LAYERED DEVICE FOR PRESSURE TREATMENT AND METHOD

Abstract

A layered device having two base films, a conductive pattern attached to the first base film facing the second base film and a bonding layer binding the first base film and the second base film together. The bonding layer includes an opening, and the conductive pattern having an exposed portion aligned with the opening in the bonding layer. Further disclosed is a spacer attached to the first base film and the exposed portion of the conductive pattern, wherein the spacer fills at least part of the space created by the opening in the bonding layer. Also disclosed is a method of producing a layered device.

Claims

1.-25. (canceled)

26. A layered device, comprising a first base film, a second base film positioned 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 filling at least partially the space between the first base film and the second base film, enclosing a portion of the conductive pattern and binding the first base film and the second base film together, wherein the bonding layer comprises an opening, the conductive pattern comprises at least one exposed portion aligned with the opening in the bonding layer, wherein at least an end portion of the exposed portion of the conductive pattern is loose and detached from the first base film, and the device further comprises a spacer attached to the first base film and the exposed portion of the conductive pattern, wherein the spacer fills at least part of the space created by the opening in the bonding layer.

27. The device of claim 26, wherein the spacer comprises two or more structures rigidly fixed to the first base film and the exposed portion of the conductive pattern, and wherein the structures are positioned adjacent to each other at a predetermined distance.

28. The device of claim 27, wherein the structures comprise material selected from: ultraviolet cross-linking polymer inks, thermally cross-linkable polymer inks and thermosetting inks.

29. The device of claim 26, wherein the spacer comprises a peel-off coating that evenly fills at least part of the space created by the opening in the bonding layer.

30. The device of claim 29, wherein the peel-off coating comprises a polymer matrix, ultraviolet or thermally cross-linkable polymer, or a solvent-based or water-based solution.

31. The device of claim 26, wherein the first base film and the second base film are non-conductive.

32. The device of claim 31, wherein the first base film and the second base film comprise a material selected from a group 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.

33. The device of claim 26, wherein the first base film and/or the second base film are transparent.

34. The device of claim 26, wherein the conductive pattern comprises a network of conductive high aspect ratio molecular structures.

35. The device of claim 26, wherein the conductive pattern comprises at least one set of conductive traces.

36. The device of claim 26, 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.

37. The device of claim 36, wherein the first and second conductive patterns are aligned to be separated in the plane of the parallel first and second base films.

38. The device of claim 26, wherein the bonding layer filling at least partially the space between the first base film and the second base film, and enclosing a portion of the conductive pattern, comprises an optically clear adhesive.

39. The device of claim 26, wherein the bonding layer is further configured to insulate the portion of the conductive pattern which it encloses.

40. The device of claim 26, wherein the spacer fills at least part of the space between the exposed portion of the conductive pattern and the second base film.

41. The device of claim 26, wherein the spacer comprises mechanically rigid material able to withstand at least 5200 bars of pressure in temperatures up to 250 C.

42. A touch sensor comprising the device of claim 26, wherein the exposed portion of the conductive pattern comprises at least one electrode of the touch sensor.

43. A method for producing a layered electronic device, comprising providing a first base film and a second base film positioned 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 a spacer on the first base film and a portion of the conductive pattern, preparing a bonding layer by cutting it to a predetermined shape comprising an opening, placing the bonding layer between the first base film and the second base film to fill at least partially the space between the first base film and the second base film, and enclosing a portion of the conductive pattern, such that the opening in the bonding layer is aligned with the location of the spacer printed on the first base film and the portion of the conductive pattern, and pressure-treating the resulting layered structure at a predetermined temperature.

44. The method of claim 43, wherein the conductive pattern is applied to a 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.

45. The method of claim 43, wherein the operations of applying a conductive pattern and printing a spacer are performed on the second base film prior to adding the adhesive between the first base film and the second base film.

46. The method of claim 43, wherein the pressure-treatment of the resulting layered structure comprises thermoforming at a temperature between 130 and 200 C.

