JP2002137928A - Welding method for quartz glass component and vertical wafer port assembly apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding method not to cause surface deformation and not necessary to reform the joined surface when a rod quartz glass component is welded with a plate component. SOLUTION: The rod quartz glass component 2 of which the one end has a convex shape like a conical shape or the like is positioned vertically to be 1-3 mm apart from the surface of the plate quartz glass component 1. The oxygen burners are set opposite each other at both the side of the rod component 2 to be the flame angle of 5-45 degrees. The heated and softened plate quartz glass component 1 and the rod quartz glass component 2 are transferred relatively and made contact bonding by the pressure on the joining surface toward vertical direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer boat made of quartz glass used for holding a wafer at the time of heat treatment of a semiconductor wafer, and to a wafer boat for holding, transferring, etc., at the time of moving, drying, and washing a wafer. A method of manufacturing a quartz glass product such as a quartz glass container or a cleaning jig, a welding method of a quartz glass member when assembling and manufacturing such a product, and a manufacturing apparatus using the welding method, more specifically, The present invention relates to an apparatus for assembling a vertical wafer boat.

[0002]

2. Description of the Related Art In a manufacturing process of a semiconductor device, quartz glass which is a high-purity material which is stable even at a high temperature and does not mix impurities into a semiconductor is used as a jig. Of the quartz glass jigs used for semiconductor manufacturing, a wafer boat and a quartz glass cleaning jig are assembled by welding a top plate and a bottom plate to a rod-shaped member having a groove as shown in FIG. I have.

Conventionally, an end face of a rod-shaped quartz glass member is brought into contact with the surface of a plate-shaped quartz glass member, and a welding rod made of quartz glass having a diameter of 2 to 3 mm is melted by an oxyhydrogen flame around a welding point with a burner held in hand. The joining method is common. Also,
As disclosed in Japanese Patent Application Laid-Open No. 4-182322, there is a method in which a welding rod is disposed between the welding ends of two quartz glass members to be welded, and then welding is performed using a laser.

[0004] The conventional method is a method in which members to be welded are all joined together via a welding rod. Therefore, if the welded portion of the welding rod is poorly melted, poor welding may result in partial welding failure due to poor heating, bubbles may be generated, or the bonding strength may be insufficient, and the welding rod itself due to excessive heating In some cases, there was a problem in terms of assembly accuracy and appearance, such as deformation of the welding surface and depression of the welding surface. For this reason, joining using a welding rod is suitable for work to increase the joining strength by heating sufficiently, but since the surface deformation is large, it is necessary to rework or reshape the joining surface with a carbon iron etc. However, it is unsuitable for those requiring precision and those performing continuous assembly work.

In the case of manufacturing a vertical wafer boat as shown in FIG. 2, in a conventional method, a quartz glass rod-shaped member is usually cut with a diamond wheel to provide a groove for mounting a wafer (after assembling into a boat). A groove may be provided), as shown in FIG. 3, a plurality of (four in this figure) groove rods are arranged at predetermined positions using a carbon jig, and a carbon jig is similarly used. Temporarily assemble the wafer boat by temporarily welding the groove bars to the top plate and the bottom plate, which are positioned parallel to the left and right at predetermined intervals, and take out the temporarily welded assembly from the carbon jig and check if it meets the specifications. Check with a three-dimensional measuring device, etc., and if correction is necessary, repeat the temporary welding and confirm that it is within the specified dimensional tolerance,
This welding was done and it was assembled.

