Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B20/00—Processes specially adapted for the production of quartz or fused silica articles, not otherwise provided for
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B23/00—Re-forming shaped glass
  • C03B23/04—Re-forming tubes or rods
  • C03B23/047—Re-forming tubes or rods by drawing
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B23/00—Re-forming shaped glass
  • C03B23/02—Re-forming glass sheets
  • C03B23/037—Re-forming glass sheets by drawing
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B23/00—Re-forming shaped glass
  • C03B23/04—Re-forming tubes or rods
  • C03B23/06—Re-forming tubes or rods by bending
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S65/00—Glass manufacturing
  • Y10S65/08—Quartz
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S65/00—Glass manufacturing
  • Y10S65/09—Tube

Definitions

• the present invention relates to a large-sized quartz glass plate, a method of manufacturing the same, and a manufacturing apparatus thereof, and more particularly, to a transparent and high-purity flat large-sized quartz glass plate, a manufacturing method and a manufacturing apparatus thereof.
• ⁇ I do not like the adhesion of impurities such as wafers.
• ⁇ Square tank for cleaning purity materials, large diameter quartz glass windows, lamp covers, etc. are made of high-purity and transparent large flat quartz glass. Manufactured using plates.
• Quartz glass used in these materials has a high viscosity even at low temperatures compared to other glasses, and is difficult to mold or cast in a molten state, so that it is difficult to obtain a plate material.
• Quartz glass is a material with excellent transparency and light transmittance. Especially for applications such as open windows and lamp covers, it is required to have almost optically good transparency. Rough and non-transparent plate materials need to be transparentized by, for example, rough polishing, followed by mirror polishing with abrasive grains or surface melting treatment with a flame, but this transparent processing is extremely troublesome. In addition to requiring labor and time, impurities and metal elements that become semiconductor poisons are liable to be mixed during polishing by the abrasive grains, and cracking due to thermal strain occurs in the surface melting treatment by flame, so that it is industrially required. Markedly unsatisfactory It is profitable.
• the block body is manufactured by melting and integrating a ground powder of natural quartzite in a predetermined mold, impurities or reaction gas generated from the mold body and residual gas in the central portion of the melt are reduced. Bubbles are likely to remain in the viscous quartz glass melt, and this tendency is more remarkable as the block becomes larger. Therefore, foreign substances and bubbles naturally appear in the large plate cut out from the block. It is difficult to apply this product to products requiring high transparency, such as open windows and lamp covers made of quartz glass, using this plate material.
• the size of a block that can be formed is substantially limited due to lack of mechanical strength and heat resistance of a mold used for fusion and integration.
• a large amount of expensive quartz glass is lost as a large cutting margin because the thickness of the diamond cutter is necessary, and only an uneconomical plate that is extremely disadvantageous industrially can be obtained. Therefore, it is also difficult to manufacture large quartz glass plates.
• the size of the cleaning square tank that can be formed from such a quartz glass plate is also limited, and it is becoming impossible to cope with an increase in the diameter of the semiconductor or wafer to be cleaned.
• a quartz glass tube 100 is cut out in the axial direction or cut into two, and a quartz glass rod is welded to the center of the periphery.
• the handle 101 is held and the dissected quartz glass tube 100 is heated and softened as a whole.
• the softened portion 100a was pressed and flattened using a carbon trowel I04 or the like on a forceps table 103 while heating and softening a portion of the portion, and the above operation was repeated and the handle was repeated.
• the other part While changing the welding position of 101, the other part is gradually flattened to form a quartz glass plate, or the quartz glass tube 100, which is entirely opened in the once bent plate shape, is heated.
• the thickness and size of the flattened quartz glass are necessarily limited.
• the maximum size is, for example, 300 x 300
• the limit is about mm, and the work requires labor and effort.