47. The method of claim 43, wherein the pressure-treatment of the resulting layered structure comprises laminating in a vacuum at a temperature between 50-300 C, or at a temperature between 150-300 C, or at a temperature between 170-190 C.

48. The method of claim 43, further comprising creating at least one loose end of the conductive pattern by die-cutting or laser cutting a portion of the conductive pattern that corresponds to the portion of the conductive pattern to which the spacer is printed.

49. The method of claim 43, further comprising cooling the device after pressure-treating.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The accompanying drawings, which are included to provide a further understanding of the layered device and the method for its production, illustrate embodiments and together with the description help to explain the principles of the above. In the drawings:

[0055] FIG. 1a schematically illustrates a sectional view of a layered device according to one embodiment;

[0056] FIG. 1b is a schematic sectional view of the layered device with spacer removed, according to an embodiment;

[0057] FIG. 1c is a schematic sectional view of the layered device with spacer structures, according to an embodiment;

[0058] FIG. 1d is a schematic sectional view of the layered device with combined spacers, according to an embodiment;

[0059] FIG. 2a schematically illustrates a top view of a device with peel-off spacer, according to one embodiment;

[0060] FIG. 2b is a schematic top view of a device with spacer structures, according to an embodiment;

[0061] FIG. 3 schematically shows a sectional view of a flexible layered device comprising a loose conductive structure, according to an embodiment; and

[0062] FIG. 4 is a block diagram of a method according to an embodiment.

DETAILED DESCRIPTION

[0063] Reference will now be made in detail to the described example embodiments, examples of which are illustrated in the accompanying drawings.

[0064] The description below discloses some embodiments in such detail that a person skilled in the art can utilize the disclosed layered device and method based on the disclosure. Not all steps of the embodiments are discussed in detail, as some of the steps can be obvious for the person skilled in the art based on this specification.

[0065] For reasons of simplicity, item numbers will be maintained in the following exemplary embodiments in the case of repeating components.

[0066] The present invention generally relates to layered electronic devices, such as touch switches, touch sensors, touch displays, heating elements, solar cells and others. In these devices, when pressure-treatment such as pressure-forming, thermoforming, lamination or any other technique is used in manufacture, it is often desired to provide electrical contact with the layered device by leaving a portion of its conductive element exposed. However, the exposed portions are prone to damage during pressure-treatment because of the force created during such process. The device according to embodiments of the present invention comprises an additional spacer element which prevents such damage and protects the exposed portion of the conductive element. The method according to an aspect provides a process for manufacturing a layered device using the spacers.

[0067] FIG. 1a illustrates schematically a sectional view of a layered device 100 according to an example implementation. The device comprises a first base film 101, a second base film 102 positioned parallel to the first one 101, a conductive pattern 104 attached to a surface of the first base film 101 facing the second base film 102, and a bonding layer 103 between them.

[0068] The first and second base films 101, 102 may be non-conductive substrates which insulate the conductive pattern 104. The base films 101, 102 can comprise a material selected from a group 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.

[0069] The conductive pattern 104 is illustrated schematically as a set of conductive traces, according to an implementation. Conductive traces are commonly used in layered electronics such as touch sensors. However, the conductive pattern 104 may have any other suitable arrangement of conductive elements.

[0070] The conductive pattern 104 may comprise a network of conductive high aspect ratio molecular structures (HARM-structures) and be useful in transparent films due to the advantageous properties of some HARM-structures.

[0071] The bonding layer 103 fills at least partially the space between the first base film 101 and the second base film 102, enclosing a portion of the conductive pattern 104 and binding the first base film 101 and the second base film 102 together. The bonding layer 103 may comprise an adhesive. The bonding layer 103 may also comprise a bonding promoter selected from a group of: acrylic adhesive, silicon adhesive, polymer adhesive, a crosslinking polymer, epoxy adhesive, polycarbonate, a thermoplastic polyurethane (TPU) and any combination thereof. The adhesive may be an optically clear adhesives (OCR) which is useful in devices that require transparent films, for example devices with displays.

