Patent Application
20160381810
The invention relates to a film composite with electrical functionality for application on a substrate. The invention further relates to a method for manufacture of such a film composite.
For example, printed or etched conductor tracks can be disposed on a circuit board for connection of components of electrical or electronic circuits. A further possibility consists in connecting the electronic components with one another via cables or wires. Via the conductor tracks, cables or wires, electrical signals can be transmitted or a voltage supply can be provided for operation of the components.
The manufacture of printed or etched conductive structures is associated with high costs and a high manufacturing complexity, especially due to expensive conductive pastes or as a consequence of the etching of the conductive structures by etching baths. Because of high preproduction costs for the necessary masks, for example for printing or etching masks, the manufacture of conductive structures by means of printing or etching techniques is worth the effort only for correspondingly high production figures. Besides the high manufacturing complexity and the expensive costs associated therewith, conductive structures on the basis of printed/etched conductor tracks or on the basis of cables or wires often have only a limited functionality. For example, a high electrical resistance occurs in particular with printed conductive pastes. Conductive structures vapor-deposited on a board also have high electrical resistance and low mechanical stability due to the thin conductor-track thickness. In addition, the thin structures make soldering impossible in many cases. From environmental viewpoints, the manufacture in particular of etched conductive structures is critical, since high environmental pollution results from the use of highly aggressive etching solutions.
The use of printed or etched conductive structures on a board leads to limited flexibility for the circuit design, because it involves a firmly joined composite between the electrically conducting structure and a backing.
Further restrictions exist with respect to the materials of a backing web on which the conductive structure is applied. Usually polyimide is used as backing material, and so transparency is lacking, even though it is often of interest, especially during application of the conductive structure in the environment of a light source.
Die-cut sheet-metal parts used heretofore for conductive structures are typically produced as bulk product or are integrated within a support structure, which in turn is associated with functional restrictions or at least leads to disadvantages in processing.
It is a concern of the present invention to provide a film composite with electrical functionality that can be applied in simple and flexible manner on a substrate. Furthermore, it is intended to specify a method for manufacture of such a film composite with electrical functionality that can be applied in simple and flexible manner on a substrate.
According to one embodiment, the film composite with electrical functionality for application on a substrate comprises at least one conductive structure, a first bonding coat, a film layer and a second bonding coat. The first bonding coat may be disposed on an underside of the at least one conductive structure. The first bonding coat may have an adhesive effect for application of the at least one conductive structure on the substrate. The second bonding coat may be disposed between an upper side of the at least one conductive structure and the film layer. The second bonding coat may have an adhesive effect, by which the film layer adheres to the at least one conductive structure.
The film composite may have a backing film, on which the at least one conductive structure and the film layer disposed over it are disposed. The film layer may extend beyond the at least one conductive structure and adhere to the backing film due to the second bonding coat, so that the film layer functions as a marking film for protection of the at least one conductive structure.
The film composite may be disposed in simple and flexible manner on a substrate, for example on a circuit board, on an operator-control panel or on housing parts. For this purpose the film composite comprising the at least one conductive structure and the film layer disposed over it is stripped from the backing film and applied with the first and second bonding coat on the substrate, for example by pasting or injection. The inventive film composite permits the transferability of the conductive structure to any other desired substrates.
The backing film may be punched out in such a way that the punched-out part of the backing film adheres at least to a partial region of the at least one conductive structure, so that the region of the first bonding coat that is disposed under the at least one conductive structure remains masked by the backing film when the film structure comprising the first bonding coat, the punched-out part of the backing film adhering underneath, the at least one conductive structure, the second bonding coat and the film layer is removed from the remaining backing film. During application on a substrate, the at least one conductive structure in this partial region does not adhere directly on the substrate. Thereby it is possible to prepare regions in the conductive structure that do not adhere but instead are protected by a portion of the backing film.
According to one possible embodiment, the at least one conductive structure, instead of adhering directly on the backing film, may be applied directly on a further film layer. The at least one conductive structure can adhere to the further film layer by means of the first bonding coat. The film composite may have a third bonding coat, which is disposed between the further film layer and the backing film. The third film layer may be pasted onto the backing film by means of the third bonding coat disposed on its underside together with the at least one conductive structure and the film layer disposed over it. In this embodiment, the at least one conductive structure is embedded between the film layer and the further film layer.