In this conventional method, a number of carbon jigs must be prepared in accordance with various standards and specifications of a wafer boat. A lot of time and labor has been spent on fine adjustment work for arranging a quartz glass member such as a top plate and a groove bar in a jig. Also, even if fine adjustment of the groove rod set is successful, if there is variation in the diameter of the groove rod itself, from the center of the set groove rod diameter to the center of the other groove rod diameter Since the distance between the products is different, there is a problem that the finished product can be assembled with dimensional tolerances different from the specifications. In any case, since each work is manual, it depends on the skill of the worker,
Further, there is a problem that an extra step called a temporary welding step has to be taken.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is intended to prevent the surface deformation occurring in the case of joining via a welding rod and to re-join the joint surface. It provides a method of welding quartz glass members that does not require reshaping, and eliminates the need for an assembling process using a carbon jig, and at the same time, omits the manual temporary welding process at this time. An object of the present invention is to provide a wafer boat welding method and apparatus suitable for a continuous assembling work process with excellent dimensional accuracy and reproducibility.

[0008]

In order to weld a rod-shaped quartz glass member end face to a plate-shaped quartz glass member surface, it has been found that the joining surface may be heated and softened, and pressure may be applied from the vertical direction to perform pressure bonding. This problem was solved by making the end face of the rod-shaped member to be welded into a convex shape, and applying pressure from a direction perpendicular to the joint surface while heating with a flame of a burner to perform pressure bonding.

Then, the rod-shaped quartz glass member and the plate-like member are
It is effective to fix one of them and move the other, or to make both movable, and to apply pressure by applying relative pressure in the direction of the joint surface. The workpiece holding portion and the plate-shaped member are relatively moved in the direction of the joining surface to apply pressure, so that a plurality of rod-shaped members can be simultaneously pressed.

Further, the convex shape of the end face to which the rod-shaped quartz glass member is joined is a wedge shape or a conical shape so as to be symmetrical from the center of the rod-shaped end face. The crimping was appropriately performed by appropriately selecting the inclination angle from the center point of the convex shape of the rod-shaped member end face or the vertex of the center plane to the peripheral surface according to the amount of crushing of the bar-shaped quartz glass member by crimping.
Flame was sent from at least two directions symmetrical from the center point of the end surface of the wedge-shaped or conical rod-shaped member, and the welding location was heated counter-currently to ensure pressure bonding. Further, it has been found that it is preferable to perform opposite heating at a flame angle of 5 to 45 degrees with respect to the surface of the plate member to be welded.

A forked burner made of quartz glass, or
A line burner is preferable for heating the welded portion, and a line burner having a U-turn at the tip end and connected to a supply pipe is preferable for uniform supply of combustion gas.
Further, it is effective to set the distance between the surface of the plate-shaped member and the top of the convex portion of the end surface of the rod-shaped member at the start of heating to 1 to 3 mm.

[0012] As a method of welding and assembling a vertical wafer boat, when assembling by welding a groove bar or a rod-shaped member to an upper flange serving as a bottom plate and a side plate serving as a top plate, the plate member of the top plate is positioned by a clamp chuck. Providing a flame angle of 5 to 45 degrees with respect to the welding surface of the plate member,
A burner is arranged opposite to send a flame from the direction, the rod-shaped quartz glass member is supported on a slidable work holding part, and the work holding part or the top plate or both are pressed so as to be pressed perpendicularly to the joint surface while heating with the burner. After the relative movement and pressure bonding, and then release the clamp of the top plate chuck, the other end face of the rod-shaped member is pressure-bonded to the bottom plate positioned by the clamp chuck to simultaneously weld many rod-shaped members to the plate material. It can be manufactured and a vertical wafer boat can be efficiently produced.

A support / rotation / movement means for supporting, rotating and moving the quartz glass top plate and the bottom plate provided at intervals on the base; a burner support / rotation / movement control means; Gas flow control means of the burner, support / moving means for supporting and moving the quartz glass rod-shaped member in the axial direction, and relative movement of the top plate, bottom plate and quartz glass rod-shaped member to apply pressure from the vertical direction to the joint surface By using a vertical wafer boat assembling apparatus provided with a pressure applying means, a wafer boat can be manufactured with high accuracy and reproducibility.