[0072] The bonding layer 103 comprises an opening 107, which may be at the side as shown with the side view of FIG. 1a, or inside the perimeter of the device 100. In an implementation, the opening 107 is arranged at the perimeter of the bonding layer 103 to provide an access point.

[0073] The conductive pattern 104 comprises at least one exposed portion aligned with the opening 107 in the bonding layer 103. The sectional view of FIGS. 1a-1d is oriented so that the opening 107 and exposed portion of the conductive pattern 104 face the viewer.

[0074] This structure provides an access point for the conductive pattern 104, however if the device 100 is subjected to pressure-forming, thermoforming, laminating or other types of pressure-treatment, there is a potential for the exposed portion of the conductive pattern 104 to be damaged from the pressure. This is at least in part because of the opening 107 in the bonding layer 103 needed to provide the access. The opening 107 exposes a portion of the conductive pattern 104 and removes support which the bonding layer 103 provided elsewhere in the device 100.

[0075] The device 100 further comprises a spacer 105 attached to the first base film 101 and the exposed portion of the conductive pattern 104, wherein the spacer 105 fills at least part of the space created by the opening 107 in the bonding layer 103. FIGS. 1a-1b illustrate an implementation wherein the spacer 105 comprises a peel-off coating 105 that evenly fills at least part of the space created by the opening 107 in the bonding layer 103. The peel-off coating 105 may comprise a polymer matrix, ultraviolet or thermally cross-linkable polymer, or a solvent-based or water-based solution.

[0076] The peel-off coating 105 can have a temporary use and be removed, for example peeled off or partially evaporated if it comprises solvent- or water-based solutions. It can be removed after the device manufacture is completed by pressure-treatment in a predetermined temperature. The pressure-treatment may comprise thermoforming at a temperature between 130 and 200 C, or laminating in a vacuum at a temperature between 170 and 190 C, or any other suitable pressure-based treatment which seals and/or forms layers of the device together and onto a surface. FIG. 1b shows the device 100 after thermoforming with the peel-off coating 105 removed, instead leaving a space 105′ which can be filled later with a filler or remain empty.

[0077] FIGS. 1c-1d illustrate an implementation wherein the spacer comprises two or more structures 106 rigidly fixed to the first base film 101 and the exposed portion of the conductive pattern 104. These structures 106 are positioned adjacent to each other at a predetermined distance.

[0078] In the implementation shown on FIG. 1c, the structures 106 are also aligned in height so that their upper surfaces lie substantially in the same plane as the lower surface of the second base film 102. The structures 106 shown in the example implementation of FIG. 1c are shaped as pillars, however any other suitable shape may be used for the spacer structures 106.

[0079] The rigidly fixed structures 106 can comprise material selected from: ultraviolet cross-linking polymer inks, thermally cross-linkable polymer inks and thermosetting inks. These materials can be rigid enough to withstand at least 5200 bars of pressure in temperatures up to 250 C, while protecting the conductive pattern 104 from damage during pressure-treatment.

[0080] FIG. 1d illustrates that the layered device 100 may comprise a combination of rigidly fixed pillars or spacer structures 106 and a peel-off additional coating 105″. In some implementations, solid singular structures may be rigidly fixed to the first base film 101, if the protection these structures provide against pressure is sufficient.

[0081] FIG. 2a is a schematic top view of a layered device 200 with a peel-off coating 206, and FIG. 2b is a schematic top view of a layered device 200 with rigidly fixed structures 206. The devices 200 shown in FIGS. 2a-2b may be one example of the devices 100 shown in FIGS. 1a-1d, accordingly. On FIG. 2b, the rigidly fixed structures are illustrated only schematically and may be positioned anywhere within the cross-dashed area 206.

[0082] In FIGS. 2a-2b the conductive pattern 204 is shown to extend into the device, as it would for example in a touch sensor implementation. The conductive pattern 204 comprises an exposed portion with an exposed end portion 207. The end portion 207 or the whole exposed portion of the conductive pattern 204 can be made loose and detached from the first base film (not seen in FIGS. 2a-2b). The second base film 202 is illustrated as the top film in the device 200. The first and/or the second 202 base films can be transparent.

