Doubly Rotated Blanks

Doubly Rotated Blanks are single crystal cultured quartz blanks fabricated with a double angular rotation suitable for operation in the thickness shear mode. This family of blanks includes the SC-cut and IT-cut and is designed to reduce the effects of stress on resonant frequency.

Doubly rotated blanks can be fabricated to a range of specifications for either of the two angles of rotation as well as the overall blank dimensions. Typical specifications for the j -rotation (i.e. the first, or X to X', rotation) are around 22° for SC-cut blanks and 19° for IT-cuts, but can vary by as much as ±10. The q -rotation (i.e. the second, or Z to Z' rotation) typically ranges from 33° to 35°. Verification of specified orientation is assured by providing us with the appropriate x-ray diffraction reference standards. As the blanks are usually angle corrected after delivery, both surfaces are lapped to a rough finish using 15 µm abrasive, unless otherwise specified.

Doubly Rotated Blanks Section Drawing
Section Drawing

Typical Specifications

Mechanical Characteristics

Units   Typical Values Tolerance
X-height x Z-width mm 16.5 x 16.5 ± 0.25
Thickness, t   As specified ± 0.013
Orientation - φ degrees As specified (18°-24°) ± 10 minutes
Orientation - θ degrees As specified (33±-35°) ± 5 minutes
Standard dimensions (other dimensions are available to meet customer-specific requirements)

Material Characteristics

Handedness Right      
Infrared a (3500 cm-1) α - units Grade B: 0.045 maximum
      Grade l  
Inclusions (diameter) 25 - 75 µm cm³ 4  
  75 - 100 µm cm³ 2  
  >100 µm cm³ 2  
Etch Channels cm² Grade 4: 300 maximum
Twins in useful volume Count None  

Surface Characteristics

  • Surface Finish: rough lapped using 15 µm abrasive.
  • Chips intruding onto surface: 1.0 mm Maximum

Seed Characteristics

  • Pure - Z, seed free material


International Electrotechnical Commission Standard, CEI/IEC 758, Second edition, 1994.

Institute of Electrical and Electronic Engineers Standard on Piezoelectricity, ANSI/IEEE Std. 176-1 987.