Examples of the quartz glass product assembled by applying the present invention include a vertical quartz glass wafer boat such as a CVD boat and a diffusion boat used in a semiconductor heat treatment process, a semiconductor wafer transfer container and a cleaning jig. And the like.

The method of welding a quartz glass member according to the present invention is particularly suitable for assembling a flat quartz glass member such as a top plate of a wafer boat by welding and joining an end face of a rod-shaped quartz glass member such as a groove rod. It is valid. For the bar-shaped member, the groove bar is used in the case of the pre-cut type that is grooved into the round bar first and then assembled into the boat, but as the post-cutting method where the round bar is grooved after assembled in the boat, the round bar is left as it is It can be used and assembled into a boat. Although the above-mentioned products are mentioned as an example, the present invention can be applied to various products. The shape of the rod-like member to be joined to the plate-like member may be a round bar, a square bar, a polygonal shape, or any other irregular shape.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, an end surface of a quartz glass rod (rod-like member) 2 having a diameter of 20 mm is formed in a V-shaped wedge shape having an inclination angle of 5.7 degrees. 1 was placed vertically at a distance of 3 mm. An oxyhydrogen flame burner 3 is disposed on both sides of the round bar 2 so as to face the plate-like member.
A flame is supplied to the joining surface at a rate of 30 liters / minute of hydrogen and 10 liters / minute of oxygen, heated and softened, and the plate-like member 1 is pressed until the round bar 2 is crushed 2 mm from the tip. And crimped. In normal welding, heating is performed to melt the objects to be welded sufficiently well and to join them by the melt flow, but in the present application, heating is for softening the member surface in advance, and by applying pressure, It is to be bonded by crimping.

Therefore, in order to increase the melt strength by melting the joint surface and causing it to melt and flow, as in the conventional case where the periphery of the bar is heated and shaped by a carbon roller or the like while heating the periphery of the bar with a burner. It is essentially different from the conventional pressurizing means being performed.

In the pressure bonding, pressure is applied such that the axis of the rod-shaped member 2 is perpendicular to the surface of the plate-shaped member. The rod-shaped member and the plate-shaped member are moved so as to be relatively close to each other. The member to be moved may be either the rod-shaped member or the plate-shaped member, or both members may be moved at the same time. By relatively moving, a pressing force is generated in a direction perpendicular to the welding surface. This movement is controlled by setting a moving speed and a moving distance by a cylinder device, thereby controlling the pressing force.

By applying an appropriate pressing force, uniform and reproducible bonding can be achieved, and heating to the vicinity of the softening point of quartz glass is sufficient without heating the bonding surface to a molten state. Can be prevented from being deformed. The pressing force can be controlled by a hydraulic cylinder or by transferring the rotating torque of an electric motor to a work support, etc., and moving the electric motor. It is preferable because it is easy to obtain The pressing force is appropriately selected depending on the shape of the member and the state of softening of the joint surface, but is preferably in the range of 0.1 to 100 g / mm ² .

The joining end face of the rod-shaped member is processed in a convex shape. When heated by the convex shape, the center of the end face is softened first, and furthermore, pressure is applied to the end face from the center to the outer peripheral portion in order, so that bubbles are hardly generated on the welding surface, Even if it occurs, it is hard to remain because it escapes outward. In addition, since welding is sequentially performed outward from the center, the welding strength can be increased with a small amount of heating. For this reason, it is not necessary to heat not only the welding surface but also the surroundings with a burner as in the conventional method, and it is not necessary to perform welding only with the heat capacity, so that the amount of heat can be reduced to a minimum and the deformation of the welding surface can be prevented. . The shape of the end face of the convex rod-shaped member is preferably symmetrical from the center of the end face in order to make the surface distribution of softening uniform, and more specifically, a wedge shape or a conical shape is effective.