In the embodiment, the film structure comprising the further film layer, the at least one conductive structure disposed over it, the film layer and the first, second and third bonding coats may be stripped from the backing film during application and pasted onto a substrate by means of the third bonding coat.
In this embodiment also, a part of the backing film may be punched out from the other backing film and may adhere to the third bonding coat. Thus the punched-out part of the backing film adheres to the third bonding coat even after the stripping of the film structure comprising the further film layer, the at least one conductive structure and the film layer from the remaining backing film. During application of the film structure onto a substrate, for example a circuit board, the punched-out part of the backing film is therefore disposed between the third bonding coat and the substrate. At the unmasked portions, the further film layer adheres to the substrate by means of the third bonding coat.
A method for manufacture of a film composite with electrical functionality is specified in claim 10. According to one embodiment of the method, a backing film is prepared first. An electrically conductive film is disposed on the backing film. For production of the at least one conductive structure in the electrically conductive film, at least one first incision line is cut in a region of the electrically conductive film in such a way that the electrically conductive film is severed by the at least one first incision line in the region of the electrically conductive film and a first region of the backing film disposed under the region of the electrically conductive film remains intact, whereby at least one conductive structure is formed in the electrically conductive film, which is separated by the at least one incision line from a remaining part of the electrically conductive structure. For preparation of the at least one conductive structure, the remaining part of the electrically conductive film is removed. A film layer is disposed on an upper side of the at least one conductive structure. At least one second incision line is cut in a region of the film layer in such a way that the film layer is severed by the at least one second incision line in the region of the film layer and a second region of the backing film disposed under the region of the film layer remains intact.
According to a possible embodiment of the method, at least one third incision line, which severs the backing film before the application of the electrically conductive film, may be cut in the backing film. Simultaneously with the cutting of the at least one second incision line, at least one fourth incision line, which severs both the film layer and the backing film, may be cut in the film layer and in the backing film disposed underneath. In such an embodiment, the punched-out part of the backing film continues to adhere under a part of the at least one conductive structure after the stripping of the film layer from the backing film.
For contacting of the at least one conductive structure, a recess may be cut in the film layer so that, during arrangement of the at least one conductive structure on the film layer, a region of the at least one conductive structure is exposed for contacting.
With the film composite, a highly functional electrically conductive structure that is simple to handle and easy to contact is made available, thus opening up diverse use possibilities. For example, the film composite may be used for connection of components of electrical or electronic circuits, for manufacture of plug connections, for manufacture in particular of a capacitive or resistive sensor system, for heating or for antenna superstructures.
The invention will be explained in more detail in the following on the basis of figures, which show exemplary embodiments of the present invention,
wherein:
The film composite 1000 further comprises a backing film 400, on which the at least one conductive structure 110 and the film layer 200 are disposed. The bonding coat 10 disposed under the at least one conductive structure 110 adheres to the backing film 400. In particular, regions T10a and T10b of the bonding coat 10 adhere to the backing film. A region T10a of the at least one conductive structure 110 adheres to the region T10a of the bonding coat 10. Likewise a region T110b of the at least one conductive structure 110 adjoining the region T110a adheres to the region T10b of the bonding coat 10. The bonding coat 10 has an adhesive effect such that, on the one hand, the at least one conductive structure adheres securely to the backing film and such that, on the other hand, the at least one conductive structure 110 can be stripped together with the bonding coat 10 from the backing film 400.
A region T20a of the bonding coat 20 is disposed over the region T110a of the at least one conductive structure 110. A region T20b of the bonding coat 20 is disposed over the region T110b of the at least one conductive structure 110. Regions T200a and T200b of the film layer 200 adhere to the bonding coat 20 over the regions T20a and T20b of the bonding coat 20. Because of the bonding coat 20, the at least one conductive structure 110 is held reliably on the film layer 200, in order to protect the at least one conductive structure 110. The force of adhesion of the bonding coat 20 on the at least one conductive structure is greater than the force of adhesion of the bonding coat 10 on the backing film 400, and so the film structure comprising the bonding coat 10, the at least one conductive structure 110, the bonding coat 20 and the film layer 200 can be stripped as a whole from the backing film.
