JP4560200B2 - Method of welding quartz glass members - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a quartz glass wafer boat used for holding a wafer during heat treatment of a semiconductor wafer, a quartz glass container used for holding or transferring a wafer during wafer transfer, drying, washing, etc. The present invention relates to a method of manufacturing a quartz glass product such as a jig, and relates to a method of welding a quartz glass member when assembling and manufacturing such a product.
[0002]
[Prior art]
In the manufacturing process of a semiconductor device, quartz glass, which is a high-purity material that is stable even at high temperatures and does not mix impurities in the semiconductor, is used as a jig. Among quartz glass jigs used for semiconductor manufacturing, wafer boats and quartz glass cleaning jigs are assembled by welding a top plate and a bottom plate to a rod-like member having grooves as shown in FIG. Yes.
[0003]
Conventionally, the end surface of a rod-like quartz glass member is applied to the surface of a plate-like quartz glass member, and a welding rod made of quartz glass having a diameter of 2 to 3 mmφ is melt-bonded with an oxyhydrogen flame around the welded place with a hand-held burner Is common. In addition, there is a method of welding using a laser after disposing a welding rod between the welded ends of two quartz glass members to be welded as disclosed in JP-A-4-182322.
[0004]
The conventional methods are methods in which members to be welded are joined and assembled via welding rods. Therefore, if the welded portion of the welding rod is poorly melted, it may cause poor welding due to poor heating, foaming may occur, or the bonding strength may be insufficient. There are cases where appearance problems such as deformation of the surface and depression of the welding surface occur in terms of assembly accuracy.
For this reason, joining using a welding rod is suitable for work that increases the strength of the joint by applying sufficient fire, but since the surface deformation is large, it is necessary to reshape the joint surface by reworking or carbon trowel. It is unsuitable for those requiring accuracy and those that perform continuous assembly work.
[0005]
When a vertical wafer boat as shown in FIG. 2 is manufactured, in the conventional method, a quartz glass rod-shaped member is usually cut with a diamond wheel to provide a groove for placing the wafer (the groove is provided after being assembled on the boat). 3), as shown in FIG. 3, a plurality of (four in this figure) groove rods are arranged so as to be in predetermined positions using a carbon jig, Temporarily welded the grooved boat to the top and bottom plates, which are positioned parallel to the left and right at intervals, to temporarily assemble the wafer boat, take out the temporarily welded assembly from the carbon jig, and measure it to meet specifications. After checking with a tool, etc., and making corrections, temporary welding was redone, and after confirming that it was within a predetermined dimensional tolerance, the main welding was performed and assembled.
[0006]
In this conventional method, a number of carbon jigs must be prepared according to the various standards and specifications of the wafer boat, and the carbon jigs must have the specified dimensions including the problem of wear of the carbon jigs. A lot of time and labor were spent on fine-tuning work for placing quartz glass members such as top plates and groove bars on the surface.
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 diameter of the set groove rod to the center of the diameter of the other groove rod Since the distances of the products differ, the finished product has a problem of being assembled with dimensional tolerances different from the specifications.
In any case, since each operation is a manual operation, it depends on the skill level of the operator, and there is a problem that an extra process called a temporary welding process must be taken.
[0007]
[Problems to be solved by the invention]
The present invention solves such problems of the prior art, prevents the surface deformation that occurs in the case of joining via a welding rod, and eliminates the need to re-form the joining surface. In addition to eliminating the need for an assembly process that uses a carbon jig, it is also possible to eliminate the manual welding process at this time, with high dimensional accuracy and excellent reproducibility. It is an object of the present invention to provide a wafer boat welding method and apparatus suitable for a typical assembly operation process.
[0008]
[Means for Solving the Problems]
When welding the end surface of the rod-shaped quartz glass member to the surface of the plate-shaped quartz glass member, it has been found that the bonding surface may be heat-softened and pressure-bonded by applying pressure from the vertical direction. The above-mentioned problems have been solved by forming the end face into a convex shape and applying pressure from a direction perpendicular to the joining surface while heating with a burner flame.