The inclination angle from the central point of the convex shape of the end surface of the rod-shaped member 2 to the peripheral surface from the center point or the vertex of the central surface is appropriately selected according to the amount of crushing of the quartz glass rod-shaped member 2 by pressing. For example, when the inclination angle of the cone is constant, the height of the cone varies depending on the diameter of the rod-shaped member 2, so that the length of the crushed rod-shaped member differs. When the cross-sectional shape of the rod-shaped member and the convex inclination angle are determined, the volume of the convex body crushed at the time of welding can be determined, so by creating a comparison table in advance, the amount of crushing of the rod-shaped member can be predicted and high accuracy can be obtained. Welding becomes possible. As an optimum range, the inclination angle of the wedge or the cone is in a range of 2 to 20 degrees, and the crushing amount is 0.5 to 8 mm. When the diameter of the rod-shaped member is 20 mmφ, the crushing amount is preferably 2 mm, and the inclination angle of the cone is preferably about 6 degrees.

The assembling apparatus stores the relationship between the diameter of the rod-shaped member, the amount of crushing, and the convex inclination angle, and reproduces the welded joint having excellent surface properties by automatically controlling the relative movement of the member. It can be performed continuously with good performance.

In the heating by the burner 3, a flame is sent from at least two directions symmetrical with respect to the center point of the end surface of the wedge-shaped or conical rod-shaped member, and the welded portion is opposedly heated.
The distance from the burner crater to the outer peripheral surface of the rod-shaped member depends on the nozzle diameter of the burner 3, but is a fixed distance between 10 and 30 mm. Further, it is desirable that the flame angle of the burner be opposed to the plate-shaped member surface to be welded at a flame angle of 5 to 45 degrees.

It is important to uniformly soften the welded surface without deforming it, and the above-described method is effective in minimizing the effects of radiant heat from the members and flaring. If the flame angle of the burner is smaller than 5 degrees, the softening of the top of the convex portion of the rod-shaped member is too fast compared to other welded parts, resulting in poor balance,
The overall welding strength is undesirably low. On the other hand, if the angle is larger than 45 degrees, the outer peripheral surface of the convex member is too fast compared to other welded portions, so that the outer peripheral shape after welding is deformed to bulge outward, and at the same time, the surface layer of the plate member is also dented. This is not preferable because of the occurrence of the flame angle, and it is more preferable to set the flame angle to 10 to 30 degrees.

When the heating by the burner 3 is started, the distance between the surface of the plate-shaped member and the top of the convex portion of the end surface of the rod-shaped member is 1 to 3 m.
It is effective to set m. If the plate-shaped member and the end surface of the rod-shaped member are kept in contact with each other, it takes time to soften the glass, so that the flame intersects with the radiant heat reflected from the plate-shaped member as a reflected flow, As a result, the wall surface around the end face of the rod-shaped member 2 is melted by the radiant heat, and the outer peripheral surface is deformed into a swelled shape by the reflected flow, which is not preferable.
When the distance between the plate-shaped member and the end surface of the rod-shaped member is less than 1 mm, the flame flow from the burner 3 tends to stay between the members, and the gas flow is poor, so that the same deformation is likely to occur. On the other hand, if it exceeds 3 mm, the heating efficiency deteriorates, and a strong flame flow is required. Therefore, the initial spacing between members is 1 to
It is preferable to set it to 3 mm.

As the burner 3, it is preferable to use a forked burner or a line burner made of quartz glass. In order to soften with a small amount of heat, it is important to balance the amount of heat supplied to the heating area. Therefore, in order to uniformly supply the supplied gas amount, a bifurcated burner is suitable when the convex shape of the end surface of the rod-shaped member 2 is a wedge shape, and a line burner is suitable when the convex shape is conical.

The line burner has a nozzle diameter of 1 to 3 mm.
There is a range from φ to the needle hole, and it is appropriately selected according to the welding member. The optimal nozzle diameter, number, and pitch are selected to prevent interference between the flames and obtain a stable molten state.

