阅读说明：本技术 一种泡生法蓝宝石单晶炉用坩埚盖结构 (Crucible cover structure for sapphire single crystal furnace by kyropoulos method ) 是由 左洪波 杨鑫宏 李铁 马宗羽 于 2020-07-22 设计创作，主要内容包括：本发明涉及一种泡生法蓝宝石单晶炉用坩埚盖结构,该结构整体由圆环钼板、钨板、间隔钼板用的钼螺母、整体通过钼螺栓以及钼丝固定连接,圆环钼板包括至少两层圆形钼片；圆形钼片、钨板中间留有直径不同的同心圆内孔,整体由间隔钼板用的钼螺母、钼螺栓以及钼丝制作的铆钉固定；坩埚盖包括上半部圆环和下半部圆环,上半部圆环外径大于下半部圆环外径,上半部圆环和下半部圆环圆心相同外径不同,同心圆内孔直径从上到下先变小在变大；每层钼片内径尺寸也不相同,坩埚盖的最下层钨板为圆形；每层钼板、钨板之间由钼螺母间隔,通过钼螺栓、钼丝穿接固定。本发明由钼丝以及间隔钼片的钼螺母穿接固定,形成头尾片可灵活拆卸结构,可以有效减小放肩阶段生长界面的底部圆锥角度,降低大尺寸晶体肩部缺陷,提高晶体晶体良率。(The invention relates to a crucible cover structure for a sapphire single crystal furnace by a kyropoulos method, which is characterized in that the whole structure is fixedly connected by a circular molybdenum plate, a tungsten plate, molybdenum nuts for spacing the molybdenum plate and a molybdenum wire through molybdenum bolts, wherein the circular molybdenum plate comprises at least two layers of circular molybdenum sheets; concentric inner holes with different diameters are reserved between the circular molybdenum sheet and the tungsten plate, and the whole body is fixed by molybdenum nuts and molybdenum bolts for spacing the molybdenum plates and rivets made of molybdenum wires; the crucible cover comprises an upper half ring and a lower half ring, the outer diameter of the upper half ring is larger than that of the lower half ring, the circle centers of the upper half ring and the lower half ring are the same and have different outer diameters, and the diameter of the inner hole of the concentric circle is reduced from top to bottom and is increased; the inner diameter of each layer of molybdenum sheets is different, and the tungsten plate at the lowest layer of the crucible cover is circular; the molybdenum plates and the tungsten plates are separated by molybdenum nuts and are fixedly connected through molybdenum bolts and molybdenum wires. According to the invention, the molybdenum wires and the molybdenum nuts for spacing the molybdenum sheets are connected and fixed in a penetrating manner to form a structure with flexibly detachable head and tail sheets, so that the bottom taper angle of a growth interface at the shouldering stage can be effectively reduced, the shoulder defect of a large-size crystal is reduced, and the yield of the crystal is improved.)

1. A crucible cover structure for a sapphire single crystal furnace by a kyropoulos method is characterized in that the whole crucible cover structure is fixedly connected by a circular molybdenum plate, a tungsten plate, molybdenum nuts for spacing the molybdenum plate and a molybdenum wire through molybdenum bolts, and the circular molybdenum plate comprises at least two layers of circular molybdenum sheets; concentric inner holes with different diameters are reserved between the circular molybdenum sheet and the tungsten plate, and the whole body is fixed by molybdenum nuts and molybdenum bolts for spacing the molybdenum plates and rivets made of molybdenum wires; the crucible cover comprises an upper half ring and a lower half ring, the outer diameter of the upper half ring is larger than that of the lower half ring, the circle centers of the upper half ring and the lower half ring are the same and have different outer diameters, and the diameter of the inner hole of the concentric circle is reduced from top to bottom and is increased; the inner diameter of each layer of molybdenum sheets is different, and the tungsten plate at the lowest layer of the crucible cover is circular; the molybdenum plates and the tungsten plates are separated by molybdenum nuts and are fixedly connected through molybdenum bolts and molybdenum wires.

2. The crucible cover structure for the kyropoulos-method sapphire single crystal furnace as claimed in claim 1, wherein the upper half ring of the crucible cover comprises at least 2 layers of circular molybdenum sheets, the lower half ring comprises at least 2 layers of circular molybdenum sheets and 1 layer of tungsten plate, and the tungsten plate is arranged at the lowest layer.

