US Patent No. 9,614,493

QUARTZ CRYSTAL DEVICE AND METHOD FOR FABRICATING THE SAME


Patent No. 9,614,493
Issue Date April 04, 2017
Title Quartz Crystal Device And Method For Fabricating The Same
Inventorship Taichi Hayasaka, Saitama (JP)
Shuichi Mizusawa, Saitama (JP)
Assignee NIHON DEMPA KOGYO CO., LTD., Tokyo (JP)

Claim of US Patent No. 9,614,493

1. A quartz crystal device which is in surface mount type, and the quartz crystal device comprising:
a quartz crystal vibrating piece, configured to vibrate at a predetermined frequency; and
a base plate made of a crystal or a glass, the base plate including an external electrode disposed on a bottom surface of
the base plate to mount the quartz crystal device, the quartz crystal vibrating piece being placed on an opposite surface
of the bottom face, wherein

the external electrode includes a metal film formed on a surface of the base plate by sputtering, and an electroless plating
film formed on a surface of the metal film by electroless plating, and

the electroless plating film includes a nickel layer, and the nickel layer including lead and bismuth.