Layered device and method for pressure treatment

Abstract

To provide a method of manufacturing a layered device.SOLUTION: To provide a layered device. The device comprises two base films, an electrically conductive pattern attached to the first base film facing the second base film, and a bonding layer bonding the first base film and the second base film together. The bonding layer includes openings and the conductive pattern includes exposed portions aligned with the openings of the bonding layer. The device further includes a spacer attached to the first base film and the exposed portion of the conductive pattern, wherein the spacer fills at least a portion of the space created by the opening in the bonding layer. The invention further relates to a method of manufacturing a layered device.SELECTED DRAWING: Figure 1a

Description

[Technical Field]

[0001] This application relates to the field of layered devices used in electronic devices. This application also relates to methods of manufacturing layered devices. [Background technology]

[0002] Pressure processing techniques are used in the fabrication of layered devices to create hermetically sealed thin electronic devices, and in some cases to form these electronic devices on surfaces. These techniques include thermoforming, vacuum forming, lamination, and many other techniques that involve the use of heat and pressure. In pressure processing, components of the device that are fragile or located in exposed areas can be damaged by pressure applied to the structure from the opposite side. Summary of the Invention

[0003] The device according to the invention is characterized by what is presented in claim 1.

[0004] The method is characterized by what is presented in claim 19.

[0005] The term "comprising" is used herein to mean including the features or acts that follow it without excluding the presence of one or more additional features or acts.

[0006] Furthermore, reference to an item before "an" will be understood to refer to one or more of those items.

[0007] The expressions "film" and "layer", unless otherwise specified, should be understood herein to refer to a structure whose lateral dimensions are substantially greater than its thickness. In that sense, a film may be considered to be a "thin" structure.

[0008] In a first aspect of the present invention, a device is provided. The device may be a layered device, a layered electronic device, a stacked device, a laminated electronic device, or any other suitable device including an electrical circuit. The device includes a first base film and a second base film arranged parallel to the first base film at a predetermined distance. The first base film and the second base film each include two surfaces, one of which faces the corresponding surface of the other film. The first base film and the second base film may be a first substrate and a second substrate. The terms "first" and "second" are used interchangeably and are used solely for clarity; for example, if the device is arranged horizontally, the first base film and the second base film may be a bottom film and a top film, respectively.

[0009] The device includes a conductive pattern attached to a surface of a first base film facing the second base film. The device also includes a bonding layer at least partially filling the space between the first base film and the second base film, surrounding a portion of the conductive pattern, and bonding the first base film and the second base film together. The bonding layer at least partially connects the first base film and the second base film to each other. The connection may be adhesive or any other type of bond, such as a non-adhesive layer that bonds the first base film and the second base film together after molding or heat treatment.

[0010] The bonding layer includes an opening, and the conductive pattern includes at least one exposed portion aligned with the opening in the bonding layer. The device further includes a spacer attached to the first base film and the exposed portion of the conductive pattern, the spacer filling at least a portion of the space created by the opening in the bonding layer.

[0011] The openings in the bonding layer and the exposed portions of the conductive pattern may be required in various electronic applications to provide access to the conductive pattern and, in some cases, connection points. The device according to the first aspect is configured to undergo thermoforming, vacuum forming, lamination, or any other pressure-based, and in some cases temperature-based, manufacturing process. In these processes, if pressure is applied uniformly across the first and second base films, the exposed portions of the conductive pattern not covered by the bonding layer due to the openings may be subject to damage due to the force of the first and second base films being pressed together and the brittleness of the conductive pattern. The device according to the first aspect includes at least one spacer filling at least a portion of the space created by the openings, thereby providing protection against damage and destruction of the conductive pattern during high-pressure processing.

[0012] In one embodiment, for example, when the opening in the bonding layer is adjacent to one boundary of the first base film and / or the second base film, at least an end of the exposed portion of the conductive pattern in the device according to the first aspect is opened and separated from the first base film, so that the exposed portion is at the edge of the conductive pattern and is therefore secured only by the bonding layer and attached to the first base film on one side, which can provide easier access to the exposed portion of the conductive pattern, for example, to provide a connection point.

[0013] In one embodiment, the spacer includes two or more structures firmly fixed to the first base film and the exposed portion of the conductive pattern, the structures being positioned adjacent to each other at a predetermined distance.