• the flattening is performed while pressing a carbon trowel or a carbon flat plate. Because of flattening, scratches due to contact with carbon trowels and carbon flat plates, irregularities on the carbon surface remain, and the surface becomes rough, and undulations due to unevenness of the flattening occur. In addition, the flattening and flattening are inferior, and the carbon iron or carbon flat plate comes into pressure contact with the upper surface of the quartz glass plate. It is. In addition, the residual impurities not only act as semiconductor poisons but also promote crystallization of the quartz glass itself, causing opacity (devitrification) due to the occurrence of microcracks due to local crystallization, and transparency. There was also a serious problem for applications requiring high performance.
• the present invention has been made in view of the above-mentioned drawbacks of the related art, and has as its object to provide a large, low-purity quartz glass plate free of bubbles, a method for producing the same, and a production apparatus therefor.
• Another object of the present invention is to provide a quartz glass plate which has no undulation on its surface, is smooth and has high flatness, and a method and apparatus for manufacturing the same.
• a quartz glass tube 1 having a notch 1a, preferably a band, cut out over a predetermined width in the tube axis direction is prepared. From the predetermined portion of the tube 1 along the circumferential direction of the tube, while being heated and softened in a strip shape over the entire width in the axial direction of the tube, the glass tube is pulled from the predetermined portion substantially tangentially to the circumference of the glass tube. It is characterized by flattening the glass tube 1.
• the glass tube 1 is fixed, and while the heating element to be heated and softened in a belt shape over the entire width in the axial direction of the tube is circulated in the circumferential direction, the tension member is spirally circulated following the heating member.
• the heating elements 3 A and 3 B are fixed in position near the notch start end 1 b of the quartz glass tube 1.
• the pulling means 2 which fixes the glass tube 1 start end 1 b, follows the glass tube 1 in a substantially tangential direction from the notch start end 1 b. It is preferable that the glass tube 1 is stretched in a straight line, thereby flattening the glass tube 1.
• the initial heating position of the heating elements 3A and 3B does not necessarily need to be set at the notch start end 1b, for example, the pulling means 2 grips the notch start end 1b.
• the notch start end 1b may not be directly heated.
• the notch start end 1b which is separated from the gripping portion, starts heating slightly upward. You may.
• the peripheral speed of the glass tube 1 and the pulling speed of the pulling means 2 do not necessarily need to be the same speed, and the thickness of the formed flat plate can be determined with respect to the thickness of the glass tube 1 by appropriately determining. However, it is possible to make the thickness thicker or thinner.
• a thin large flat glass plate can be formed.
• the tension means 2 force s a force capable of directly gripping the notch start end 1 b of the quartz glass tube 1
• the grip portion is a metal
• impurities are generated from the grip portion by heat during heating and softening. Since it is difficult to form a quartz glass plate with high purity due to intrusion, it is desirable to grip with high purity and heat resistant carbon and ceramic materials such as alumina, SiC, zirconia, and silicon nitride. It is very difficult to completely eliminate impurity contamination in the vicinity from the part.
• the notch start end 1b is not directly gripped by the gripping portion, but is pulled in a state of being quickly connected via the quartz glass material 4.
• the heating of the glass tube 1 may be performed from one side. However, if a temperature difference occurs between the front and back sides, it becomes difficult to perform uniform pulling.
• quartz glass tube 1 it is more preferable to heat the quartz glass tube 1 from both the front and back surfaces over the entire width in the tube axis direction.
• the heating elements 3 A and 38 are rod-shaped heaters made of 3 iC, carbon, or the like, or a heating element that can be constituted by a panner assembly in which a number of burner nozzles are arranged in a row.
• 3A and 3B in order to eliminate the variation in the amount of heat supplied in the axial direction of the quartz glass tube, relative movement between the heating section and the quartz glass tube 1 is relatively reciprocated in the axial direction of the tube.
• the glass tube 1 is softened linearly or in a strip shape over the entire width while the heating elements 3A and 3B are reciprocated.
