CN204138819U - Kyropoulos sapphire single crystal growth furnace insulation side screen - Google Patents

Abstract

The utility model relates to a Kyropoulos sapphire single crystal growth furnace, in particular to a thermal insulation side screen of a kyropoulos sapphire single crystal growth furnace. The thermal insulation side screen is arranged between the heater and the stainless steel shell, and the thermal insulation side screen includes an inner layer of tungsten screen and an outer layer of zirconia fiber thermal insulation brick layer. The design of this heat preservation side screen makes the system have lighter weight and better heat preservation effect, the axial and radial temperature gradient in the crystal is reduced, and the thermal stress and dislocation density in the crystal are reduced at the same time, reaching Reduce power consumption and improve crystal quality.

Description

Kyropoulos sapphire single crystal growth furnace insulation side screen

technical field

The utility model relates to a Kyropoulos sapphire single crystal growth furnace, in particular to a thermal insulation side screen of a kyropoulos sapphire single crystal growth furnace.

Background technique:

The Kyropoulos method was invented by Kyropouls in 1926. Its growth principle and technical characteristics are as follows: put the crystal raw material into a high-temperature-resistant crucible to heat and melt it, and adjust the temperature field in the furnace so that the upper part of the melt is at a temperature slightly higher than the melting point. State: Make the seed crystal on the seed crystal rod contact the molten liquid surface, after the surface melts slightly, lower the surface temperature to the melting point, pull and rotate the seed crystal rod, so that the top of the melt is in a supercooled state and crystallizes on the seed crystal , in the process of continuous pulling, grow cylindrical crystals.

The principle of crystal growth by Kyropoulos method and pulling method is similar, but the quality of sapphire crystals grown by Kyropoulos method is higher. From the technical point of view, the growth process of pulling method includes the stages of seeding, shouldering, equal diameter and shouldering. , and the above stages need to be continuously pulled to complete; the crystal growth and annealing process of the Kyropoulos method are carried out in the crucible, the crystal is not pulled out of the crucible, and the sapphire crystal is like growing from the melt; In the Kyropoulos growth process, the seed crystal is lifted and rotated during the process of seeding and shouldering, while the seed crystal stops rotating in the equal diameter growth stage, which is only slightly lifted according to the actual situation; in fact, the crystal growth and annealing process of the Kyropoulos method are all in the In the crucible, the crystal is not pulled out of the crucible, so the temperature field is easy to control and the crystal quality is high.

One of the main applications of sapphire is as a substrate material, and the main method for preparing substrate material sapphire is the Kyropoulos method.

The melting point of sapphire crystal is about 2050°C. The Kyropoulos method is one of the most mainstream growth methods at present, and a key factor affecting the quality of sapphire single crystal grown by the Kyropoulos method is the distribution of the thermal field in the furnace. Therefore, under the high temperature conditions of 2050°C, the selection of insulation side screen materials and the design of the structure are particularly important.

At present, the thermal insulation side screens commonly used for growing large-size sapphire single crystals by the Kyropoulos method are mainly composed of molybdenum metal multi-layer screens, tungsten metal multi-layer screens, and tungsten-molybdenum metal multi-layer screens. This kind of thermal insulation side screen mainly relies on the vacuum effect between the layers to achieve the thermal insulation effect, but the tungsten-molybdenum material itself is a metal material, its thermal insulation effect is poor, the thermal field distribution is uneven, and the molybdenum screen will volatilize a lot of impurities at high temperature, these Factors will result in high energy consumption for crystal growth, excessive crystal defects, and high cost.

Utility model content

The technical problem to be solved by the utility model is to provide a thermal insulation side screen of a Kyropoulos sapphire single crystal growth furnace which can increase the crystal yield and reduce the average power consumption of a single crystal.

The technical solution adopted by the utility model to solve the problem is:

A thermal insulation side screen of a sapphire single crystal growth furnace by the Kyropoulos method is arranged between a heater and a steel shell. The inner layer of the thermal insulation side screen is a tungsten screen, and the outer layer is a zirconia fiber thermal insulation brick layer.