3. The crucible cover structure for the kyropoulos-method sapphire single crystal furnace as claimed in claim 2, wherein the adjacent spacing of the circular molybdenum sheets is 3-6 mm.

4. The crucible cover structure for the kyropoulos-method sapphire single crystal furnace as claimed in claim 3, wherein the diameter of the through holes of 8-12 concentric circles is phi 8-phi 12mm, which are uniformly distributed at the edge of the circular molybdenum sheet.

5. The crucible cover structure for the kyropoulos-method sapphire single crystal furnace as claimed in claim 4, wherein 12-16 concentric circular through holes with the diameter of phi 3-phi 5mm are uniformly distributed on the circular molybdenum sheet of the middle layer of the circular molybdenum sheet removing head-tail sheet.

6. The crucible cover structure for the kyropoulos-method sapphire single crystal furnace as set forth in claim 5, wherein the thickness of the circular molybdenum sheet is 2mm to 5 mm; the thickness of the tungsten plate is 5mm-8 m.

7. The crucible cover structure for the kyropoulos-method sapphire single crystal furnace as claimed in claim 6, wherein the whole crucible cover structure is fixed by a molybdenum bolt and a rivet made of molybdenum wire; the molybdenum bolts fix the whole outer ring of the crucible cover structure, the molybdenum bolts sequentially penetrate through the bottom layer and the top layer and are screwed through the nuts, the circular molybdenum sheet in the middle layer fixes the whole inner ring of the crucible cover structure through the rivets made of molybdenum wires, and the crucible cover structure with the head piece and the tail piece capable of being flexibly detached is formed.

8. The crucible cover structure for the kyropoulos-method sapphire single crystal furnace as claimed in claim 7, wherein the whole crucible cover structure is composed of 5-10 layers, and the outer diameter of the upper half annular circular molybdenum sheet is phi 450-phi 600 mm; the outer diameter of the lower half circular molybdenum sheet is phi 420-phi 570 mm; the diameter of the central hole of the middle layer circular molybdenum sheet is phi 100-phi 140mm, the diameter of each layer of circular molybdenum sheet gradually increases by 20-30mm when the middle layer circular molybdenum sheet is extended upwards, and the diameter of each layer of circular molybdenum sheet gradually increases by 15-25mm when the middle layer circular molybdenum sheet is extended downwards.

9. The crucible cover structure for the kyropoulos-method sapphire single crystal furnace as claimed in claim 8, wherein the lower half ring molybdenum sheet is always one layer more than the upper half ring molybdenum sheet.

10. The crucible cover structure for a kyropoulos-method sapphire single crystal furnace as set forth in claim 9, wherein the lower half ring is placed inside the crucible and has a diameter 10-30mm smaller than the inner diameter of the crucible.

Technical Field

The invention relates to the field of thermal field heat preservation of a sapphire single crystal furnace by a kyropoulos method, in particular to a crucible cover structure for the sapphire single crystal furnace by the kyropoulos method.

Background

Sapphire is pure oxideSingle crystal form of aluminum, chemical composition being Al₂O₃. Sapphire has a mohs hardness of 9, second only to diamond, and has good optical transmittance, thermal conductivity, electrical insulation, and excellent mechanical properties. Application fields of sapphire include window materials, electronic devices, wear-resistant elements, high-temperature insulators, LED substrates, military fairings and the like.

The growth of the sapphire single crystal by the kyropoulos method has strict requirements on the axial and radial temperature gradients in the furnace, and a reasonable temperature gradient is beneficial to the formation of a crystal growth convex interface, especially when a large-size sapphire single crystal is grown, the larger the crystal size is, the larger the growth difficulty is, the problems of high seeding difficulty, easiness in crucible adhesion, high crystal stress and the like are easy to occur, and the defects of faults, cracks, cloud mist and the like of the crystal are caused; the reasonable top heat preservation design can meet the radial temperature gradient required by large-size crystals, is beneficial to the formation of a growth convex interface and improves the yield of the crystals. In addition, the problem of high-temperature deformation of the crucible cover structure is also one of the important factors influencing the yield of crystals, so that the upper heat-insulating structure which has a larger radial temperature gradient, facilitates the formation of a reasonable growth interface and prolongs the service life of the crucible cover is very necessary.