The film layer 200 has a region T200c and the bonding coat 20 disposed underneath the film layer 200 has a region T20c, wherein the region T200c of the film layer 200 and the region T20c of the bonding coat 20 extend beyond the at least one conductive structure 110. The region T20c of the bonding coat 20 also adheres to the backing film 400, and so the at least one conductive structure 110 is masked by the film layer 200. For better illustration in
For contacting of the at least one conductive structure 110, a recess 210 can be provided in one region of the film layer 200. Thus a portion A110a of the at least one conductive structure is masked by the film layer 200, whereas in the region of the recess 210 a portion A110b of the at Least one conductive structure 110 is exposed, meaning not masked by the film layer 200, and can be contacted from externally.
At least one incision line S3, which runs perpendicular to the sheet plane in
With the electrically conductive structure, the film composite has an electrical functionality and can be used flexibly. The film structure comprising the bonding coat 10, the at least one conductive structure 110, the bonding coat 20 and the film layer 200 can be stripped in simple manner from the backing film and applied by means of the bonding coat 10 on a substrate. Furthermore, the electrically conductive structure can be coupled onto a plug. Corresponding embodiments of the film composite, prepared for coupling onto a plug or applied onto a substrate, are illustrated in
The exposed, non-masked region of the at least one conductive structure 110 forms a so-called terminal lug for contacting of the at least one conductive structure. The exposed portion of the at least one conductive structure adheres directly to the substrate 3000. According to a further possible embodiment, the conductive structure 110 with the bonding coat 10 disposed underneath it may be underlaid with the backing film 400 in the region of the terminal lug and thus does not adhere to the substrate.
The film structure comprising the backing film 400 and the electrically conductive film 100 laminated onto it is then fed to a die-cutting device D for punching-out of contours into the film 100. By means of the die-cutting device D, at least one incision line S1 is cut in a region B100 of the film 100 and the bonding coat 10 lying underneath this region in such a way that the film 100 and the bonding coat 10 lying underneath are severed by the at least one incision line S1 in the region B100 of the film 100 and a region B400a of the backing film 400 disposed under the region B100 of the film 100 remains intact. The regions B100 and B400a are shown in
A drum T8 contains a web of the film layer 200 with the bonding coat 20 applied underneath. Just as the bonding coat 10, the bonding coat 20 may be made as an adhesive coating. The film layer 200 is unwound from the drum T8 together with the bonding coat 20 and can be fed to a die-cutting device F. In the die-cutting device F, the recess 210 shown in
The film web 200 coated with the bonding coat 20 is then fed to a laminating device E. In the laminating device E, the film layer 200 is arranged on an upper side of the at least one conductive structure 110 and of the backing-film web 400. For this purpose, the film layer 200 is laminated by means of the bonding coat 20 onto the at least one conductive structure 110 and the backing film 400 in the laminating device E.
The film structure comprising the backing film 400, the at least one conductive structure 110, which by means of the bonding coat 10 disposed underneath adheres to the backing film 400, and the film layer 200, which by means of the bonding coat 20 disposed underneath is pasted onto the upper side of the at least one conductive structure 110, is then fed to a die-cutting device G.
In the die-cutting device G, at least one incision line S2 is cut in a region B200a of the film layer 200 and of the bonding coat 20 lying underneath it in such a way that the film layer 200 and the bonding coat 20 lying underneath are severed by the at least one incision line S2 in the region B200a of the film layer 200 and a region B400b of the backing film 400 disposed under the region of the film layer 200 remains intact. In the die-cutting device G, therefore, the contour of the film structure comprising the bonding coat 10, the at least one conductive structure 110, the bonding coat 20 and the film layer 200 on the backing film 400 is punched out. The separated remaining grid of the film layer 200 is wound onto a drum T9. The remaining film composite 1000 is wound onto a drum T10.
