DE102011052016A1 - Kit for a crucible, crucible and method of making a crucible - Google Patents

Abstract

In order to provide a kit, by means of which a carbide-ceramic crucible for secure absorption of molten material can be produced, it is proposed that the kit comprises at least one bottom wall member for forming a bottom wall of the crucible and at least one side wall member for forming a side wall of the crucible, wherein the at least one Bottom wall element and / or the at least one side wall element is a fiber ceramic body or a preform for a Faserkeramikkörper.

Description

The present invention relates to a kit for a crucible for receiving molten material, such as molten silicon.

Melting crucibles can be made, for example, from quartz glass.

The present invention has for its object to provide a kit for a carbide ceramic crucible, which allows a secure recording of molten material.

This object is achieved in that the kit comprises at least one bottom wall member for forming a bottom wall of the crucible and at least one side wall member for forming a side wall of the crucible, wherein the at least one bottom wall element and / or the at least one side wall element is a fiber ceramic body or a preform for a Fiber ceramic body is.

Because the at least one bottom wall element and / or the at least one side wall element is a fiber ceramic body or a preform body for a fiber ceramic body, a particularly stable carbide ceramic crucible can be produced by means of the kit.

In particular, it can be provided that a reusable carbide-ceramic crucible can be produced by means of the kit.

By a fibrous ceramic body is meant in this specification and the appended claims a ceramic body comprising fibers. A fiber here is preferably an elongate, thin and flexible starting material which is present, for example, as filament, as filament yarn, as a fiber bundle, as a fiber strand, as a roving and / or as a roving ribbon.

In particular, it may be provided that the fibers comprise silicon carbide fibers.

Furthermore, a fibrous ceramic body can be understood as meaning a body which is produced from a preform, wherein the preform comprises fibers. A fiber ceramic body may thus be, for example, a body which comprises a product made of fibers, for example siliconized carbon fibers or siliconized carbon fiber pre-bodies. In such a case, fibers in the actual state are no longer present in the fiber ceramic body in the finished state. Rather, the fiber ceramic body then in the finished state comprises a material which has been formed by a reaction with the fibers.

A preform body for a fiber ceramic body is to be understood in particular as meaning a body which consists of a starting material for producing the fiber ceramic body and at least approximately already has the shape of the fiber ceramic body to be produced. A preform may also be an at least approximately finished body having the body at any stage until the completion of the Faserkeramikkörpers. For example, a preform may be a green body, a porous carbon body, a brown body, etc.

In one embodiment of the invention, it is provided that the kit comprises at least one edge element for reinforcing at least one edge of the crucible. In this way, in particular two adjoining side wall elements and / or a side wall element adjoining a bottom wall element can be reinforced and / or additionally sealed.

Furthermore, it can be provided that the kit comprises at least one corner element for reinforcing at least one corner of the crucible. Such a corner element can also serve to reinforce and / or seal the crucible to be produced.

It can be advantageous if the at least one edge element has an at least approximately L-shaped cross section. In this way, a particularly simple arrangement of two adjacent, at an angle of approximately 90 ° to each other arranged elements take place.

The at least one edge element preferably comprises two planar sections which enclose an angle which is for example approximately 90 °, but preferably more than 90 °, in particular for example approximately 100 °.

In one embodiment of the invention it is provided that a plurality of interconnected and / or interconnectable edge elements are provided which form a receiving device for receiving the at least one bottom wall element and / or the at least one side wall element. In this way, a particularly simple production of the crucible by means of the kit can take place in that the at least one bottom wall element and / or the at least one side wall element introduced into the receiving device, in particular inserted into the receiving device, are.

In particular, it may be provided here that the receiving device serves to receive all bottom wall elements and all side wall elements for producing the crucible.

It can be advantageous if the at least one bottom wall element and / or the at least one side wall element comprises fibers which extend at least approximately parallel to a surface of the at least one bottom wall element and / or the at least one side wall element facing an interior of the crucible in the assembled state of the crucible , In this way, a particularly stable embodiment of the at least one bottom wall element and / or the at least one side wall element is possible. In particular, in this way undesired expansion and / or undesired shrinkage of the at least one bottom wall element and / or the at least one side wall element during heating or cooling thereof can be prevented if the fibers are selected such that they counteract a temperature-dependent change in length.

Alternatively or additionally, it may be provided that the at least one bottom wall element and / or the at least one side wall element comprises fibers which extend at least approximately over an entire width of the at least one bottom wall element or the at least one side wall element. In this way, reinforcement can be achieved by means of the fibers over the entire width of the at least one bottom wall element or of the at least one side wall element.