[0009]
Then, it is effective to fix the rod-like quartz glass member and the plate-like member by fixing one of them and moving the other, or allowing both to move and relatively moving them in the joining surface direction and applying pressure. The plurality of rod-like quartz glass members are supported by the work holding portion, and the plurality of rod-like members can be simultaneously pressed by moving the work holding portion and the plate-like member relatively in the joining surface direction and applying pressure.
[0010]
Furthermore, the convex shape of the end surface to which the rod-shaped quartz glass member is joined is a wedge shape or a cone shape so as to be symmetrical from the center of the rod-shaped end surface.
By appropriately selecting the central point of the convex shape of the end surface of the rod-shaped member or the inclination angle from the vertex of the center surface to the peripheral surface according to the amount of crushing of the rod-shaped quartz glass member by the pressure bonding, the pressure bonding is appropriately performed.
Crimping was ensured by sending a flame from at least two directions symmetrical from the center point of the wedge-shaped or conical-shaped end surface of the rod-shaped member and opposingly heating the welded portions. Furthermore, it discovered that it was preferable to counter-heat at the flame angle of 5-45 degree | times with respect to the plate-shaped member surface to weld.
[0011]
A quartz glass bifurcated burner or a line burner is preferable for heating the welded portion, and the tip of the line burner is U-turned and connected to a supply pipe is preferable for uniform supply of combustion gas. .
In addition, it is effective to set the distance between the surface of the plate-like member at the start of heating and the convex vertex of the end face of the rod-like member to 1 to 3 mm.
[0012]
When welding and assembling a vertical wafer boat by welding a groove rod or rod-like member to the upper flange as the bottom plate and the side plate as the top plate, position the plate member of the top plate with the clamp chuck, A flame angle of 5 to 45 degrees is provided with respect to the welding surface of the member, the burner is arranged so as to send the flame from at least two directions, the rod-shaped quartz glass member is supported by the slidable work holding part, and heated by the burner. The workpiece holder or the top plate or both are moved relative to each other so that they are pressed perpendicularly to the joining surface, and then joined by pressure bonding.Then, after the top plate chuck clamp is released, the other plate-shaped member is placed on the bottom plate positioned by the clamp chuck. The end surfaces can be joined by pressure bonding, and a large number of rod-shaped members can be manufactured by simultaneous welding to a plate material, and a vertical wafer boat can be efficiently produced.
[0013]
And a support / rotation / movement means for supporting, rotating and moving the quartz glass top plate and the bottom plate provided on the base at intervals, a support / rotation / movement control means for the burner, and a gas for the burner Flow rate control means, support / moving means for supporting and moving the quartz glass rod-shaped member in the axial direction, and pressure applying means for moving the top plate, bottom plate and quartz glass rod-shaped member relative to each other and applying pressure from the vertical direction to the joint surface The wafer boat can be manufactured with high accuracy and reproducibility.
[0014]
Examples of quartz glass products to be assembled by applying the present invention include vertical quartz glass wafer boats such as CVD boats and diffusion boats used in semiconductor heat treatment processes, semiconductor wafer transport containers, and cleaning jigs. It is done.
[0015]
The method for welding a quartz glass member of the present invention is particularly effective when assembling the end surface of a rod-like quartz glass member such as a groove rod by welding to a flat quartz glass member such as a top plate of a wafer boat. .
The rod-shaped member uses a groove rod in the case of the front cutting method that is first grooved into a round bar and then assembled into a boat. You can use it and assemble it into a boat.
Although the above-mentioned product is given as an example, it can be applied to various products.
The shape of the rod-shaped member to be joined to the plate-shaped member is applicable to a round bar, a square bar, a polygonal shape, or other irregular shapes.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the end surface of a quartz glass rod (rod-shaped member) 2 having a diameter of 20 mm is formed in a V-shaped wedge shape with an inclination angle of 5.7 degrees, and is separated from the surface of the quartz glass plate-shaped member 1 by 3 mm. Positioned vertically. An oxyhydrogen flame burner 3 is placed opposite to both sides of the round bar 2 and is positioned 15 mm away from the plate member at an angle of 20 degrees, and a flame is applied to the joint surface at 30 liters / minute of hydrogen and 10 liters / minute of oxygen. The sample was supplied, heated and softened, and the round bar 2 was pressed against the plate member 1 until it was crushed by 2 mm from the tip, and was crimped.
