Patent Description:
The flexible display panel is a deformable and bendable display apparatus. The flexible display panel may be applied into the electronic paper, LCD, OLED etc. An OLED (organic light-emitting diode) flexible display panel has the advantages, such as, low consumption, thin thickness and rollable ability, thus it largely attracts the peoples' eyes.

The OLED flexible display panel may include a flexible substrate, OLED display components and connecting lines for connecting the OLED display components. The OLED display components may include an anode electrode, a cathode electrode opposite to the anode electrode and a functional layer between the anode electrode and the cathode electrode. The OLED display panel is lighted by means of the semiconductor material and the organic light-emitting material being driven by the electric field between the anode electrode and the cathode electrode, to inject or recombine the carries.

A polyimide (PI) flexible substrate is a type of flexible substrate with good bendability and temperature resistance. Therefore it is widely used as the substrate of the OLED flexible display panel. In order to reduce the stress mismatch between the flexible substrate and TFT (thin film transistor) component films and to improve the stability during bending, the flexible substrate may be designed to have island structures. However, it is difficult to form the island structures on a polyimide flexible substrate. <CIT> is a related prior art for this field. More particularly, <CIT> discloses a method for preparing layer transfer thin crystalline silicon by using an adjacency shadow effect assisted array method, which uses a single crystal silicon wafer as a mother substrate, and a grown silicon film can inherit crystal quality of the mother substrate, and after the silicon film is peeled off, the mother substrate can be reused after simple processing.

Accordingly, the present disclosure aims to provide a TFT substrate and a method for manufacturing the same to form the island structures on a substrate so as to improve the stability of the substrate during bending.

To solve the above mentioned problem, a technical scheme adopted by the present disclosure is to provide a method for manufacturing a TFT substrate according to claim <NUM>.

To solve the above mentioned problem, another technical scheme adopted by the present disclosure is to provide a non-claimed method for manufacturing a TFT substrate. The non-claimed method comprises:.

providing a silicon-wafer plate; forming first masking structures on the silicon-wafer plate and etching to form island structures; cutting the island structures layer by layer to form a silicon-wafer sub-plate; and attaching the silicon-wafer sub-plate on a substrate to form the TFT substrate.

To solve the above mentioned problem, another technical scheme adopted by the present disclosure is to provide a TFT susbtrate according to claim <NUM>.

The method of the present disclosure may include forming first masking structures on a silicon-wafer substrate, etching to form island structures, cutting layer by layer the island structures and then attaching onto a substrate to form a TFT substrate. Therefore, the implementation of the present disclosure may improve the stability of the substrate during bending and reduce the stress mismatch between the substrate and a TFT component film.

The disclosure will now be described in detail with reference to the accompanying drawings and examples.

To solve the above mentioned problem, a technical scheme adopted by the present disclosure is to provide a method for manufacturing a TFT substrate. The method comprises: providing a silicon-wafer plate; forming first masking structures on the silicon-wafer plate and plasma etching to form island structures; cutting the island structures layer by layer to form a silicon-wafer sub-plate; attaching the silicon-wafer sub-plate on a substrate to form the TFT substrate. The method will be depicted in detail as follows.

Referring to <FIG> is a flow chart of the method for manufacturing a TFT substrate according to an embodiment of the present disclosure.

In this embodiment, in order to implement island elements on a flexible substrate, a silicon-wafer plate may be taken as material to prepare the island structures to be attached on the flexible substrate. Those skilled in the art should understand, materials having similar molecular structure as the silicon-wafer which may match the flexible substrate, such as the chemical elements in the same family of silicon, may also be utilized to prepare the island elements.

S102: Forming first masking structures on the silicon-wafer plate and etching to form island structures.

In this embodiment, a metal layer may be deposited as first masking structures on the silicon-wafer plate. Then the island structures may be formed by etching the silicon-wafer plate. The metal layer may be a layer of nickel.

S103: Cutting the island structures layer by layer to form silicon-wafer sub-plates.

In this embodiment, after the island structures are formed by etching the silicon-wafer plate, the island structures on the silicon-wafer plate may be cut layer by layer according to the structure and size of the island structures to be formed on the TFT substrate, so as to obtain silicon-wafer sub-plates as the island structures on the substrate.

S104: Attaching the silicon-wafer sub-plate onto the substrate to form the TFT substrate.

