Quartz Lumbered D Bars

Lumbered D Bars

This document provides typical specifications for single crystal cultured quartz material grown on a Z-plate seed and lumbered so as to simplify the cutting of wafers for the family of doubly rotated crystals operating in the thickness shear mode. The additional rotation is about the Z-axis and is designed to reduce the effects of stress on resonant frequency.

Lumbered D Bars are manufactured such that doubly rotated blanks are easily obtained when the D-bar is wafered using procedures similar to those used to fabricate AT-cut blanks. The φ - rotation (i.e. the first, or X to X´, rotation), nominal values of which are typically around 22° for bars used to make SC-cut blanks and 19° for IT-cuts, is provided as shown. The θ - rotation (i.e. the second, or Z to Z´, rotation) is delivered when the bar is wafered, the primary difference between AT wafering and this θ - rotation being a slight reduction in the cutting angle.

Section Drawing

Mechanical Characteristics

Description	Units	Typical Values	Tolerance
X´-height x Z-width	mm	13.3x12.7	± 0.13
		16.5x15.2	± 0.13
		17.8x16.5	± 0.13
Y´-Iength	mm	63.5	+ 2.5, -0
Orientation of X´-surface @ Z-axis	degrees	0	± 15 minutes
Orientation of Z-surface @ X´-axis	degrees	0	± 15 minutes
@Y´-axis	degrees	0	± 15 minutes
Flatness of -X´ lumbered surface	mm	Flat	± 0.1
Surface finish of -X´ lumbered surface, Ra	µm	4.0	maximum
Dimensions above are standard. Other dimensions are available to meet customer specific requirements

Material Characteristics

Handedness			Right
Infrared α (3500 cm^-1)		α - units	Grade B: 0.045		maximum
			Grade ll	Grade l
Inclusions (diameter)	25 - 75 µm	cm³	5	4	maximum
	75 - 100µm	cm³	4	2	maximum
	>100µm	cm³	3	2	maximum
Etch Channels		cm²	Grade 4 : 300		maximum
Twins and Cracks in Useful Volume		Count	None

Seed Characteristics

Pure - Z, seed free material

Marking and Packaging

Supplier logo, grind lot number, part number and "Minus X" are marked on the minus-X surface of each bar. Reference Z-surface is marked "Z reference".
Bars are shrink-wrapped to cardboard backing and stacked within double walled cardboard boxes.
Total piece count, net weight, gross weight and part number are marked on the exterior of the carton.

References

International Electrotechnical Commission Standard, CEI/IEC 758, Second edition, 1993-04.

Institute of Electrical and Electronic Engineers Standard on Piezoelectricity, ANSI/IEEE Std. 176-1987.

_{©Vides.Web Roditi International 2004} _{Reproduced by kind permission of Sawyer Research Products, Inc.© Sawyer Research Products, Inc. Specifications subject to change without notice.All rights reserved}