Piezoelectric vibration plate, piezoelectric vibration device, and manufacturing method for piezoelectric vibration device

A piezoelectric vibration device, comprising:

• a piezoelectric vibration plate, the piezoelectric vibration plate comprising:
• a piezoelectric substrate having a substantially rectangular shape in plan view;
• a first driving electrode and a second driving electrode formed on main surfaces on both sides of the piezoelectric substrate;
• and
• a first mounting terminal and a second mounting terminal disposed at ends on both sides of the piezoelectric substrate in a direction along one of two pairs of opposing sides of the substantially rectangular shape in plan view, the first mounting terminal and the second mounting terminal being respectively connected to the first driving electrode and the second driving electrode,
• the piezoelectric vibration device further comprising:
• a first sealing member;
• and
• a second sealing member,
• the first sealing member and the second sealing member being respectively adherable to the main surfaces of the piezoelectric vibration plate in a manner that cover the first driving electrode and the second driving electrode of the piezoelectric vibration plate, at least one of the first sealing member or the second sealing member being a film including a resin,
• the first mounting terminal and the second mounting terminal each comprising:
• a metal film for mounting purpose formed on the piezoelectric substrate, the metal films for mounting purpose each comprising a solder-resistant metal film;
• and
• a metal film for driving purpose formed on the metal film for mounting purpose, the metal films for driving purpose being formed in continuity with the first driving electrode and the second driving electrode, the metal films for driving purpose constituting the first driving electrode and the second driving electrode, wherein
• a dividing groove is formed in each of the metal films for mounting purpose and the metal films for driving purpose on the metal films for mounting purpose in a manner that traverses a direction along the one of two pairs of opposing sides of the piezoelectric substrate, and
• the dividing groove divides the metal film for mounting purpose in part and the metal film for driving purpose to allow exposure of the solder-resistant metal film.

A manufacturing method for a piezoelectric vibration device, the manufacturing method comprising preparing a piezoelectric wafer in order to provide a piezoelectric vibration plate comprising:

• a piezoelectric substrate having a substantially rectangular shape in plan view;
• a first driving electrode and a second driving electrode formed on main surfaces on both sides of the piezoelectric substrate;
• and
• a first mounting terminal and a second mounting terminal formed at ends on both sides of the piezoelectric substrate in a direction along one of two pairs of opposing sides of the substantially rectangular shape in plan view, the first mounting terminal and the second mounting terminal being respectively connected to the first driving electrode and the second driving electrode,
• the manufacturing method further comprising:
• an external shape forming step of forming external shapes of a plurality of the piezoelectric substrates on the piezoelectric wafer;
• a metal film for mounting purpose forming step of patterning a metal film for mounting purpose including a solder-resistant metal film on each of the piezoelectric substrates obtained in the external shape forming step to form the metal film for mounting purpose in regions that will constitute the first and second mounting terminals;
• a metal film forming step of patterning a metal film for driving purpose on each of the piezoelectric substrates respectively having thereon the metal films for mounting purpose formed earlier in the metal film for mounting purpose forming step and on each of the metal films for mounting purpose to form the metal film for driving purpose in regions that will constitute the first and second mounting terminals and in regions that will constitute the first and second driving electrodes, thus obtaining the piezoelectric vibration plate;
• an adhering step of adhering a film including a resin to at least one of the main surfaces in each of a plurality of the piezoelectric vibration plates respectively having thereon the metal films for driving purpose formed earlier in the metal film forming step to seal at least one of the first driving electrode or the second driving electrode;
• and
• a separating step of separating the piezoelectric vibration plates into individual pieces after the film is adhered thereto in the adhering step,
• the metal film forming step further comprising forming the metal films for driving purpose on the metal films for mounting purpose in regions that will constitute the first mounting terminal and the second mounting terminal in continuity with the metal films for driving purpose in regions that will constitute the first driving electrode and the second driving electrode, wherein
• in the metal film forming step, a dividing groove is formed in each of the metal
• films for mounting purpose and the metal films for driving purpose on the metal films for mounting purpose in a manner that traverses a direction along the one of two pairs of opposing sides of the piezoelectric substrate, and
• the dividing groove divides the metal film for mounting purpose in part and the metal film for driving purpose to allow exposure of the solder-resistant metal film.