In this embodiment, the substrate may be a polyimide (PI) flexible substrate. The polyimide flexible substrate itself has a certain adhesive capacity. Accordingly, one of the silicon-wafer sub-plates may be attached onto the polyimide flexible substrate with the help of the adhesive capacity of the polyimide flexible substrate. In subsequence processes, the silicon-wafer sub-plate may be taken as the island structures matching TFT components in order to manufacture the TFT substrate.

The present disclosure provides a method including forming first masking structures on a silicon-wafer substrate, etching the silicon-wafer substrate via the first masking structures to form island structures, cutting layer by layer the island structures and then attaching the silicon-wafer sub-plate onto a substrate to form the TFT substrate. Therefore, the implementation of the present disclosure may improve the stability of the substrate during bending and reduce the stress mismatch between the substrate and a TFT component film.

Referring to <FIG> is a flow chart of the method for manufacturing a TFT substrate according to another embodiment of the present disclosure.

In this embodiment, in order to implement island structures on a flexible substrate, a silicon-wafer plate may be taken as material to prepare the island structures attached on the flexible substrate. Those skilled in the art should understand, materials having similar molecular structure as the silicon-wafer which may match the flexible substrate, such as the chemical elements in the same family of silicon, may also be utilized to prepare the island structure.

S202: forming first masking structures on the silicon-wafer plate and etching to form island structures.

Referring to <FIG>, in this embodiment, the silicon-wafer plate <NUM> may be coated with a layer of photoresist material. The photoresist material may be patterned by removing a portion of the photoresist material where the first masking structures <NUM> are to be set and keeping the remained photoresist material. Then a fist masking layer may be formed on a side of the silicon-wafer plate <NUM> which is coated with the photoresist material, wherein the first masking layer may cover the surface of the silicon-wafer plate and the photoresist material thereon. A portion of the first masking layer which covers the photoresist material may be removed with etching solution corresponding to the photoresist material while the left of the first masking layer which does not cover the photoresist material is kept. Thus the first masking structures <NUM> may be formed. By further plasma etching the silicon-wafer plate <NUM> and the first masking structures <NUM>, island structures <NUM> may be formed.

In one embodiment, the photoresist material coating the silicon-wafer plate <NUM> may be positive photoresist. A portion of the photoresist material on the silicon-wafer plate <NUM> where the first masking structures are to be set may be exposed to light. After applying developer, the photoresist material on the silicon-wafer plate <NUM> where the first masking structures <NUM> are to be set may be removed because the positive photoresist exposed to light will become liquid and washable by the etching solution. Apparently, the photoresist material coating the silicon-wafer plate <NUM> may alternatively be negative photoresist. All of the photoresist material on the silicon-wafer plate <NUM> except for the portion where the first masking structures <NUM> are to be set may be exposed to light. After applying developer, the photoresist material on the silicon-wafer plate <NUM> where the first masking structures <NUM> are to be set may be removed because only the negative photoresist exposed to light will become solid,. In this embodiment, if the photoresist material is negative photoresist, a portion of the photoresist material on the silicon-wafer plate <NUM> where the first masking structures <NUM> are to be set may not be exposed to light while the left is exposed to light and hardened. Thus, the photoresist material on the silicon-wafer plate <NUM> where the first masking structures <NUM> are to be set may be washed away by etching solution.

In one embodiment, the exposure time of the photoresist material on the surface of the silicon-wafer plate <NUM> may be determined according to the height of the pattern to be formed. It should be noted that the exposure time should be long enough for removing the photoresist material on the surface of the silicon-wafer plate <NUM> at the location where the first masking structures <NUM> are to be set.

In one embodiment, a plasma beam may be shot towards the surface of the silicon-wafer plate <NUM> and the first masking structures <NUM>. The plasma hits the silicon-wafer plate <NUM> so that the required island structures <NUM> may be formed.

In one embodiment, the first masking structures <NUM> may include nickel or other metal. Apparently, those skilled in the art should understand that elements having similar chemical and physical characters as nickel, such as elements of the same family of nickel, may also be utilized as the first masking structures <NUM> of this embodiment.

In one embodiment, the thickness of the first masking structures <NUM> may be <NUM>. Apparently, those skilled in the art should understand that the thickness of the first masking structures <NUM> should be thick enough for the first masking structures <NUM> to function as the etching mask during plasma etching of the silicon-wafer plate <NUM>.

S203: Depositing a layer of second masking structures on the silicon-wafer plate and forming a first protection layer.