It may be favorable if the at least one bottom wall element and / or the at least one side wall element comprises fibers which extend at least approximately over an entire length of the at least one bottom wall element or over an entire height of the at least one side wall element. In this way too, a stable and preferably temperature-invariant configuration of the at least one bottom wall element and / or the at least one side wall element can take place.

Furthermore, it can be provided that the at least one bottom wall element and / or the at least one side wall element comprises fibers which extend at least approximately over the entire thickness of the at least one bottom wall element or the at least one side wall element. In particular, when this is in this case in a fiber direction highly thermally conductive fibers, in this way a particularly efficient heat transfer from an interior of the crucible in the assembled state thereof to an outside of the crucible can take place.

In one embodiment of the invention, it is provided that the fibers of the fiber-ceramic body or of the preform for the fiber-ceramic body comprise carbon fibers and / or carbide fibers.

In particular, it can be provided that the carbide fibers are silicon carbide fibers, tungsten carbide fibers or titanium carbide fibers. In principle, however, any type of material can be chosen which forms a carbide structure in combination with carbon.

The fibers of the fiber ceramic body are preferably filament bundles.

In one embodiment of the invention it is provided that the at least one bottom wall element and / or the at least one side wall element are graphitized for influencing the thermal conductivity.

The kit according to the invention can preferably be used for producing a carbide-ceramic crucible, in particular a carbide-ceramic crucible according to the invention.

The crucible according to the invention preferably has the features and / or advantages described above in connection with the kit according to the invention.

In particular, it may be provided that in the assembled state of the crucible, an angle which is enclosed by a bottom wall and a side wall of the crucible is greater than 90 °, for example at least about 95 °, in particular about 100 °. In this way, a crucible opening slightly upward toward an opening can be formed, so that a material which has been taken up in the molten state by means of the crucible and solidified therein can be removed from the crucible particularly easily.

It may also be favorable if an angle which is enclosed by two adjacent side walls of the crucible is greater than 90 °, in particular at least approximately 95 °, for example approximately 100 °. In this way, a crucible which opens upwards against the direction of gravity and which has a horizontal cross-section which increases in an upward direction in the direction of the gravitational force, is particularly easy to produce.

In particular, it can be provided that at least one side wall element is trapezoidal in order to be able to produce at least one trapezoidal side wall of the crucible. Such a trapezoidal side wall is preferably aligned so that it tapers in the assembled state of the crucible in the direction of gravity downwards. In particular, when a plurality of such trapezoidal side wall elements are provided for the formation of trapezoidal side walls, a crucible can be produced in a particularly simple manner, which has an upwardly increasing horizontal cross-section.

It may be favorable when the crucible is at least partially wrapped with a, for example resin impregnated, fiber.

For example, it can be provided that at least one side wall element, in particular all side wall elements, and / or at least one bottom wall element is wrapped with a fiber.

It can be advantageous if a fluid-tight shell is formed by means of the crucible. In particular, it can be provided in this case that the fluid-tight shell is wrapped with a, for example resin-impregnated, fiber. In this way, the fluid-tight shell can be made particularly stable.

Furthermore, the present invention relates to a method for producing a crucible.

The invention is in this respect the task of providing a crucible, which allows a secure recording of molten material.

• – Herstellen von mindestens einem Bodenwandelement und von mindestens vier Seitenwandelementen, wobei mindestens ein Bodenwandelement und/oder mindestens ein Seitenwandelement ein Faserkeramikkörper oder ein Vorkörper für den Faserkeramikkörper ist;
• – Verbinden des mindestens einen Bodenwandelements und der mindestens vier Seitenwandelemente miteinander.

This object is achieved according to the invention in that a carbide-ceramic crucible is produced by:

• - Producing at least one bottom wall element and at least four side wall elements, wherein at least one bottom wall element and / or at least one side wall element is a fiber ceramic body or a preform for the fiber ceramic body;
• - Connecting the at least one bottom wall element and the at least four side wall elements together.

Because at least one bottom wall element and / or at least one side wall element is a fiber ceramic body or a preform body for the fiber ceramic body, a crucible can be produced particularly simply by means of the method according to the invention. By means of a crucible produced in this way, molten material can be taken up very securely.

The production steps for producing the carbide-ceramic crucible can in principle be carried out in any order. For example, it may be provided that at least one preform body is first connected to at least one further preform body and subsequently formed as a fiber ceramic body. Alternatively, however, it can also be provided that at least two fiber ceramic bodies are completely finished and then connected to one another.

