Method of forming pattern having step difference and method of making thin film transistor and liquid crystal display using the same

1. A method of forming a pattern having a step difference comprising the steps of:

a) forming a first pattern having a predetermined shape on a first printing roll using a first printing plate;

b) rotating the first printing roll on a substrate to transfer the first pattern onto the substrate;

c) forming a second pattern having a different shape from the first pattern on a second printing roll using a second printing plate, wherein the second printing roll is different then the first printing roll and the second printing plate is different from the first printing plate; and

d) rotating the second printing roll on the substrate, to transfer the second pattern onto the first pattern.

2. The method according to claim 1 , wherein at least one of step a) or step c) comprises depositing a pattern material on at least one of the first or second printing rolls, and rotating at least one of the first or second printing rolls on at least one of the first or second printing plate provided with a projection having a predetermined shape.

3. The method according to claim 2 , wherein rotating the first or second printing roll comprises transferring a portion of the pattern material onto the projection of the first or second printing plate and leaving a portion of the pattern material on the first or second printing roll to form a predetermined pattern on the first or second printing roll.

4. The method according to claim 1 , wherein at least one of step a) or and step c) comprises: preparing the first or second printing plate provided with a recess having a predetermined shape; forming a pattern material in the recess; and rotating the first or second printing roll on the first or second printing plate.

5. The method according to claim 4 , wherein rotating the first or second printing roll comprises transferring the pattern material in the recess of the first or second printing plate onto the first or second printing roll to form a predetermined pattern on the first or second printing roll.

6. The method according to claim 1 , wherein at least one of step a) or and step c) comprises: forming a convex structure having a predetermined shape on the first or second printing roll; and rotating the first or second printing roll on the first or second printing plate having a pattern material formed thereon.

7. The method according to claim 6 , wherein rotating the first or second printing roll comprises transferring the pattern material onto the convex structure to form a predetermined pattern on the first or second printing roll.

8. The method according to claim 1 , wherein rotating the second printing roll on the substrate, to transfer the second pattern onto the substrate comprises forming the second pattern on the first pattern.

9. The method according to claim 1 , wherein rotating the second printing roll on the substrate, to transfer the second pattern onto the substrate comprises forming the second pattern at a side of the first pattern.

10. The method according to claim 1 , rotating the second printing roll on the substrate, to transfer the second pattern onto the substrate comprises forming a pattern having a step difference that comprises a substantial U-shape in cross-section.

11. The method according to claim 1 , wherein in one of steps a) or c) rotating the first printing roll or the second printing roll further comprises using a printing device comprising a main body having a plurality of nozzle units in the main body, the main body having a plurality of grooves therein to receive the pattern material and each nozzle unit having a slit that is coupled to the grooves to discharge a pattern material.

12. The method according to claim 1 , wherein the steps c)/d) are initiated a predetermined time after steps a)/b) and before completing transfer of the first pattern onto the substrate.

13. A method of forming a pattern having a step difference comprising the steps of:

a) forming a first pattern having a predetermined shape on a first printing roll using a first printing plate;

b) forming a second pattern having a different shape from the first pattern on a second printing roll using a second printing plate, wherein the second printing roll being different then the first printing roll and the second printing plate is different from the first printing plate; and

c) sequentially rotating the first printing roll on a substrate to transfer the first pattern onto the substrate and rotating the second printing roll on the substrate, to transfer the second pattern onto the first pattern.

14. The method according to claim 13 , wherein forming a first pattern and forming a second pattern comprises sequentially rotating the first and second printing rolls on the first and second printing plates, respectively, such that a the first pattern is transferred onto the first printing roll and the second pattern is transferred onto the second printing roll.

15. The method according to claim 13 , wherein forming a first pattern and forming a second pattern further comprises coating pattern material on the first and second printing rolls using respective first and second printing nozzles.

16. The method according to claim 13 further comprising positioning the first and second printing plates and the substrate on a moving rail, wherein the moving rail moves relative to the first and second printing rolls.

17. The method according to claim 13 , wherein one of the first printing roll or the second printing roll further comprises a main body and a plurality of nozzle units below the main body, the main body having a plurality of grooves therein to receive the pattern material and each nozzle unit having a slit that is coupled to the grooves to discharge the pattern material.