Monolithic piezoelectric transformer and method for manufacturing the same
AssigneeMurata Manufacturing Co., Ltd.
InventorsTakahiro Matto, Toshiaki Kaji, Toshio Imanishi
Life of this patent
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Abstract
A monolithic piezoelectric transformer includes a drive portion and a power generation portion. The drive portion includes a plurality of polarized piezoelectric ceramic layers and a plurality of internal electrodes that are alternately layered on each other. The drive portion is provided with external input electrodes connected to the internal electrodes. The power generation portion includes a piezoelectric ceramic member and an output electrode. The internal electrodes are formed of a fired metal containing at least one of silver and palladium and at least one of rhodium and iridium.
Claims20
A monolithic piezoelectric transformer having a plurality of integrally sintered piezoelectric ceramic layers, comprising:
- a drive portion including a plurality of the piezoelectric ceramic layers polarized in the layered direction, a plurality of internal electrodes alternately layered with the piezoelectric layers, and a pair of external input electrodes each of which is connected to different internal electrodes, and
- a power generation portion including a piezoelectric ceramic member polarized in the direction perpendicular to the layered direction and an output electrode,
- wherein the internal electrodes comprises a primary metal which is at least one of silver and palladium and a secondary metal at least one of rhodium and iridium.
A method for manufacturing a monolithic piezoelectric transformer, comprising
- firing a piezoelectric ceramic composite comprising a plurality of piezoelectric ceramic layer green sheets and at least two internal electrode paste layers comprising a primary metal which is at least one of silver and palladium and a secondary metal which is at least one of rhodium and iridium, each of paste layers being disposed between different interfaces of two adjacent green sheets;
- polarizing a portion the fired piezoelectric ceramic composite in the layered direction thereof to prepare a drive portion, and polarizing a portion the fired piezoelectric ceramic composite in the direction perpendicular to the layered direction to prepare a power generation portion;
- and
- connecting each member of a pair of external input electrodes to a different one of the fired internal electrode paste layers on the drive portion, and connecting an output electrode on the power generation portion.
A method for manufacturing a monolithic piezoelectric transformer, comprising
- applying an internal electrode paste containing a primary metal which is at least one of silver and palladium and a secondary metal which is at least one of rhodium and iridium onto at least two green sheets containing a piezoelectric ceramic material to form an internal electrode paste layer on each said green sheet;
- layering the green sheets with the internal electrode paste layer to prepare a piezoelectric ceramic composite;
- firing the piezoelectric ceramic composite;
- polarizing a portion the fired piezoelectric ceramic composite in the layered direction thereof to prepare a drive portion, and polarizing a portion the fired piezoelectric ceramic composite in the direction perpendicular to the layered direction to prepare a power generation portion;
- and
- forming a pair of external input electrodes each of which is connected to a different one of the internal electrodes, on the drive portion, and forming an output electrode on the power generation portion.
Dependencies are inferred from the claim text.