WISOL CO., LTD.

A bulk acoustic wave (BAW) package according to an embodiment of the present invention includes: a BAW filter including a substrate having at least one cavity on an upper surface thereof, a lower electrode formed above the substrate, a piezoelectric layer formed above the lower electrode, and an upper electrode formed above the piezoelectric layer; and a package structure formed above the BAW filter to protect the BAW filter, wherein the package structure includes a wall layer extending in a vertical direction to surround a peripheral portion of the BAW filter; a first roof layer having a plate-shaped structure formed in a horizontal direction on an upper portion of the wall layer; a second roof layer formed to surround a lateral portion of the wall layer and an upper portion of the first roof layer; and a redistribution layer formed on one side of the second roof layer to electrically connect the package structure and the BAW filter.

A bulk acoustic wave (BAW) package according to an embodiment of the present disclosure comprises a BAW filter including a substrate having at least one cavity on an upper surface thereof, a lower electrode formed above the substrate, a piezoelectric layer formed above the lower electrode, and an upper electrode formed above the piezoelectric layer; and a package structure formed above the BAW filter to protect the BAW filter, wherein the package structure comprises a roof layer including a passive element and a wall layer extending vertically along edges of the roof layer.

A dual-mode SAW resonator constituting a receiver filter according to the present invention includes a first resonator and a second resonator, each being comprised of a plurality of interdigital transducer (IDT) elements; a signal metal pattern connecting signal terminals formed on the plurality of IDT elements; a ground metal pattern connecting ground terminals formed on the above plurality of IDT elements; and a single insulating film configured to insulate the signal metal pattern from the ground metal pattern, wherein the first resonator and the second resonator are connected in series.

Provided is a duplexer connected to an antenna to receive and transmit signals in different frequency bands, the duplexer comprising a receiving filter and a transmission filter, wherein the receiving filter filters a low-frequency band of the same band being used and the transmission filter filters a high-frequency band of the same band, wherein the receiving filter comprises at least two or more series resonators connected in series; and two or more parallel resonators connected in parallel, respectively, to the series resonators, a first parallel resonator and a second parallel resonator, which constitute the parallel resonators, are sequentially connected closest to the antenna, and the second parallel resonator has a relatively higher resonant frequency than the first parallel resonator.

Provided is a method of manufacturing a piezoelectric substrate for SAW resonators with improved resonance characteristics and a piezoelectric substrate for SAW resonators manufactured by this method. The manufacturing method of a piezoelectric substrate for a SAW resonator includes preparing a laminated substrate, and heat-treating the laminated substrate to reduce the gas contained in at least one layer of the laminated substrate.

Provided is a resonator with a common reflector, and more specifically, to a resonator with a common reflector in a surface acoustic wave (SAW) device having multiple resonators, where a reflector of one resonator is shared with the reflector of another resonator. By forming a common reflector, the area required for resonator formation on the substrate can be reduced.

Disclosed is an acoustic resonator including a substrate including a first cavity, a first electrode formed above the substrate, a piezoelectric layer formed on one surface of the first electrode, and a second electrode formed on one surface of the piezoelectric layer. Here, the piezoelectric layer includes a longitudinal section not to cover a longitudinal section of the first electrode. Also, the second electrode covers the longitudinal section of the piezoelectric layer and extends to a first interpolar cavity which spaces the first electrode at least partially apart from the piezoelectric layer. A quality factor may be increased by fixing an increase in resistance which occurs due to thin film electrodes.

The present invention relates to a surface acoustic wave filter with connected bar pistons, the filter comprising: on a substrate where a support substrate, an energy confinement layer, and a piezoelectric layer are sequentially laminated, an IDT electrode unit including a first bus bar and a second bus bar extended in a first direction and spaced apart from each other in a second direction perpendicular to the first direction, and a plurality of first IDT electrodes and a plurality of second IDT electrodes alternately extended from the first bus bar and the second bus bar in the second direction, and spaced apart from each other in the first direction; and lower and upper bar pistons formed in a shape of a strip extended in the first direction to cover tips of the plurality of first IDT electrodes and the plurality of second IDT electrodes, wherein the upper bar piston and the lower bar piston are connected by bar piston connection units in an area excluding the IDT electrode unit.

Provided is a surface acoustic wave device and a method of manufacturing the same. The surface acoustic wave device includes: a semiconductor support substrate; a modified substrate surface layer formed on a surface of the support substrate; a low acoustic velocity layer formed on the modified substrate surface layer; a piezoelectric layer formed on the low acoustic velocity layer; and a plurality of IDT electrodes disposed on the piezoelectric layer, wherein surface roughness of one side of the modified substrate surface layer is 0.2nm or lower.

A film bulk acoustic resonator (FBAR) chip and package structure with improved power tolerance includes: a first substrate having a plurality of FBARs each having a bottom electrode, a piezoelectric material, and a top electrode, and first bonding pads connected to the bottom electrodes or the top electrodes of the FBARs; and a second substrate having a plurality of vias passing therethrough, second bonding pads located on one end surface of the vias facing the first substrate, and external connection pads located on the other end surface of the vias which does not face the first substrate, wherein the first substrate and the second substrate are bonded by means of bonding of the first bonding pads and the second bonding pads.