Abstract: An ultrasonic transducer includes: a first electrode layer disposed on an upper substrate and a support; a second electrode layer which is disposed on a lower surface of the upper substrate and is separated from the first electrode layer; an upper electrode disposed on an upper surface of a membrane to contact an upper surface of the first electrode layer; a trench formed through the upper electrode, the membrane, the support, and the upper substrate; and a pad substrate disposed under the upper substrate and including bonding pads that electrically connect to the first and second electrode layers, respectively.

Abstract: An ultrasonic transducer and a method of manufacturing the same are disclosed. The ultrasonic transducer includes a first electrode layer which is disposed to cover a conductive substrate and an inner wall and a top of a via hole penetrating a membrane and has a top surface at a same height as a top surface of the membrane; a second electrode layer which is disposed on a bottom surface of the conductive substrate to be spaced apart from the first electrode layer; and a top electrode which is disposed on the top surface of the membrane and which contacts the top surface of the first electrode layer.

Abstract: A shadow mask, a method of manufacturing the shadow mask, and a method of forming a thin film using the shadow mask are provided. The shadow mask includes an upper layer and a lower layer. The upper layer includes a first opening. The lower layer is formed on a lower surface of the upper layer around the first opening and includes an opening having the same size as the first opening. When the thin film is formed using the shadow mask, the lower layer of the shadow mask is close to the edge of a cavity of a substrate, and a position on which the thin film may be formed as defined by the lower layer of the shadow mask. Therefore, the thickness of the thin film can be uniform.

Abstract: A piezoelectric microspeaker fabricated by a method including: forming a lower drive unit by forming a first drive electrode by depositing and etching a first thin conductive layer on a substrate, forming a first piezoelectric plate by depositing and etching a first piezoelectric layer on the first drive electrode, and forming a first common electrode by depositing and etching a second conductive layer on the first piezoelectric plate; after forming the lower drive unit, forming a diaphragm by depositing a non-conductive layer on the first common electrode; and forming an upper drive unit by forming a second common electrode by depositing and etching a third conductive layer on the diaphragm, forming a second piezoelectric plate by depositing and etching a second piezoelectric layer on the second common electrode, and forming a second drive electrode by depositing and etching a fourth conductive layer on the second piezoelectric plate.

Abstract: Provided are a piezoelectric micro speaker and a method of manufacturing the same. The piezoelectric micro speaker includes: a substrate having a cavity therein; a diaphragm that is disposed on the substrate, the diaphragm including a vibrating membrane that overlaps the cavity; a piezoelectric actuator that is disposed on the vibrating membrane; and a weight that is disposed in the cavity and attached to a center portion of the vibrating membrane.

Abstract: A piezoelectric micro speaker and a method of manufacturing the same are provided. The piezoelectric micro speaker includes a device plate, a front plate bonded on a front surface of the device plate, and a rear plate bonded on a rear surface of the device plate. The device plate includes a diaphragm, a piezoelectric actuator that vibrates the diaphragm, and a front cavity disposed in front of the diaphragm. The front plate includes a radiation hole connected to the front cavity. The rear plate includes a rear cavity formed in a surface of the rear plate facing the piezoelectric actuator, and a bent hole connected to the rear cavity. A sound absorption layer is formed on an inner surface of the rear cavity and absorbs sound radiated backward from the diaphragm so as to suppress the sound from being reflected on the rear plate.

Abstract: A piezoelectric micro speaker and a method of manufacturing the same are provided. The piezoelectric micro speaker includes a substrate having a cavity formed therein and a diaphragm that is disposed on the substrate that overlaps the cavity. A plurality of first vibrating membranes having concentric annular ring shapes are disposed in a first region of the diaphragm corresponding to a center of the cavity. A second vibrating membrane including a different material from that of the first vibrating membranes is formed in the second region of the diaphragm corresponding to an edge of the cavity. A piezoelectric actuator for vibrating the first vibrating membranes is formed on and between the concentric annular rings of the first vibrating membranes.

Abstract: An ultrasonic transducer structure, an ultrasonic transducer, and a method of manufacturing the ultrasonic transducer are provided. The ultrasonic transducer structure includes a driving wafer that includes a driving circuit; and an ultrasonic transducer wafer that is disposed on the driving wafer and includes a first wafer in which a via-hole is formed, a first insulating layer formed on the first wafer, a second wafer spaced apart from the first insulating layer, and a cavity formed between the first insulating layer and the second wafer.

Abstract: A micro speaker includes a substrate having a cavity formed therein, a diaphragm formed on the substrate overlapping the cavity. The diaphragm includes a first vibration membrane formed in a first area corresponding to a center portion of the cavity and a second vibration membrane formed in a second area corresponding to an edge portion of the cavity and formed of material different from that used for the first vibration membrane. A piezoelectric actuator is formed including a first electrode layer formed on the first vibration membrane, a piezoelectric layer formed on the first electrode layer, and a second electrode layer formed on the piezoelectric layer, and first and second curved lead wires, respectively connected to the first and second electrode layers across the second area, which are symmetrical to the center of the piezoelectric actuator.

