputtering, reactive evaporation, etc. and all kinds of chemical vapor deposition methods such as thermal chemical vapor deposition (CVD), photo assisted chemical vapor deposition (PACVD), plasma enhanced chemical vapor deposition (PECVD), etc.
The organic layer may be applied by all kinds of coatings techniques, such spin coating, slot-die coating, kiss-coating, hot-melt coating, spray coating, etc. and all kinds of printing techniques, such as inkjet printing, gravure printing, flexographic printing, screen printing, rotary screen printing, etc.
A still further way of carrying out the method of manufacturing the foil is shown in
In a second step S21, shown in
Subsequently, in step S22 shown in
In step S23, shown in
Therewith a patterned surface portion is obtained with a free surface as shown in
Subsequently, in step S24, shown in
After lamination the carrier portion TC2 of the metal foil TC is removed, so that only the metal structure, forming the electrically conductive structure 20, embedded in the barrier 32, 36, 34 and carried by the substrate 10 remains. Removal of the carrier portion TC2 takes place in a step S26 as shown in
Further details about this method can be found in WO 2011/016724 for example. Alternatively, or in addition it is possible to provide the metal substrate in the form of a first and a second metal layer 10a, 10b that are separated by an etch stop layer 10c, as is shown in
The second electrically conductive layer 44 does not need to be transparent. In an embodiment the second electrically conductive layer 44 may comprise sub-layers, for example a sub-layer of Ba having a thickness of about 5 nm, arranged against the electro-optic layer, and a sub-layer of aluminium having a thickness in the range of 100-400 nm
Dependent on the type of electro-optic element, e.g. photo-voltaic device, light-emitting device or electro-chrome device, the electro-optic layer 46 may comprise a plurality of sub-layers. For example in a light-emitting device, the electro-optic layer 46 may for example comprise in addition to a light-emitting sub-layer further comprise a hole-injection layer, an electron-injection layer etc.
In the embodiment shown, the electro-optic layer 46 extends beyond the first electrically conductive layer in the direction of the electrically conductive element 22a and therewith provides for an insulation between the first and the second electrically conductive layer 42, 44.
The electro-optic component further comprises a protection layer 50 that in combination with the barrier structure 30 formed by the layers 32, 34, 36 and the electrically conductive structure 20 embedded therein encloses the electro-optic element 40 therewith providing a protection against ingress of moisture. The protection layer 50 typically comprises a stack of sub-layers. In a first embodiment the protection layer 50 is a stack comprising an organic sub-layer sandwiched between a first and a second inorganic sub-layer. The stack may comprise further organic and inorganic sub-layers that alternate each other. The organic sub-layers may comprise a moisture getter. Alternatively the protection layer 50 may comprise a stack of sub-layers of different inorganic materials that alternate each other.
As can be seen in
A method of manufacturing an electro-optic component from a foil as described above, for example the foil of
In a first step S30 as illustrated in
In a next step S31 as illustrated in
In
The so encapsulated electro-optic elements 40 may then be separated from each other according to separation lines C.
Electric contacts 71, 72 for both electrically conductive layers 42, 44 can then formed by a feed-through element in the substrate 10. Preferably however, an exposed portion 24c of the mesh 24 and an exposed portion 22c of the electrically conductive element 22a are used as electric contacts. Feed-through elements in that case are not necessary. Due to the fact that the mesh 24 laterally encloses the separate zone, and in that a barrier surface is formed by the inorganic layer 34 and the electrically conductive structure 20, both electrodes 42 and 44 of the electro-optic element can be easily connected to an external conductor while preventing ingress of moisture or other atmospherical substances.
In the claims the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single component or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.
Number | Date | Country | Kind |
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12180925.5 | Aug 2012 | EP | regional |
This application is a continuation-in-part of International Application PCT/NL2013/050602, filed Aug. 16, 2013, which claims priority to Application EP 12180925.5, filed Aug. 17, 2012. Benefit of the filing date of each of these prior applications is hereby claimed. Each of these prior applications is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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Parent | PCT/NL2013/050602 | Aug 2013 | US |
Child | 14624001 | US |