• a heating source is arranged inside the tube. Therefore, it is difficult to use a material having a very small diameter, and a transparent quartz glass tube having a diameter of 100 to 500 mm and a thickness of 2 to 20 mm is practically preferable.
• the glass plate is of high purity for use as a window or a square tank, and specifically, Na, Li, Fe, A1, Cu, Ca, Ni,
• the content of each element of B, Mg, Y, Ti, and Cr is less than or equal to i00 (weight) ppm, and it is more preferable that the elements of Na, K, and Cu have low diffusion and are easily contaminated.
• the element such as Ca is preferably a transparent high-purity quartz glass plate of 0.5 ppm or less.
• the above invention is a method of forming a flat plate member from the quartz glass tube 1.
• a large flat plate-like quartz glass plate is prepared, and the glass plate is placed at one end from the other end. It is also possible to form a curved glass plate by successively stretching the wire having a linear shape across the entire width from the one end to a predetermined shape while heating and softening it in a belt shape.
• the second invention of the present invention provides an apparatus suitable for carrying out the manufacturing method, and is characterized by a preferably band-shaped notch cut out over a predetermined width in the pipe axis direction.
• a quartz glass tube 1 having 1a; a means 5 for rotating the glass tube 1 about the tube axis; and a full width of the glass tube 1 in the tube axis direction! :
• the present invention provides a supporting means 6 for supporting the quartz glass tube 1 on the peripheral surface, and the supporting means 6 and the rotating means 5 so that the axis of the rotating means 5 and the axis of the quartz glass tube 1 can coincide with each other.
• a supporting means 6 for supporting the quartz glass tube 1 on the peripheral surface, and the supporting means 6 and the rotating means 5 so that the axis of the rotating means 5 and the axis of the quartz glass tube 1 can coincide with each other.
• the initial support position of the quartz glass tube 1 by the support means can be set at a position where the notch start end 1b is located farther from the notch end 1c in the radial direction than the center of the tube axis. Is preferred.
• the rotating means 5 is also configured to directly grip the notch start end 1b of the quartz glass tube 1 using a gripping member or the like, impurities may enter the gripping portion during heating and softening, resulting in low purity.
• the rotating means 5 is constituted by a rotating plate or an arm member rotatable about a rotating shaft without directly gripping the notch start end 1b by the gripping portion. It is preferable that the quartz glass tube 1 is rotatable following the rotation of the arm member after the gap between the notch ends 1 c of the glass tube 1 is welded with the quartz glass material 8.
• the notch end 1c is held by a heat-resistant carbon or ceramic material such as alumina, SiC, zirconia, or silicon nitride.
• a heat-resistant carbon or ceramic material such as alumina, SiC, zirconia, or silicon nitride.
• the thickness of the flat plate to be formed can be appropriately adjusted. Therefore, it is preferable to provide a speed changing means or the like so that the peripheral speed of the quartz glass tube 1 rotated by the rotating means 5 and the pulling speed of the pulling means 2 can be relatively shifted.
• the heating means is constituted by a pair of rod-shaped heaters or burners and other heating elements 3 A and 3 B which are arranged to face each other with the glass tube 1 interposed therebetween. It is preferable that the glass tube 1 is uniformly softened in a strip shape over the entire width while the pair of heating members 3A and 3B are reciprocated in the tube axis direction.
• the diameter may be at least 100 mm or more. is necessary. If the wall thickness is too small, it will be deformed during softening by heating, and it will not be possible to heat evenly with a too large thickness. Therefore, the wall thickness is preferably about 2 to 20 mm.
• the flat plate manufactured using the quartz glass tube 1 can be formed as a high-purity transparent quartz glass plate having a long side of at least 300 mm and a thickness of about 2 to 20 mm.
• the quartz glass tube 1 is formed from a relatively small lump of quartz glass (ingot), there is almost no mixed input of air bubbles and foreign substances such as impurities like a large block body, and the quartz glass tube to be formed is As a result, the plate body has a high purity and a high transparency suitable for a window or a square tank.
• the glass plate is made of Na, Li, Fe, A1, Cu, Ca, Ni
• the sum of the contents of each element of B, Mg, Y, Ti, and Cr is 100 (weight) ppm or less, and more preferably, each element of Na, K, and Cu, which is easily diffused, and Ca, which is easily contaminated.
