Method of aligning a substrate, mask to be aligned with the same, and flat panel display apparatus using the same
View Patent ↗A method of aligning a substrate includes forming a first alignment hole in the substrate, preparing a mask with a second alignment hole narrower than the first alignment hole, modifying a surface reflectance around either the first alignment hole or the second alignment hole to form a treatment region, positioning the mask below the substrate, such that the first and second alignment holes overlap, and operating a sensor unit above the first alignment hole to examine alignment of the first and second alignment holes.
1. A method of aligning a substrate, comprising:
forming a first alignment hole in the substrate;
preparing a mask with a second alignment hole, the second alignment hole being narrower than the first alignment hole;
modifying a surface reflectance around the second alignment hole to form a treatment region;
positioning the mask below the substrate, such that the first and second alignment holes overlap and the treatment region is seen through the first alignment hole; and
operating a sensor unit above the first alignment hole to examine alignment of the first and second alignment holes.
2. The method as claimed in claim 1 , wherein modifying the surface reflectance includes modifying a surface color.
3. The method as claimed in claim 1 , wherein operating the sensor unit includes operating a CCD camera.
4. The method as claimed in claim 1 , wherein forming the treatment region includes irradiating an area around the second alignment hole having a width of about 1 mm or less.
5. The method as claimed claim 1 , wherein forming the treatment region includes etching or melting.
6. The method as claimed in claim 1 , wherein forming the treatment region includes irradiating an area around the second alignment hole to a thickness of about 30 μm to about 100 μm.
7. The method as claimed in claim 1 , wherein modifying the surface reflectance includes modifying a surface roughness.
8. The method as claimed in claim 1 , wherein the substrate is made of an opaque material.
9. The method as claimed in claim 1 , wherein forming the treatment region includes forming a region having inner and outer boundaries.
10. The method as claimed in claim 8 , wherein the opaque material is metal.
11. The method as claimed in claim 8 , wherein the opaque material is metal and the mask is metal.
12. The method as claimed in claim 9 , wherein forming the treatment region includes treating an area on an upper surface of the mask around the second alignment hole, so that the inner boundary is concentric with the second alignment hole.
13. The method as claimed in claim 12 , wherein forming the treatment region includes laser irradiation, metal deposition, chemical mechanical polishing or sand blasting.
14. The method as claimed in claim 12 , wherein forming the treatment region includes forming a region having the inner boundary spaced apart from the second alignment hole.
15. The method as claimed in claim 12 , wherein forming the treatment region includes forming the inner boundary narrower than the first alignment hole.
16. The method as claimed in claim 12 , wherein forming the treatment region includes forming the outer boundary wider than the first alignment hole.
17. A method of aligning a substrate, comprising:
forming a first alignment hole in the substrate;
preparing a mask with a second alignment hole, the second alignment hole being narrower than the first alignment hole;
modifying a surface reflectance of an upper surface of the mask around the second alignment hole to form a treatment region including a region having inner and outer boundaries, the inner boundary being concentric with the second alignment hole;
positioning the mask below the substrate, such that the first and second alignment holes overlap; and
operating a sensor unit above the first alignment hole to examine alignment of the first and second alignment holes.