摘要:
A surface acoustic wave device includes a substrate including lithium niobate; a IDT being provided on an upper surface of the substrate and including a plurality of electrode fingers; and a protective film covering the IDT and having an uneven shape on an upper surface thereof. When a pitch width of one pitch of the IDT is p, a width of one of the electrode fingers is p1, a width between the electrode fingers is p2, and a thickness of the IDT is h, following relations are satisfied, p1+p2=p, and h/(2×p)≧4.5%. With this configuration, an appropriate reflection characteristic is realized, and the surface acoustic wave device having excellent temperature coefficient of frequency and electrical characteristic can be obtained.
摘要:
A surface acoustic wave device includes a substrate including lithium niobate; a IDT being provided on an upper surface of the substrate and including a plurality of electrode fingers; and a protective film covering the IDT and having an uneven shape on an upper surface thereof. When a pitch width of one pitch of the IDT is p, a width of one of the electrode fingers is p1, a width between the electrode fingers is p2, and a thickness of the IDT is h, following relations are satisfied, p1+p2=p, and h/(2×p)≧4.5%. With this configuration, an appropriate reflection characteristic is realized, and the surface acoustic wave device having excellent temperature coefficient of frequency and electrical characteristic can be obtained.
摘要:
A plurality of surface acoustic wave resonators including a comb electrode and a grating reflector are coupled on a piezoelectric substrate. Dielectric film is formed on the surface of at least one surface acoustic wave resonator. No dielectric film is formed on the surface of at least one other surface acoustic wave resonator. Thus, a SAW filter where the insertion loss into a pass band is small, the steepness is sufficient, and the band is wide can be obtained.
摘要:
An electronic part, an object of which is to improve temperature characteristics and electrical properties, includes a substrate (1), a comb-type electrode (2) that is disposed on the upper surface of the substrate (1), and a protective film (4) that covers the comb-type electrode (2) and has an uneven shape at its top surface. If the pitch width of one pitch in the uneven shape of the protective film (4) is L, the width of one pitch of a convex portion (4a) of the unevenness in the uneven shape of the protective film (4) is L1, the width of one pitch of a concave portion (4b) thereof is L2, the pitch width of one pitch of the comb-type electrode (2) is p, the width of one of electrode fingers which form the comb-type electrode (2) is p1 and the width between the electrode fingers is p2, then each parameter is set so that the following expressions are satisfied, L1≦p1 and L2≧p2 (herein, the correlations of L≈p, p1+p2=p and L1+L2=L are satisfied).
摘要:
A surface acoustic wave device includes a piezoelectric element, an IDT electrode formed on the piezoelectric element for exciting a principal wave, a reflection film formed on the piezoelectric element having a higher reflectivity than the reflectivity of the piezoelectric element in a visible light wavelength region, and a light permeable dielectric layer formed on the piezoelectric element, at least a part of the IDT electrode, and the reflection film. Accordingly, when measuring the film thickness of the light permeable dielectric layer by light interference method, the reflected light from the reflection film having a higher reflectivity than the reflectivity of the piezoelectric element in a visible light wavelength region can be utilized, so that the film thickness can be measured more accurately.
摘要:
The present invention provides a surface acoustic wave resonator capable of improving a leak of a surface acoustic wave in the transverse direction and reducing the spurious and having superior characteristics. In a surface acoustic wave filter according to the present invention, an interdigital transducer electrode and reflector electrodes are formed on a piezoelectric substrate, and a SiO2 thin film is formed on at least a portion of the interdigital transducer electrode. The interdigital transducer electrode includes a bus-bar electrode region, a dummy electrode region and a finger overlap region, such that the SiO2 thin film is removed from upper sections of the bus-bar electrode regions of the interdigital transducer electrode.
摘要:
A surface acoustic wave device includes a piezoelectric element, an IDT electrode formed on the piezoelectric element for exciting a principal wave, a reflection film formed on the piezoelectric element having a higher reflectivity than the reflectivity of the piezoelectric element in a visible light wavelength region, and a light permeable dielectric layer formed on the piezoelectric element, at least a part of the IDT electrode, and the reflection film. Accordingly, when measuring the film thickness of the light permeable dielectric layer by light interference method, the reflected light from the reflection film having a higher reflectivity than the reflectivity of the piezoelectric element in a visible light wavelength region can be utilized, so that the film thickness can be measured more accurately.
摘要:
The present invention provides a surface acoustic wave resonator capable of improving the leak of a surface acoustic wave in the transverse direction and reducing the spurious and having superior characteristics. In a surface acoustic wave filter according to the present invention, an interdigital transducer electrode and reflector electrodes are formed on a piezoelectric substrate, and a SiO2 thin film is further formed thereon. The interdigital transducer electrode includes a bus-bar electrode region, a dummy electrode region and a finger overlap region, and the SiO2 thin film is removed from upper sections of the bus-bar electrode regions in the interdigital transducer electrode.
摘要:
A plurality of surface acoustic wave resonators (15through 20) including a comb electrode and a grating reflector are coupled on piezoelectric substrate (12). Dielectric film (14) is formed on the surface of at least one surface acoustic wave resonator, of surface acoustic wave resonators (15 through 20). No dielectric film (14) is formed on the surface of at least another surface acoustic wave resonator. Thus, an SAW filter where the insertion loss into a band is small, the steepness is sufficient, and the band is wide can be obtained.
摘要:
An elastic wave element includes a piezoelectric substrate, an interdigital electrode provided on the piezoelectric substrate, a silicon oxide film covering the interdigital electrode, and a silicon nitride oxide film provided on the silicon oxide film. A film thickness H of the silicon oxide film and a wave length λ of an elastic wave propagating through the piezoelectric substrate satisfies a relation of H/λ≧0.15. The elastic wave element reduces fluctuation of propagation characteristics of elastic waves, and has high reliability.