In normal welding, the objects to be welded are melted sufficiently well by heating and are joined by the melt flow, but this application is for pre-softening the member surface, It is to be bonded by pressure bonding.
[0017]
Therefore, as in the conventional case where the periphery of the bar is heated with a burner and the place is pressure-shaped with a carbon roller or the like, the joining surface is melted and melted and flowed to increase the melt strength. This is essentially different from conventional pressurizing means.
[0018]
In the pressure bonding, pressure is applied so that the axis of the rod-shaped member 2 is perpendicular to the plate-shaped member surface. The rod-like member and the plate-like member are moved so as to be relatively close to each other, but the member to be moved may be either the rod-like member or the plate-like member, or both members may be moved simultaneously.
By relatively moving, a pressing force from a direction perpendicular to the welding surface is generated, and this movement is controlled by setting a moving speed and a moving distance by a cylinder device, thereby controlling the pressing force.
[0019]
By applying an appropriate pressing force, uniform and reproducible joining is possible, and heating to the vicinity of the softening point of quartz glass is possible without heating the joining surface to the molten state, so deformation of the joining surface is possible. It becomes possible to prevent.
The pressing force is based on a fluid pressure cylinder or by transferring the rotational torque of the electric motor to the work support, etc. It is preferable because it is easy to obtain.
The pressing force is appropriately selected according to the shape of the member and the softened state of the joint surface, but is preferably in the range of 0.1 to 100 g / mm ² .
[0020]
The joining end face of the rod-shaped member is processed into a convex shape. When heated by the convex shape, the center part of the end face is first softened, and further, pressure is applied to the outer peripheral part in order from the center part of the end face. Even if it occurs, it is difficult to remain because it escapes outward. Further, since welding is sequentially performed from the center toward the outside, the welding strength can be increased even with a small heating amount. For this reason, it is not necessary to heat not only the welding surface but also its surroundings with a burner as in the conventional method, and welding only with its heat capacity, so that the amount of heat can be reduced to the minimum, and deformation of the welding surface can be prevented. .
The end face shape of the convex bar-like member is preferably a symmetrical shape from the center of the end face in order to make the surface distribution of softening uniform. Specifically, a wedge shape or a cone shape is effective.
[0021]
The inclination angle from the center point of the convex shape of the end surface of the rod-shaped member 2 or the vertex of the center surface to the peripheral surface is appropriately selected according to the amount of crushing of the quartz glass rod-shaped member 2 by pressure bonding. For example, if the inclination angle of the cone is constant, the length of the rod-shaped member to be crushed varies depending on the diameter of the rod-shaped member 2 and thus the height of the cone is different. Once the cross-sectional shape of the bar-shaped member and the convex inclination angle are determined, the volume of the convex body that is crushed during welding can be obtained, so by creating a comparison table in advance, the amount of crushing of the bar-shaped member can be predicted with high accuracy Welding is possible. As an optimum range, the inclination angle of the wedge or cone is in the 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 conical inclination angle is preferably about 6 degrees.
[0022]
The assembly device stores the contrast between the diameter of the rod-shaped member, the amount of crushing, and the convex inclination angle, and automatically controls the relative movement of the member to continuously perform welding joints with excellent surface properties with high reproducibility. Can be done manually.
[0023]
The heating by the burner 3 sends a flame from at least two directions which are symmetrical from the center point of the end surface of the wedge-shaped or conical rod-shaped member, and heats the welded portions facing each other. The distance from the burner crater to the outer peripheral surface of the rod-shaped member is a constant distance of 10 to 30 mm, although it depends on the nozzle diameter of the burner 3. Moreover, it is desirable that the flame angle of the burner is oppositely heated at a flame angle of 5 to 45 degrees with respect to the plate-like member surface to be welded.
