Krystaly, Hradec Králové, a.s.
 

Terms, definitions and characteristics

Term
Ref.symbol Definitions
 Material    
 Synthetic
 quartz crystal
SQC Synthetic quartz crystal with quality grade C or better,
inclusion density Grade II and etch channel density Grade 2,
( according EN/IEC 60758 )
 Lithium Niobate LN Crystal material with Curie temperature within specified value and with single domain structure by polarization process
 Lithium Tantalate LT Crystal material with Curie temperature within specified value and with single domain structure by polarization process
 Dimensions    
 Diameter
D Diameter of circular portion of wafer in millimeters or inchs
 Thickness
T Thickness at the center of wafer measured by thickness meter having an accuracy of 1 µm
 Orientation flat OF Cut surface intersecting around wafer for indication of wafer orientation
 Index flat
 ( secondary )
IF Cut surface intersecting around wafer for additional indication of wafer orientation (according customer specification)
 Bevel   A round shaping of wafer on the edge
 Surface orientation   Crystallographical orientation of the axis perpendicular to the surface of wafer
 Surface
 characteristics
   
 Flatness TV5 Thickness variation of wafer for five points
(one at the center and 4 points at the edge)
 LTV   Local thickness variation
 Bow   Bending deformation of wafer
 Warp   Deformation of wafer, definition see IEC 62276, Ed.1
 Defects    Perturbations on polished ( working ) wafer surface.
Detail definitions of defects, see IEC 62276.
 Back surface
 roughness
Ra Definition according ISO 468, value according customer specification
Alternative: specification by abrasive grain size.

 
 
 

KRYSTALY 

Hradec Králové, a.s. 
Okružní 1144 
500 03 Hradec Králové 3 
Česká republika