Finally, it can also be provided that several steps for the production of the crucible are carried out simultaneously, for example it can be provided that an infiltration process of a preform with carbonaceous material, the curing of the preform and / or a pyrolysis are performed simultaneously.

The method according to the invention preferably has the features and / or advantages described above in connection with the kit according to the invention and / or with the crucible according to the invention.

In one embodiment of the method according to the invention, it can be provided that at least one edge element for reinforcing at least one edge of the crucible is arranged in an edge region on two adjoining side wall elements and / or in an edge region on a bottom wall element and an adjacent side wall element. In this way, in particular a simplified sealing of the crucible can be made to prevent unwanted outflow of molten material disposed therein.

It may be advantageous if a receiving device for receiving the at least one bottom wall element and / or the at least one side wall element is formed from a plurality of edge elements of the crucible.

The at least one bottom wall element and / or the at least one side wall element are preferably arranged in the receiving device, in particular inserted into the receiving device.

It may be favorable if the at least one bottom wall element and the at least four side wall elements are connected to one another to form a fluid-tight shell.

Furthermore, it can be provided that the at least one edge element is connected to the at least one bottom wall element and / or the side wall elements.

In particular, it can be provided for connecting the individual components to one another that the components are siliconized together. In this way, a particularly simple cohesive connection results.

It may be advantageous if at least one bottom wall element, at least one side wall element and / or at least one edge element for reinforcing at least one edge of the crucible in an edge region on two adjacent side wall elements and / or in an edge region on a bottom wall element and an adjacent side wall element with a Fiber wrapped. In this way, a targeted reinforcement of the crucible to be produced can be achieved.

By means of the method according to the invention, in particular, a shell which is fluid-tight in the direction of gravity and can be produced to the sides, which forms the carbide-ceramic crucible, can be produced.

In particular for sealing regions of the crucible in which different components, for example a bottom wall element and a side wall element or two side wall elements adjoin one another, it can be provided that a substance formed, for example, as a paste is applied to this area and the crucible is subsequently aftertreated, for example siliconized and / or pyrolyzed in order to enable a, in particular fluid-tight, connection of the components to one another.

It may be favorable if a fluid-tight shell formed by means of the crucible is wrapped with a fiber, for example a resin-impregnated fiber.

In principle, a wrapping with a fiber can take place at any time during the production process of the crucible. For example, the wrapping can be done with a fiber, when the side wall elements and the at least one bottom wall element are arranged in the receiving device of the crucible. In this way, a treatment of the fiber can be carried out together with the treatment of the other components of the crucible.

Alternatively or additionally, it can be provided that a wrapping with at least one fiber after a silicidation and / or pyrolysis of at least one side wall element and / or at least one bottom wall element and / or at least one edge element takes place and the crucible with the wrapped fiber aftertreated, for example re-siliconized and / or pyrolyzed again.

Furthermore, the kit according to the invention, the crucible according to the invention and / or the method according to the invention may have the features and / or advantages described below:
In particular, when the crucible is formed from an at least approximately temperature-invariant material, a simple detachment of material solidified in the crucible can be carried out particularly simply by contracting the material during solidification and automatically releasing it from the crucible that is invariable in its expansion.

The crucible preferably has an interior with sharp edges, so that in the crucible arranged, solidified material is particularly easy to remove and thus an increased waste can be avoided in the further processing of the material.

The crucible according to the invention is preferably constructed in a differential construction, with particular C / C-SiC-containing fiber-ceramic being used for the individual components.

The kit according to the invention and / or the crucible according to the invention preferably comprise five flat plates, eight edge elements and four corner elements.

Further features and / or advantages of the invention are the subject of the following description and the diagrammatic representation of an embodiment.

In the drawings show:

1 a schematic perspective view of a crucible;

2 a schematic plan view from above on a receiving device of the crucible from 1 ;

3 a schematic side view of the recording device 2 ;

4 a schematic perspective view of a side wall element of the crucible from 1 ;

5 a schematic perspective view of a bottom wall element of the crucible from 1 ;

6 one of the 2 corresponding representation of the recording device 2 with four sidewall elements disposed therein and a bottom wall element disposed therein; and

7 one of the 3 corresponding schematic side view of the receiving device together with side wall elements and bottom wall element according to 6 ,

Identical or functionally equivalent elements are provided with the same reference numerals in all figures.

One in the 1 to 7 shown as a whole with 100 designated crucible is from a kit 102 produced.

