Electric characteristics of double convex lens type quartz resonators on one quartz blank

The objective of this research is to study electric characteristics of double identical two-steps quartz resonators in two concave lens-shapes on one quartz blank. After two concave quartz pockets of single-sided inverted mesa type were made by chemical etching, they were machined from front and rear sides by a dual-face polishing table, and we discovered the following. 1) Two concave pockets were found to become identical convex lens shapes. 2) The longer they were machined the higher they grew stepwise with identical geometry. 3) The deeper the concave blank was polished, the longer the separation between the primary oscillation and secondary and higher ones became. 4) When the quartz plate is etched by HF acid, the damaged amorphous layer becomes approximately 0.2 /spl mu/m. After this was removed by mechanical polishing, the surface became extremely smooth, and these double resonators could be used as an accurate bio-sensor to measure chemical reactions such as an allergy-reargin reaction. 5) When the quartz blank was processed as above, the sensor was discovered to show a intrinsic higher electrical performance.