摘要:
A method of manufacturing a thin quartz crystal wafer from a quartz crystal block which is cut from a crystal body of synthetic quartz crystal and has a flat principal surface, comprises the steps of (a) converging a laser beam at a region in said quartz crystal block at a predetermined depth from the principal surface thereof to cause multiphoton phenomenon state, thereby breaking Si—O—Si bonds of quartz crystal in said region to form voids in said region, and (b) peeling said thin quartz crystal wafer from a body of said quartz crystal block along said voids. The above process is repeatedly performed on one quartz crystal block to peel off a plurality of thin quartz crystal wafers successively from the principal surface of the quartz crystal block. Each of the thin quartz crystal wafers is divided into individual quartz crystal blanks for making quartz crystal units.
摘要:
A tuning fork type quartz crystal unit has a base and a pair of arms extending from respective ends of the base in a crystallographic Y direction of quartz crystal. Each of the arms comprises a first crystal member and a second crystal member which extend in the Y direction. The first crystal member and the second crystal member are joined to each other in a crystallographic YZ plane by a direct bonding such that the first crystal member and the second crystal member have respective crystallographic X directions oriented away from each other and extending parallel to each other. Each of the arms has excitation electrodes disposed respectively on a pair of exposed surfaces thereof which lie in the YZ plane. The direct bonding comprises, for example, a siloxane bond by which the first crystal member and the second crystal member are joined to each other.
摘要:
Excitation electrodes are respectively affixed to central portions of both surfaces of a long plate-shaped AT-cut crystal resonator, the central portion starts a thickness shear oscillation in the length direction of the crystal resonator when an electric signal is applied to the central portion of the crystal resonator through the excitation electrodes. And, channel-shaped, half-circular-shaped, or trapezoid grooves in cross-section are respectively formed in the plate width direction on middle portions between the center portion and end portions of the crystal resonator. These grooves are formed so as to be symmetrical with respect to a thicknesswise central position of the crystal resonator through a well-known etching technique such as photo-etching and the like.
摘要:
A surface mount crystal unit comprising a crystal blank, a planar mounting substrate made of silicon and a cover having a shape with a recess and made of glass containing ions having high mobility. The mounting substrate and the cover are bonded by means of anode bonding and the crystal blank is hermetically sealed in a case made up of the mounting substrate and the cover. The mounting substrate has connection electrodes used for a connection with the crystal blank and external terminals to be used to surface-mount the crystal unit. The connection electrodes and external terminals are electrically connected.
摘要:
Excitation electrodes are respectively affixed to central portions of both surfaces of a long plate-shaped AT-cut crystal resonator, the central portion starts a thickness shear oscillation in the length direction of the crystal resonator when an electric signal is applied to the central portion of the crystal resonator through the excitation electrodes. And, channel-shaped, half-circular-shaped, or trapezoid grooves in cross-section are respectively formed in the plate width direction on middle portions between the center portion and end portions of the crystal resonator. These grooves are formed so as to be symmetrical with respect to a thicknesswise central position of the crystal resonator through a well-known etching technique such as photo-etching and the like.
摘要:
The nuclear fusion reactor of the present invention presents a new vacuum vessel for enclosing plasma particles where a reactor wall exposed to the above plasma particles has a piled structure. A plurality of heat-resisting ceramic tiles are metallurgically bonded to a metal-base body having a cooling means through a brazing material. The ceramic tiles are preferably composed of sintered silicon carbide of high density and containing a little beryllium oxide between the boundaries of crystal grains.
摘要:
A structure for fitting a fuel tank in an automotive vehicle comprises a rear floor panel fixed at a rear portion of the automotive vehicle, a rear seat cross member fixed to the under side of the rear floor panel across the automotive vehicle, a seat belt anchor fixing cross member fixed to the under side of the rear floor panel across the automotive vehicle, and a pair of bands suspended between the rear seat cross member and the seat belt anchor fixing cross member for supporting the fuel tank in position between the rear seat cross member and the seat belt anchor fixing cross member.
摘要:
A lighting apparatus for a vacuum apparatus that allows light to enter the inside of the vacuum apparatus through an observation window and makes it possible to see the inside of the vacuum apparatus through the observation window by illuminating the inside of the vacuum apparatus includes a coupling adapter that is removably coupled to the observation window via a coupling unit, an opening that is formed in a central part of the coupling adapter and allows the inside of the vacuum apparatus to be seen through the observation window, and a plurality of LEDs (light-emitting diodes) that are placed in the coupling adapter and face the observation window. The lighting apparatus is attached to the observation window for seeing the inside of the vacuum apparatus and illuminates the inside of the vacuum apparatus.
摘要:
A crystal element has a crystal blank which is cut from a crystal of quartz and has a principal plane orthogonal to a Y″-axis, where the Y- and Z-axes are rotated by an angle of α around the X-axis in the crystal to be designated as the Y′- and Z′-axes, and the X- and Y′-axes are rotated by an angle of β around the Z′-axis to be designated as the X′- and Y″-axes. The crystal blank has mutually orthogonal two null stress-sensitivity axes. In the crystal blank, the thickness of the center part at which two null stress-sensitivity axes intersect is increased, and a ridge line portion defining a quadrangular pyramid like shape from the center part toward the outer peripheral part is formed. The sectional thickness of the crystal blank along the base thereof is larger in the central region and becomes gradually smaller toward both ends.
摘要:
A crystal element has a crystal blank which is cut from a crystal of quartz and has a principal plane orthogonal to a Y″-axis, where the Y- and Z-axes are rotated by an angle of α around the X-axis in the crystal to be designated as the Y′- and Z′-axes, and the X- and Y′-axes are rotated by an angle of β around the Z′-axis to be designated as the X′- and Y″-axes. The crystal blank has mutually orthogonal two null stress-sensitivity axes. In the crystal blank, the thickness of the center part at which two null stress-sensitivity axes intersect is increased, and a ridge line portion defining a quadrangular pyramid like shape from the center part toward the outer peripheral part is formed. The sectional thickness of the crystal blank along the base thereof is larger in the central region and becomes gradually smaller toward both ends.