摘要:
In the electrode of a surface acoustic wave apparatus, the element concentration of copper in the aluminum alloy film is higher in the neighbors of grain boundary than the concentration within the crystal grain, and segregates to the neighbors of crystal grain boundary. In the electrode of this surface acoustic wave apparatus, the concentration of copper existing in the form of copper element, rather than in the form of intermetallic compound of copper and aluminum precipitated to the crystal grain boundary, is higher in the crystal grain boundary than the concentration within the crystal grain, and is in the segregation state. A ratio of a copper concentration in the neighbors of grain boundary to a copper concentration within the crystal grain in an aluminum alloy film forming an electrode of a surface acoustic wave apparatus is greater than 1.6. It is preferable that an electrode formed on a surface of the piezoelectric substrate is made of an aluminum alloy film doped with a copper in a range from 0.5 wt % to 2 wt %.
摘要:
A surface acoustic wave device includes a piezoelectric substrate having Al or Al alloy electrodes formed on a surface of the substrate, a metal oxide film provided on the substrate and the electrodes. The metal oxide film is formed by a process including depositing a metal thin film having a thickness sufficiently thin so that the deposited metal thin film is discontinuous including voids, and oxidizing the discontinuous metal thin film, and the metal oxide film includes a continuous portion without voids covering the electrodes.
摘要:
The surface acoustic wave device of the invention comprises a piezoelectric substrate made up of 64° rotated Y-cut lithium niobate (64LN) or 36° rotated Y-cut lithium tantalate (36LT) and an interdigital electrode formed thereon. The interdigital electrode comprises a titanium buffer metal film and an aluminum film formed thereon. On the 64LN substrate, both the titanium buffer metal film and the aluminum film are converted into a single-crystal film that manifests itself in a spot form alone upon selected-area electron diffraction. By forming the aluminum film on the 36LT substrate with the titanium buffer metal film located therebetween, it is possible to obtain a high-orientation, polycrystalline aluminum film oriented in the (111) direction. The aluminum film is made up of a single-crystal film or a high-orientation polycrystalline film oriented in the (111) direction, whereby migration of aluminum atoms is inhibited, resulting in a power-durability improvement.
摘要:
An object of the invention is to provide a SAW device having an electrode film on a lithium tantalate substrate having a cut angle approximate to 36 degree rotated Y cut, the electrode film including an aluminum single crystal film having improved power durability. The SAW device has interdigital electrodes on a substrate. The substrate is constructed of a 38 to 44 degree rotated Y cut lithium tantalate single crystal, each interdigital electrode includes a titanium film and an aluminum film formed thereon, and the aluminum film is a single crystal film which develops only spots on selected area electron diffraction analysis.
摘要:
In a surface acoustic wave element according to an embodiment of this invention, raised electrodes 20 formed on thin film electrodes 18 are provided with throughholes 31. Additionally, bumps 26 arranged on the raised electrodes 20 reach the thin film electrode 18 by going through an oxide film 18a of the thin film electrodes 18 after part of the bumps enters the throughholes 31 of the raised electrodes 20. By doing this, conduction is achieved between the thin film electrodes 18 and the bumps 26 formed on a piezoelectric monocrystal substrate 28. Thus, a solid oxide film 18a is formed on the surface of the thin film electrodes 18 formed from monocrystal aluminum, but part of the bumps 26 which enters the throughholes 31 of the raised electrodes 20 goes through this oxide film 18a, so conduction between the thin film electrode 18 and the bump 26 is achieved with higher accuracy.
摘要:
A basic portion layer 21 of a substrate electrode 12a connected to a projecting electrode 13 electrically and mechanically on a substrate member of ceramics. The substrate member on which the basic portion layer 21 is formed is subjected to sintering. A surface of the basic portion layer 21 in the sintered substrate member is polished. On the polished basic portion layer 21, the plating layers 22, 23. are formed, so that surface roughness of the substrate electrode 12a may be, for example, not larger than 0.1 μmRMS Accordingly, junction strength of an integrated circuit element mounted on a packaging substrate by a flip-chip method can be improved.
摘要:
A basic portion layer 21 of a substrate electrode 12a connected to a projecting electrode 13 electrically and mechanically on a substrate member of ceramics. The substrate member on which the basic portion layer 21 is formed is subjected to sintering. A surface of the basic portion layer 21 in the sintered substrate member is polished. On the polished basic portion layer 21, the plating layers 22, 23are formed, so that surface roughness of the substrate electrode 12a may be, for example, not larger than 0.1 μmRMS. Accordingly, junction strength of an integrated circuit element mounted on a packaging substrate by a flip-chip method can be improved.
摘要:
A basic portion layer 21 of a substrate electrode 12a connected to a projecting electrode 13 electrically and mechanically on a substrate member of ceramics. The substrate member on which the basic portion layer 21 is formed is subjected to sintering. A surface of the basic portion layer 21 in the sintered substrate member is polished. On the polished basic portion layer 21, the plating layers 22, 23 are formed, so that surface roughness of the substrate electrode 12a may be, for example, not larger than 0.1 μmRMS. Accordingly, junction strength of an integrated circuit element mounted on a packaging substrate by a flip-chip method can be improved.
摘要:
In a surface acoustic wave element according to an embodiment of this invention, raised electrodes 20 formed on thin film electrodes 18 are provided with throughholes 31. Additionally, bumps 26 arranged on the raised electrodes 20 reach the thin film electrode 18 by going through an oxide film 18a of the thin film electrodes 18 after part of the bumps enters the throughholes 31 of the raised electrodes 20. By doing this, conduction is achieved between the thin film electrodes 18 and the bumps 26 formed on a piezoelectric monocrystal substrate 28. Thus, a solid oxide film 18a is formed on the surface of the thin film electrodes 18 formed from monocrystal aluminum, but part of the bumps 26 which enters the throughholes 31 of the raised electrodes 20 goes through this oxide film 18a, so conduction between the thin film electrode 18 and the bump 26 is achieved with higher accuracy.
摘要:
An SAW element 11 comprises a first wiring section 20 formed between an input terminal 18 and an output terminal 19, a plurality of first SAW resonators 15 which are located in serial to the first wiring section 20, a plurality of second SAW resonators 16 which are located in serial to the first wiring section 20 at the side of the input terminal 18 or at the side of the output terminal 19 with respect to the first SAW resonators 15, a plurality of second wiring section 22 which are formed between an intermediate point of the second SAW resonators 16 each other in the first wiring section 20 and a reference voltage electrode 21, and a plurality of third SAW resonators 17 which are located in the second wiring section 22, respectively, and which have anti-resonant frequencies corresponding with resonant frequencies of the second SAW resonators 16.