[0014] The structures according to this embodiment may include pillars, spacer dots, or any other suitable structures for preventing excessive pressure on the conductive pattern during further manufacturing. Two or more structures may also be positioned adjacent to an element of the conductive pattern for better protection. The structures may be aligned in height so that their upper surfaces are positioned at substantially the same level, thus creating a discontinuous surface on the upper layer to be pressed against, thereby uniformly protecting the conductive pattern from damage.

[0015] In one embodiment, the spacer structure comprises a material selected from UV cross-linkable polymer inks, thermally cross-linkable polymer inks, and thermosetting inks. These materials provide the combination of rigidity, flexibility, and heat resistance necessary for protection during thermoforming. The material may also be UV cured.

[0016] In an alternative embodiment, the spacer may have a solid form that is not separated into separate structures.

[0017] In one embodiment, the spacer includes a release coating that uniformly fills at least a portion of the space created by the openings in the tie layer.

[0018] The release coating can protect the conductive pattern and is useful in applications where the conductive pattern has one or more loose ends after thermoforming, allowing the release coating to be removed (peel away). However, the posts or other spacer structures from the previous embodiments that are rigidly secured to the first base film may be more durable and provide higher pressure and heat resistance.

[0019] The release coating may include a polymer matrix, a UV- or thermally crosslinkable polymer, which may be cured by temperature or UV light after printing and before the device is processed to release the coating. In addition to or as an alternative to crosslinking, the release coating may also include a solvent or water-based solution, where the solvent or water is evaporated in a drying process following the printing process.

[0020] In further embodiments, the spacer may comprise a combination of two or more separate spacer structures positioned adjacent to one another and rigidly secured to the first base film and release coating.

[0021] In one embodiment, the first base film and the second base film are non-conductive, thereby providing insulation for the conductive pattern disposed therebetween. The non-conductive first base film and the second base film may comprise a material selected from the group consisting of polyethylene terephthalate, polycarbonate, polymethyl methacrylate, cyclic olefin copolymer, triacetate, cyclic olefin copolymer, poly(vinyl chloride), poly(ethylene 2,6-naphthalate), polyimide, polypropylene, polyethylene, and any combination thereof.

[0022] In one embodiment, the first base film and / or the second base film are transparent. The term "transparent" should be understood herein, unless otherwise specified, to refer to the optical transparency of the base film or its components and materials in the relevant wavelength range in question. A transparent material or structure refers to a material or structure that allows light, or generally electromagnetic radiation, of such relevant wavelengths to propagate through such material or structure. The relevant wavelength range may depend on the application in which the laminated transparent film is used. In one embodiment, the relevant wavelength range is the visible wavelength range of about 390 to about 700 nanometers. In one embodiment, the preferred wavelength range is 850 to 1550 nanometers.

[0023] Furthermore, the transparency of a base film or a component thereof primarily refers to the transparency through the thickness of the laminate film or component thereof, so that a sufficient portion of the light energy incident on the base film or component thereof propagates through it in the thickness direction to be "transparent." This portion may depend on the application for which the base film is used. In one embodiment, the transmittance of the first base film and / or the second base film or component thereof is 20-99.99% of the light energy incident perpendicularly to the laminate film at the location where the transparent conductive material is present. In one embodiment, the transmittance is 20% or more, or 30% or more, or 40% or more, or 50% or more, or 60% or more, or 70% or more, or 80% or more, or 90% or more. The transmittance may be measured according to standards JIS-K7361 and ASTM D1003.

[0024] In one embodiment, the conductive pattern comprises a network of conductive, high aspect ratio molecular structures (HARM structures).

[0025] A conductive "HARMS structure" refers to a conductive "nanostructure," i.e., a structure with one or more characteristic dimensions on the nanometer scale, i.e., about 100 nanometers or less. A "high aspect ratio" refers to the dimensions of two perpendicular conductive structures being on a significantly different order of magnitude. For example, a nanostructure may have a length that is tens or hundreds of times longer than its thickness and / or width. In a HARMS structure network, many nanostructures are interconnected to form a network of electrically interconnected molecules. Considered on a macroscopic scale, a HARMS network forms a solid, monolithic material in which the individual molecular structures are unoriented or disoriented, i.e., substantially randomly oriented or oriented. Various types of HARMS networks can be fabricated in the form of thin, transparent layers with suitable resistivities.