According to one possible embodiment, a die-cutting device A may be disposed between the drum T1 and the laminating device C for punching-out of a portion of the backing film 400, which during stripping of the film structure comprising the bonding coat 10, the at least one conductive structure 110, the bonding coat 20 and the film layer 200 adheres under a part T110a of the at least one conductive structure. By means of the die-cutting device A, at least one incision line S3 can be cut into a region B400c of the backing film 400 in such a way that the backing film 400 is severed in the region B400c of the backing film. For example, the at least one incision line S3 can run perpendicular to the at least one conductive structure 110 in the backing film 400.
For punching-out of the portion of the backing film, at least one incision line S4 can be cut in the die-cutting device G in a region B200b of the film layer 200 and of the bonding coat 20 lying underneath and in a region B400d of the backing film 400 disposed under the region B200b of the film layer 200 in such a way that the film layer 200 and the bonding coat 20 are completely severed in the region B200b, as is the backing film 400 in the region B400d. The incision line S4 can run, for example, parallel to the course of the at least one conductive structure 110 and, for example, perpendicular to the at least one incision line S3. Because of the cutting of the incision lines S3 and S4, a part of the backing film remains adhering under the part T110a of the at least one conductive structure 110 after the stripping of the film structure comprising the bonding coat 10, the at least one conductive structure 110, the bonding coat 20 and the film layer 200 from the backing film 400.
In the embodiment, sketched on the basis of
All regions T30a, T30b and T30c of the bonding coat 30 adhere to the backing film 400. The bonding coat 30 may be formed, for example, as an adhesive coating or as a primer, especially as a lacquer coat. The bonding coat 30 is therefore disposed between the backing film 400 and the film layer 300. The adhesive effect of the bonding coat 30 is designed such that the film structure comprising the bonding coat 30, the film layer 300, the bonding coat 10, the at least one conductive structure 110, the bonding coat 20 and the film layer 200 adheres securely to the backing film and on the other hand can be stripped as a whole from the backing film 400, especially manually. The force of adhesion of the bonding coat 20 to the at least one conductive structure is higher than the force of adhesion of the bonding coat 30 to the backing film 400.
Otherwise the regions T100a, T10b of the bonding coat 10, the regions T110a, T110b of the at least one conductive structure 110, the regions T20a, T20b of the bonding coat 20 and the regions T200a, T200b of the film layer 200 adhere to one another as described on the basis of
Incision lines S3, by which a part of the backing film 400 may be punched out from the backing film 400 in one direction, may be provided in the backing film 400. For complete punching-out of the portion of the backing film, a further incision line S4 is cut into the backing film, thus severing the backing film parallel, for example, to the at least one conductive structure 110 and thus perpendicular, for example, to the incision line S3. When the film structure comprising the bonding coat 30, the film layer 300, the bonding coat 10, the at least one conductive structure 110, the bonding coat 20 and the film layer 200 are lifted from the backing film 400, the punched-out part of the backing film 400 adheres to the part T30a of the bonding coat 30.
Figure GB shows the embodiment of the film composite 2000 after the stripping of the backing film and a subsequent application onto a substrate, for example onto an operator-control panel 3000. The film composite 2000 is formed in such a way that, in the condition of the part T110a of the conductive structure pasted onto the substrate 3000, the part T200a of the film layer 200 and the part T300a of the film layer 300 is disposed on the backing film 400. The backing film 400 is disposed directly on the substrate 3000. The parts T300b and T300c of the film layer 300 adhere to the substrate 3000 by means of the bonding coat 30 adhering directly to the substrate.
The remaining web comprising the film layer 300 and the bonding coat 30 is fed to the laminating device B. In the laminating device B, the film layer 300 together with the bonding coat 30 is laminated onto the backing film 400.
In the laminating device C, the film layer 100 is then laminated onto the film layer 300 by means of the bonding coat 10. Furthermore, by means of the die-cutting device D, the contour of the at least one conductive structure 110 is punched out of the film layer 100 by cutting an incision line S1 into a region B100 of the electrically conductive film 100 and the bonding coat 10 disposed underneath and severing the film layer 100 and the bonding coat 10, albeit without severing a region B300a of the film layer 300 and of the bonding coat 30 disposed underneath as well as a region B400a of the backing film disposed under the region B300a.
