Patent ID: 8330560
Filing Date: 2012-12-11
Classification: H03H

Abstract:
1. A method of frequency adjustment of a tuning-fork type crystal resonator having a tuning-fork shaped piece of quartz crystal in which a pair of tuning fork arms extend from a tuning fork base, comprising a first frequency adjustment step for adjusting an oscillation frequency by forming inclined surfaces spanning from outer peripheral surfaces surrounding said pair of tuning fork arms toward distal end surfaces, by using a femtosecond laser irradiated in a direction from said outer peripheral surfaces toward said distal end surfaces, or in a direction from said distal end surfaces toward said outer peripheral surfaces, wherein said tuning-fork shaped quartz crystal piece has an adjustment metal film on a main surface on a tip side of said tuning fork arm, and there is provided a second frequency adjustment step for removing part of said adjustment metal film using a laser, after said first frequency adjustment step using said femtosecond laser, wherein the laser used in said second frequency adjustment step is a femtosecond laser with lower power than the laser power of said first frequency adjustment step.