JPS626136Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a structure for attaching and detaching the core tube of an image furnace used for manufacturing single crystals by the floating zone method.

An image furnace places a thermal light source at one focus of a reflecting mirror consisting of a spheroidal mirror, places a sample at the other focus, and focuses the light (radiation) emitted from the thermal light source at the focal point on the sample side. and heats the sample.
This device has a single elliptical type where the reflecting mirror is made up of only one spheroidal surface, a bielliptic type where the reflecting mirror is made up of a combination of two spheroidal surfaces, and a bielliptic type where the reflecting mirror is made up of a combination of two spheroidal surfaces, and a three or more spheroidal reflecting mirror. There is a multi-elliptical type that is composed of a combination of surfaces.

Usually, in an image furnace, a transparent furnace tube is inserted between the sample and the reflector to avoid contaminating the reflector with evaporated gas from the heated sample. The present invention relates to a structure for attaching and detaching the reactor core tube.

Next, the structure and drawbacks of a conventional image furnace will be explained with reference to the drawings, taking a bielliptic type device as an example.

FIG. 1 is a cross-sectional view showing a heating furnace portion of a twin elliptical image furnace having a conventional structure.

In the figure, 101 is a reflecting mirror, and its reflecting mirror surfaces 102a and 102b are spheroidal surfaces obtained by rotating an ellipse with F ₁ F ₂ as its focal point on the x-axis.
It is composed of an ellipsoid of revolution, which is an ellipse whose focal point is F ₂ F ₃ and rotated on the x-axis. Further, the reflecting mirror 101 includes a fixed reflecting mirror section 103 and an openable/closable reflecting mirror section 104.
It consists of Reference numerals 105a and 105b are thermal light source lamps placed at the focal point F ₁ F ₃ of the reflecting mirror surfaces 102a and 102b, respectively, and halogen lamps or the like are used. 106 is an upper sample, 107 is a lower sample, and 108 is a melted zone (molten zone) heated and melted. Also, 109 is the furnace core tube,
It consists of a transparent quartz tube 110 and silicone rubber caps 111a and 111b placed over both ends of the tube. The furnace core tube 109 has a compression coil spring 11
It is pressed and fixed within the reflecting mirror by the core tube holder 113 with the pressing force of 2. Furnace tube holder 1
13 can be moved up and down within the reflector by moving a lever 114 fixed thereto up and down, while the upper sample 106 is fixed to the upper shaft 116 via the upper sample holder 115, and the upper shaft 1
16 can be moved up and down by an upper shaft feeding mechanism (not shown).

Further, the lower sample 107 is fixed to a lower shaft 120 via a lower sample holder 119, and the lower shaft 120 can be moved up and down by a lower shaft feeding mechanism (not shown).

Furthermore, the inner side 121 of the reflecting mirror 101 is provided with an O-ring 1.
22, 123, 124, 125, and 126 to maintain airtightness from the outside air. Furthermore, the inside and outside of the furnace tube 109 on the inside 121 of the reflecting mirror are sealed with a cap 111 made of silicone rubber to prevent the reflecting mirror surface from being contaminated by gas generated from the sample.

Note that the reason why the interior of the reflector is sealed here is that it is often necessary to fill the atmosphere around the sample with, for example, an inert gas, and at this time, the reflector is sealed in order to ensure the purity of the atmospheric gas. This is because the gas inside the mirror needs to be purged under vacuum, and some samples require a pressurized atmosphere (for example, several atmospheres). In this case, supporting the core tube with the core tube holder alone is insufficient to ensure airtightness or airtightness of several atmospheres inside the core tube. The internal and external pressures are the same, and the seals inside and outside the core tube are designed to prevent only the evaporated gas generated from the sample from reaching the reflecting surface of the reflector from inside the core tube.

Next, the attachment and detachment of the furnace core tube will be explained.

FIG. 2 is a sectional view of the heating furnace portion showing the state of attachment and detachment of the furnace core tube in the conventional structure of FIG. 1. That is, when attaching and detaching the reactor core tube, the upper shaft 116 and the lower shaft 120 are moved upward and downward by their respective feeding mechanisms (not shown),
A space larger than the length l of the reactor core tube is created between the upper sample 106 and the lower sample 107, and the reactor core tube 10 is inserted through the circular opening window 127 created by opening the opening/closing reflector 104.
9 is being attached and detached. At this time, the lever 114
By pushing up, the clamping by the core tube holder 115 is released and the core tube can be attached and removed.

However, in such a conventional structure, the cap of the furnace tube is exposed inside the reflector and exposed to direct light from the thermal light source.
1 overheats and melts. For this reason, the conventional image furnace with the structure shown in Figure 1 could only be used for heating at a low temperature of about 1000°C.

In order to eliminate these drawbacks, the present invention provides a hood that covers the cap of the reactor core tube, blocks direct light from the thermal light source to the cap, prevents the temperature of the cap from rising, and also takes into consideration the attachment and detachment of the reactor core tube. By forming the hood on the core tube holders provided independently above and below the core tube, the core tube can be used during high-temperature heating without impairing the function of attaching and detaching the core tube. This will be explained in detail below with reference to the drawings.

FIG. 3 is a sectional view of a heating furnace portion of a bielliptical image furnace showing an embodiment of the present invention. In the figure, 201 is a water-cooled reflecting mirror, and its reflecting mirror surfaces 202a and 202b are respectively constructed of spheroidal surfaces obtained by rotating an ellipse with F ₁ 'F ₂ ' as the focal point on the X' axis. Further, the reflecting mirror 201 consists of a fixed reflecting mirror section 203 and an openable/closable reflecting mirror section 204.