[0083] In addition to the first conductive pattern 204 attached to the first base film, illustrated in FIGS. 2a-2b as the outer part of the circuitry and the two pins positioned on the outside, device 200 can also comprise a second conductive pattern 214 (or any number thereof). The second conductive pattern 214 is attached to the second base film 202 at a surface facing the first base film. Although this is 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 according to this implementation. The first and second conductive patterns 204, 214 in this implementation are aligned to be separated in the plane of the parallel first and second 202 base films. This way the conductive patterns 204, 214 are arranged to avoid contact with each other during pressure treatment.

[0084] FIG. 3 is a schematic side view of an example layered device comprising two conductive patterns 304, 314 attached to the first base film 301 and the second base film 302, respectively. The device comprises a non-conductive bonding layer 303 insulating the conductive patterns 304, 314 and filling the space between the first and second base films 301, 302.

[0085] The device further comprises an opening in the adhesive layer 303 which is marked by the vertical lines on FIG. 3. The device also comprises a spacer 305 positioned between the conductive layers 304, 314 in place of the adhesive in the opening. The exposed portion of the conductive pattern 314 is made loose and detached from the first base film for easier external access (on the fight in FIG. 3). In FIG. 3 at least the material of the second base film 302 allows it to be flexible.

[0086] FIG. 4 is a flow chart of a method for producing a layered electronic device according to an aspect. The method comprises providing 401 a first base film and a second base film positioned parallel to each other. The base films may be provided in a chamber or reactor for further assembly. The method further comprises applying 402 a conductive pattern to an upper surface of the first base film and printing 403 a spacer on the first base film and portion of the conductive pattern. The method then includes forming 404 a bonding layer filling the space between the first and second base films.

[0087] Method also includes creating 405 an opening in bonding layer aligned with the spacer, for example by cutting it to a predetermined shape, such that the opening is aligned with the location of the spacer printed on the first base film and the portion of the conductive pattern.

[0088] Method is finished by pressure-treating 406 the resulting layered structure at a predetermined temperature. The pressure-treatment can be provided by any appropriate means and involves applying pressure to one of, or both the base films. In an implementation, the pressure-treatment also includes treating the resulting layered structure with UV crosslinking. In some examples, the pressure-treatment 406 of the resulting layered structure may comprise thermoforming at a temperature between 130-200 C, or any other suitable technique such as lamination and vacuum forming.

[0089] The operations prior to treating the resulting layered structures can provide a layered device as described in relation to any of the layered devices shown in FIGS. 1a-3. Treating the resulting layered structure finalizes the production of a layered device. According to some implementations, treating may include forming, thermoforming, laminating or other techniques of pressure-treatment. The benefits of the method include efficiency of production and an improved resulting layered structure which is protected during the final pressure-treatment step, among others.

[0090] The conductive pattern may be applied to a 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. A second conductive pattern can also be applied to a surface of the second base film.

[0091] The operations of applying 402 a conductive pattern and printing 403 a spacer can be performed on the second base film prior to forming 404 the bonding layer between the first base film and the second base film. The conductive pattern on the second base film may be facing the first film or applied on the opposite surface of the second base film. The operations of the method may also be carried out multiple times to create a laminated or multilayered device comprising spacers between base films to reinforce the exposed portions of the conductive pattern during pressure-treatment.

[0092] The method may further comprise creating at least one loose end of the conductive pattern by die-cutting or laser cutting a portion of the conductive pattern that corresponds to the portion of the conductive pattern to which the spacer is printed.

[0093] Creating a loose or detachable end of the conductive pattern prior to treating 406 can provide easier access to the exposed portion of the conductive pattern, for example for providing a connection point to electrodes if the conductive pattern comprises electrodes.

[0094] After pressure-treating 406, the method may also comprise cooling off the device (not shown on FIG. 4). The cooling operation may be required for securing a shape e.g. after thermoforming or any other process.

[0095] As it is clear to a person skilled in the art, the invention is not limited to the examples and implementations described above, but the implementations can freely vary within the scope of the claims.