JPH04182322A - Method and device for welding quartz member - Google Patents

Abstract

PURPOSE:To prevent thermal cracking and the redeposition of the sublimed vapor and to obtain a high-quality product in the laser welding by forming a gap between the end faces of the plural quartz members to be welded. CONSTITUTION:A laser beam 1b is dispersed beyond a focus 1c and defocused to irradiate a filler rod 4 arranged between quartz members 2 and 3 and the end faces 2a and 3a of the members 2 and 3, and the rod 4 is melted to make a padding 4a. The tip 7a of a gas spray nozzle 7 is always positioned close to the molten region of the rod 4, a working gas is supplied in the welding direction from the side to prevent the deposition of the sublimate generated by welding, and the entire welding zone including the padding 4a is made transparent. A gap 8 is set between the members 2 and 3, and a groove 13 is provided on the end faces 2a and 3a. Consequently, the area is increased, the penetration reaches to the rear, and the members are stably, uniformly and smoothly welded since the filler is fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION Field of Industrial Application The present invention relates to a method and a device for welding quartz parts by means of a laser.

2. Description of the Related Art Various quartz members are used as members for high-temperature processing of semiconductor wafers. Conventionally, such quartz members have been cut into predetermined dimensions and then manually welded, generally using oxyhydrogen flame gas.

Problems to be Solved by the Invention Since quartz has a high melting point, a highly concentrated heat source is required as a heat source. In the past, oxyhydrogen flame gas was generally used as the heat source, which posed the risk of explosion during work. Not only that, but the work place was prone to high temperatures and humidity, creating a poor work environment.

In addition, since the welding was done by hand, a skilled person was required. Furthermore, multiple workers were required to perform the work at the same time. As a result, work efficiency was poor. Furthermore, the quality of the product tends to vary and has poor quality stability. For example, quartz products were often contaminated with water and impurities.

When welding metal materials, laser welding is often used because it has smaller thermal contraction, higher precision, and less heat influence than plasma welding, but when laser welding quartz materials, Quartz has a high melting point and is difficult to soften, and once it begins to melt, sublimation (evaporation) begins. When carried out under the melting conditions of metal materials, thermal cracking due to the temperature gradient near the molten part occurs. There was also the problem that sublimed gas would re-deposit.

The purpose of this invention is to provide excellent safety and productivity;
Moreover, it is an object of the present invention to provide a method and apparatus for welding a quartz member with good quality.

[Structure of the Invention] Means for Solving the Problems This invention provides a quartz member welding method in which a plurality of quartz members are welded by laser irradiation. Welding of a quartz member, characterized in that the end face is placed on a support with a gap, a quartz welding material is placed in the gap, and welding is performed by irradiating a defocused laser beam from above. The method is summarized.

In a preferred embodiment of the present invention, a groove is formed between both end faces of two quartz members to be welded, and a rod-shaped or powdered welding material is placed at least in the groove. The quartz members are welded by irradiating laser light.

Before placing welding materials on the end faces of multiple quartz members, place the quartz member setting means (for example, a stand made of carbon, etc.) across both end faces of the quartz members to support both quartz members from below, and then It is desirable to set the member on a table and place a rod-shaped or powdered welding material in the space formed by the table and both end faces of the quartz member (that is, the groove or gap -5=gap). For example, form a figure 7-shaped groove, provide a gap of 0.5 to 5 mm under the figure 7-shaped groove, set a carbon stand under it, and place the welding material at least in the groove. Then, the welding material is irradiated with a laser.

In the present invention, in order to create a gap between the end faces of a plurality of quartz members to be welded, when the welding material is irradiated with a laser,
Even, reliable and good welding is performed in the entire welding area.

Embodiments In FIGS. 1 to 3, reference numeral 1 schematically indicates an example of a laser device. A condensing lens 1a and the like are provided inside the laser device 1. The laser device 1 is configured to condense laser light 1b to form a condensing point IC between the laser device 1 and the quartz members 2 and 3 to be welded. The laser beam 1b is focused at its focal point 1-C
The filler rod 4 disposed between the two quartz parts 2 and 3 and the end faces 2a and 3a of the two quartz parts 4/12 and 3 are irradiated with a defocused laser beam. It has become so. The laser beam hits the filler rod 6 (=J
When the quartz member is irradiated closely, the end of the quartz member is heated and the filler rod 6 is melted, forming a build-up 4a.

An operating mechanism (not shown) is provided to spray gas so that the tip 7a of the nozzle 7 is always near the melting point of the filler rod 4. The tip 7a of the nozzle 7 flows processing gas from the side in the welding direction to prevent the sublimate produced by welding from becoming a speck, and to give a transparent finish to the entire welded area including the build-up 4a. . An example of the processing gas is air or an inert gas, and the blowing rate is preferably about 20 Q/min.

A gap 8 is set between both quartz members 2 and 3. This gap is preferably 0.5 to 5t++m.

If it is less than 0.5 mm, quartz will sublimate a lot and the heat conduction will be poorer than that of metal, so continuous bonding will not be possible on the back side and the strength of the welded part will be insufficient. If it is 5 mm or more, poor penetration occurs and a continuous bond cannot be stably obtained. Furthermore, from the viewpoint of strength and smoothness of appearance, a gap of 1 to 3 mm is optimal.

A welding material arrangement means similar to that for metal is provided so that the filler rod 4 is at an angle of 00 to 70° with respect to the quartz members 2 and 3.
so that it has an angle A of .

