An apparatus for producing an optical data recording medium comprising a turn table adapted to support a substrate of the recording medium and a nozzle for dropping a coating liquid onto the substrate, the coating liquid dropped on the substrate being spread over the substrate by a rotational force of the turn table to form a coating layer, the apparatus being provided with a gas flow suppressing type housing which is partitioned off from the atmosphere so as to suppress the convection current flowing, due to the rotation of the turn table, toward a central portion of the substrate and further toward the outer circumferential portion thereof along a top surface of the substrate and to suppress the evaporation of a solvent of the coating liquid into the atmosphere, the nozzle being arranged above the inner circumferential portion of the substrate with its end portion being directed to the outer circumferential portion of the substrate, the end portion of the nozzle being inclined so as to form an angle less than 90 degrees relative to the substrate as viewed from a side of the substrate, the coating liquid application being carried out in a hermetically sealed atmosphere within a sealed chamber.
The present invention provides an apparatus and method for forming a protective film on a disc-shaped recording medium including providing a turntable having a center aperture, setting the disc-shaped recording medium having a center opening on the turntable with the center opening being aligned with the center aperture, covering at least the center opening of the disc-shaped recording medium with a rotating disc having a portion larger in diameter than the center opening of the disc-shaped recording medium, and supplying a protective film material to the center of the rotating disc and simultaneously rotating the turntable, the disc-shaped recording medium, and the disc to cause an outward radial flow of the protective film material off the disc and onto the disc-shaped recording medium so that the protective film is obtained and has a thickness with a small variation.
The present invention provides an apparatus and method for forming a protective film on a disc-shaped recording medium including providing a turnable having a center aperture, setting the disc-shaped recording medium having a center opening on the turnable with the center opening being aligned with the center aperture, covering at least the center opening of the disc-shaped recording medium with a rotating disc having a portion larger in diameter than the center opening of the disc-shaped recording medium, and supplying a protective film material to the center of the rotating disc and simultaneously rotating the turnable, the disc-shaped recording medium, and the disc to cause an outward radial flow of the protective film material off the disc and onto the disc-shaped recording medium so that the protective film is obtained and has thickness with a small variation.
A spin-apply tool avoids contamination of a substrate back surface by providing exhaust along or beyond a periphery of a splash shield. The peripheral exhaust pulls a mist of droplets of liquid spun off the substrate away from the substrate. The spin-apply tool includes a spin chuck for holding the substrate, a basin extending around the chuck, a splash shield in the basin, and an exhaust substantially symmetric with the center of the substrate. The chuck surface defines a plane, and the splash shield extends as a ring around the chuck at an angle to that plane sufficient to deflect liquid flying off the chuck down to the basin. The basin may have a removable liner that can be cleaned and reused. Use of solvent to clean the backside of substrates is avoided. And a basin drain is eliminated, eliminating the need for any solvent consumption.
A substrate is rotated at a first bead of less than or equal to 500 rpm per second. A coating composition solution is applied to the substrate at this point. The substrate is then accelerated at a first rate of between 300 and 1200 rpm per second. When the speed of the substrate reaches approximately 3000 rpm per second, a second acceleration is initiated at a second rate of greater than or equal to 3000 rpm. The coating composition is set and the substrate is decelerated. This process provides a more conformal coating of the composition providing better push-pull unwritten variability.