In the case where the line burner nozzles 31 are arranged in a line, for example, in a row of seven nozzles and emit a flame, the nozzle at the position furthest from the gas supply side of the supply pipe has the largest gas flow rate.
Since the amount of gas discharged from the nozzle in front of the supply pipe is the smallest, the amount of heat supplied differs at the nozzle position and the balance is lost. Therefore, the nozzle diameters are changed in the order in which they are arranged to achieve balance. In addition, the balance is achieved by changing the length of the nozzle protruding from the supply pipe in the arrangement order while keeping the nozzle diameter the same. However, this method has a problem that it takes time and effort to process the burner and cannot cope with changes in gas pressure and gas supply amount.

As shown in FIG.
The line burner formed at 0 is suitable as the burner of the method of the present invention because the flame flow from each nozzle is uniformly radiated and the calorific value is uniformly supplied irrespective of the position of the nozzle 31. The tip is formed in a loop 30 and a nozzle 3
By adopting a structure in which 1 is formed in a line shape, the mixed gas of the supplied oxyhydrogen gas orbits in the gas pipeline, so that the gas flow in the supply pipeline is biased due to the position of the nozzle 31. Thus, each nozzle of the line burner can be formed in the same shape, and a uniform gas flow can be supplied, so that a uniform flame can be supplied.

A vertical wafer boat assembling apparatus A vertical wafer boat assembling apparatus using the welding method of the present invention will be described. As shown in FIG. 5, a top plate chuck 51 and a bottom plate chuck 52 are provided on the base 4 at an interval. Each of the chucks 51 and 52 is provided with a vacuum suction device for clamping the top plate 11 and the bottom plate 12, is rotatable, and is movable in the axial direction. In the movement, the moving speed and the moving distance are set and controlled by the cylinder device, and the pressing force applied to the welding surface is controlled. On the sides of both chucks 51 and 52, two sets of heating line burners 3 that can move in the axial direction and the vertical direction are arranged in opposition, and the number corresponding to the groove rod 2 to be welded is provided. In order to adjust the flame emission angle with respect to the top plate 11 and the bottom plate 12, the line burner 3 is rotatably held.

Further, after the rod-shaped member 2 is pressure-welded to the plate-shaped member 1, a burner 3 for wire-drawing the welded portion is provided.
2 is attached to the arm 6 of the 6-axis articulated robot.
In addition, four mass flow meters for controlling the supply of hydrogen and oxygen gas to the line burner 3 at a constant level are provided.

Between the top plate chuck 51 and the bottom plate chuck 52, four groove bars 2 are held at predetermined positions, and are moved on the base 4 in the axial direction to apply a pressing force during welding. A slide device 7 for pressing the groove bar 2 and the top plate 11 and the bottom plate 12 is provided. The clamp 71 for holding and fixing the groove rod 2 of the slide device 7 has a structure in which the center of the groove rod 2 is the center of the setting, so that even if the diameter of the groove rod 2 changes, the welding position does not shift. It is. In the case where the rod-shaped member is a grooved rod, the precision maintenance and reproducibility can be further improved by fitting and holding the grooved rod in a comb-shaped pedestal manufactured according to the groove shape.

The top plate 11 and the bottom plate 12 are connected to the vacuum chuck 5
Four groove rods 2 fixed at 1, 52 and having conical end faces
Is fixed at a predetermined position by the clamp 71 of the slide device 7.

The line burner 3 is mounted on the welding surface of the top plate 11.
Is rotated and set at an angle of 25 degrees, and the line burners 3 are arranged to face each groove bar 2 so that the flame can be sent from two directions. Move the slide device 7 to the top plate 11 side,
The distance between the conical tip of the groove bar 2 and the top plate 11 is set to 2 mm. The top plate 11 and the four groove bars are simultaneously heated by the line burners 3 set at four places, and when softened, the slide device 7 is moved to the top plate 11 while being heated, so that the end of the groove bar 2 is 2 mm. It is pressed against the top plate 11 until it is crushed, and the groove rods 2 are simultaneously pressed on four pieces. After the pressing, the holding of the top plate by the top plate chuck 51 is released, and the line burner 3
Are moved in the vertical direction, respectively, and the wire bonding burner 32 attached to the arm 6 of the six-axis articulated robot performs wire-drawing at four crimping portions.

