摘要:
Provided is a vitreous silica crucible for pulling silicon single crystals, which can melt a silicon raw material in a short time and improve production yield of silicon single crystals by temporal change of an opaque vitreous silica layer. The vitreous silica crucible includes an opaque vitreous silica layer(11) provided on an outer surface thereof and containing plural bubbles, and a transparent vitreous silica layer(12) provided on an inner surface and not containing bubbles substantially. The opaque vitreous silica layer(11) has a bubble diameter distribution in which the content of bubbles having a diameter of less than 40 μm is 10% or more and less than 30%, the content of bubbles having a diameter of 40 μm or more and less than 90 μm is 40% or more and less than 80%, and the content of bubbles having a diameter equal to or more than 90 μm is 10% or more and less than 30%. Relatively small bubbles contained in the opaque vitreous silica layer(11) contribute to the thermal conductivity of a crucible at an initial pulling stage, and relatively large bubbles contained in the opaque vitreous silica layer are expanded through a long-term pulling process to thereby largely contribute to the warmth retaining property of the crucible at a later pulling stage.
摘要:
A coil-type electronic component has a coil inside or on the surface of its base material and is characterized in that: the base material is constituted by a group of grains of a soft magnetic alloy containing iron, silicon and other element that oxidizes more easily than iron; the surface of each soft magnetic alloy grain has an oxide layer formed on its surface as a result of oxidization of the grain; this oxide layer contains the other element that oxidizes more easily than iron by a quantity larger than that in the soft magnetic alloy grain; and grains are bonded with one another via this oxide layer.
摘要:
A coil-type electronic component has a coil inside or on the surface of its base material wherein the base material in the coil-type electronic component is constituted by a group of grains of a soft magnetic alloy containing iron, silicon and other element that oxidizes more easily than iron; the surface of each soft magnetic alloy grain has an oxide layer formed on its surface as a result of oxidization of the grain; this oxide layer contains the other element that oxidizes more easily than iron by a quantity larger than that in the soft magnetic alloy grain; and grains are bonded with one another via this oxide layer. The coil-type electronic component can be produced at low cost and combines high magnetic permeability with high saturation magnetic flux density.
摘要:
A silica glass crucible having a sidewall portion and a bottom portion is provided with a first synthetic silica glass layer constituting an inner layer at least in the sidewall portion, a second synthetic silica glass layer constituting an inner layer at least in a region including a center of the bottom portion, and a natural silica glass layer constituting an outer layer in the sidewall portion and the bottom portion. A melting rate of the second synthetic silica glass layer with respect to a silicon melt is higher than that of the first synthetic silica glass layer. An aluminum concentration of the second synthetic silica glass layer is higher than that of the first synthetic silica glass layer.
摘要:
A vitreous silica crucible manufacturing apparatus includes a plurality of carbon electrodes configured to heat and melt raw material powder by arc discharge, and a value of a ratio R2/R1 of a diameter R2 of a front end of each of the carbon electrodes to a diameter R1 of a base end is set in a range of 0.6 to 0.8. Each carbon electrode has a diameter reduction portion formed at a front end position and reduced in diameter from a diameter R3 of a base end side to the diameter R2 of the front end. When a length of the diameter reduction portion is L1, the diameter of the front end is R2, the diameter of the base end is R1, an angle between the axis lines of the carbon electrodes is θ1, and X=(R1−R2)/2, a value of L1−(X/tan(θ1/2)) is set in a range of 50 to 150 mm.
摘要:
The purpose of the present invention is to provide a crucible which has high viscosity at high temperature, and can be used for a long time, and can be manufactured at low cost, and a method of manufacturing the same. The composite crucible 10 is characterized in the use of mullite (3Al2O3.2SiO2) as the basic material of the crucible. The composite crucible 10 has the crucible body 11 made of mullite material whose main component is alumina and silica, and a transparent vitreous silica layer 12 formed on the inner surface of the crucible body 11. The thickness of the transparent vitreous silica layer 12 is smaller than that of the crucible body 11. The crucible body 11 can be formed by the slip casting method, and the transparent vitreous silica layer 12 can be formed by the thermal spraying method.
摘要:
The present invention provides a vitreous silica crucible which can suppress buckling and sidewall lowering of the crucible without fear of mixing of impurities into silicon melt. According to the present invention, provided is a vitreous silica crucible for pulling a silicon single crystal, wherein a ratio I2/I1 is 0.67 to 1.17, where I1 and I2 are area intensities of the peaks at 492 cm−1 and 606 cm−1, respectively, in Raman spectrum of vitreous silica of the region having a thickness of 2 mm from an outer surface to an inner surface of a wall of the crucible.
摘要:
A vitreous silica crucible for pulling single-crystal silicon, which is formed of vitreous silica and has a bottomed cylindrical shape, wherein, in a liquid-level movement range in the inner surface of the crucible, ranging from a position corresponding to the liquid surface level of a silicon melt at the time of stating the pulling of single-crystal silicon to a position corresponding to the liquid surface level of a silicon melt at the time of finishing the pulling of single-crystal silicon, the concentration of an OH group included in the vitreous silica is higher in an erosion thickness portion of the inner surface of the crucible than that in the range lower than the liquid surface level which is positioned below the liquid-level movement range.
摘要:
A driving device, small in size and light in weight, is to stabilize the position of a surface-deforming element while reducing the effect of gravity thus enabling stable transfer and positioning. The driving device is structured to hold a movable member integrated with a piezoelectric vibrator and a lens by a shaft provided at a tip of a spring extended from an inner surface to center of a passageway. The shaft extends through an opening formed in a protrusion of the movable member. By a tensile force of the spring, the movable member at its outer periphery is pulled radially and held. When applying a voltage with a waveform changing sharply to the piezoelectric vibrator, the movable member flexes maximally upward or downward to have a reduced diameter and an increasing acceleration thereby making a movement. Then, when a frictional force increases, the protrusion is held at a point where the movable member moves. Because of being held by a tensile force, the effect of gravity decreases and hence the movable member is stabilized in position relative to a direction of transfer.
摘要:
A silica glass crucible causing fewer pinholes in silicon single crystals is provided by a method of preventing pinholes by performing the pulling up of a silicon single crystal while restraining the dissolution rate of the crucible inner surface to 20 μm/hr or less, using a silica glass crucible for the pulling up of silicon single crystals, wherein the area of crystalline silica formed by crystallization of amorphous silica is restricted to 10% or less of the crucible inner surface area, or the density of pits formed from open bubbles on the crucible inner surface is restricted to 0.01 to 0.2 counts/mm2.