Method of manufacturing a flexible electronic device and flexible device
An electrical element, such as a thin-film transistor, is defined on a flexible substrate, in that the substrate is attached to a carrier by an adhesive layer, and is delaminated after definition of the transistor. This is for instance due to illumination by UV-radiation. An opaque coating is provided to protect any semiconductor material. A heat treatment is preferably given before application of the layers of the transistor to reduce stress in the adhesive layer.
1. A flexible electronic device comprising:
a substrate having a first and an opposite second side;
an adhesive layer disposed on the first side of the substrate, having a reactive additive;
a thin-film electronic element disposed on the second side of the substrate; and
a coating layer disposed between the first side of the substrate and the adhesive layer, the coating layer protecting a layer of the thin-film electronic element against UV radiation;
wherein the substrate is disposed between the adhesive layer and the thin-film electronic element, and the substrate is selected from a group consisting of polyvinylchloride, polyethyleneterephtalate, and polyethylene naphthalate.
2. The flexible electronic device as claimed in claim 1 , wherein the thin-film electronic element comprises a plurality of transistors and an electro-optical layer disposed on the transistors to form a display, and at least part of the transistors function as pixel transistors of the display.
3. The flexible electronic device as claimed in claim 2 , wherein each of the transistors comprises an organic semiconductor material.
4. The flexible electronic device as claimed in claim 3 , wherein each of the transistors further comprises a source and a drain electrode mutually separated through a channel and a metallic gate electrode separated from the channel through a gate dielectric, and the metallic gate electrode is disposed between the gate dielectric and the adhesive layer.
5. The flexible electronic device as claimed in claim 2 , further comprising a protective layer disposed between the transistors and the electro-optical layer.
6. The flexible electronic device as claimed in claim 5 , wherein the protective layer is a reflective layer.
7. The flexible electronic device as claimed in claim 5 , further comprising a planarization layer disposed between the protective layer and the electro-optical layer.
8. The flexible electronic device as claimed in claim 1 , wherein the adhesive layer comprises a main polymeric component and the reactive additive is an UV-sensitive reactive additive, and the UV-sensitive reactive additive upon illumination with UV radiation will increase the glass transition temperature of the polymeric component.
9. The flexible electronic device as claimed in claim 1 , wherein the adhesive layer comprises at least one dye.
10. The flexible electronic device as claimed in claim 1 , wherein the second side of the substrate is hydrophilic and a planarization layer is disposed on the second side of the substrate.
11. The flexible electronic device as claimed in claim 1 , wherein the thin-film electronic element comprises a transistor.