Subsequently, the slide device 7 is moved to the melting position on the bottom plate 12 side, and the distance between the end face of the groove 2 and the bottom plate 12 is similarly set to 2 mm. When the bottom plate 12 and the four groove bars 2 are simultaneously heated by the line burner 3 and softened, the slide device 7 is moved to the bottom plate 12 side when the bottom plate 12 and the four groove bars 2 are softened.
Are crimped simultaneously. In the crimping section, four crimping sections are wire-lined by a wire-drawing burner 32 attached to a six-axis articulated robot. After the welding of the bottom plate 12 and the groove bar 2 is completed, the clamp of the bottom plate chuck 52 is released, and the slide device 7 is returned to the center of both chucks and stopped. Clamp 71 of groove rod 2
Unlock and remove the assembled vertical wafer boat.

As a result of inspecting the vertical wafer boat thus obtained, no deformation such as swelling or dent was observed in any of the eight places where the groove bar was press-bonded to the top plate and the bottom plate. The standard tolerance from the reference surface of the wafer boat to the first groove is ± 0.1m without any shape collapse.
m, which satisfied the high accuracy specification.

As another embodiment of the wafer boat assembling apparatus, an example will be described in which the groove bar 2 of the bar member is fixed, and the plate member 1 is moved toward the end face of the bar member 2 and pressed.

As in the case of the first embodiment, a flame angle of 25 degrees is provided with respect to the welding surface of the top plate 11, and the line burners 3 are arranged to face each other so as to send the flame from two directions. Top plate chuck 5
1 is moved to the melting position, and the distance between the top plate welding surface and the groove rod end surface is 2
mm. The top plate 11 and the four groove bars 2 are simultaneously heated by the line burner 3 and when softened, the top plate chuck 51 is slid to the groove bar 2 side, and the groove bar 2 is pressed perpendicularly to the joint surface and pressurized. The plate 11 and the four groove bars 2 are pressed simultaneously. A burner 32 attached to a six-axis articulated robot arm performs wire-drawing at four crimping portions. After the welding of the top plate 11 and the groove bar 2 is completed, the top plate chuck 51 is released.

Subsequently, the chuck 52 of the bottom plate 12 is moved toward the groove bar 2 to maintain a distance of 2 mm between the other end face of the groove bar 2 and the bottom plate 12. Bottom plate 1 with line burner 3
The two and four groove bars 2 are simultaneously heated and softened, the bottom plate chuck 52 is moved in the direction of the groove bar end surface, and the bottom plate 12 and the four groove bars 2 are simultaneously crimped, and the crimping portion is similarly wire-lined. Do it. The chuck of the bottom plate 12 is released, and then the clamp of the groove bar 2 is released, and the assembled vertical wafer boat is removed from the apparatus.

As a result of inspecting the obtained product, no deformation such as swelling or dent was observed at eight places where the groove bar was joined to the top plate and the bottom plate, and 10 m from the flange.
The groove shape of the first groove of the groove bar at the position of m does not collapse, and the standard tolerance from the reference surface of the wafer boat to the first groove is within a range of ± 0.1 mm, which satisfies the high precision specification. Was something.

[0041]

According to the present invention, since the end face of the rod-shaped member is formed in a convex shape, and pressure is applied from the vertical direction to the joint surface while being heated by the flame of the burner to perform pressure bonding, the welding rod conventionally required for welding a quartz glass member is used. Is unnecessary, and the surface deformation of the joint surface can be prevented, so that it is not necessary to reshape the joint surface. Further, in the process of assembling the wafer boat, it is not necessary to use a carbon jig, and at the same time, the temporary welding process which has been performed manually can be omitted.