[0024]
It is important to uniformly soften the welding surface without deforming it, and the above-described method is effective in avoiding the influence of radiant heat and bonfire from the member as much as possible. If the flame angle of the burner is less than 5 degrees, softening of the convex portion apex portion of the rod-shaped member is too early as compared with other welding locations and the balance is poor, and the overall welding strength is lowered, which is not preferable. On the other hand, if the angle is greater than 45 degrees, the outer peripheral surface of the convex member is too early compared to other welding locations, and the outer peripheral shape after welding bulges outward, and at the same time, the plate member surface layer is also recessed. Is not preferable, and a flame angle of 10 to 30 degrees is more preferable.
[0025]
It is effective to set the distance between the surface of the plate-like member at the start of heating by the burner 3 and the convex vertex of the end face of the rod-like member to 1 to 3 mm.
When the plate-like member and the end face of the rod-like member are kept in contact with each other, since it takes time to make the glass softened, the flame interlaces with the radiant heat reflected from the plate-like member as a reflected flow, As a result, the wall surface around the end surface of the rod-shaped member 2 is melted by radiant heat, and the outer peripheral surface is deformed by the reflected flow, which is not preferable. Further, if the distance between the plate-like member and the end face of the rod-like 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. Moreover, if it exceeds 3 mm, heating efficiency will worsen and a strong flame flow will be needed. Therefore, it is preferable to set the initial interval between the members to 1 to 3 mm.
[0026]
The burner 3 is preferably a quartz glass bifurcated burner or a line burner. In order to soften with a small amount of heat, it is important to balance the amount of heat supplied to the heating region. Therefore, in order to supply the gas amount to be supplied uniformly, a bifurcated burner is suitable when the convex shape of the end face of the rod-shaped member 2 is a wedge shape, and a line burner is suitable when the convex shape is a conical shape.
[0027]
The line burner has a nozzle diameter ranging from 1 to 3 mmφ to a needle hole, and is appropriately selected according to the welding member. The optimum nozzle diameter, number and pitch are selected so as to prevent interference between flames and obtain a stable molten state.
[0028]
When, for example, seven line burner nozzles 31 are arranged in a row and a flame is emitted, the gas flow rate of the nozzle farthest from the gas supply side of the supply pipe is the highest, and the gas is discharged from the nozzle nearest to the supply pipe. Since the amount of gas to be produced is the smallest, the supply amount of heat differs depending on the position of the nozzle, and the balance is lost. In addition, the nozzle diameter is made the same, and the length of the nozzle protruding from the supply pipe is changed in the order of arrangement to achieve a balance.
However, this method has a problem that it takes time to process the burner and cannot cope with changes in gas pressure and gas supply amount.
[0029]
The line burner having the nozzle tip formed in the loop 30 as shown in FIG. 4 irradiates the flame flow from each nozzle uniformly regardless of the position of the nozzle 31 and supplies the amount of heat uniformly. Suitable as
Since the tip is formed in the loop 30 and the nozzle 31 is formed in a line shape in the loop portion, the mixed gas of the supplied oxyhydrogen gas circulates in the gas pipe, so the position of the nozzle 31 This eliminates the uneven gas flow in the supply pipe, allows the nozzles of the line burner to have the same shape, enables a uniform gas flow to be supplied, and provides a uniform flame.
[0030]
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. Both chucks 51 and 52 are provided with a vacuum suction device for clamping the top plate 11 and the bottom plate 12, can be rotated, and can be moved in the axial direction. The movement is controlled by setting and controlling the moving speed and moving distance with the cylinder device to control the pressing force applied to the welding surface.
On both sides of the chucks 51 and 52, two heating line burners 3 that are movable in the axial direction and the vertical direction are arranged so as to face each other, and the number corresponding to the groove rod 2 to be welded is provided. In order to adjust the flame radiation angle with respect to the top plate 11 and the bottom plate 12, the line burner 3 is rotatably held.
[0031]
Furthermore, after the rod-like member 2 is pressure welded to the plate-like member 1, a burner 32 is attached to the arm 6 of the 6-axis multi-joint robot for performing a line drawing process of the welded portion.
In addition, four systems of mass flow meters are provided that control the supply of hydrogen and oxygen gas to the line burner 3 at a constant level.