The laser beam is dispersed by adjusting the focal point 1-C of the laser beam 1b to be separated from the end surfaces 2a and 3a of the quartz members 2 and 3 by a predetermined distance, so that the beam diameter of the laser beam 1b at the welding location is relatively large. Make it bigger. For example, by appropriately setting the focal point at 1° C., a beam having a diameter of about 25 mm is formed at the end faces 2a and 3a of the quartz members 2 and 3. Only the filler rod 6 emits the laser beam 1.
In addition to being heated by the quartz members 2 and 3, the end surfaces 2a and 3a of the quartz members 2 and 3 are also heated to some extent. As a result, the end faces 2a and 3a of the quartz parts +)f2 and 3 are first preheated and then welded, thereby reducing the amount of thermal strain.

Grooves 13 are provided on the end faces 2a and 3a of both quartz members 2.3. The shape of this groove 13 is preferably a 7-shape as shown in the illustrated example. When the angle of groove 13 is set to 30 to 120 degrees, the area becomes wider (this allows the welding to penetrate well to the back side, and the filler is fixed, so welding can be performed stably. Of course, groove 4-3 Can be made into any shape.

In addition, the filler rod 4 is not only made circular in cross section as in the examples shown in FIGS. 1 to 3, but also the cross section of the filler rod 1-5 is square as shown in FIG. It is also possible for the quartz part shrine 15a to protrude slightly downward from the gap 8 between the quartz part shrines 2 and 3. Acute angle part 1 of filler rod 15
5a continuously protrudes by the same height from between the end faces 2a and 3a of both quartz members. As a result, the welding around the gap 8 can be finished with good quality. In the example of FIG. 1 as well, it is preferable to set both quartz members 2.3 on the stand 8. In that case, a recess is formed in the upper surface of the base 8, and the acute angle portion 15a is inserted into the recess. By using a table having such a recess, it is possible to prevent impurities from entering the table due to the material of the table, and the back surface can have a curvature, thereby improving strength.

Of course, the filler rod may have a cross-sectional shape other than the above-mentioned shape, such as a rhombus or a rectangle.

Furthermore, the welding material is the filler rod 4 as described above (
It may also be placed in powder form.

It is also possible to use a combination of powdered welding material and rod-shaped welding material.

As shown in FIG. 5, it is also possible for the quartz parts 2 and 3 to be welded to be arranged at an angle to each other and to form a substantially V-shaped groove with their end faces 2a and 3a. Also in this case, a gap 8 is formed between both quartz members 2 and 3 following the groove.

As shown in FIG. 6, three quartz members 2°3 and 17
It is also possible to arrange the filler rods 4 in the two grooves formed between the quartz members and weld them in the same manner as described above.

As shown in FIG. 7, it is preferable to perform welding in two stages instead of one stage, and to configure the build-up formed by welding into two layers.

First, as shown in FIG. 7(A), a first filler rod 4 having a relatively smaller diameter than the groove is inserted between two quartz members 2 and 3.
The quartz members 2 and 3 are placed in the groove formed by the end face of the quartz members 2 and 3 and supported from below by a stand 18 to set the quartz members 2 and 3 in a predetermined position. After that, stable welding of the back surface is performed using a laser beam from above. FIG. 7(B) shows a relatively thin first build-up 20 formed in this manner. The first build-up 20 is formed along the base 18 at the lower part of the end surfaces of the quartz members 2 and 3. Next, as shown in FIG. 7(C), a second filler rod 4 having a larger diameter than the first filler is placed on the first build-up 20. This second filler rod 4 is irradiated with a laser beam and welded as described above to form a second build-up 21 as shown in FIG. 7(D), and finally the quartz members 2 and 3 to weld.

Note that the filler rods and powder may be arranged manually, or may be arranged manually and automatically.

The setting of the quartz members to be welded is preferably done automatically, but may be done manually depending on the situation.

[Effects of the Invention] Particularly, the back surface of the welded part can be joined evenly and smoothly over the entire area. The joint part tends to have a shape with curvature, and the joint strength is high. Since the welded area is smooth, there is less adhesion of impurities.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing an example of a quartz welding device according to the present invention, FIG. 2 is a schematic side view showing the device shown in FIG. 1, and FIG.
1 is a schematic sectional view showing another embodiment of the invention; FIG. 5 is a schematic sectional view showing yet another embodiment of the invention; A schematic sectional view showing still another embodiment of the invention. FIGS. 7A to 7D are schematic explanatory views showing a two-step welding process of the invention. 1, , , , , Laser device 1 a, 081. , ,Condenser lens lb, , , , Laser light lc, , ,Condensing point 2.3. , , , Quartz member 2a, 3a, , End face 4 of quartz member, , Filler rod 4a, , Overlay 7, , Gas blowing Nozzle 8 is attached.
,, gap 13. Bevel 15 Filler rod 18 Mouth 17 Quartz member 20 First overlay 21, , , , , 2nd fill-in agent Patent attorney [11th side Toru ・ [D 1

Claims (1)

[Claims] 1. In a quartz member welding method in which a plurality of quartz members are welded by laser irradiation, a groove is provided on the end face of at least one of the quartz members, and a gap is provided between the end faces of the quartz members to form a support stand. A method for welding a quartz member, the method comprising: placing a quartz welding material in the gap; and performing welding by irradiating a defocused laser beam onto the material. 2. Set a plurality of quartz members by creating grooves between their end faces, place a first welding material in the grooves, irradiate the first welding material with a laser to form a back surface in advance, and then After that, a second welding material larger than the first welding material is placed on top of the first welding material.
A method for welding a quartz member, which comprises arranging a welding material and irradiating the second welding material with a laser to form a second build-up. 3. A quartz member setting means for supporting and setting a plurality of quartz members from below with gaps created between their end faces, and a welding material for applying welding material between the end faces of the plurality of quartz members thus set. A welding device for a quartz member, characterized in that it is provided with a welding material arranging means for arranging the welding material, and a laser device for irradiating the thus arranged welding material with a laser beam.