Patent Application
20130059118
This application claims the priority benefit of Taiwan application serial no. 100131528, filed on Sep. 1, 2011. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
1. Technical Field
The disclosure relates to a substrate structure and a method of fabricating the same, in particular, to a flexible substrate structure and a method of fabricating the same.
2. Related Art
A roll-to-roll continuous process is superior in low cost of fab construction and large-area productions, is quite suitable for application in a thin film transistor (TFT) array process, and has competitive edge over a sheet-to-sheet process of silicon semiconductor used nowadays.
Currently, a substrate employed in a general roll-to-roll continuous process is a flexible plastic substrate, such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), polyimide (PI), and the forms of the product are mainly single-layer patterning of an indium tin oxide (ITO) thin film or single-layer patterning of a multi-layer thin film. To fabricate and develop electronic components, a photolithography process of more than two layers must be employed. However, the flexible plastic substrate will be seriously deformed due to membrane stress in the process and reel tension of the equipment, thereby causing a large error in alignment precision of photolithography of layers above the second one, so that it is difficult to fabricate the electronic components.
The disclosure is directed to a flexible substrate structure, which is capable of significantly reducing the alignment errors among layers subsequently formed in photolithography and accomplishing a patterning process of more than two layers (including two layers).
A flexible substrate structure is introduced herein, which includes a flexible metal carrier, a surface-modified layer and a flexible plastic substrate. The flexible metal carrier includes a first region and a second region. The surface-modified layer is located on and contacts with the first region of the flexible metal carrier. The flexible plastic substrate is located over the first region and the second region. The flexible plastic substrate over the first region contacts with the surface-modified layer. The flexible plastic substrate over the second region contacts with the flexible metal carrier.
A method of fabricating a flexible substrate structure is further introduced herein, which includes: providing a flexible metal carrier including at least one first region and at least one second region; forming a surface-modified layer on the first region of the flexible metal carrier; and forming a flexible plastic substrate over the first region and the second region of the flexible metal carrier, in which the flexible plastic substrate over the first region contacts with the surface-modified layer, and the flexible plastic substrate over the second region contacts with the flexible metal carrier.
The flexible substrate structure according to the disclosure can greatly improve the alignment precision among layers subsequently formed in photolithography and increase the yield of the process.
In the method of fabricating a flexible substrate structure according to the disclosure, a simple and rapid method can be used for fabrication, and in the removal of the flexible plastic substrate, the flexible plastic substrate only needs to be cut longitudinally to the surface-modified layer, so that the flexible plastic substrates over the first regions can be separated from the surface-modified layers on the flexible plastic substrates.
Several exemplary embodiments accompanied with drawings are described in detail below to further describe the disclosure in details.
The accompanying drawings are included to provide further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments and, together with the description, serve to explain the principles of the disclosure.
Referring to
The flexible metal carrier 10 includes a first region 10A and a second region 10B. The second region 10B is located around the first region 10A, and the region over the first region 10A is, for example, used for forming flexible electronic components, and the region over the second region 10B is, for example, a peripheral region of the flexible electronic components. Referring to
The surface-modified layer 12 is located on and contacts with the first region 10A of the flexible metal carrier 10. A process of forming the surface-modified layer 12 may be regarded as a process of planarizing the first region 10A of the flexible metal carrier 10. A roughness of the formed surface-modified layer 12 is smaller than the roughness of the flexible metal carrier 10. In an embodiment, the roughness of the surface-modified layer 12 is smaller than 10 nm, for example, 1 nm to 10 nm. The adhesion of the surface-modified layer 12 to the flexible metal carrier 10 is greater than an adhesion of the flexible plastic substrate 14 to the surface-modified layer 12. The adhesion of the surface-modified layer 12 to the flexible metal carrier 10 is, for example, 1 B to 5 B, in which B is an adhesion unit referring to ASTM (American Standard Test Method) D339. A material of the surface-modified layer 12 includes silicone epoxy, polyimide (pyromellitic dianhydride-diaminodiphenyl ether) (PI(PMDA-ODA)) or Teflon. A thickness of the surface-modified layer 12 is, for example, 1 to 10 μm. The surface-modified layer 12 may be formed by various known coating methods, for example, dip coating, spin coating, roll coating or spray coating. The surface-modified layer 12 may be formed on the first region 10A shown in
The flexible plastic substrate 14 is located over the first region 10A and the second region 10B. The flexible plastic substrate 14 over the first region 10A contacts with the surface-modified layer 12, and the flexible plastic substrate 14 over the second region 10B contacts with the flexible metal carrier 10. The adhesion of the flexible plastic substrate 14 to the surface-modified layer 12 is smaller than the adhesion of the surface-modified layer 12 to the flexible metal carrier 10, and the adhesion of the flexible plastic substrate 14 to the flexible metal carrier 10 is greater than the adhesion of the flexible plastic substrate 14 to the surface-modified layer 12. In an embodiment, the adhesion of the flexible plastic substrate 14 to the surface-modified layer 12 is smaller than the adhesion of the surface-modified layer 12 to the flexible metal carrier 10 by 1 B to 5 B, and the adhesion of the flexible plastic substrate 14 to the flexible metal carrier 10 is greater than the adhesion of the flexible plastic substrate 14 to the surface-modified layer 12 by 1 B to 5 B. In an embodiment, the adhesion of the flexible plastic substrate 14 to the flexible metal carrier 10 is 1 B to 5 B, and the adhesion of the flexible plastic substrate 14 to the surface-modified layer 12 is 0 B. Herein, the adhesion is measured by a cross-cut adhesion test method. A material of the flexible plastic substrate 14 is, for example, polyimide (PI), polycarboxylate (PC), polyether sulfone (PES), PET, PEN, polyamide (PA), pernigraniline (PNB), polyetheretherketone (PEEK) or polyetherimide (PEI) or a combination thereof. A thickness of the flexible plastic substrate 14 is, for example, 10 μm to 200 nm. The flexible plastic substrate 14 may be formed by various known coating methods, for example, dip coating, spin coating, roll coating or spray coating. Since the material of the carrier 10 is metal, during the coating of the flexible plastic substrate 14, the flexible plastic substrate 14 will not be seriously deformed due to the reel tension of the equipment and the resulting membrane stress, and thus the flexible plastic substrate 14 may be formed by a roll-to-roll method. However, the method of forming the flexible plastic substrate 14 is not limited to the roll-to-roll method, and may also be a sheet-to-sheet method or any other suitable method. The flexible plastic substrate 14 may be formed over the first region 10A and the second region 10B shown in
Referring to
Referring to
Then, referring to
The flexible substrate structure according to the disclosure includes a flexible metal carrier. The rigidity of metal in the flexible metal carrier can overcome the reel tension of the equipment and can reduce the deformation of subsequently formed layer or substrate. As a result, even if the subsequent layer is formed by a roll-to-roll process method, the photolithography thereof still has sufficient alignment precision, so that the lithographic alignment error is significantly reduced, and the alignment offset can be smaller than 10 μm. Therefore, a patterning process of more than two layers is accomplished, and the yield of the process is increased.
In addition, the flexible substrate structure according to the disclosure includes a surface-modified layer. The adhesion of the surface-modified layer to the flexible plastic substrate thereon is smaller than the adhesion of the surface-modified layer to the flexible metal carrier there-below, that is, an excellent separation interface exists between the surface-modified layer and the flexible plastic substrate. Therefore, when the flexible plastic substrate over the first region is cut longitudinally to the surface-modified layer, the flexible plastic substrate over the first region can be automatically separated from the surface-modified layer thereon and be removed.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 100131528 | Sep 2011 | TW | national |