After the stripping of the punched-out grid of the electrically conductive film 100, the film layer 200 is laminated onto the at least one conductive structure 110 and the film layer 300 in the laminating device E. In the die-cutting device G, the at least one incision line S2 is cut into the film composite in such a way that a region B200a of the film layer 200 and of the bonding coat 20 disposed underneath as well as a region B300b of the film layer 300 disposed under the region B200a of the film layer 200 and of the bonding coat 30 disposed underneath are completely severed. A region B400b of the backing film 400 disposed under the region B300b remains intact.
According to one possible embodiment, at least one incision line S4 can be cut in die-cutting device G into a region B200b of the film layer 200 and of the bonding coat 20 as well as into a region B300c of the film layer 300 disposed under the region B200b of the film layer 200 and of the bonding coat 30 as well as into a region B400d of the backing film 400 disposed under the region B300c of the film layer 300 in such a way that the film layer 200 together with the bonding coat 20 is completely severed in the region B200b, as are the film layer 300 together with the bonding coat 30 in the region B300c and the backing film 400 in the region B400d. The incision line S4 may run parallel, for example, to the at least one conductive structure 110 and perpendicular, for example, to the at least one incision line S3, which is cut into the backing film 400 in the die-cutting device A.
In the embodiment, sketched on the basis of
In the film composite 1000 and 2000, the portions A110b of the at least one conductive structure 110 exposed by the recess 210 can be protected from corrosion by using, for example a tinned conductor film as film 100.
If the conducting coat has corrosion tendency, the further possibility exists of subsequently tinning the exposed terminal lugs A110b or other exposed regions. According to a further embodiment, printable conductive paste, for example carbon paste or silver paste, may be printed in the relevant region of the terminal lugs. Optionally, this may be done already before the manufacturing process, during the manufacturing process or even after it. A further possibility of corrosion protection consists in casting the terminal lugs at least in the contacting region after contacting of the film composite in a subassembly. For this purpose, for example, a plug may be cast internally with potting compound.
When the bonding coats 10, 20 and 30 are formed as adhesive coatings on the electrically conductive film 100 and the film layers 200 and 300, various types of adhesives, for example heat-reactive adhesives or printable adhesives may be used to bond the individual layers of the film composite securely and thus stabilize them mechanically. Likewise the use of transfer adhesives, which are formed as pure adhesive coating, is possible, as is alternatively the use of double-sided adhesive tapes, meaning an adhesive coating with reinforcement by, for example, an intermediate layer of film or paper. The adhesive coatings can be formed as detachably adhering or permanently adhering adhesives. The forces of adhesion of the respective adhesive must be matched to the detachment behavior of the surface to be applied. These forces of adhesion should preferably lie in the range of 0.01 N/25 mm to 50 N/25 mm.
In the region of the terminal lug, the backing film can be formed without die-cutting or slitting. In this case the adhesive coating of the terminal lug is open downward after the stripping of the backing film. If the backing film is provided with a die cut or respectively slit S3 and S4 in the region of the terminal lug, the terminal lug may be masked on its underside by the punched-out part of the backing film.
The recess 210 in the film layer 200 may be omitted if the contacting is established, for example, by crimping or by contactless electrical coupling, for example by induction. The recess 210 in the film layer 200 may be cut either before lamination by die-cutting of a hole and removal of the remaining material. The recess may also be cut after the lamination, if for this purpose the region of the recess is prepared by use of locally differentiated forces of adhesion or a differentiation of forces of adhesion by a printed adhesive mask. In addition to or as an alternative to the cutting of a recess, the film layer 200 can be made narrower in the region of the contacting, so that certain conductive parts of the structure remain free for the contacting.
The cutting of contours in the individual film layers can be achieved not only by die-cutting but also alternatively by other separation methods, for example by plotter cutting, laser cutting or water-jet cutting.
Besides the film composites shown in
The simplified film structure as well as the film structure, shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2014 102 519.9 | Feb 2014 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2015/053935 | 2/25/2015 | WO | 00 |