Disclosure of Invention

The invention aims to provide a crucible cover structure for a sapphire single crystal furnace by a kyropoulos method, which is convenient to disassemble, low in use cost, good in heat preservation effect and beneficial to growing large-size and high-quality sapphire single crystal furnaces.

The purpose of the invention is realized as follows: the structure is characterized in that the whole structure is fixedly connected by a circular molybdenum plate, a tungsten plate, molybdenum nuts for spacing the molybdenum plate and a molybdenum wire through molybdenum bolts, and the circular molybdenum plate comprises at least two layers of circular molybdenum sheets; concentric inner holes with different diameters are reserved between the circular molybdenum sheet and the tungsten plate, and the whole body is fixed by molybdenum nuts and molybdenum bolts for spacing the molybdenum plates and rivets made of molybdenum wires; the crucible cover comprises an upper half ring and a lower half ring, the outer diameter of the upper half ring is larger than that of the lower half ring, the circle centers of the upper half ring and the lower half ring are the same and have different outer diameters, and the diameter of the inner hole of the concentric circle is reduced from top to bottom and is increased; the inner diameter of each layer of molybdenum sheets is different, and the tungsten plate at the lowest layer of the crucible cover is circular; the molybdenum plates and the tungsten plates are separated by molybdenum nuts and are fixedly connected through molybdenum bolts and molybdenum wires.

The invention also has the following features:

1. the upper half part of the circular ring of the crucible cover comprises at least 2 layers of circular molybdenum sheets, the lower half part of the circular ring comprises at least 2 layers of circular molybdenum sheets and 1 layer of tungsten plate, and the tungsten plate is arranged at the lowest layer.

2. The adjacent interval of the circular molybdenum sheets is 3-6 mm.

3. 8-12 concentric circular through holes with the diameter of phi 8-phi 12mm are uniformly distributed at the edge of the circular molybdenum sheet of the crucible cover structure.

4. 12-16 concentric circular through holes with the diameter of phi 3-phi 5mm are uniformly distributed on the middle layer circular molybdenum sheet of the crucible cover structure removing head and tail sheets.

5. The thickness of the circular molybdenum sheet with the crucible cover structure is 2mm-5 mm; the thickness of the tungsten plate is 5mm-8 m.

6. The whole crucible cover structure is fixed by a molybdenum bolt and a rivet made of molybdenum wires; the molybdenum bolts fix the outer ring of the crucible cover, the crucible cover sequentially penetrates through the nuts from the bottom layer to the top layer to be screwed, and the molybdenum sheet in the middle layer fixes the inner ring of the crucible cover through the rivets made of molybdenum wires to form a structure with flexibly detachable head and tail sheets.

7. The crucible cover structure is integrally formed by 5-10 layers, and the outer diameter of the circular molybdenum sheet on the upper half part is phi 450-phi 600 mm; the outer diameter of the lower half circular molybdenum sheet is phi 420-phi 570 mm; the diameter of a central hole of the molybdenum sheet in the middle layer of the crucible cover structure is phi 100-phi 140mm, the diameter of the central hole gradually increases by 20-30mm along the circular molybdenum sheet in the middle layer towards each layer, and the diameter of the central hole gradually increases by 15-25mm along the circular molybdenum sheet in the middle layer towards each layer downwards.

8. The lower half ring molybdenum sheet is always one layer more than the upper half ring molybdenum sheet.

9. The lower half ring is arranged in the crucible, and the diameter of the lower half ring is 10-30mm smaller than the inner diameter of the crucible.

The invention has the following beneficial effects:

1. the molybdenum bolt sleeve fundamentally avoids the problem that the two-end nut fixing mode cannot be loosened due to high-temperature use or after multiple uses; the molybdenum bolt sleeve is used for realizing flexible disassembly of the head position sheet of the crucible cover and enhancing interchangeability of original auxiliary materials, so that the production cost is saved and the safe use of the crucible cover is ensured.

2. The hourglass-shaped crystal shouldering device has the unique design, and under the dual functions of heat preservation and reflection, the radial temperature of the crystal in the shouldering stage is effectively increased, the formation of a conical angle at the bottom of the crystal is facilitated, and the defect of the shoulder of the crystal is reduced.

