Summary

Orientation angles


Fig.2 Cut Angels

Orientation angles from the crystal axis are selected according to use (oscillation frequencies and electrical characteristics) .
Fig. 2 shows the main cutting angles. Table 1 shows the typical values of vibration modes, frequency ranges and capacitance ratios.
For example, the most widely used AT-cut crystal wafer, is parallel to a plane inclined about 35°15' from the Z-axis.
In the case of 28 MHz fundamental-wave thickness-shear vibration, the wafer thickness is approximately 0.06mm.

Table 1 Basic Characteristics

Vibration Mode Cut Frequency Range (kHz) Frequency Formula (kHz) Capacitance Ratio (Typical)
Thickness-shear
Overtone Order AT Fundamental 800 to 5000
2000 to 80000
1670/t
1670/t
300 to 450
220
AT 3rd Overtone
AT 5th Overtone
AT 7th Overtone
AT 9th Overtone
20000 to 90000
40000 to 130000
100000 to 200000
150000 to 230000
1670×n/t n²×250
n : Overtone Order
BT Fundamental 2000 to 35000 2560/t 650
Flexural vibration (Tuning fork)
+2°X 16 to 100 700×w/l² 450
Length-width-flexure
XY
NT
1 to 35
4 to 100
5700×t/l²
5000×w/l²
600
900
Length-extensional
+5°X 40 to 200 2730/l 140
Face-shear
CT
DT
SL
250 to 1000
80 to 500
300 to 1100
3080/l
2070/l
460/l
400
450
450
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