[0026] In one embodiment, the conductive HARM structure comprises metal nanowires, such as silver nanowires.

[0027] In one embodiment, the conductive HARM structure network comprises carbon nanostructures. In one embodiment, the carbon nanostructures comprise carbon nanotubes, carbon nanobuds, carbon nanoribbons, or any combination thereof. In one embodiment, the carbon nanostructures comprise carbon nanobuds, i.e., carbon nanobud molecules. Carbon nanobuds or carbon nanobud molecules have fullerene or fullerene-like molecules covalently bonded to the sides of tubular carbon molecules. Carbon nanostructures, particularly carbon nanobuds, may be advantageous from electrical, optical (transparency), and mechanical (rigidity combined with flexibility and / or deformability) perspectives.

[0028] In one embodiment, the conductive pattern includes at least one set of conductive traces. The conductive traces can be used in various layered electronic devices. In some cases, the conductive traces can be particularly fragile and easily damaged by pressure applied through the first and second base films, which necessitates an additional protective structure, such as a spacer according to the first aspect.

[0029] In one embodiment, the device further includes a second conductive pattern attached to a surface of a second base film facing the first base film, and the conductive pattern attached to the surface of the first base film facing the second base film is the first conductive pattern. This embodiment provides a device with at least two conductive patterns facing each other and attached to opposing base films. In this embodiment, the spacer protects the first and second conductive patterns from damage that may be caused by pressure applied during, for example, thermoforming or lamination. The spacer may also prevent the conductive traces from shorting each other.

[0030] In alternative embodiments, the second conductive pattern may be attached to the opposite side of the first base film or the opposite side of the second base film.

[0031] In one embodiment, the first conductive pattern and the second conductive pattern are aligned so that they are separated within the plane of the parallel first and second base films. In this embodiment, the conductive patterns are separated so that they are insulated from each other and will not be damaged during high-pressure processing. For example, in applications such as touch sensors, the electrodes may be in different planes and may not overlap.

[0032] In one embodiment, the bonding layer at least partially fills the space between the first base film and the second base film and surrounds a portion of the conductive pattern, and the bonding layer may also include a bonding promoter selected from the group consisting of an acrylic adhesive, a silicone adhesive, a polymer adhesive, a cross-linked polymer, an epoxy adhesive, a polycarbonate, a thermoplastic polyurethane (TPU), and any combination thereof.

[0033] The adhesive may be an optically clear adhesive (OCR), which is advantageous in devices requiring a transparent film, such as devices with displays.

[0034] In one embodiment, the bonding layer is further configured to insulate the portion of the conductive pattern surrounded by the bonding layer, with the adhesive acting as an insulator for the conductive pattern, eliminating the need for additional insulating structures or separating the conductive elements from one another.

[0035] In one embodiment, the spacer fills at least a portion of the space between the exposed portion of the conductive pattern and the second base film. The spacer may also have adhesive properties and be easily removed, or may replace the adhesive in the opening, insulating the exposed portion of the conductive pattern without opening or removing parts of the device.

[0036] In one embodiment, the spacer comprises a mechanically rigid material capable of withstanding pressures of at least 5200 bar at temperatures up to 250° C. In one embodiment, the material is capable of withstanding pressures at temperatures up to 180° C. These mechanically rigid materials may comprise a UV-curable polymer matrix, a screen-printable ink, a water-based polymer matrix, or other suitable materials. Examples of suitable materials are Nor-Cote UVS-161 for rigidly fixed spacers, and Kiwomask S 110, Kiwomask S 111, or Kiwomask S 150 for release coatings.

[0037] In one embodiment, the device comprises three or more base films attached to one another in a laminated configuration by adhesive, wherein each adjacent pair of base films may comprise a conductive pattern and spacers in openings in each layer of adhesive as described in the first aspect.

[0038] In an exemplary embodiment, there is provided a touch sensor comprising the device of any of the preceding embodiments. The exposed portion of the conductive pattern comprises at least one electrode of the touch sensor. In other embodiments, touch switches, touch sensors, solar panels, heating elements, and other devices may not advantageously incorporate a device according to the first aspect.