3. The lower half part of the crucible cover is embedded into the crucible, so that the overall heat preservation effect of the crucible can be improved, and the heat loss is reduced, thereby reducing the power consumption and the cost.

Drawings

FIG. 1 is a schematic structural view of the present invention;

fig. 2 is a side view of fig. 1.

Detailed Description

The invention is described in detail below with reference to the accompanying drawings:

referring to fig. 1-2, the whole structure of the present embodiment is formed by fixedly connecting a circular molybdenum plate 1, a tungsten plate 6, a molybdenum nut 5 for spacing the molybdenum plates, and a molybdenum bolt 4 and a molybdenum wire 2. A circular through hole with the same circle center and different diameters is reserved in the middle of the crucible cover and penetrates through the seed crystal rod 7, the layers are separated by the nut 5, the whole outer ring of the crucible cover is fixed by the molybdenum bolt 4 and the molybdenum nut 3 matched with the bolt, the inner ring is connected with the rivet 2 made of molybdenum wires for removing the head and tail pieces and penetrating through the separation nut 2 between the layers, and a head and tail piece structure convenient to disassemble and assemble is formed. The crucible cover is easy to deform due to long-term high temperature, and the head and tail pieces of the crucible cover can be flexibly detached by using the molybdenum bolts 4, so that the service life is effectively prolonged. Wherein, the crucible cover is divided into an upper part and a lower part, the outer diameter of the molybdenum plate 1 of the upper part is the same, and the inner diameter is gradually reduced from the upper part to the lower part; the lower half section is composed of a plurality of layers of molybdenum sheets 1 and a tungsten plate 6, and the bottom tungsten plate can strengthen the heat preservation of the upper part. The outer diameter is the same, and the inner diameter is gradually increased from the top to the bottom. The hourglass-shaped design of the circular through hole in the middle of the crucible cover comprehensively considers the dual functions of heat resistance for transferring heat outwards when the molybdenum sheet is insulated and heat reflecting part of heat through the molybdenum plate, so that the radial temperature gradient in a temperature field is more uniform, a better shoulder shape is obtained, and the internal stress of crystals is reduced. The crucible cover is integrally arranged on the crucible 8, and the lower half section of the crucible cover is arranged in the crucible to integrally form a sealed thermal field heat preservation structure.

The upper half part of the circular ring of the crucible cover comprises 9 layers of circular molybdenum sheets, the lower half part of the circular ring comprises 5 layers of circular molybdenum sheets and 1 layer of tungsten plate, and the tungsten plate is arranged at the lowest layer. The lower half circular molybdenum sheet is always one layer more than the upper half circular molybdenum sheet. The upper half ring comprises 4 layers of circular molybdenum sheets; the adjacent interval of the circular molybdenum sheets is 5 mm. The edge of the circular molybdenum sheet is uniformly distributed with 10 concentric through holes with the diameter phi of 10 mm. 14 concentric circular through holes with the diameter of phi 4mm are uniformly distributed on the circular molybdenum sheet of the middle layer without the head and tail sheets. The thickness of the circular molybdenum sheet is 3 mm; the thickness of the tungsten plate is 6 mm.

The crucible cover structure of the embodiment is integrally fixed by a molybdenum bolt and a rivet made of molybdenum wires; the molybdenum bolts fix the outer ring of the crucible cover, the crucible cover sequentially penetrates through the nuts from the bottom layer to the top layer to be screwed, and the molybdenum sheet in the middle layer fixes the inner ring of the crucible cover through the rivets made of molybdenum wires to form a structure with flexibly detachable head and tail sheets. The outer diameter of the circular molybdenum sheet of the upper half part is phi 500 mm; the outer diameter of the lower half circular molybdenum sheet is phi 550 mm; the diameter of a central hole of the molybdenum sheet in the middle layer of the crucible cover structure is phi 100-phi 140mm, the diameter of the central hole gradually increases by 20-30mm along the circular molybdenum sheet in the middle layer towards each layer, and the diameter of the central hole gradually increases by 15-25mm along the circular molybdenum sheet in the middle layer towards each layer downwards. The lower half ring is arranged in the crucible, and the diameter of the lower half ring is 10-30mm smaller than the inner diameter of the crucible.