Crystal Fiduciary Mark Grinding Fixture
Original Publication Date: 1985-Sep-01
Included in the Prior Art Database: 2005-Feb-19
A vee-notch and chordal flat on a wafer identify the front and back surface and the crystal structure, as well as the product type (part number) by the angular orientation of the vee-notch with respect to the crystal structure and the included angle between the notch and the flat. The marking is most efficiently performed in gross on the boule after the grinding to size to a true cylinder by the apparatus illustrated. The cylindrically ground crystal 10 is supported in vee-block 12 (Figs. 1 and 2) and manually rotated while the etched end face of the crystal is viewed with an optical microscope 14 to orient the angular position of the crystalline structure with respect to 12 o'clock to a desired one of a plurality of positions (three, as illustrated).