[0032]
Between the top plate chuck 51 and the bottom plate chuck 52, the four groove rods 2 are held at predetermined positions, and are moved on the base 4 in the axial direction to apply a pressing force at the time of welding so that the groove rod 2 And a slide device 7 for crimping the top plate 11 and the bottom plate 12 are 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 setting, so that the welding position does not shift even if the diameter of the groove rod 2 is changed. It is. When the rod-shaped member is a groove rod, the accuracy is maintained and the reproducibility is further improved by fitting and holding the groove rod in a comb-shaped cradle manufactured in accordance with the groove shape.
[0033]
The top plate 11 and the bottom plate 12 are fixed by the vacuum chucks 51 and 52, and the four groove rods 2 whose end surfaces are conical are fixed at predetermined positions by the clamps 71 of the slide device 7.
[0034]
The line burner 3 is rotated with respect to the welding surface of the top plate 11 and set at an angle of 25 degrees, and the line burner 3 is arranged so as to face each groove rod 2 so that a flame can be sent from two directions. The slide device 7 is moved to the top plate 11 side, and 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 rods are heated at the same time with the line burner 3 set at four locations, and when the softened state is heated, the slide device 7 is moved to the top plate 11 side, and the end of the groove rod 2 is 2 mm. It is pressed against the top plate 11 until it is crushed, and the groove rods 2 are simultaneously crimped to the four.
After the crimping, the holding of the top plate by the top plate chuck 51 is released, the line burner 3 is moved up and down in the vertical direction, and the wire at the four crimping parts is lined by the wire burner 32 attached to the arm 6 of the 6-axis articulated robot. Take it.
[0035]
Subsequently, the slide device 7 is moved to the melting position on the bottom plate 12 side, and the distance between the end surface of the groove rod 2 and the bottom plate 12 is similarly set to 2 mm. The bottom plate 12 and the four groove rods 2 are simultaneously heated by the line burner 3, and when the softening is performed, the slide device 7 is moved to the bottom plate 12 side to simultaneously press the bottom plate 12 and the four groove rods 2 together. The crimping part performs line drawing at four crimping parts by a line burner 32 attached to a 6-axis articulated robot. After the welding of the bottom plate 12 and the groove rod 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. The clamp 71 of the groove rod 2 is released, and the assembled vertical wafer boat is taken out.
[0036]
As a result of inspecting the vertical wafer boat obtained in this way, no deformation such as bulge or dent was observed in any of the 8 places where the groove rod was crimped and joined to the top plate and the bottom plate, and the groove shape of the groove rod collapsed. In fact, the standard tolerance from the reference plane of the wafer boat to the first groove was within a range of ± 0.1 mm, and the high-precision specification was satisfied.
[0037]
As another embodiment of the wafer boat assembling apparatus, an example will be described in which the grooved rod 2 of the rod-shaped member is fixed and the plate-shaped member 1 is moved toward the end surface of the rod-shaped member 2 for pressure bonding.
[0038]
Similar to 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 burner 3 is disposed so as to face the flame from two directions. The top plate chuck 51 is moved to the melting position, and the distance between the top plate welding surface and the end face of the groove rod is maintained at a distance of 2 mm. When the top plate 11 and the four groove rods 2 are simultaneously heated and softened by the line burner 3, the top plate chuck 51 is slid to the groove rod 2 side, and the groove rod 2 is pressed perpendicularly to the joining surface to be pressurized. The plate 11 and the four groove rods 2 are simultaneously crimped. The burner 32 attached to the 6-axis articulated robot arm is used to wire the four crimping parts. After the top plate 11 and the groove rod 2 are completely welded, the top plate chuck 51 is released.
[0039]
Subsequently, the chuck 52 of the bottom plate 12 is moved toward the groove rod 2, and the distance between the other end surface of the groove rod 2 and the bottom plate 12 is maintained at a distance of 2 mm. The bottom plate 12 and the four groove rods 2 are simultaneously heated and softened by the line burner 3, the bottom plate chuck 52 is moved in the direction of the groove rod end surface, and the bottom plate 12 and the four groove rods 2 are simultaneously crimped. Make a line drawing.
