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AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsRyouichi Takayama, Mitsuhiro Furukawa, Yuji Murashima, Toru Sakuragawa, Koji Nomura
Estimating the term…
As the electrode material of a surface acoustic wave device, a laminated body laminating a second metal layer 5 on a first metal layer 4 is stacked up in two or more stages, and the first metal layer 4 is a metal of which coefficient of diffusion to Al is smaller than the coefficient of self diffusion of Al, and the second metal layer 5 is composed of an Al alloy of three elements or more containing at least one or more metals which forms solid solution with Al at ordinary temperature, and at least one or more metals forming segregation at the grain boundary of Al or an intermetallic compound with Al at ordinary temperature, and therefore the surface acoustic wave device excellent in electric power tolerance, compatible with the conventional pattern forming technology, stable thermally, and capable of preventing increase of insertion loss can be obtained.
A surface acoustic wave device having an electrode, said electrode comprising at least two laminated bodies, each laminated body having a second metal layer stacked up on a first metal layer, wherein said at least two laminated bodies are stacked on a substrate, wherein the first metal layer is composed of a metal of which coefficient of diffusion to Al is smaller than the coefficient of self diffusion of Al, and the second metal layer is composed of an Al alloy comprising at least three elements, said at least three elements including at least one metal which forms solid solution with Al at ordinary temperature, and said at least three elements farther including one from the group consisting of at least one metal forming segregation all the grain boundary of Al in said Al alloy or forming an intermetallic compound with Al in said Al alloy at ordinary temperature.
A surface acoustic wave device having an electrode comprising at least one laminated body, said at least one laminated body including a first metal layer having a first and second side, a second metal layer, and a third metal layer, said second metal layer disposed on said first side of said first metal layer and said third metal layer disposed on said second side of said first metal layer, said laminated body disposed on a substrate, wherein the second metal layer and third metal layer are each composed of an Al alloy comprising at least three elements, said at least three elements including at least one metal which forms solid solution with Al at ordinary temperature, and said at least three elements further including one from the group consisting of at least one metal forming segregation at the grain boundary of Al in said Al alloy or forming an intermetallic compound with Al in said Al alloy at ordinary temperature, and the first metal layer is composed of a metal of which coefficient of diffusion to Al is smaller than the coefficient of self diffusion of Al.
A surface acoustic wave device having an electrode comprising at least one laminated body, said at least one laminated body including a first metal layer having a first and second side, a second metal layer, and a third metal layer, said second metal layer disposed on said first side of said first metal layer and said third metal layer disposed on said second side of said first metal layer, said laminated body disposed on a substrate, wherein the second metal layer is composed of an Al alloy comprising at least three elements, said at least three elements including at least one metal which forms solid solution with Al at ordinary temperature, and said at least three elements further including one from the group consisting of at least one metal forming segregation at the grain boundary of Al or forming an intermetallic compound with Al at ordinary temperature, and the first metal layer is composed of a metal of which coefficient of diffusion to Al is smaller than the coefficient of self diffusion of Al, said third metal layer is located farther from said substrate than said second metal layer, wherein said third metal layer is lower in sheet resistance than said second metal layer, said third metal layer is composed of an Al alloy of at least two elements different in type or composition from the Al alloy forming said second metal layer.
Dependencies are inferred from the claim text.