Piezoelectric device and MEMS device

An MEMS device, comprising:

• a first substrate on which an MEMS element is disposed and a first electrode coupled to the MEMS element is provided on a first surface, wherein the first substrate is provided with a plurality of the first electrodes;
• a second substrate that has a second surface provided with a second electrode configured to be coupled to a control circuit, wherein the second substrate is provided with a plurality of the second electrodes corresponding to the plurality of the first electrodes;
• a third substrate that has a third surface disposed between the first substrate and the second substrate and bonded to the first surface of the first substrate, and a fourth surface facing the second surface of the second substrate, wherein
• the third substrate has a through hole passing through from the third surface to the fourth surface, and a third electrode provided in the through hole and coupled to the first electrode,
• the third substrate is provided with a plurality of the through holes and a plurality of the third electrodes corresponding to the plurality of the first electrodes, and each one of the third electrodes is coupled to each one of the second electrodes, and
• the second electrode is coupled to the third electrode and is electrically coupled to the first electrode via the third electrode;
• and
• a wall portion that partitions between adjacent ones of the second electrodes is provided between the second substrate and the third substrate.

A piezoelectric device, comprising:

• a first substrate that includes a first surface on which a piezoelectric element and a first electrode coupled to the piezoelectric element are disposed;
• a second substrate that includes a second surface on which a second electrode configured to be coupled to a control circuit is disposed;
• a third substrate that is disposed between the first substrate and the second substrate, and includes a third surface bonded to the first surface and a fourth surface facing the second surface, wherein
• the second substrate includes a first region in which the third substrate and the first substrate are stacked, and a second region that surrounds the first region at an outer side of the first region,
• the third substrate has a through hole passing through from the third surface to the fourth surface, and a third electrode provided in the through hole and coupled to the first electrode, and
• the second electrode is coupled to the third electrode and is electrically coupled to the first electrode via the third electrode;
• and
• a tubular portion that protrudes in a stacking direction in which the third substrate and the first substrate are stacked is provided in the second region of the second substrate, and the second substrate and the third substrate are disposed in a tube of the tubular portion.