[0039] In one embodiment, the first base film or the second base film has a thickness of 1 to 5000 μm, or 10 to 2000 μm, or 30 to 500 μm, or 50 to 300 μm. This preferred size is suitable for most device applications, such as touch switches, touch sensors, heating elements, and solar cells. However, in some applications, the thickness of the base film may also be thicker. The first base film and the second base film may have the same or different thicknesses.

[0040] In a second aspect, a method for fabricating a layered electronic device is provided. The method includes the steps of: providing a first base film and a second base film arranged parallel to the first base film at a predetermined distance; applying a conductive pattern to the surface of the first base film facing the second base film; printing spacers on the first base film and portions of the conductive pattern; preparing a bonding layer by cutting the bonding layer into a predetermined shape including openings; disposing the bonding layer between the first and second base films so that the openings in the bonding layer align with the positions of the spacers printed on the first base film and portions of the conductive pattern, at least partially filling the space between the first and second base films and surrounding portions of the conductive pattern; and treating the resulting layered structure at a predetermined pressure and temperature. The bonding layer may include an adhesive or a thermoplastic film that can melt at the predetermined temperature.

[0041] The bonding layer may be disposed between the first and second base films in various ways. In one embodiment, the bonding layer is pattern-printed onto the first base film and the conductive pattern. The printed bonding layer pattern may include one or more openings, so that in this embodiment, the steps of preparing the bonding layer and disposing it between the films can be performed in one step.

[0042] A previous step of processing the resulting layered structure can provide a layered device as described in any of the embodiments of the first aspect. Processing the resulting layered structure completes the fabrication of the layered device. In embodiments, processing may include molding, thermoforming, lamination, and other pressure processing techniques. Advantages of this method include, among others, efficiency of fabrication and an improved resulting layered structure that is protected during the final pressure processing step.

[0043] In one embodiment, the conductive pattern is applied to the surface of the first base film facing the second base film by depositing a conductive material and etching the conductive material to create the pattern. In one embodiment, the conductive pattern is also applied to the surface of the second base film. In one embodiment, the conductive pattern is formed in the conductive material after the conductive material is deposited on the first base film and / or the second base film.

[0044] In one embodiment, depending on the material of the conductive pattern, the conductive material may be deposited using various procedures existing in the art, for example, the conductive material may be deposited by sputtering under vacuum conditions, printing, electroplating, vapor phase deposition, force field deposition, deposition from solution using spray coating or spin drying, or any other suitable method.

[0045] Various processes may be used for patterning. In one embodiment, a laser process, an etching process, direct printing, a mechanical process, a combustion process, or any combination thereof is used for patterning. In one embodiment, the laser process is laser ablation. In one embodiment, the etching process is a photolithography process. In one embodiment, the pattern is formed simultaneously with or after the conductive material is deposited on the first base film and / or the second base film.

[0046] In one embodiment, the steps of adding the conductive pattern and printing the spacers are performed on the second base film before adding a tie layer between the first and second base films. The conductive pattern on the second base film may be applied to the surface facing the first film or to the opposite surface of the second base film. The steps of this method may also be performed multiple times to create a laminated or multi-layer device that includes spacers between the base films to reinforce the exposed portions of the conductive pattern during pressure processing.

[0047] In one embodiment, the pressure treatment of the resulting layered structure comprises thermoforming at a temperature of 130-200°C.

[0048] In one embodiment, pressure treating the resulting layered structure comprises laminating in a vacuum at a temperature between 50 and 300° C., or between 150 and 300° C., or between 170 and 190° C. In further embodiments, pressure treating may comprise a combination of techniques such as thermoforming, lamination, etc.

[0049] In one embodiment, the method further includes creating at least one open end of the conductive pattern by die-cutting or laser-cutting a portion of the conductive pattern corresponding to the portion of the conductive pattern on which the spacer is printed.

[0050] Creating open or removable ends of the conductive pattern prior to processing can provide easier access to the exposed portions of the conductive pattern, for example, to provide connection points to electrodes if the conductive pattern includes electrodes.

[0051] In one embodiment, the method further comprises the step of cooling the device after the pressure treatment, which may be necessary, for example, to set the shape after thermoforming or any other process.

[0052] It will be understood that the benefits and advantages described above may relate to one embodiment or to several embodiments, and embodiments are not limited to those that solve any or all of the problems presented or that have any or all of the benefits and advantages described.