Abstract: An ultrasonic transducer and a method of manufacturing the same. The ultrasonic transducer includes a substrate, a supporting unit that is disposed on the substrate and comprises a through-hole, a thin-film disposed over the substrate in a region corresponding to the through-hole, wherein the thin-film is separated from the substrate and the supporting unit, and a connection unit that connects the supporting unit to the thin-film. In the method of manufacturing the ultrasonic transducer, a plurality of SOI wafers and a Si wafer are bonded without performing an aligning process.

Abstract: Provided are a piezoelectric micro-acoustic transducer and a method of fabricating the same. In the piezoelectric micro-acoustic transducer, a diaphragm is divided into a first region and a second region. The first region may be formed of a material capable of maximizing the exciting force, and the second region may be formed of a material having less initial stress and a lower Young's modulus than the first region. Also, the second region has a corrugated shape.

Abstract: Provided are a piezoelectric microspeaker and a method of fabricating the same. In the piezoelectric microspeaker, a diaphragm includes a first region and a second region. The first region may be formed of a material capable of maximizing an exciting force, and the second region may be formed of a material having less initial stress and a lower Young's modulus than the first region.

Abstract: Provided is a piezoelectric micro speaker. The piezoelectric micro speaker includes a device plate having a front cavity, a front plate having a radiation hole which communicates with the front cavity in front of the device plate, and a rear plate having a rear cavity and a vent portion. A rear portion of the device plate forms a wall of the vent portion. The device plate includes at least one first vent hole which communicates with the vent portion, and the front plate includes at least one second vent hole which communicates with the first vent hole.

Abstract: A method for fabricating a micro speaker is provided, including forming a package wafer and a device wafer by batch processing, bonding the package wafer and the device wafer to each other, and forming a diaphragm by isotropic-etching a back surface of the device wafer using a xenon difluoride (XeF2). As a result, a micro-electronic-mechanic system (MEMS) technology-based piezoelectric micro speaker having a wide frequency response range is realized, by batch processing, thereby providing simplified structure and processing and reducing fabricating cost.

Abstract: Provided are a piezoelectric acoustic transducer and a method of fabricating the same. In the piezoelectric acoustic transducer, a piezoelectric portion is formed in a portion of a diaphragm, and a deformation layer is formed in another portion of the diaphragm. Deformation of the piezoelectric portion is transferred to the deformation layer, or deformation of the deformation layer is transferred to the piezoelectric layer so that the deformation layer vibrates with the piezoelectric layer.

Abstract: An acoustic transducer includes a first driving unit group including at least one electrode and a second driving unit group including at least one electrode. The first driving unit group is driven at a first phase, and the second driving unit group is driven at a second phase that is different from the first phase.

Abstract: A cell of an ultrasonic transducer is provided. The cell includes a substrate; a supporting portion disposed on the substrate; a thin film spaced apart from the substrate and the supporting portion; and a connection portion which connects the supporting portion and the thin film. The connection portion may include a deformation portion that is elastically deformable. A channel of the ultrasonic transducer includes a plurality of cells arranged in an array. The ultrasonic transducer includes a plurality of channels arranged in an array.

Abstract: A piezoelectric microspeaker and a method of fabricating the same are provided. The piezoelectric microspeaker includes a substrate having a through hole therein; a diaphragm disposed on the substrate and covering the through hole; and a plurality of piezoelectric actuators including a piezoelectric member, a first electrode, and a second electrode, wherein the first and second electrodes are configured to induce an electric field in the piezoelectric member. The piezoelectric actuators include a central actuator, which is disposed on a central portion of the diaphragm and a plurality of edge actuators, which are disposed a predetermined distance apart from the central actuator and are formed on a plurality of edge portions of the diaphragm.

Abstract: Provided are a piezoelectric micro-acoustic transducer and a method of fabricating the same. In the piezoelectric micro-acoustic transducer, a diaphragm is divided into a first region and a second region. The first region may be formed of a material capable of maximizing the exciting force, and the second region may be formed of a material having less initial stress and a lower Young's modulus than the first region. Also, the second region has a corrugated shape.

Abstract: Provided is a piezoelectric micro speaker. The piezoelectric micro speaker includes a device plate having a front cavity, a front plate having a radiation hole which communicates with the front cavity in front of the device plate, and a rear plate having a rear cavity and a vent portion. A rear portion of the device plate forms a wall of the vent portion. The device plate includes at least one first vent hole which communicates with the vent portion, and the front plate includes at least one second vent hole which communicates with the first vent hole.