Conveyors: fluid current – Pulsing fluid current
Reexamination Certificate
2000-08-11
2001-12-04
Ellis, Christopher P. (Department: 3651)
Conveyors: fluid current
Pulsing fluid current
C227S114000, C221S162000, C221S202000, C221S217000
Reexamination Certificate
active
06325571
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for conveying particulate objects between steps to process particulate objects, e.g., particulate polycrystalline silicon, used in manufacturing spherical semiconductor devices.
2. Description of the Related Art
Hitherto, normally, to form semiconductor devices, a method of forming a circuit pattern on a silicon wafer and dicing it as required for forming chips has been adopted. In recent years, an art of forming a circuit pattern on a ball semiconductor of spherical single crystal silicon, etc., having a diameter of 1 mm or less and manufacturing semiconductor elements thereon has been proposed.
For example, a technique to form discrete elements of MOS devices, solar batteries, optical sensors, etc., or semiconductor integrated circuits by use of spherical single crystal silicon has been proposed. To form discrete devices and integrated circuits, particulate objects, e.g., polycrystalline or single crystal silicon balls, obtained by, for example, crushing an ingot into particulate objects of desired size, are subjected to various treatment steps of a grinding step, a lapping step, a mirror polishing step, a washing step, a thin film forming step, a resist application step, a photolithograpy step, an etching step, etc., and conveying steps. A heat treatment step for transforming polycrystalline silicon into single crystal silicon or amorphous silicon is sometimes used. To efficiently manufacture the spherical semiconductor elements, the treatment steps and the conveying steps need to be concatenated to form a line.
The treatment steps are executed in various atmospheres containing not only gases of active gases, inert gases, etc., but also liquids of water, solutions, etc. To efficiently manufacture and treat the spherical semiconductor elements, it is necessary to concatenate the steps of manufacturing and treating the spherical objects of spherical silicon by means of hollow, cylindrical means, e.g., pipes, and to convey the spherical objects within the cylindrical means by the utilization of a conveying force of fluid.
The inventors proposed a spherical object conveying apparatus capable of conveying spherical objects of spherical single crystal silicon, one by one.
Particulate objects of polycrystalline silicon as a starting material are not perfectly spherical and indefinite in shape. Therefore, it is difficult to convey those objects one by one. If two or larger number of the particulate objects are put in the conveying path, it is difficult to automatically convey and treat the particulate objects, and hence it is impossible to treat the particulate objects of spherical silicon within the closed space of the pipe, for example. For this reason, the spherical silicon cannot fully exhibit its advantages, and this fact greatly hinders the progress of the ball semiconductor.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a particulate object conveying apparatus for efficiently conveying particulate objects of indefinite shape, e.g., particulate objects of polycrystalline silicon, one by one.
To achieve the above object, there is provided a particulate object conveying apparatus comprising: a stagnating portion for stagnating particulate objects; a rotor having a plural number of grooves formed in and equidistantly arrayed on its outer circumference surface, when ascending, the grooves passing the stagnating portion; and object driving-out means for driving the particulate object out of each groove of the rotor.(first aspect)
Preferably, a particulate object conveying path including fluid accelerating means using a fluid pressure is coupled to the receiving path.
The particulate object conveying apparatus more effectively operates when the particulate objects are those of polycrystalline silicon being indefinite in shape before the polishing of them.
In the particulate object conveying apparatus thus constructed, particulate objects are put one by one into each groove formed in the outer circumferential surface of the rotor as the rotor rotates. Two or more number of particulate objects mistakenly put into one groove drop by its weight when those are lifted with the rotating rotor and reaches at the highest position. Accordingly, only the particulate objects each put in one groove reach the particulate object receiving path, and are transferred one by one to the receiving path.
The second aspect of the apparatus is an particulate object conveying apparatus according to the first aspect, wherein the depth of each said groove is within the range of 0.5 to 1.5 times as large as the diameter of each said particulate object to be conveyed.
The third aspect of the apparatus is an particulate object conveying apparatus according to the first aspect, wherein said particulate objects are particulate objects of polycrystalline silicon.
The fourth aspect of the apparatus is an particulate object conveying apparatus according to the first aspect, wherein said rotor is shaped like a disc which is rotatable about a rotary shaft
3
, and said stagnating portion is provided on one of the sides of said rotor and has a gap of a fixed width, the cross section of said stagnating portion takes a fan-shape spreading out about said rotary shaft, particulate object supplied to the stagnating portion stagnates therein.
The fifth aspect of the apparatus is an particulate object conveying apparatus according to the first aspect, wherein a first spreading angle from the vertex of the fan-shape of said stagnating portion toward the object driving-out means is within the range of 15 to 40 degrees and a second spreading angle from the vertex of the fan-shape of said stagnating portion toward an inlet side of said stagnating portion is within the range of 95 to 120 degrees.
The sixth aspect of the apparatus is an particulate object conveying apparatus according to the first aspect, wherein said particulate object driving-out means comprises a particulate object receiving path disposed under said rotor, and receives the particulate object one by one from said grooves of said rotor when each groove containing a particulate object reaches just above said particulate object receiving path.
The seventh aspect of the apparatus is an particulate object conveying apparatus according to the first aspect, which is further comprising:
a storage section, disposed above said rotor, for storing particulate objects of polycrystalline silicon;
a supplying pipe line of which the inner surface is tapered; and
a valve coupled to said supplying pipe line at a location closer to said storage section; wherein the particulate objects of polycrystalline silicon stored in said storage section is guided into said stagnating portion by said supplying pipe line coupled with said valve.
The eighth aspect of the apparatus is an particulate object conveying apparatus according to the sixth aspect, which is further comprising accelerating means, coupled to said receiving path, for accelerating the particulate objects being conveyed through said receiving path by the utilization of a fluid pressure.
The ninth aspect of the apparatus is an particulate object conveying apparatus according to the first aspect, which is further comprising:
a tubular flow passage, coupled to said particulate object driving-out means,
spiral stream formation means for allowing a carrier fluid to flow in from a tangent direction of said tubular flow passage and forming a spiral stream of the carrier fluid;
a supply pipe for supplying a spherical object together with a first atmosphere;
a first atmosphere suction and discharge section for bringing the first atmosphere containing the spherical object into contact with the spiral stream in the proximity of an exit of said supply pipe for guiding the spherical object so that the spherical object passes through a center and selectively sucking outward and discharging the first atmosphere together with the spiral stream for removing the first atmosphere; and
a second atmosphere su
Higuchi Akikazu
Ishida Migaku
Ellis Christopher P.
Greenblum & Bernstein P.L.C.
Mitsui High-tec Inc.
Ridley Richard
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