[0053] The above-described embodiments may be used in any combination with each other. Some embodiments may be combined together to form further embodiments. The method, layered device, use, or touch sensor film to which the present application relates may include at least one of the above-described embodiments.

[0054] The accompanying drawings, which are included to provide a further understanding of the layered device and its method of manufacture, illustrate embodiments and, together with the description, serve to explain the principles described above. [Brief explanation of the drawings]

[0055] [Figure 1a] 1A and 1B show schematic cross-sectional views of a layered device according to an embodiment; [Figure 1b] FIG. 1 is a schematic cross-sectional view of a layered device with spacers removed according to one embodiment. [Figure 1c] 1 is a schematic cross-sectional view of a layered device with a spacer structure according to an embodiment. [Figure 1d] 1 is a schematic cross-sectional view of a layered device in combination with a spacer according to one embodiment. [Figure 2a] 1A and 1B show schematic top views of devices with peeling spacers according to an embodiment; [Figure 2b] 1 is a schematic top view of a device with a spacer structure according to an embodiment; [Figure 3] 1A and 1B illustrate schematic cross-sectional views of flexible layered devices including open conductive structures according to one embodiment. [Figure 4] FIG. 1 is a block diagram of a method according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0056] Reference will now be made in detail to the exemplary embodiments described herein, examples of which are illustrated in the accompanying drawings.

[0057] The following description discloses several embodiments in detail to enable those skilled in the art to utilize the disclosed layered devices and methods based on the disclosure. Not all steps of the embodiments are described in detail because some steps may be apparent to those skilled in the art based on this specification.

[0058] For simplicity, in the case of repeating parts, the item number is maintained in the following exemplary embodiment.

[0059] The present invention generally relates to layered electronic devices, such as touch switches, touch sensors, touch displays, heating elements, solar cells, and the like. In these devices, when pressure processes, such as pressure molding, thermoforming, lamination, or other techniques, are used in fabrication, it is often desirable to provide electrical contact to the layered device by leaving portions of the conductive elements exposed. However, the exposed portions are susceptible to damage during pressure processes due to the forces generated during such processes. Devices according to embodiments of the present invention include additional spacer elements that prevent such damage and protect the exposed portions of the conductive elements. A method according to one aspect provides a process for fabricating a layered device using spacers.

[0060] 1a shows a schematic cross-sectional view of a layered device 100 according to an exemplary implementation. The device includes a first base film 101, a second base film 102 arranged parallel to the first base film 101, a conductive pattern 104 attached to the surface of the first base film 101 facing the second base film 102, and a bonding layer 103 therebetween.

[0061] The first base film 101 and the second base film 102 may be non-conductive substrates that insulate the conductive pattern 104. The base films 101, 102 may comprise a material selected from the group consisting of polyethylene terephthalate, polycarbonate, polymethyl methacrylate, cyclic olefin copolymer, triacetate, cyclic olefin copolymer, poly(vinyl chloride), poly(ethylene 2,6-naphthalate), polyimide, polypropylene, polyethylene, and any combination thereof.

[0062] The conductive pattern 104 is shown generally as a set of conductive traces, depending on the implementation, which are commonly used in layered electronics such as touch sensors.

[0063] However, the conductive pattern 104 may have any other suitable arrangement of conductive elements.

[0064] The conductive pattern 104 may include a network of conductive, high aspect ratio molecular structures (HARM structures), which are useful in transparent films due to some of the advantageous properties of HARM structures.

[0065] The bonding layer 103 at least partially fills the space between the first base film 101 and the second base film 102, surrounds a portion of the conductive pattern 104, and bonds the first base film 101 and the second base film 102 together. The bonding layer 103 may include an adhesive. The bonding layer 103 may also include a bonding promoter selected from the group of acrylic adhesives, silicone adhesives, polymer adhesives, cross-linked polymers, epoxy adhesives, polycarbonates, thermoplastic polyurethanes (TPUs), and any combination thereof. The adhesive may be an optically clear adhesive (OCR), which is useful in devices requiring a transparent film, such as devices with displays.

[0066] Bonding layer 103 includes openings 107, which may be on the side as shown in the side view of Figure 1a, or may be inside the perimeter of device 100. In one implementation, openings 107 are located around the perimeter of bonding layer 103 to provide access points.

