Saw filter device and package for accommodating the same
AssigneeNRS Technologies Inc.
InventorsYoshihiro Takahashi, Tadaaki Tuda, Yasushi Yamamoto, Hiroshi Kawahara
Life of this patent
Estimating the term…
Abstract
A GND terminal 74 extends into a package 7, and the inwardly extending portion has a laterally extending portion (lateral portion) and a longitudinally extending portion (longitudinal portion). The lateral and longitudinal portions of the GND terminal 74 form an L-shaped metal portion 80 extending in a recess 78 of the package 7. When accommodating an SAW filter 100 in the package 7, the SAW package 100 is set in the recess 78 of the package 7 such that the back surface of the chip substrate is in contact with the L-shaped portion 80.
Claims32
A surface acoustic wave (SAW) filter device with a chip substrate of a piezoelectric material, comprising:
- a plurality of interdigital transducers accommodated in a plastic package;
- a terminal member connected to said plastic package, wherein said terminal member comprises a lateral extending portion recessed into said package which contacts the back surface of the chip substrate,
- wherein common potential means for providing a common potential in the interdigital transducers, charge neutralizing means for neutralizing charge generated on the chip substrate due to polarization, or charge escape means for causing escape of charge generated on the chip substrate due to polarization, is provided as electric discharge preventing means for preventing electric discharge among the plurality of interdigital transducers on the chip substrate.
An SAW filter device with comprising:
- a chip substrate of a piezoelectric material having a plurality of interdigital transducers and accommodated in a plastic package;
- and
- an electric discharge preventing means for preventing electric discharge among the plurality of interdigital electric patterns, wherein said electric discharge preventing means includes opposed portions of the interdigital transducers having non-sharp shapes.
A surface acoustic wave (SAW) filter device with a chip substrate of a piezoelectric material, comprising:
- a plurality of interdigital transducers and accommodated in a plastic package,
- wherein said plastic package comprises a terminal member comprises metal extending out of the package and extending into the package such as to form an L-shaped portion, the chip substrate being accommodated in the plastic package such that the back surface of the chip substrate is in contact with the L-shaped portion,
- wherein a first pattern as an extension of part of the interdigital transducers, a second pattern spaced apart from the first pattern and a dummy electrode pattern connected to the second pattern are formed on the front surface of the chip substrate as an electric discharge preventing means for preventing electric discharge among the plurality of interdigital electric patterns.
A package for accommodating a surface acoustic wave (SAW) filter formed on the front surface of a chip substrate, said package comprising:
- a plastic molding formed having a front surface, a back surface, an edge wall, and a central recess for receiving said SAW filter;
- and
- a plurality of terminals extending out of the package and extending into the package,
- wherein one of said terminals comprises an L-shaped portion and the back surface of said chip substrate contacts said L-shaped portion.
A surface acoustic wave (SAW) filter device with a chip substrate of a piezoelectric material, comprising:
- a plurality of interdigital transducers and accommodated in a plastic package, said plastic package comprising a terminal member made of metal extending out of the package and extending into the package such as to form an L-shaped portion, the chip substrate being accommodated in the plastic such that the back surface of the chip substrate is in contact with the L-shaped portion,
- wherein common potential means for providing a common potential in the interdigital transducers, charge neutralizing means for neutralizing charge generated on the chip substrate due to polarization, or charge escape means for causing escape of charge generated on the chip substrate due to polarization, is provided as electric discharge preventing means for preventing electric discharge among the plurality of interdigital transducers on the chip substrate.
A surface acoustic wave (SAW) device, comprising:
- a chip substrate having a front surface and a back surface and formed from a piezoelectric material;
- a plurality of interdigital transducers formed on the front surface of said chip substrate;
- a high resistivity thin film provided between the chip substrate and the interdigital transducers, wherein said high resistivity film prevents electric discharge among the plurality of interdigital transducers on the chip substrate;
- a plastic package receiving said SAW filter;
- and
- a plurality of terminal members connected to said plastic package,
- wherein one of said terminal members comprises a lateral extending portion recessed into said package which contacts the back surface of said chip substrate.
Dependencies are inferred from the claim text.