Non-contact porous air bearing and glass flattening device
Thin substrates, such as flat glass panels, are levitated on a porous media air bearing creating a pressurized film of air and preloaded against the air film by negative pressure areas. The pressure can be distributed most uniformly across the pressure areas by defusing the pressure through a porous medium. Such a bearing can be used for glass flattening by holding the glass such that the unevenness is migrated to the side opposite the side to be worked on.
1. A method for locally flattening natural thickness errors of glass, the method comprising:
(a) providing vacuum preloaded air bearings, arrayed around or near to an area of the glass to be flattened;
(b) positioning the glass with the side of the glass to be flattened facing the air bearings; and
(c) supporting the glass with the vacuum preloaded air bearings to flatten the side of the glass to be flattened by causing the natural thickness errors to move from the side of the glass to be flattened to the opposite side of the glass, the natural thickness errors being in a range from 5 to 7 microns.
2. A method as claimed in claim 1 , further comprising (d) processing a portion of the flattened side of the glass by; patterning with light, laser, ink, physical imprinting; inspecting, scanning, repairing or coating for manufacturing electronic circuits.
3. A method as claimed in claim 2 , wherein the glass moves relative to the bearings and processing, parallel to the face of the bearings in the X and or Y direction.
4. A method as claimed in claim 2 , wherein the bearings and the processing move relative to the glass in the X and or Y direction.