• Such elements can form a transparent quartz glass plate set at 0.5 ppm or less, and can be suitably used as a cleaning window for a single-crystal pulling apparatus, such as a window or a wafer. .
• the Na, Li, Fe, A1, Cu, Ca, Ni, B, Mg The sum of the content of each element of Y, Ti, and Cr can be set to 200 ppb or less.
• FIG. 1 is a basic configuration diagram showing the manufacturing apparatus of the present invention
• FIG. 2 is an operation diagram showing the manufacturing procedure
• FIG. 3 is a front view showing the overall configuration of the apparatus
• FIG. 4 is a perspective view showing the main configuration of the apparatus. is there.
• FIG. 5 shows a process of flattening a quartz glass tube according to the prior art.
• FIG. 3 shows an overall configuration diagram of a flat plate manufacturing system according to an embodiment of the present invention, and a support mechanism for supporting a quartz glass tube 1 cut in a band shape in the tube axis direction by a pair of upper and lower support rollers 57, 58. 50, a support and transport device 70 including a transport mechanism 60 for transporting the support mechanism 50 to a predetermined position on the flat plate forming apparatus 10 side;
• It consists of a combination of a flat plate forming apparatus 10 comprising a pulling means 2 for pulling linearly in a substantially tangential direction from a notch starting end 1 b.
• the transport mechanism 60 is provided on a base 80 via a traveling screw shaft 61 extending horizontally toward the flat plate forming apparatus 10 side, and a nut portion 62 screwed to the screw shaft 61. It comprises a horizontal table 64 that moves toward and away from the flat plate forming apparatus 10 by the forward and reverse rotation of the drive motor 63, and a vertical tower 65 that stands vertically on the horizontal table 64, and the vertical tower 65.
• a vertical screw rail 67 is attached to the front, a vertical screw shaft 67 extending vertically in the tower 65 in parallel with the guide rail 66, and a drive for rotating the vertical screw shaft 67 forward and reverse.
• Install motor 68 is provided on a base 80 via a traveling screw shaft 61 extending horizontally toward the flat plate forming apparatus 10 side, and a nut portion 62 screwed to the screw shaft 61. It comprises a horizontal table 64 that moves toward and away from the flat plate forming apparatus 10 by the forward and reverse rotation of the drive motor 63, and a vertical tower 65 that stands
• the support mechanism 50 includes a drive motor 53 and a vertical stay 51 having a rotary screw shaft 54 that rotates forward and reverse in response to the drive of the drive motor 53, and extends vertically over substantially the entire length of the stay.
• a nut portion 55 is screwed onto the rotary screw shaft 54, and a pair of support stays 56A and 56B are moved up and down in a direction in which the rotary screw shaft 54 comes in contact with and separate from each other by forward and reverse rotation of the rotary screw shaft 54.
• the support stays 56 A and 56 B are horizontally extended from the base side where the nut portion 55 is attached, and a pair of support rollers 57 and 5 are respectively provided on the upper surface and the lower surface facing each other.
• the rotation means 5 is provided with supports 21 and 22 on both sides in the axial direction of the glass tube 1 arrangement space in which the quartz glass tube 1 is provided, respectively, and is rotated on the one support 22.
• the drive motor 23 to which the plate 24 is attached is driven and rotated on an extension of the axis of the drive motor 23 on the support base 21 on the opposite side of the glass tube 1 installation space.
• Install mechanism 6B is provided with supports 21 and 22 on both sides in the axial direction of the glass tube 1 arrangement space in which the quartz glass tube 1 is provided, respectively, and is rotated on the one support 22.
• the drive motor 23 has a rotating shaft 23a on which a circular rotating plate 24 facing the quartz glass tube 1 is attached, and one end of the rotating plate 24 having a cutout end of the quartz glass tube 1. 1 Hold the holding member 11A of the glass strip 8 to be welded to c.
• the distance (radius) between the center of the rotary plate 24 and the holding position of the holding member 11A is made to match the radius of the quartz glass tube 1.
• the driven rotary mechanism 6B is a pair of movable bases 26 mounted on a movable base 26 movable along two parallel rails 25 extended in the axial direction on another support base 21.
• Large diameter bearings 26 A and 26 B which are rotatably supported by the bearings 26 A and 26 B, and whose axis is aligned with the rotation shaft 23 a of the drive motor 23.