The chuck of the bottom plate 12 is released, and then the clamp of the groove rod 2 is released, and the assembled vertical wafer boat is taken out from the apparatus.
[0040]
As a result of inspection of the obtained product, no deformation such as swelling or dent was observed in any of the 8 places where the groove rod was joined to the top plate and the bottom plate, and the first groove of the groove rod located 10 mm from the flange. The groove shape was not collapsed, and the standard tolerance from the reference plane of the wafer boat to the first groove was also within a range of ± 0.1 mm, satisfying the high precision specification.
[0041]
【The invention's effect】
The end face of the rod-shaped member has a convex shape and is heated by the flame of the burner to apply pressure from the vertical direction to the joint surface for pressure bonding, eliminating the need for the conventional welding rod required for quartz glass member welding. Surface deformation of the surfaces can be prevented, and there is no need to reshape the joint surfaces.
Further, in the wafer boat assembly process, it is not necessary to use a carbon jig, and at the same time, the temporary welding process that has been performed manually can be omitted.
[0042]
In addition, even if there are variations in the diameter of the rod-shaped member, the rod-shaped member is always held at the center of the diameter by the clamp, so it can be assembled with high accuracy and good reproducibility. Can be joined and assembled.
With a method for welding quartz glass members having high dimensional accuracy and excellent reproducibility, a plurality of rod-like members can be welded and joined to a plate-like body at the same time, making it possible to manufacture a wafer boat efficiently.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a welding state.
FIG. 2 is a perspective view of a vertical wafer boat.
FIG. 3 is an explanatory diagram 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]
1 Plate member 2 Bar member 3 Burner

Claims (11)

A quartz glass member that heats and softens the joint surface between the convex end surface of the rod-shaped member having a convex end surface and the plate-like member, and presses the rod-like member and / or plate-like member perpendicularly to the joint surface to perform pressure bonding. Welding method. The method for welding a quartz glass member according to claim 1, wherein the rod-like quartz glass member and the plate-like member are pressed and pressure-bonded by relative movement. 3. The method for welding a quartz glass member according to claim 1, wherein the plurality of rod-shaped members are supported by the workpiece holding portion, and the plurality of rod-shaped members are simultaneously pressure-bonded by relatively moving the workpiece holding portion and the plate-like member. . 4. The method for welding a quartz glass member according to claim 1, wherein the convex shape of the joining end face of the rod-like member is a wedge-shaped or conical shape that is symmetrical with respect to the center of the end face. 5. The method for welding a quartz glass member according to claim 4, wherein the inclination angle of the wedge or the cone is 2 degrees to 20 degrees. 6. The method for welding a quartz glass member according to claim 4, wherein flames are sent from at least two directions symmetrically from the center point of the wedge-shaped or conical shape, and the welding locations are oppositely heated. 7. The method for welding a quartz glass member according to claim 6, wherein the flame angle of the burner with respect to the plate-like member surface is 5 to 45 degrees. The method for welding quartz glass members according to any one of claims 1 to 7, wherein the heating means is a quartz glass bifurcated burner or a line burner. 9. The method for welding a quartz glass member according to claim 8, wherein the tip of the line burner is formed in a loop, and a plurality of nozzles are formed in a line shape at the tip. The method for welding a quartz glass member according to any one of claims 1 to 9, wherein a distance between the surface of the plate-like member and the convex vertex of the end face of the rod-like member at the start of heating is 1 to 3 mm. The top plate is positioned and fixed, and a plurality of groove rods or groove rod rod-shaped members whose end surfaces are convex are held perpendicular to the top plate, and the welded portion between the top plate and the groove rod or groove rod rod-shaped member The flame is sent at a flame angle of 5 to 45 degrees from at least two directions, and a pressing force is applied from the vertical direction to the joining surface while heating, and a plurality of groove rods or rod members for groove rods are simultaneously bonded to the top plate by pressure bonding. Similarly, a method for assembling a vertical wafer boat in which a bottom plate and a groove rod or a rod-shaped member for a groove rod are joined by pressure bonding.

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