[0067] Conductive pattern 104 includes at least one exposed portion that is aligned with opening 107 in bonding layer 103. The cross-sectional views of Figures 1a-1d are oriented so that opening 107 and the exposed portion of conductive pattern 104 face the viewer.

[0068] While this structure provides an access point to the conductive pattern 104, if the device 100 is subjected to pressure forming, thermoforming, lamination, or other types of pressure processing, the exposed portions of the conductive pattern 104 may be damaged by the pressure. This is at least in part due to the opening 107 in the bonding layer 103 that is required to provide access. The opening 107 exposes a portion of the conductive pattern 104 and removes the support that the bonding layer 103 provided elsewhere on the device 100.

[0069] The device 100 further includes spacers 105 attached to the first base film 101 and the exposed portions of the conductive pattern 104, the spacers 105 filling at least a portion of the space created by the openings 107 in the bonding layer 103. Figures 1a-1b show an implementation in which the spacers 105 include a release coating 105 that uniformly fills at least a portion of the space created by the openings 107 in the bonding layer 103. The release coating 105 may include a polymer matrix, a UV- or thermal-crosslinkable polymer, or a solvent- or water-based solution.

[0070] The release coating 105 can be used temporarily and removed, for example, by peeling or partially evaporating if it contains a solvent or water-based solution. A pressure treatment at a predetermined temperature can remove the release coating after completing device fabrication. The pressure treatment may include thermoforming at temperatures between 130 and 200°C, lamination in a vacuum at temperatures between 170 and 190°C, or any other suitable pressure-based process that seals and / or forms the layers of the device together on a surface. FIG. 1b shows the device 100 after thermoforming, in which the release coating 105 has been removed, leaving instead a space 105' that may later be filled with a filler or remain empty.

[0071] 1c-1d show an implementation in which the spacer comprises two or more structures 106 firmly fixed to the first base film 101 and to the exposed portions of the conductive pattern 104. These structures 106 are positioned adjacent to each other at a predetermined distance.

[0072] 1c, the structures 106 are also aligned in height such that their upper surfaces are substantially flush with the lower surface of the second base film 102. The structures 106 shown in the exemplary implementation of FIG. 1c are formed as pillars, although any other suitable shape may be used for the spacer structures 106.

[0073] The rigidly fixed structure 106 may comprise a material selected from ultraviolet cross-linkable polymer inks, thermally cross-linkable polymer inks, and thermosetting inks, which may be sufficiently rigid to withstand pressures of at least 5200 bar at temperatures up to 250° C. while protecting the conductive pattern 104 from damage during pressure processing.

[0074] FIG. 1d shows that the layered device 100 may include a combination of rigidly fixed post or spacer structures 106 and an additional release coating 105''. In some implementations, these structures may be rigidly fixed to the first base film 101 if the protection that the solid special structures provide against pressure is sufficient.

[0075] Figure 2a is a schematic top view of a layered device 200 with a release coating 206, and Figure 2b is a schematic top view of a layered device 200 with a rigidly fixed structure 206. Thus, device 200 shown in Figures 2a-2b may be an example of device 100 shown in Figures 1a-1d. In Figure 2b, the rigidly fixed structure is shown only schematically and may be located anywhere within dashed area 206.

[0076] 2a-2b, a conductive pattern 204 is shown extending into the device, such as in a touch sensor implementation. The conductive pattern 204 includes an exposed portion with an exposed end 207. The end 207 or the entire exposed portion of the conductive pattern 204 is open and separated from the first base film (not shown in FIGS. 2a-2b). A second base film 202 is shown as the top film of the device 200. The first base film and / or the second base film 202 can be transparent.

[0077] In addition to the first conductive pattern 204 attached to the first base film and the two externally disposed pins shown in FIGS. 2a-2b as the outer portion of the circuit, the device 200 can also include a second conductive pattern 214 (or any number thereof). The second conductive pattern 214 is attached to the second base film 202 on the surface facing the first base film. Although not visible in FIGS. 2a-2b, the second conductive pattern 214 is attached to the inward-facing surface of the second, upper base film 202 in this implementation. The first conductive pattern 204 and the second conductive pattern 214 in this implementation are aligned so as to be separated within the plane of the parallel first and second base films 202. In this manner, the conductive patterns 204, 214 are positioned to avoid contact with each other during pressure application.

