Synthetic Quartz Crystal ■ Standard Specifications of Synthetic Quartz Crystal ● Handedness of Crystal Right-handed quartz crystal, unless otherwise specified. ● Direction and Dimensions of Seed Crystal Direction There are four directions according to applications as follows: ● Quality 0°00'±30', 1°00'±30' 1°30'±30', 2°00'±30' Dimensions Twins Unit : mm Electric and optical twins are not included. Z plate Direction External appearance 0°00' X-axis dimension No cracks or bubbles that affect electric characteristics are found 41.0±1.0 Z-axis dimension in the effective length. 1°30' 89.0±1.0 43.0±1.0 68.0±1.0 Max. 2.5 Inclusions ● Standard Specifications of Lumbered Synthetic Quartz Crystal The following grades are set for the maximum number of inclusions contained in the Z zone according to IEC60758. Grade Size of an inclusion and maximum number of inclusions in 1 cm3 Application 10 to 30μm 30 to 70μm 70 to 100μm 100μm to Ia Max. 2 Max. 1 Max. 0 Ib Max. 3 Max. 2 Max. 1 I Max. 6 Max. 4 Max. 2 Max. 0 For photolithographic Max. 1 processing Max. 2 Max. 5 Max. 4 For high-frequency and highMax. 3 quality oscillators and SAW III Max. 12 Max. 8 Max. 6 Max. 4 For industrial crystal oscillators II Max. 9 Angle of a processed surface Angle of the Z surface in the Y’-axis direction : 0°00'±30', 1°00'±30' 1°30'±30', 2°00'±30' Angle of the Z surface in the X-axis direction : 0°00'±15' Angle of the X surface in the Y’-axis direction : Infrared absorption coefficient α 0°00'±15' Angle of the X surface in the Z’-axis direction : 0°00'±15' The following grades are set for the infrared absorption coefficient Dimensional tolerance α (the wave number 3585 cm–1 is used) according to IEC60758. X-axis direction : ±0.1mm Infrared absorption Reference infrared Grade coefficient α3585 Q value Z’-axis direction : ±0.2mm Application Surface finishing Aa Max. 0.015 Min. 3.8 million A Max. 0.024 Min. 3 million B Max. 0.050 Min. 2.4 million Seed crystal location Max. 0.069 For high-frequency industrial crystal Min. 1.8 million oscillators that require a temperature characteristic equivalent to a low α value The location of the seed crystal is included in the shaded part C D Max. 0.100 E Max. 0.160 For high-quality crystal oscillators With a diamond wheel of #80 or larger (oblique line) in the figure below. Min. 1.4 million For a low-price low-frequency Min. 1 million c rystal oscillator Y-cut cross section Z Z/2 Etch channel density ρ The following grades are set for etch channel density ρ according to IEC60758. Grade Maximum ρ (per cm2) : Seed crystal Application 3.5 mm max. 1aa 2 1a 50 1 10 2 30 High frequency fundamental crystal units Chemical Etching,SAW Device 3 100 For industrial Crystal Units - The following are displayed on the X surface: 4 300 Conventional Crystal Units Direction of a seed crystal Handedness of a crystal (RH or LH) Manufacturing lot number Manufacturer name (NDK) A sensor using thick crystal to be required long periods of chemical etching. ● Marking sq08_101018_standard1_e