Compared with the prior art, the utility model adopting the above-mentioned technical solution has the following beneficial effects:

The system has a better thermal insulation effect, reduces the power consumption of a single crystal, reduces the axial and radial temperature gradients in the crystal, and reduces the thermal stress and dislocation density in the crystal.

As preferably, the further technical scheme of the utility model is:

The tungsten screen is a double-layer tungsten cylinder rolled from double-layer parallel tungsten sheets.

The thickness of the tungsten sheet is 0.5-2.5mm, and the distance between two layers of tungsten sheets is 1-5mm.

The zirconia fiber insulation brick layer is a cylinder made of double-layer zirconia fiber bricks.

The thickness of the single-layer zirconia fiber brick is 20-40mm.

Description of drawings

Fig. 1 is the structural representation of the utility model embodiment;

Fig. 2 is a side view of the tungsten screen in Fig. 1;

Figure 3 is a top view of the tungsten screen in Figure 2;

Fig. 4 is a side view of the zirconia fiber insulation brick layer in Fig. 1;

Fig. 5 is a top view of the zirconia fiber insulation brick layer in Fig. 1;

In the figure: crucible 1, heater 2, tungsten screen 3, zirconia fiber insulation brick layer 4, steel shell 5, outer tungsten cylinder 31, inner tungsten cylinder 32, D2 tantalum nail 33, outer zirconia fiber brick 41 , inner layer zirconia fiber brick 42.

Detailed ways

The utility model is described in detail below through the embodiments shown in the accompanying drawings, and the examples given are only used to illustrate the technical solution of the utility model more clearly, but not to limit the protection scope of the utility model.

Referring to Fig. 1 , the thermal insulation side screen of the Kyropoulos sapphire single crystal growth furnace is arranged between the heater 2 and the steel shell 5 , the inner layer of the thermal insulation side screen is tungsten screen 3 , and the outer layer is zirconia fiber thermal insulation brick layer 4 .

Referring to Fig. 2 and Fig. 3, the tungsten screen 3 is a double-layer tungsten cylinder composed of an outer tungsten cylinder 31 and an inner tungsten cylinder 32. The double-layer tungsten cylinder is rolled by double-layer parallel tungsten sheets, and each layer of tungsten It is connected by a single tungsten sheet, the intersection of the single tungsten sheet is 40mm, forming a rectangle, the height is 900mm, and the thickness of the tungsten sheet is 1.5mm; Two tungsten wire clips are fixed, the interval between the two clips is 22.5°, and the interval between the two layers of tungsten cylinders (tungsten sheets) is 5mm.

Referring to Fig. 4 and Fig. 5, the zirconia fiber insulation brick layer 4 is a double-layer zirconia fiber brick cylinder made of an outer layer of zirconia fiber bricks 41 and an inner layer of zirconia fiber bricks 42. The thickness is 30mm, and the height of the double-layer zirconia fiber brick cylinder is 860mm.

The thermal insulation side screen structure described in this embodiment is especially suitable for growing high-temperature oxide crystals by the Kyropoulos method.

Claims (5)

1. A kyropoulos sapphire single crystal growth furnace insulation side screen, which is arranged between the heater and the stainless steel shell, is characterized in that the insulation side screen inner layer is a tungsten screen, and the outer layer is a zirconia fiber insulation brick layer. 2. The thermal insulation side screen of the kyropoulos sapphire single crystal growth furnace according to claim 1, wherein the tungsten screen is a double-layer tungsten cylinder rolled up by double-layer parallel tungsten sheets. 3. The heat preservation side screen of the kyropoulos sapphire single crystal growth furnace according to claim 2, wherein the thickness of the tungsten sheet is 0.5-2.5mm, and the distance between the two layers of tungsten sheets is 1-5mm. 4. The insulation side screen of the kyropoulos sapphire single crystal growth furnace according to claim 1, wherein the zirconia fiber insulation brick layer is a cylinder made of double-layer zirconia fiber bricks. 5. the insulation side screen of the kyropoulos sapphire single crystal growth furnace according to claim 4, is characterized in that, the thickness of described zirconia fiber brick is 20-40mm.