Piezoelectric resonator device, manufacturing method for piezoelectric...

A piezoelectric vibration device comprising:

• a piezoelectric vibration plate where an excitation electrode is formed;
• and
• an upper lid member and a lower lid member that hermetically seal the excitation electrode,
• the upper lid member having a region on one main surface where the lower lid member is joined,
• the lower lid member having a region on one main surface where the upper lid member is joined and a region on the other main surface where an external member is joined,
• wherein a joining layer constituting a joining material is formed in each of the joining region of the upper lid member and the joining region of the lower lid member,
• the joining region of the upper lid member and the joining region of the lower lid member are joined to each other via the joining materials, and
• at least one of a substrate of the joining region of the upper lid member and a substrate of the joining region of the lower lid member has a roughened surface.

A manufacturing method for a piezoelectric vibration device comprising a piezoelectric vibration plate where an excitation electrode is formed, and an upper lid member and a lower lid member that hermetically seal the excitation electrode, the piezoelectric vibration plate having a region where the upper lid member is joined and a region where the lower lid member is joined on front and back main surfaces, the upper lid member having a region on one main surface where the piezoelectric vibration plate is joined, the lower lid member having a region on one main surface where the piezoelectric vibration plate is joined, wherein the joining region of the piezoelectric vibration plate and the joining region of the upper lid member are joined to each other via a joining material, and the joining region of the piezoelectric vibration plate and the joining region of the lower lid member are joined to each other via a joining material,

• the manufacturing method comprising:
• a metal film formation step of laminating a metal film constituted by at least two types of metals on at least one of a substrate of the joining region of the piezoelectric vibration plate, a substrate of the joining region of the upper lid member, and a substrate of the joining region of the lower lid member;
• a diffusion step of promoting metal diffusion inside the metal film by heat processing after the metal film formation step;
• and
• an etching step of roughening a surface of the substrate by performing wet etching with an etchant caused to penetrate into the metal film obtained after the diffusion step and thereby forming a large number of micropores in the surface of the substrate.

A method for etching a constituent member of a piezoelectric vibration device that has a region on at least one main surface where an external member is joined, the method comprising:

• a metal film formation step of laminating a metal film constituted by at least two types of metals on a substrate of the joining region of the constituent member;
• a diffusion step of promoting metal diffusion inside the metal film by heat processing after the metal film formation step;
• and
• an etching step of roughening a surface of the substrate by performing wet etching with an etchant caused to penetrate into the metal film obtained after the diffusion step and thereby forming a large number of micropores in the surface of the substrate.