IMPROVED CRYSTAL BLANK ANGLE CORRECTION

THE TEMPERATURE DEPENDENCE OF QUARTZ CRYSTAL RESONATOR FREQUENCIES IS DETERMINE PRINCIPALLY BY THE CRYSTALLOGRAPHIC ORIENTATION OF CRYSTAL BLANKS. AS FREQUENCY REQUIREMENTS BECOME MORE STRINGENT, THE REQUIRED ANGLE TOLERANCES CAN BECOME TIGHTER THAN THE TYPICAL CAPABILITY OF MANY PRODUCTION PROCESSES. FOR THE EFFICIENT PRODUCTION OF PRECISION ATIAND SC-CUT RESONATORS WITH HIGH RESULTANT YIELDS, AN EFFECTIVE TECHNIQUE MUST BE DEVISED TO CORRECT PRODUCTION ANGLE SPREADS TO ACCEPTABLE DEVICE LIMITS. MANY METHODS HAVE BEEN UTILIZED TO ACCOMPLISH CRYSTAL BLANK ANGLE CORRECTION, WITH VARYING DEGREES OF PRACTICAL SUCCESS. AS FREQUENCY CONTROL ELEMENTS ARE REQUIRED TO MEET THEIR SPECIFICATIONS OVER WIDER AND WIDER ENVIRONMENTAL EXTREMES,MORE EMPHASIS IS PLACED ON THE SC-CUT CRYSTAL RESONATOR. THE DOUBLYROTATED CRYSTAL CUT NOW REQUIRES THE MANUFACTURER TO ACCURATELY CONTROL TWO ANGLES OF ROTATION. WHAT IS SUBMITTED IN THIS PROPOSAL IS AN IMPLEMENTATION OF AN ANGLE CORRECTION TECHNIQUE WHICH WOULD ALLOW FOR THE SIMULTANEOUS ADJUSTMENT OF BOTH THE PHI AND THETA ANGLES ON AN SCCUT BLANK WITH A SINGLE LAPPING OPERATION ON A STANDARD PIECE OF LAP EQUIPMENT.