Abstract: A perpendicular magnetic recording (PMR) head is provided which records data in a PMR medium. The PMR head includes a main pole having an end portion disposed on an air bearing surface (ABS) that is opposite to the PMR medium; a return yoke spaced apart from the main pole; a sub-yoke starting from the other end portion and extending away from the PMR medium, so as to magnetically connect the main pole with the return yoke; and a coil disposed to enclose the sub-yoke.

Abstract: Provided is a magnetic memory device that uses a current induced switching (CID) method. The magnetic memory device that uses a CID method includes a lower electrode, a magnetic resistance structure that is formed on the lower electrode which comprises a free layer whose widths of two sides are varied, and an upper electrode formed on the magnetic resistance structure.

Abstract: Provided is a perpendicular magnetic recording head for high density recording. The perpendicular magnetic recording head includes a coil, a return pole, a sub-yoke, and a main pole. The main pole has a pole tip including a second end surface that is spaced a predetermined distance from the return pole and faces the perpendicular magnetic recording medium, and surrounding at least a portion of the first end surface.

Abstract: A perpendicular magnetic recording head and a method of manufacturing the same are provided. The perpendicular magnetic recording head includes a main pole, a return yoke, and a coil which generates a magnetic field such that the main pole may record information on a recording medium. The coil has a structure that surrounds the main pole in a solenoid shape.

Abstract: A resonator, a band-pass filter, and a duplexer are provided. In the resonator, a first electrode is formed of a nonmagnetic conductive material. A ferromagnetic fixed layer is disposed on the first electrode and has a magnetization direction which is fixed. A nonmagnetic conductive layer is disposed on the ferromagnetic fixed layer. A ferromagnetic free layer is disposed on the nonmagnetic conductive layer and has a magnetization direction which varies depending on an external magnetic field. A second electrode is disposed on the ferromagnetic free layer and comprises a nonmagnetic conductive material. The band-pass filter and the duplexer are configured using the resonator. The band-pass filter and the duplexer can operate in a high-frequency range and be miniaturized. The bandwidth of the band-pass filter and the duplexer can be adjusted and the band-pass filter and the duplexer can be formed in one body with an integrated circuit.

Abstract: The present invention relates to a WLP fabrication method capable of welding a lid wafer with a device wafer by using laser illumination. The WLP fabrication method can rapidly weld bonding metal strips of device and lid wafers with each other in order to couple the lid wafer with the device wafer while sealing an internal cavity from the outside without giving any thermal effect to a drive unit in the device wafer.

Abstract: An integrated filter including a film bulk acoustic resonator (FBAR) and a surface acoustic wave (SAW) resonator and a method of fabricating the integrated filter. The integrated filter includes: a substrate; a first electrode positioned in a predetermined first area on an upper surface of the substrate; a first piezoelectric layer positioned on the first electrode; a second electrode positioned on the first piezoelectric layer; a second piezoelectric layer positioned in a predetermined second area on the upper surface of the substrate; and at least one inter-digital transducer (IDT) electrode positioned on the second piezoelectric layer. The IDT electrode includes: a first IDT electrode formed in a comb structure on the second piezoelectric layer; and a second IDT electrode formed in a comb structure on the second piezoelectric layer so as to mesh with the first IDT electrode. The first and second piezoelectric layers are formed of an identical material.

Abstract: Disclosed herein is a film bulk acoustic resonator (FBAR), an FBAR based duplexer device, and a manufacturing method thereof, which a plurality of sacrificial layer units are formed on a substrate wafer so as to be spaced apart from one another at regular distances, and device functional portions are formed on the sacrificial layer units, respectively. The device functional portions have a piezoelectric layer unit and a plurality of electrodes. Then, side wall and roof of protective formed by the use of dry film. After hardening the dry film, the wafer is cut into a plurality of the wafer sections so as to contain the device functional portions, respectively.

Abstract: Disclosed herein is an FBAR based duplexer device and a manufacturing method thereof, which can achieve miniaturization, and reduction of a manufacturing cost and enhancement of a yield due to a simplified process. According to the present invention, first, a plurality of FBAR chips are prepared. Each of the FBAR chips includes a substrate, air gaps and piezoelectric layer unit; which are successively arranged, a plurality of electrode pads electrically connected to the piezoelectric layer unit, and bump balls formed on the electrode pads in a one to one ratio. Then, a duplexer substrate having a duplexing circuit is prepared, and a plurality of the FBAR chips come into contact with the duplexer substrate. In this state, they are reversed so that the substrates of the FBAR chips face upward, and the bump balls are bonded to the duplexer substrate.

Abstract: An FBAR device includes a substrate structure provided with an upper surface, a seed layer formed on the upper surface of the substrate structure and made of one selected from gold (Au) and titanium (Ti), and one or more acoustic resonant portions. Each of the acoustic resonant portions includes a lower electrode film formed on the seed layer and made of molybdenum (Mo), a piezoelectric layer formed on the lower electrode film and made of aluminum nitride (AlN), and an upper electrode film formed on the piezoelectric layer.

Abstract: Disclosed herein is an FBAR based duplexer device and a manufacturing method thereof, which can achieve miniaturization, and reduction of a manufacturing cost and enhancement of a yield due to a simplified process. According to the present invention, first, a plurality of FBAR chips are prepared. Each of the FBAR chips comprises a substrate, air gaps and piezoelectric layer unit, which are successively arranged, a plurality of electrode pads electrically connected to the piezoelectric layer unit, and bump balls formed on the electrode pads in a one to one ratio. Then, a duplexer substrate having a duplexing circuit is prepared, and a plurality of the FBAR chips come into contact with the duplexer substrate. In this state, they are reversed so that the substrates of the FBAR chips face upward, and the bump balls are bonded to the duplexer substrate.