FOURTH QUARTERLY FRCGRESS REPORT INVESTIGATION OF LOW FREQUENCY AT-CUT CRYSTAL PLATES

摘要

The method of finishing these quartz plates to the pre-etch frequency has been changed to realize greater freedom from spurious responses and to eliminate one variable, thickness, for all crystals of the same frequency. This new process employs a contour lapping technique to replace the former lapping by the Sipp-Eastwood method. In other words, the final lapping to desired frequency is now accomplished by working on the contoured faces instead of on the small, flat, central faces. This process also permits better control of edge thickness, which is important in obtaining minimum effective resistance.