• the arm 29 extends in the direction orthogonal to the axis at the tip of the shaft 28, and the notch end of the quartz glass tube 1 has one end at the tip of the arm 20.
• the distance (radius) between the center of the shaft portion 28 and the holding position of the holding member 11B is made to match the radius of the quartz glass tube 1 as in the case of the rotary plate 24.
• the fluid cylinder 31 on one support 22 and the guide rail 3 on the other support 21 2 is disposed along the axis, and a support 33 attached with a pair of heating elements 3A and 3B is mounted between the two members.
• the support 33 has one end fixed to the shaft of the fluid cylinder 31 and the other end fixed to a vertical piece 34 fitted on the guide rail 32,
• the holder 31 is configured to be able to reciprocate along the axis by the reciprocating motion, and is bent in an L-shape so that it can face the support 33 and the quartz glass tube 1 notch start end 1 b in the middle position.
• the sub-support 3 3 B thus fixed is fixed, and a substantially flat heating element 3 composed of a large number of panner nozzles is fixed to each of the supports 33 and 33 B.
• the stroke of the fluid cylinder 31 and the length of the guide rail 32 are set to a length that can be retracted from the position where the auxiliary support member 33 and the quartz glass tube 1 are disposed.
• the heating elements 3 ⁇ and 3 ⁇ are configured by connecting a number of burner nozzles, each having an injection hole facing the quartz glass tube 1 side, so as to be capable of ejecting propane or oxyhydrogen flame. Set the length slightly larger than the axis width of the glass tube.
• the bow extension means 2 has a vertical guide rail 41 attached to the front of a vertical base 40 vertically erected on a base 80, and a guide rail inside the vertical base 40.
• a vertical screw shaft 4 2 extending vertically in parallel with 4 1 and a drive motor 4 3 for rotating the vertical screw shaft 4 2 forward and reverse are disposed, and the guide rail 4 1 is attached to the front end of the glass ribbon.
• a tension table 45 to which the holding member 44 of the plate 4 is attached is fitted so as to be able to move up and down freely, and the tension table 45 is connected to the vertical screw shaft 42 via a nut 46.
• the pulling table 45 has arms extending on both sides thereof toward the quartz glass tube 1 side, and a clamping member 44 is attached to the end of the arm, and one end is cut out of the quartz glass tube 1. Attach the holding member 4 4 of the band-shaped glass plate 4 welded to the start end 1 b and pulled down vertically.
• the drive motor 23 incorporates a transmission so that its rotation speed can be adjusted arbitrarily.
• a pure quartz glass tube 1 with an outer diameter of 0 240 mm and a wall thickness of 4 mm is cut at a length of 500 mm, and ⁇ : about 10 to 15 ° (about 30 mm)
• a notched quartz glass tube 1 cut into a band with a notch width is prepared.
• the content of impurities in the glass tube 1 is determined by the Na, Li, Fe, A1, Cu, Ca, Ni,
• the quartz glass tube 1 is set so that the notch start end 1 is on a horizontal line and the notch end 1 c is retracted inside the start end 1 b by a distance h.
• the transfer mechanism 60 is placed on the pair of support rollers 57, 58 of the lower support stays 56A, 56B.
• the distance h is sufficient if it is retracted to the extent that it does not hinder the welding of a glass strip 4 for pulling the glass tube 1 to the notch start end 1b, which will be described later.
• the angle ⁇ may be set arbitrarily in the range of 10 to 15 °.
• the drive motor 53 in the vertical stay 51 is rotated forward to approach the lower and upper support stays 56 A, 56 B.
• the quartz glass tube 1 is positioned and clamped by a pair of upper and lower support rollers 57, 58.
• the supporting mechanism 50 holding the quartz glass tube 1 was first raised to a height coinciding with the axis of the rotating means 5 of the flat plate forming apparatus 10 using a driving motor in the vertical column 6 ⁇ .
• the horizontal table 64 is moved horizontally by the traveling of the horizontal platform 64 to a position coinciding with the axis of the rotating means 5 on the flat plate forming apparatus 10 side.
• the piston shaft 31a of the fluid cylinder 31 is extended so as not to come into contact with the sub support 33 of the heating mechanism 30.
• a strip-shaped quartz glass plate 8 made of synthetic quartz glass with high purity was welded in parallel to the both end surfaces of the notched end 1c side in the axial direction, and the rotating plates 24 Between the holding member 11A and the holding member 11A at the end of the arm.
