A crystal blank includes a pair of tableland-shaped first mesa parts projecting from a flat plate and a pair of tableland-shaped second mesa parts projecting from the pair of first mesa parts. The flat plate's length in a long direction is less than 1000 m. The first mesa part is on an inner side of the flat plate's major surface. The second mesa part is on the first mesa part's inner side of an upper surface's outer edge at two ends of the long direction and has a width equivalent to the first mesa part's upper surface at two sides of a short direction. An excitation electrode reaches the second mesa part's outer edge of the upper surface, is located on the inner side of the first mesa part, and on the second mesa part's inner side of the upper surface's outer edge at two sides of the short direction.

A microelectromechanical resonator device has: a main body, with a first surface and a second surface, opposite to one another along a vertical axis, and made of a first layer and a second layer, arranged on the first layer; a cap, having a respective first surface and a respective second surface, opposite to one another along the vertical axis, and coupled to the main body by bonding elements; and a piezoelectric resonator structure formed by: a mobile element, constituted by a resonator portion of the first layer, suspended in cantilever fashion with respect to an internal cavity provided in the second layer and moreover, on the opposite side, with respect to a housing cavity provided in the cap; a region of piezoelectric material, arranged on the mobile element on the first surface of the main body; and a top electrode, arranged on the region of piezoelectric material, the mobile element constituting a bottom electrode of the piezoelectric resonator structure.

Piezoelectric devices are described fabricated in packaging buildup layers. In one example, a package has a plurality of conductive routing layers and a plurality of organic dielectric layers between the conductive routing layers. A die attach area has a plurality of vias to connect to a microelectronic die, the vias connecting to respective conductive routing layers. A piezoelectric device is formed on an organic dielectric layer, the piezoelectric device having at least one electrode coupled to a conductive routing layer.

A rectangular quartz crystal blank having long sides substantially parallel to a Z axis of the quartz crystal blank, and short sides substantially parallel to an X axis of the quartz crystal blank. The quartz crystal blank includes a center region, a second region and a third region that are adjacent to the center region along a long-side direction, and a fourth region and a fifth region that are adjacent to the first region along a short-side direction. A thickness of the second region and a thickness of the third region are smaller than a thickness of the first region, and/or a thickness of the fourth region and a thickness of the fifth region are smaller than a thickness of the first region, and 25.90W/T27.17, where W is a length of a short side and T is a thickness.

The oscillating element includes a crystal blank, a pair of excitation electrodes, and a pair of pad portions. The crystal blank includes a pair of major surfaces, at least partially configured by crystal planes, and side surfaces which connect outer edges of the pair of major surfaces. Further, it includes a mesa portion and an outer peripheral portion which surrounds the mesa portion and has a thickness between the pair of major surfaces thinner than that of the mesa portion. The excitation electrodes are individually located on the pair of major surfaces. The pair of pad portions are located on one of the pairs of major surfaces and are electrically connected with the excitation electrodes. At least a portion of an edge part which is in contact with a crystal plane includes a projecting portion, which does not exceed the height of the mesa portion from the outer peripheral portion.

A crystal unit includes an AT-cut crystal element and a container. The AT-cut crystal element has an approximately rectangular planar shape. The AT-cut crystal element includes a first inclined portion, second inclined portions, and a first secured portion. The first inclined portion is inclined such that the crystal element decreases in thickness from a proximity of the first side to the first side. The second inclined portions are disposed on respective both ends of the first side, the second inclined portions being formed integrally with the first inclined portion. The second inclined portions are inclined gentler than the first inclined portion. The first secured portion and a second secured portion are formed integrally with the second inclined portion. The first secured portion and the second secured portion each project out from the first side to outside the crystal element to be used for securing with the securing members.

Piezoelectric devices are described fabricated in packaging buildup layers. In one example, a package has a plurality of conductive routing layers and a plurality of organic dielectric layers between the conductive routing layers. A die attach area has a plurality of vias to connect to a microelectronic die, the vias connecting to respective conductive routing layers. A piezoelectric device is formed on an organic dielectric layer, the piezoelectric device having at least one electrode coupled to a conductive routing layer.

A piezoelectric oscillator, and method of making the same, includes an oscillation substrate comprising an oscillating part and a surrounding part, wherein the surrounding part is thinner than the oscillating part, and oscillating electrodes disposed on an upper surface and a lower surface of the oscillating part. The oscillation substrate is configured according to H=400.59S+1.751.5, wherein H=100(T2/T1) and S=T2/(L1L2), wherein L1 represents an entire length of the oscillation substrate, L2 represents a length of the oscillating part, T1 represents a thickness of the oscillating part, and T2 represents a step height between the oscillating part and the surrounding part.

A vibrator group manufacturing method includes measuring resonance frequencies of first to n-th vibrators with respect to a vibrator group including the first to n-th vibrators arranged in a matrix, n being an integer of 2 or greater, and storing attachment information of the vibrator group in a storage device, the attachment information including identification information imparted to the vibrator group, pieces of first to n-th positional information indicating positions of the first to n-th vibrators, and pieces of first to n-th characteristic information based on measurement results of the resonance frequencies of the first to n-th vibrators.

Piezoelectric devices are described fabricated in packaging buildup layers. In one example, a package has a plurality of conductive routing layers and a plurality of organic dielectric layers between the conductive routing layers. A die attach area has a plurality of vias to connect to a microelectronic die, the vias connecting to respective conductive routing layers. A piezoelectric device is formed on an organic dielectric layer, the piezoelectric device having at least one electrode coupled to a conductive routing layer.