Switchable and/or tunable filters, methods of manufacture and design structures are disclosed herein. The method of forming the filters includes forming at least one piezoelectric filter structure comprising a plurality of electrodes formed to be in contact with at least one piezoelectric substrate. The method further includes forming a micro-electro-mechanical structure (MEMS) comprising a MEMS beam in which, upon actuation, the MEMS beam will turn on the at least one piezoelectric filter structure by interleaving electrodes in contact with the piezoelectric substrate or sandwiching the at least one piezoelectric substrate between the electrodes.

A crystal resonator element 2 has excitation electrodes 23a, 23b formed on front and back main surfaces of a crystal resonator plate. Each of the excitation electrodes is made of a ternary alloy containing silver as a major component, a first additive, and a second additive. The first additive is a metal element having a lower sputtering yield than silver and being resistant to corrosion in an etching liquid. The second additive is an element for forming a solid solution with silver. Outer peripheries of the excitation electrodes are first additive-rich regions 9 in which the first additive is rich.

A crystal unit includes an AT-cut crystal element, excitation electrodes, extraction electrodes. The AT-cut crystal element has an approximately rectangular planar shape. The excitation electrodes are disposed on front and back of principal surfaces of the AT-cut crystal element. The extraction electrodes are extended from the excitation electrodes to a side of one side of the AT-cut crystal element via a side surface of the AT-cut crystal element. Assuming that an extraction angle of the extraction electrode from the principal surface to the side surface is defined as an angle with respect to an X-axis of a crystallographic axis of a crystal, the angle is equal to or greater than 59 degrees and equal to or less than 87 degrees.

A vibrator, a vibrating element and a method for producing the vibrating element may include vibrating piece having a central portion and a peripheral portion. The vibrator, the vibrating element and the method may further include a pair of excitation electrodes provided on a first side and a second side of a main surface of the central portion. The vibrator, the vibrating element and the method may further include a pair of connection electrodes provided on the peripheral portion and electrically connected to the pair of excitation electrodes. The vibrator, the vibrating element and the method may further include a substrate configured to be connected to the pair of connection electrodes via an electrically-conductive holding member interposed therebetween and configured to support the vibration element in an excitable manner.

A piezoelectric resonator unit comprises a first enclosure portion that includes a first principal surface portion and a substantially curtain-shaped portion which cooperate to define a first recessed portion. The first principal surface portion has a first flat principal surface and the substantially curtain-shaped portion surrounds the first principal surface when viewed from a normal direction to the first principal surface. A second enclosure portion has a flat second principal surface and cooperates with the first recessed portion to define an enclosure which houses a piezoelectric resonator. A brazing material joins a distal end of the first enclosure portion to the second enclosure portion to hermetically seal the enclosure. An inner peripheral surface of the substantially curtain-shaped portion includes a stepped portion that is defined by adjacent thicker and a thinner portions of the substantially curtain-shaped portion. A surface of the stepped portion is formed of a single material.

A crystal unit includes an AT-cut crystal element that has a planar shape in a rectangular shape and a part as a thick portion. The crystal element includes a first end portion, a first depressed portion, the thick portion, a second depressed portion, and a second end portion in an order from a side of one short side in viewing a cross section taken along a longitudinal direction near a center of the short side. The first depressed portion is a depressed portion disposed from the thick portion toward the first end portion side, depressed with a predetermined angle a and subsequently bulged, and connected to the first end portion. The second depressed portion is a depressed portion disposed from the thick portion toward the second end portion side, depressed with a predetermined angle b and subsequently bulged, and connected to the second end portion.

A quartz crystal device includes a crystal element, a container, a conductive adhesive having flexibility, first pillow portions, and a second pillow portion. The first pillow portions hold the crystal element floated from an inner bottom surface of the container at the proximities of the two positions. The second pillow portion opposes the crystal element at a proximity of a second side. The second side opposes the first side of the crystal element. A height of the first pillow portion is represented as h and a length of the first pillow portion in a direction perpendicular to the first side is represented as X1, where the h is 20 m to 50 m and the X1 is 150 m or less. The conductive adhesive covers at least a top surface and a side surface of the first pillow portion. The side surface is in a center side of the crystal element.

A piezoelectric resonator unit that includes a piezoelectric resonator, a substrate including a protruding portion, and a cap joined to the protruding portion. The piezoelectric resonator unit has a first relation of (W1+T1)w1<(W1+2T1), where, in a long-side sectional view, w1 is a width of an inside of an opening in the cap, T1 is a width of the protruding portion, and W1 is a width of the upper surface of the substrate between parts of the protruding portion; and has a second relation of (W2+T2)w2<(W2+2T2), where, in a short-side sectional view, w2 is a width of the inside of the opening in the cap, T2 is a width of the protruding portion, and W2 is a width of the upper surface of the substrate between parts of the protruding portion.

A crystal resonator element 2 has excitation electrodes 23a, 23b formed on front and back main surfaces of a crystal resonator plate. Each of the excitation electrodes is made of a ternary alloy containing silver as a major component, a first additive, and a second additive. The first additive is a metal element having a lower sputtering yield than silver and being resistant to corrosion in an etching liquid. The second additive is an element for forming a solid solution with silver. Outer peripheries of the excitation electrodes are first additive-rich regions 9 in which the first additive is rich.

Switchable and/or tunable filters, methods of manufacture and design structures are disclosed herein. The method of forming the filters includes forming at least one piezoelectric filter structure comprising a plurality of electrodes formed to be in contact with at least one piezoelectric substrate. The method further includes forming a micro-electro-mechanical structure (MEMS) comprising a MEMS beam in which, upon actuation, the MEMS beam will turn on the at least one piezoelectric filter structure by interleaving electrodes in contact with the piezoelectric substrate or sandwiching the at least one piezoelectric substrate between the electrodes.