Further, even if the diameter of the rod-shaped member varies, the rod-shaped member is always held at the center position of the diameter by the clamp, so that it is possible to assemble with high precision and reproducibility, and it is not necessary to rework the welded portion. It is possible to join and assemble efficiently. A plurality of rod-shaped members can be simultaneously welded and joined to a plate-like body by a method of welding quartz glass members having high dimensional accuracy and excellent reproducibility, and it has become possible to efficiently manufacture a wafer boat.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a welding state.

FIG. 2 is a perspective view of a vertical wafer boat.

FIG. 3 is an explanatory view of a carbon jig.

FIG. 4 is a plan view of a line burner having a loop.

FIG. 5 is a front view of the wafer boat assembling apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plate-shaped member 2 Rod-shaped member 3 Burner

Claims (13)

[Claims] 1. A method for welding a quartz glass member in which a joining surface between an end surface of a rod-shaped member and a plate-shaped member is heated and softened, and the rod-shaped member and / or the plate-shaped member is pressed perpendicularly to the joining surface and pressure-bonded. 2. A method for welding a quartz glass member in which the end surface of a rod-shaped member is formed in a convex shape, and is pressed vertically to a joint surface with a plate-like member while being heated and pressure-bonded. 3. The method according to claim 1, wherein the rod-shaped quartz glass member and the plate-shaped member are pressed by being relatively moved.
A method for welding quartz glass members to be crimped. 4. A plurality of bar-shaped quartz glass members are supported by a work holding portion, and the plurality of bar-shaped members are simultaneously pressed by moving the work holding portion and the plate-shaped member relative to each other. Method for welding quartz glass members. 5. The welding of a quartz glass member according to claim 1, wherein the convex shape of the joint end surface of the rod-shaped quartz glass member is a wedge-shaped or conical shape that is symmetric with respect to the center of the end surface. Method. 6. The method for welding a quartz glass member according to claim 5, wherein the inclination angle of the wedge or the cone is 2 degrees to 20 degrees. 7. The method for welding a quartz glass member according to claim 5, wherein a flame is sent symmetrically from at least two directions from a center point of the wedge-shaped or conical shape, and the welding portion is opposedly heated. 8. The method for welding a quartz glass member according to claim 7, wherein the flame angle of the burner with respect to the plate member surface is 5 to 45 degrees. 9. The method for welding a quartz glass member according to claim 1, wherein the heating means is a forked burner or a line burner made of quartz glass. 10. A method for welding a quartz glass member according to claim 9, wherein the end of the line burner is formed in a loop, and a plurality of nozzles are formed in a line at the end. 11. A method for welding a quartz glass member according to claim 1, wherein the distance between the surface of the plate member and the apex of the projection on the end surface of the rod member at the start of heating is 1 to 3 mm. 12. A top plate is positioned and fixed, and a plurality of groove bars or rod members for a groove bar having a convex end surface are held vertically to the top plate, and the top plate and the groove bars or the rod members for the groove bar are held. A flame is sent at a flame angle of 5 to 45 degrees from at least two directions to the welded part with the member, and a pressing force is applied from the vertical direction to the joint surface while heating, so that a plurality of groove rods or rod-like members for groove rods are simultaneously heated. A method for assembling a vertical wafer boat, which is pressure-bonded to a plate and similarly pressure-bonded to a bottom plate and a groove bar or a rod-shaped member for a groove rod. 13. An axially movable top plate chuck and a bottom plate chuck provided at intervals on a base, and a plurality of groove bars or groove bar members provided between the top plate chuck and the bottom plate chuck. Fixed and axially movable slide device,
A burner for heating the joint surface between the top plate or the bottom plate and the groove bar, and a pressure applying mechanism for controlling the movement of the top plate chuck, the bottom plate chuck and the slide device to apply a pressing force to the joint surface from a vertical direction are provided. Vertical wafer boat assembly equipment.