Cut and Grind

Abstract

With the advent of t h e SC-cut c rys ta l , which as a n i n f l e c t i o n t e m p e r a t u r e at 95"C, o r i e n t a t i o n a n g l e s have become t i g h t e r i n t o l e r a n c e b e c a u s e t h e o p e r a t i n g tempera ture is u s u a l l y n e a r t h e i n f l e c t i o n t e m p e r a t u r e , and the angles are d i f f i c u l t t o m e a s u r e for two r e a s o n s . F i r s t , h e m e a s u r e m e n t n e c e s s i t a t e s t h e u s e of weak X-ray p l a n e s r e q u i r i n g a v e r y s e n s i t i v e d e t e c t o r and some ca l cu la t ions . Second , t he small t o l e r a n c e r e q u i r e s a v e r y p r e c i s e f i x t u r e t o h o l d t h e q u a r t z p l a t e a n d t h u s d e f i n e s t h e s u r f a c e t o b e measured. Often, a laser beam must be used to de te rmine t h e p o s i t i o n of t h e c e n t r a l s u r f a c e of the b lank .