| 摘要 |
PURPOSE:To obtain a miniature crystal vibrator with its inflection-point temperature close to the normal temperature by setting the cutting angle and slanting angle of an AT cut with length set in the X-axial direction of a crystal piece within fixed ranges and then by fixing the length of the X axis between 5 and 10mm. CONSTITUTION:The length is set in the X-axial direction of a crystal piece, and the normal line of its main surface is perpendicular to the X axis while an cutting angle from the Y axis to Z axis is fixed at 35 deg. 10'; and its flank is slanted from the normal line of the main surface to the Z axis to change the angle like 2 deg., 5 deg. and 10 deg., and length is varied to 3-15mm. Here, the figure shows variation in the inflection- point temperature of frequency temperature characteristics in this case. According to it, the inflection-point temperature becomes equal to the normal temperature at a slanting angle of approximate 5 deg. with length between 5 and 10mm. Further, the cutting angle is between 35 deg.8' and 35 deg.16' within the practical range where the variation rate of a frequency within the temperature range of -10 deg.C-+60 deg.C is less than + or -30ppm when the cutting angle is changed 35 deg.20'-35 deg.5'. Consequently, setting the slanting angle and length to 4 deg.-6 deg., and 5-10mm respectively makes it possible to obtain a miniature AT-cut thickness sliding vibration crystal vibrator with its inflection-point temperature close to the normal point. |