[0078] 3 is a schematic side view of an exemplary layered device including two conductive patterns 304, 314 attached to a first base film 301 and a second base film 302, respectively. The device includes a non-conductive bonding layer 303 that insulates the conductive patterns 304, 314 and fills the space between the first base film 301 and the second base film 302.

[0079] The device further includes an opening in the adhesive layer 303, marked by a vertical line in Figure 3. The device also includes a spacer 305 disposed between the conductive layers 304, 314 in place of adhesive in the opening. The exposed portion of the conductive pattern 314 is open and separated from the first base film (right side of Figure 3) to facilitate external access. In Figure 3, the material of at least the second base film 302 allows it to be flexible.

[0080] FIG. 4 is a flowchart of a method for fabricating a layered electronic device according to one embodiment. The method includes step 401 of providing a first base film and a second base film arranged parallel to one another. The base films may be provided to a chamber or reactor for further assembly. The method further includes step 402 of adding a conductive pattern to the top surface of the first base film and step 403 of printing spacers on the first base film and portions of the conductive pattern. Next, the method includes step 404 of forming a bonding layer that fills the space between the first base film and the second base film. The method also includes step 405 of creating openings in the bonding layer, for example, by cutting the bonding layer aligned with the spacers to a predetermined shape, such that the openings align with the positions of the spacers printed on the first base film and portions of the conductive pattern.

[0081] The method concludes with step 406 of pressurizing the resulting layered structure at a predetermined temperature. The pressurizing may be provided by any suitable means and may include applying pressure to one or both of the base films. In one implementation, the pressurizing may also include treating the resulting layered structure with UV crosslinking. In some embodiments, pressurizing 406 the resulting layered structure may include thermoforming at a temperature of 130-200°C, or any other suitable technique, such as lamination and vacuum forming.

[0082] Prior processing of the resulting layered structure can provide a layered device such as that described with respect to any of the layered devices shown in Figures 1a-3. Processing of the resulting layered structure completes the fabrication of the layered device. In some implementations, processing may include molding, thermoforming, lamination, and other pressure processing techniques. Advantages of this method include, among others, efficiency of fabrication and an improved resulting layered structure that is protected during the final pressure processing step.

[0083] The conductive pattern may be applied to the surface of the first base film facing the second base film by depositing a conductive material and etching the conductive material to create the pattern. The second conductive pattern may also be applied to the surface of the second base film.

[0084] The conductive pattern applying step 402 and the spacer printing step 403 are performed on the second base film before the bonding layer forming step 404 between the first and second base films. The conductive pattern on the second base film may be applied to either the surface facing the first film or the opposite surface of the second base film. The steps of this method may also be performed multiple times to create a laminated or multi-layer device that includes spacers between the base films to reinforce the exposed portions of the conductive pattern during the pressing process.

[0085] The method may further include creating at least one open end of the conductive pattern by die-cutting or laser-cutting a portion of the conductive pattern corresponding to the portion of the conductive pattern on which the spacer is printed.

[0086] Creating open or removable ends of the conductive pattern prior to processing step 406 can provide easier access to the exposed portions of the conductive pattern, for example, to provide connection points to electrodes if the conductive pattern includes electrodes.

[0087] After the pressure treatment step 406, the method may also include a step of cooling the device (not shown in FIG. 4), which may be necessary, for example, to set the shape after thermoforming or any other process.

[0088] It is clear to those skilled in the art that the present invention is not limited to the above examples and implementations, but the implementations can be freely varied within the scope of the claims.

Claims

1. a first base film; a second base film disposed parallel to the first base film at a predetermined distance; a conductive pattern attached to a surface of the first base film facing the second base film; a bonding layer at least partially filling a space between the first base film and the second base film, surrounding a portion of the conductive pattern, and bonding the first base film and the second base film together, the bonding layer includes an opening, and the conductive pattern includes at least one exposed portion aligned with the opening in the bonding layer; The layered device further includes a spacer attached to the first base film and the exposed portion of the conductive pattern, the spacer filling at least a portion of the space created by the opening in the bonding layer.

2. 2. The device of claim 1, wherein the spacer comprises two or more structures firmly secured to the first base film and the exposed portion of the conductive pattern, the structures being positioned adjacent to each other at a predetermined distance.

