The automatic photoresist coating machine on the spherical surface

The photoresist coating is an important micromachining process widely applied in engineering. The formed film should be uniform and enough thin to assure the quality of final pattern whose line width is micrometer or nanometer. It is more difficult to process it on the spherical surface than on the flat. In this work, mathematic model of film thickness on the spherical surface is proposed by using hydromechanics. The key factors that influence the film thickness are obtained from the analysis of coating process. Then, the rational parameters which be controlled by the automatic photoresist coating machine can be final set up according to the result of the coating experiments. And the accuracy analysis of the key part which is used for the main process is performed by the error analytics. This machine not only makes the whole coating process automation, but also monitors the film quality in real time. It is adequate for aspheric surface also.