Abstract: An energy trapping piezoelectric device trapping a thickness vibration into projections which suppress a reflection of a vibration from end portions of electrodes provided substantially on a piezoelectric plate, and which suppress unnecessary spurious vibrations, low impedance and higher frequency, and a method of easily producing such a piezoelectric device are provided. The piezoelectric device has an energy trapping projection provided over a piezoelectric plate, and a top electrode is divided into a exciting electrode and dummy electrode. A small gap is provided between the divided electrodes, and the electrodes are electrically insulated from each other. The thickness vibration is not generally reflected, and vibrating energies due to the thickness vibrations are substantially trapped into the projections provided on the piezoelectric plate.

Abstract: A method of manufacturing a composite substrate and the composite substrate manufactured thereby wherein surfaces of first and second substrates having different thermal expansion coefficients are mirror finished and layered on each other. A first heat treatment is applied after which a part of the second substrate is removed to a depth sufficient to expose the first substrate. A final second heat treatment directly bonds the substrates.

Abstract: A piezoelectric device is manufactured by: (1) mirror finishing surfaces of a first substrate and a second substrate made of a piezoelectric element; (2) forming grooves on at least one of the two surfaces of the first and second substrates; (3) joining the mirror-finished surfaces of the first substrate and the second substrate; (4) applying heat to the joined substrates and bonding them; (5) forming an opening on the first substrate so that a part of the exposed areas of the second substrate is exposed through the opening; (6) forming piezoelectric devices by forming electrodes on at least one of the second substrate through the opening and a corresponding area to the exposed area on the rear side of the second substrate; and (7) dividing the bonded substrates into portions each having one of the piezoelectric devices. Through this manufacturing method, piezoelectric devices with high yield ratios and high reliability can be obtained.

Abstract: Integrated circuits utilizing piezoelectric elements can be advantageously constructed by bonding elements together via direct bonds. Such integrated circuits include an electro-acoustic hybrid integrated circuit such as a voltage controlled oscillator wherein a semiconductor substrate having an active element is bonded through direct bonding to a surface acoustic wave resonator or a quartz oscillator as an electro-acoustic element. A quartz device can also be provided which includes a quartz plate, excitation electrodes on opposite surfaces, and a holding member made of a material having a thermal expansion coefficient substantially equal to that of the quartz plate. The holding member is connected to the quartz plate by direct bonding without using any adhesives. Because the thermal expansion coefficients of the quartz plate and the holding member are equal, no thermal stress occurs in the bonding area.

Abstract: A method of manufacturing a composite substrate and the composite substrate manufactured thereby wherein surfaces of first and second substrates having different thermal expansion coefficients are mirror finished and layered on each other. A first heat treatment is applied after which a part of the second substrate is removed to a depth sufficient to expose the first substrate. A final second heat treatment directly bonds the substrates.

Abstract: Integrated circuits utilizing piezoelectric elements can be advantageously constructed by bonding elements together via direct bonds. Such integrated circuits include an electro-acoustic hybrid integrated circuit such as a voltage controlled oscillator wherein a semiconductor substrate having an active element is bonded through direct bonding to a surface acoustic wave resonator or a quartz oscillator as an electro-acoustic element. A quartz device can also be provided which includes a quartz plate, excitation electrodes on opposite surfaces, and a holding member made of a material having a thermal expansion coefficient substantially equal to that of the quartz plate. The holding member is connected to the quartz plate by direct bonding without using any adhesives. Because the thermal expansion coefficients of the quartz plate and the holding member are equal, no thermal stress occurs in the bonding area.

Abstract: The following steps are performed when processing electronic components such as piezoelectric devices. At Step 1 inter-atom bond is created between a functional member such as a quartz crystal plate and a first substrate, and the functional member and the quartz crystal plate are directly joined together. At Step 2, the functional member and a second substrate are fixed together with an adhesive agent or by a direct bond. At Step 3, the first substrate is removed chemically or mechanically, with said functional member and said second substrate still being joined together. A step of polishing said functional member for the adjustment of thickness thereof may be done between Step 1 and Step 2. For example, a silicon dioxide thin film may be provided between the functional member and the first substrate. Since no adhesive layer exists between the functional member and the first substrate, this improves the degree of plane of the functional member when joined to the first substrate.

Abstract: This invention relates to a process for manufacturing a spray urethane elastomer. More particularly it relates to a process for manufacturing a solventless, non-cellular spray urethane elastomer, which comprises spraying a partial prepolymer component having a high molar ratio of NCO/OH prepared from an organic polyisocyanate and from polytetramethylene ether glycol (PTMEG) having a molecular weight of 400 to 2000 and a resin component containing the PTMEG, a specified chain extender and an organobismuth compound catalyst onto a substrate by use of a two components high pressure spray machine.According to the present invention, spraying only of the stock solutions by use of the two components high pressure spray machine accomplishes coating and the stock solutions are cured in one second to ten and several seconds after being sprayed without producing cells even when thick-coated.