Crystal resonator

A crystal resonator includes a crystal element and excitation electrodes. The crystal element has a pair of principal surfaces parallel to an X'-axis and a Z'-axis. The X'-axis is an axis of rotating an X-axis as a crystallographic axis of a crystal in a range of 15 degrees to 25 degrees around a Z-axis as a crystallographic axis of the crystal. The Z'-axis is an axis of rotating the Z-axis in a range of 33 degrees to 35 degrees around the X'-axis. The excitation electrodes are formed on the respective principal surfaces of the crystal element. Elliptical mesa portions or elliptical inverted mesa portions are formed on the respective principal surfaces. The mesa portions project from outer peripheries of the principal surfaces. The inverted mesa portions are depressed from the outer peripheries of the principal surfaces. 本发明提供种晶体振子，该晶体振子能够抑制副振动与主振动的耦合且将晶体阻抗值抑制得低。晶体振子(100)包括：晶体片(110)，具有与X′轴及Z′轴平行的对主面，所述X′轴是使作为晶体的结晶轴的X轴以作为晶体的结晶轴的Z轴为中心而在15度至25度的范围内旋转所得，所述Z′轴是使Z轴以X′轴为中心而在33度至35度的范围内旋转所得；以及激振电极(120)，形成于晶体片的各主面。在各主