FORMING A MARK ON A GEMSTONE OR INDUSTRIAL DIAMOND

摘要

To form a micro mark on the table (7a) of a diamond (7), a holder or dop (11) with the diamond (7) is spun, a photo resist is applied to the table (7a), the resist is baked by heating the base of the dop (11), and the dop (11) is transferred to the table (30) of apparatus for exposing the resist. The resist is exposed using an exposure radiation with a pattern which is a reduced image of a mask (35), working through an objective lens (38). The exposure radiation is projected by a radiation source (31) and can be 350 to 450 nm. In order to locate, orientate and focus the image, the radiation source (31) is arranged to project light in the wavelength range 500 to 550 nm, which does not affect the resist, forming a setting-up image on the table (7a). the setting-up image is viewed in an observation plane (44) through the objective lens (38) and a beam splitter (36). After exposure, the resist is developed and the exposed area of the table (7a) is then milled using a plasma.