SPECIFYING QL'ARTZ CRYSTAL ORIENTATION 



235 



then have their x axes determined by etching and X-rays and cut up by the 

 Z section cutting method. 



By turning the base plate on the angle bracket and dicing the wafers at 

 an angle any orientation can be obtained. 



2.4 Z Section or Vertical Cutting 



Having a true Z basal section it is first marked for the +.v axis. The 

 simplest procedure is to use the star mark; for right-hand quartz (R.H.Q.) 



\+ 



+ + 



Fig. 2.14 — Marking the "sense" of righthand and lefthand sections 



Fig. 2.15 — Making the rotations Ai 



the rays should point toward the plus electric axis, for left-hand quartz 

 the rays should point towards the negative electric axis. 



The section is now placed on the carriage plate, one ray pointing towards 

 the operator (which ray is decided on the basis of the economy of quartz). 