Referring to <FIG>, in this embodiment, a layer of second masking structures <NUM> may be deposited on a surface of the silicon-wafer plate <NUM> where the island structures <NUM> have been formed. A first protection layer <NUM> may be formed and then hardened on a portion of the second masking structures <NUM> which is not located on the island structures of the silicon-wafer plate <NUM>.

In one embodiment, in order to harden the first protection layer <NUM>, the first protection layer <NUM> may be placed in a first temperature environment during a first predetermined time. By hardening the first protection layer <NUM> with a constant temperature, the adhesive force between the first protection layer <NUM> and the second masking structures <NUM> may be enhanced. The first temperature may be <NUM> and the first predetermined time may be <NUM>. Those skilled in the art should understand that the first temperature and the first predetermined time may be determined according to the thickness and area of the first protection layer <NUM>, and intend to make the first protection layer <NUM> to have enough stiffness and enough adhesive force with the second masking structures. The above-mentioned values are just illustrative and should not be taken as limit to the scope of the present disclosure.

In one embodiment, the first protection layer <NUM> may include polymethyl methacrylate (PMMA). The portion of the second masking structures <NUM> which is not located on the island structures <NUM> of the silicon-wafer plate <NUM> may be coated with <NUM> of PMMA which may help to attach the second masking structures <NUM> to the silicon-wafer plate <NUM>. PMMA should be thick enough to provide enough adhesive force between the layer of second masking structures <NUM> and the silicon-wafer plate <NUM> and may be determined based on the size and thickness of the layer of second masking structures <NUM>. Those skilled in the art should understand that the first protection <NUM> may also include other adhesive colloid, and the thickness of the colloid may be determined based on the adhesion between the silicon-wafer plate <NUM> and the layer of second masking structures <NUM>, and the size and thickness of the layer of second masking structures <NUM>.

In one embodiment, the second masking structures <NUM> may also be deposited on the surface of the island structures <NUM>. The second masking structures <NUM> may be deposited on the surface of the silicon-wafer plate <NUM> by PVD (physical vapor deposition) such as vacuum plating, sputtering or ion plating.

In one embodiment, the layer of second masking structures <NUM> may be a metal layer of gold. The second masking structures <NUM> may be deposited on a portion of the silicon-wafer plate <NUM> where the island structures <NUM> are not formed so as to facilitate the separation of the bottom of the island structures <NUM> from the first protection layer <NUM>. Apparently, those skilled in the art should understand that other metals which may facilitate the separation of the bottom of the island structures <NUM> from the first protection layer <NUM> may also be utilized to form the second masking structures <NUM>.

In one embodiment, the thickness of the layer of second masking structures <NUM> may be <NUM>. Apparently, those skilled in the art may understand that the thickness of the layer of second masking structures <NUM> should be large enough for facilitating the separation of the bottom of the island structure <NUM> from the first protection layer <NUM>.

S204: Removing the layer of second masking structures on the surface of the island structures and forming a second protection layer wrapping around the island structures.

Referring to <FIG>, in this embodiment, etching solution corresponding to the second masking structures <NUM> may be utilized to etch the second masking structures <NUM> on the surface of the island structures <NUM>. The second masking structures <NUM> deposited on the portion of the silicon-wafer plate <NUM> where the island structures <NUM> are not formed may not be etched by the etching solution since it is covered by the first protection layer <NUM>. Consequently, only the second masking structures <NUM> deposited on the surface of the island structures <NUM> far away from the first protection layer <NUM> will be etched. Then a second protection layer <NUM> wrapping around the island structure <NUM> may be formed and hardened on the silicon-wafer plate <NUM>.

In one embodiment, in order to harden the second protection layer <NUM>, the second protection layer <NUM> may be placed in a second temperature environment during a second predetermined time. By hardening the second protection layer <NUM> with a constant temperature, the adhesive force between the second protection layer <NUM> and the island structure <NUM> may be enhanced. The second temperature may be <NUM> and the second predetermined time may be <NUM>. Those skilled in the art should understand that the second temperature and the second predetermined time may be determined according to the thickness and area of the second protection layer <NUM>, and intend to make the second protection layer <NUM> to have enough stiffness and adhesive force with the island structures <NUM>. The above-mentioned values are just illustrative and should not be taken as limit to the scope of the present disclosure.

S205: cutting layer by layer the island structures and the second protection layer to obtain second protection sub-layers.