3. The device of claim 2 , wherein the structure comprises a material selected from ultraviolet cross-linkable polymer inks, thermally cross-linkable polymer inks, and thermally curable inks.

4. The device of claim 1 , wherein the spacer includes a release coating that uniformly fills at least a portion of the space created by the opening in the bonding layer.

5. The device of claim 4 , wherein the release coating comprises a polymer matrix, a UV or thermal crosslinkable polymer, or a solvent-based or water-based solution.

6. The device according to any one of claims 1 to 5, wherein at least an end of the exposed portion of the conductive pattern is open and separated from the first base film.

7. The device according to any one of claims 1 to 6, wherein the first base film and the second base film are non-conductive.

8. 8. The device of claim 7, wherein the first base film and the second base film comprise a material selected from the group consisting of polyethylene terephthalate, polycarbonate, polymethyl methacrylate, cyclic olefin copolymer, triacetate, cyclic olefin copolymer, poly(vinyl chloride), poly(ethylene 2,6-naphthalate), polyimide, polypropylene, polyethylene, and any combination thereof.

9. The device according to any one of claims 1 to 8, wherein the first base film and / or the second base film is transparent.

10. The device according to any one of claims 1 to 9, wherein the conductive pattern comprises a network that is a molecular structure having electrical conductivity and a high aspect ratio.

11. The device of any preceding claim, wherein the conductive pattern comprises at least one set of conductive traces.

12. 12. The device of claim 1, further comprising a second conductive pattern attached to a surface of the second base film facing the first base film, wherein the conductive pattern attached to the surface of the first base film facing the second base film is a first conductive pattern.

13. 13. The device of claim 12, wherein the first conductive pattern and the second conductive pattern are aligned so as to be separated within the plane of the first base film and the second base film, which are parallel.

14. The device of any one of claims 1 to 13, wherein the bonding layer that at least partially fills the space between the first base film and the second base film and surrounds a portion of the conductive pattern comprises an optically transparent adhesive.

15. The device of any preceding claim, wherein the bonding layer is further configured to insulate a portion of the conductive pattern surrounded by the bonding layer.

16. The device according to any one of claims 1 to 15, wherein the spacer fills at least a portion of the space between the exposed portion of the conductive pattern and the second base film.

17. A device according to any preceding claim, wherein the spacer comprises a mechanically rigid material capable of withstanding a pressure of at least 5200 bar at a temperature of up to 250°C.

18. A touch sensor comprising the device of any preceding claim, wherein the exposed portion of the conductive pattern comprises at least one electrode of the touch sensor.

19. providing a first base film and a second base film arranged parallel to the first base film at a predetermined distance; applying a conductive pattern to a surface of the first base film facing the second base film; printing spacers on the first base film and a portion of the conductive pattern; preparing a tie layer by cutting it into a predetermined shape containing an opening; disposing the bonding layer between the first base film and the second base film such that the openings in the bonding layer are aligned with the positions of the spacers printed on the first base film and a portion of the conductive pattern, at least partially filling the space between the first base film and the second base film and surrounding a portion of the conductive pattern; subjecting the resulting layered structure to a pressure treatment at a predetermined temperature; 1. A method for fabricating a layered electronic device, comprising:

20. 20. The method of claim 19, wherein the conductive pattern is applied to the surface of the first base film facing the second base film by depositing a conductive material and etching the conductive material to create a pattern.

21. 21. The method of claim 19 or 20, wherein the steps of adding a conductive pattern and printing spacers are performed on the second base film before adding adhesive between the first base film and the second base film.

22. The method according to any of claims 19 to 21, wherein the pressure treatment of the obtained layered structure comprises thermoforming at a temperature of 130 to 200°C.

23. 22. The method of any of claims 19 to 21, wherein the pressure treatment of the obtained layered structure comprises laminating in vacuum at a temperature between 50 and 300°C, or between 150 and 300°C, or between 170 and 190°C.

24. 24. The method of any of claims 19 to 23, further comprising the step of creating at least one open end of the conductive pattern by die-cutting or laser-cutting a portion of the conductive pattern corresponding to a portion of the conductive pattern on which the spacer is printed.

25. The method of any one of claims 19 to 24, further comprising the step of cooling the device after pressure treatment.

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