205a and 205b are reflective mirror surfaces 20, respectively.
Thermal light source lamps are placed at the focal points F ₁ ' and F ₃ ' of 2a and 202b, 206 is the upper sample, 207 is the lower sample, and 208 is the melted region heated and melted.

Further, 209 is a furnace tube, which is composed of a quartz tube 210 and caps 211a and 211b made of a heat-resistant elastic material such as silicone rubber, which are placed over both ends of the quartz tube 210. The furnace core tube 209 is pressed and fixed within the reflector by metal furnace core tube holders 213a, 213b by the pressing force of compression coil springs 212a, 212b. Furnace tube holder 213a,
213b is the lever 2 fixed thereto.
By moving 14a and 214b up and down, the reflecting mirror can be moved up and down independently.

In addition, caps 211a and 21 are provided at the portions of the core tube holders 213a and 213b that come into contact with the core tubes.
Hoods 215a and 215b are formed to cover the thermal light sources 205a and 205b.
Direct light from 5b connects to caps 211a and 211b.
The amount is set so that it does not enter.

Furthermore, as in the conventional example shown in FIG.
The upper shaft 217 can be moved up and down by an upper shaft feeding mechanism (not shown). Further, the lower sample 207 is fixed to a lower shaft 221 via a lower sample holder 220, and the lower shaft 221 can be moved up and down by a lower shaft feeding mechanism (not shown).

Moreover, the inner side 222 of the reflecting mirror 201 has O-rings 223a, 223b, 224a, 224b, 22
5a, 225b, and 226 to maintain airtightness from the outside air. Furthermore, the inside and outside of the reactor core tube 209 at the inside 222 of the reflecting mirror are sealed with a cap 211 made of a heat-resistant elastic material such as silicone rubber. The evaporated gas never reaches the reflecting mirror surface.

FIG. 4 is a sectional view of the core tube portion showing the state during attachment and detachment of the core tube in the embodiment of FIG. 3;
The method for attaching and detaching the furnace core tube will be explained below with reference to FIG.

The attachment and detachment of the reactor core tube is done by moving the upper and lower shafts up and down, respectively, as in the conventional method, creating a space between the upper sample 206 and the lower sample 207 that is equal to or larger than the length l' of the reactor core tube. Furthermore, the opening/closing reflector section 204 is opened, and the operation is carried out through the circular window 227 of the reflector that is created at this time. However, in the case of the present invention, the lever 214a is lifted up and the lever 214b is pulled down to open a space equal to or more than the length l' of the furnace tube between the upper and lower quartz tube holders 213a and 213b. Perform attachment/detachment.

As can be seen from this embodiment, according to the present invention, the direct light from the thermal light source lamp is blocked by the hood of the quartz tube holder, the cap is not heated by the lamp light, and the quartz tube holder itself The tube is made of a metal with good thermal conductivity, and is cooled by heat conduction from a water-cooled reflector, so it maintains a sufficiently low temperature, and the quartz tube also transmits the lamp light, so it does not get heated. Since there is no heat, the cap will not overheat. Therefore, it has become possible to heat the sample to a high temperature of, for example, 2100°C without melting and damaging the cap. Moreover, the function of attaching and detaching the furnace tube, which the conventional image furnace had, is not impaired in any way.

As described above, by carrying out the present invention, it is possible to avoid overheating and melting of the cap of the reactor core tube even when the sample is heated to about 2100° C. without impairing the function of attaching and detaching the reactor core tube.

Although a bi-elliptical image furnace has been described here, the present invention can also be applied to a single-ellipse or multi-ellipse image furnace, and the same effects can be produced.

Further, as the thermal light source lamp mentioned in the above explanation, any lamp such as a halogen lamp, a xenon lamp, a mercury lamp, etc. can be used.

Furthermore, as for the material of the cap, it is obvious that other than silicone rubber, a heat-resistant elastic body such as Viton rubber can also be used.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the heating furnace part of a bi-elliptic image furnace with a conventional structure, and Figure 2 is a cross-sectional view of the
FIG. 3 is a cross-sectional view of a heating furnace portion of a bielliptic image furnace showing an embodiment of the present invention; FIG. 3 is a sectional view of the heating furnace portion showing the state of attachment and detachment of the furnace core tube in the embodiment of FIG. 3. FIG. In the figure, 201 is a reflecting mirror, 203 is a fixed reflecting mirror part, 204 is an opening/closing reflecting mirror part, 205a, 20
5b is a thermal light source lamp, 206 is an upper sample, 207
is the lower sample, 209 is the furnace tube, 210 is the quartz tube,
211a, 211b are caps, 212a, 21
2b is a compression coil spring, 213a, 213b are furnace tube holders, 214a, 214b are levers, 21
5a and 215b are hoods.

Claims (1)

[Scope of utility model registration request] An image furnace that heats a sample by placing a thermal light source lamp at one focal point of a reflecting mirror consisting of one or more spheroidal surfaces and concentrating light on the sample placed at the other focal point. In the image reactor, the two core tube holders that hold the core tube from both sides move independently due to the pressing force of compression coil springs in the reflector, and the parts of the two core tube holders that come into contact with the core tube An image furnace characterized in that it has a hood that covers the outside of the cap of the furnace tube, and the hood has a depth sufficient to prevent direct light from the thermal light source lamp from hitting the cap of the furnace tube.