PIEZOELECTRIC DEVICE AND MANUFACTURING METHOD THEREOF

PROBLEM TO BE SOLVED: To prevent active elements from being damaged by a burn when a piezoelectric device is marked with a product name, lot number, etc. by laser light.SOLUTION: The present invention relates to a piezoelectric device and a manufacturing method thereof, comprising a piezoelectric substrate 2; comb-shaped electrodes 3 formed on a principal plane 2b of the piezoelectric substrate 2; wiring electrodes 4 each having an element wiring disposed adjacent to the comb-shaped electrodes 3; an outer enclosure wall 8 having an opening 8a which encloses the outer periphery of the wiring electrodes 4; a ceiling wall 9 which seals the upper end face of the outer enclosure wall 8 to form a hollow section S; and through electrodes 6 which are disposed penetrating a reverse side 2d from the principal plane 2b of the piezoelectric substrate 2 and which electrically connect the wiring electrodes 4 and terminal electrodes 5 disposed on the reverse side 2d of the piezoelectric substrate 2. The piezoelectric device thus composed is characterized in that a colored liquid hardening layer 7 is formed on the reverse side 2d of the piezoelectric substrate 2, on which layer characters, symbols, etc. are indicated.