• the band-shaped quartz glass plates 4 are similarly welded to the left and right sides of the end face of the notch start end 1 b so as to hang vertically downward along the tangential direction, and the lower ends thereof are fixed to the holding members 4 4 of the pulling table 45. Let it be pinched.
• the drive motor 53 in the vertical stay 51 is inverted to separate the lower and upper support stays 56 A and 56 B that have positioned and supported the quartz glass tube 1.
• the transport mechanism 60 is retracted from the support position and returned to the original position.
• the fluid cylinder 31 is retracted to allow the sub support 33 of the heating mechanism 30 to enter the quartz glass tube 1, and the heating elements 3A and 3B are sandwiched by the notch start end 1h. It is configured to be able to confront.
• the heating elements 3A and 3B are blown horizontally and the combustion gas is blown from both sides of the pipe to the full width of the pipe axis. I do.
• the heating elements 3A and 3B are formed by an integrated nozzle burner, linear heating tends to be non-uniform due to the spacing between the panners. By reciprocating at stroke intervals slightly smaller than the interval, uniform heating is possible.
• the notch start end 1 b force is thermally softened by the linear heating, the rotation of the quartz glass tube 1 by the driving motor 23 and the lowering of the notch start end 1 b by the pulling means 2 are started simultaneously.
• a flat plate having the same thickness can be formed if the pulling speed is completely matched with the orbiting speed of the entire period, and a flat plate thinner than the quartz glass tube 1 can be obtained by setting the pulling speed slightly higher. . Conversely, by slightly lowering the pulling speed, a flat plate thicker than the glass tube 1 can be obtained.
• a flat plate is formed up to the position shown in FIG. 2 (D) as described above, and immediately before the notch end 1c of the quartz glass tube 1 reaches the heating position of the heating elements 3A and 3B. Then, the heating of the heating bodies 3A and 3B, the rotation of the rotating means 5, and the pulling of the bowing means 2 are stopped.
• the flattened quartz glass plate is cut from the welded band-shaped quartz glass glass plate and removed from the forming apparatus 10, and then the unflattened notch end 1 c side portion is cut. A flat plate is formed.
• the flat plate is subjected to predetermined post-processing such as washing and annealing, and then shipped as a product.
• the quartz glass plate thus extended in a flat shape is cooled and formed into a large transparent quartz glass plate.
• the flat plate thus formed has no surface waviness, and has an impurity content of Na, Li, Fe, A1, Cu, Ca, Ni, B, Mg, Y,
• the total content of each element of T i and Cr was less than 200 ppb, and there was almost no change from the impurity concentration before the plate was formed.
• a transparent quartz glass tube with an outer diameter of i 6 240 mm, a wall thickness of 4 mm, a length of 500 mm, and a notch width of about 30 mm was used.
• the quartz glass plate was manufactured according to the same procedure as above, with the revolving speed being 6 Omm / min and the tensile speed being changed to 50 mm / mi ⁇ , 0 mmmin, 65 mm / min and 70 mmmin, respectively.
• the thickness can be changed to 4.8 mm, 4.Omm, 3.7 mm, and 3.4 mm, respectively, and the flat plate thus formed can form a good flat plate without surface undulation.
• a quartz glass plate which is large, high-purity, free of bubbles, and has a smooth and flat surface without undulation can be obtained easily and effectively. Therefore, it is extremely advantageous for manufacturing a square tank for wafer cleaning or a reflector made of quartz glass.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Glass Melting And Manufacturing (AREA)
• Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)

Priority Applications (8)

Applications Claiming Priority (1)

Publications (1)

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ID=14042458

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (14)

Citations (1)

Family Cites Families (7)

• 1992
  • 1992-07-31 WO PCT/JP1992/000976 patent/WO1994003404A1/ja active IP Right Grant
  • 1992-07-31 KR KR1019940701006A patent/KR970009008B1/ko not_active Expired - Fee Related
  • 1992-07-31 EP EP92916522A patent/EP0607433B2/en not_active Expired - Lifetime
  • 1992-07-31 KR KR1019940701006A patent/KR940702469A/ko active Granted
  • 1992-07-31 DE DE69227521T patent/DE69227521T3/de not_active Expired - Fee Related
  • 1992-07-31 JP JP6505171A patent/JP2825977B2/ja not_active Expired - Lifetime
  • 1992-08-27 TW TW081106772A patent/TW309511B/zh active
• 1994
  • 1994-07-31 US US08/211,455 patent/US5683483A/en not_active Expired - Lifetime

Patent Citations (1)

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