Referring to <FIG>, in this embodiment, second protection sub-layers <NUM> may be obtained by cutting layer by layer the island structures <NUM> and the second protection layer <NUM> wrapping around. The second protection sub-layers <NUM> wrap around a same number of silicon-wafer sub-plates as the island structures, which will be utilized in subsequent processes for manufacturing the TFT substrate.

In one embodiment, the second protection layer <NUM> may include an epoxy layer. The second protection layer <NUM> wrapping around the silicon-wafer sub-plates may be hardened to maintain the distance D of each two of the silicon-wafer sub-plates. Those skilled in the art should understand, the distance D may be determined according to the required distance between the island structures on the TFT substrate.

In one embodiment, the island structures <NUM> and the second protection layer <NUM> wrapping around may be cut along a cutting direction parallel to the extending direction of the silicon-wafer plate <NUM>. Apparently, those skilled in the art should understand, the island structures <NUM> and the second protection layer <NUM> wrapping around may also be cut one by one so as to acquire the silicon-wafer sub-plates <NUM> for manufacturing the island elements on the TFT substrate. The thickness of the second protection layer <NUM> may be determined according to the required thickness of the island elements on the TFT substrate.

In one embodiment, a nanometer diamond cutter may be utilized to cut layer by layer the island structures <NUM> and the second protection layer <NUM> wrapping around so as to obtain the second protection sub-layer <NUM>. Apparently, those skilled in the art should understand that other nano-sized cutting tools such as laser may also be utilized.

S206: Attaching the second protection sub-layer onto the substrate and etching the second protection sub-layer to expose the silicon-wafer sub-plates so as to acquire the TFT substrate.

Referring to <FIG>, in this embodiment, the substrate may be a polyimide (PI) flexible substrate. The polyimide flexible substrate itself has a certain adhesive capacity. It should be understood that any substrate having a certain adhesive capacity may also be utilized to manufacturing the TFT substrate <NUM> of the present disclosure.

The second protection sub-layer <NUM> obtained in the previous steps may be attached onto a substrate <NUM>. The silicon-wafer sub-plates <NUM> may be exposed by plasma etching the second protection layer <NUM>. After plasma etching, the second protection layer <NUM> on the substrate <NUM> may be removed, and the silicon-wafer sub-plates may be kept as the island elements of the TFT substrate. Then the substrate <NUM> may be placed in a third temperature environment during a third predetermined time so as to enhance the adhesive force between the silicon-wafer sub-plates <NUM> and the substrate <NUM>. The silicon-wafer sub-plates <NUM> may be utilized as the island elements matching the TFT components for the sequent processes.

In one embodiment, the third temperature may be <NUM> and the third predetermined time may be <NUM>. Those skilled in the art should understand, the third temperature and the third predetermined time may be determined based on the thickness and area of the silicon-wafer sub-plates <NUM> and the adhesion between the silicon-wafer sub-plates <NUM> and the substrate <NUM>, and intend to provide enough adhesive force between the silicon-wafer sub-plates <NUM> and the substrate <NUM>. The above-mentioned values are just illustrative and should not be taken as limit to the scope of the present disclosure.

In conclusion, according to the present disclosure, the island structures may be obtained by etching the silicon-wafer plate via the first masking structures, and the silicon-wafer sub-plates for manufacturing the island elements of the TFT substrate may be obtained by cutting layer by layer the island structures. The acquired silicon-wafer sub-plates may be attached onto the substrate to form the TFT substrate. Therefore, the present disclosure may improve the stability of the substrate during bending and reduce the stress mismatch between the substrate and the film of a TFT component.

Referring to <FIG> shows a diagram of the TFT substrate according to an embodiment of the present disclosure.

Claim 1:
A method for manufacturing a TFT substrate, characterized in that the method for manufacturing the TFT substrate comprises:
providing a silicon-wafer plate (<NUM>) coated with a layer of photoresist material;
patterning the photoresist material with an etching solution corresponding to the photoresist material to form first masking structures (<NUM>) on the silicon-wafer plate (<NUM>),
plasma etching the silicon-wafer plate (<NUM>) via the first masking structures (<NUM>) to form island structures (<NUM>);
cutting the island structures (<NUM>) layer by layer along a direction parallel to an extending direction of the silicon-wafer plate (<NUM>) to form a silicon-wafer sub-plate (<NUM>); and
attaching the silicon-wafer sub-plate (<NUM>) on a substrate (<NUM>) to form the TFT substrate.