Piezoelectric device and method for manufacturing the same

A piezoelectric device comprising:

• a piezoelectric substrate;
• comb-shaped electrodes formed on a principal surface of the piezoelectric substrate;
• lead-out wirings connected to the comb-shaped electrodes, the lead-out wirings being disposed to extend to an outer edge of the piezoelectric substrate;
• an outer surrounding wall layer arranged surrounding an outer periphery of the piezoelectric substrate including the lead-out wirings, the outer surrounding wall layer forming a hollow portion that serves as an operation space for the comb-shaped electrodes;
• and
• a top board that bridges the outer surrounding wall layer to seal the hollow portion, wherein:
• the top board is constituted of a heat resistant resin that is mixed with filler of an inorganic material to improve a mechanical strength,
• the lead-out wiring is formed on each of paired opposing side surface sides of the outer surrounding wall layer,
• a metal plating layer is formed to be insulated into a plurality of partitions, the metal plating layer being formed across paired opposing side surfaces of the outer surrounding wall layer, a top surface of the top board connected to the paired opposing side surfaces of the outer surrounding wall layer, and the outer edge of the piezoelectric substrate connected to the paired opposing side surfaces of the outer surrounding wall layer, and
• the metal plating layer is electrically connected to the lead-out wiring in the outer edge of the piezoelectric substrate to provide the metal plating layer on the top surface of the top board as a mounting terminal and to provide the metal plating layer on the side surface of the outer surrounding wall layer as a side surface wiring configured to connect the lead-out wiring to the mounting terminal.