The kit 102 includes for this purpose a receiving device 104 , four sidewall elements 106 and a bottom wall element 108 ,

The cradle 104 forms a frame device 110 for the sidewall elements 106 and the bottom wall element 108 so that the sidewall elements 106 and the bottom wall element 108 Particularly simple relative to each other can be arranged to the crucible 100 manufacture.

The cradle 104 includes several edge elements for this purpose 112 which run along a lower edge 114 of the crucible 100 a substantially square picture 116 for receiving the bottom wall element 108 form. Starting from four corners 118 the square admission 116 the cradle 104 four edge elements extend 112 as lateral edges 120 approximately opposite to the direction of gravity 122 up.

The lateral edges 120 of the crucible 100 forming edge elements 112 are however slightly opposite to the direction of gravity 122 arranged inclined, leaving a perpendicular to the direction of gravity 122 taken horizontal cross section through the crucible 100 in the assembled state of the crucible 100 in the direction of gravity 122 tapers downwards.

By means of the lateral edges 120 forming edge elements 112 are thus trapezoidal shots 124 the cradle 104 educated. In these trapezoidal shots 124 can the four this trapezoidal side wall elements 106 to be ordered.

By means of the in the square admission 116 arranged bottom wall element 108 becomes a bottom wall 126 of the crucible 100 educated.

The ones in the trapezoidal pictures 124 the cradle 104 arranged side wall elements 106 form sidewalls 128 of the crucible 100 ,

Due to the trapezoidal configuration of the side wall elements 106 and the inclined arrangement of the lateral edges 120 of the crucible 100 forming edge elements 112 close both adjacent sidewall elements 106 between each other as well as the bottom wall element 108 and the sidewall elements adjacent thereto 106 an angle with each other, which is greater than 90 °. For example, this angle is about 100 °.

In the assembled state of the crucible 100 For example, it has a height H of, for example, 450 mm, a length L of, for example, about 600 mm, and a width B of, for example, 600 mm, both the length and the width at the longest or widest point in the direction opposite to the direction of gravity 122 upper end 130 of the crucible 100 is specified.

In particular from the 2 and 3 the angle of inclination α is seen, which causes the crucible 100 in the assembled state thereof in the direction of gravity 122 tapered downwards.

4 shows a schematic perspective view of a trapezoidal side wall element 106 of the kit 102 ,

5 shows a schematic perspective view of the cuboid bottom wall element 108 of the kit 102 ,

The 6 and 7 finally show a melting pot 100 in which the components of the kit 102 namely the receiving device 104 , the sidewall elements 106 and the bottom wall element 108 are arranged loosely together. The dimensioning of the sidewall elements 106 and the bottom wall element 108 corresponds to 6 not the actual dimensioning. Rather, the sidewall elements 106 and the bottom wall element 108 shown reduced to clarify the structure. In reality, the sidewall elements bump 106 and the bottom wall element 108 to each other to ensure a stable connection of the components with each other.

For the formation of the fluid-tight crucible 100 the components must still be connected to each other, which can be done for example by jointly siliciding the components.

The crucible described above 100 is made as follows:
Basically, every component of the kit 102 that is, each edge element 112 the cradle 104 , each sidewall element 106 and each bottom wall element 108 be formed as a fiber ceramic body or a preform for a fiber ceramic body.

For example, if all components of the kit 102 are formed as a finished fiber ceramic body, a simple production of the crucible 100 be done by the components, such as in 6 represented, loosely arranged together. For example, by means of a connecting paste can then on the connection points between the individual components of the kit 102 a silicon-containing material, for example, be applied, so that by a thermal treatment of the loosely assembled kit 102 a cohesive connection of the components of the kit 102 can be achieved with each other to the fluid-tight crucible 100 manufacture.

Alternatively, however, it may also be provided that at least one of the components of the kit 102 is a preform for a Faserkeramikkörper before the crucible 100 is completed.

For example, it may be provided that the side wall elements 106 and the bottom wall element 108 and / or the receiving device 104 are first precursor body for Faserkeramikkörper. After the loose arrangement of the sidewall elements 106 and the bottom wall element 108 in the cradle 104 can then, for example, in one step, both the completion of the components as Faserkeramikkörper and the connection of the components of the kit 102 together to produce the crucible 100 respectively. For example, this can be done in a Siliziervorgang, which in particular a cohesive connection of the components of the kit 102 can be obtained with each other.

If the preforms for the fiber ceramic bodies are formed from carbon, in particular from carbon fiber-containing carbon, a particularly stable crucible is thus obtained 100 made of a fiber-reinforced silicon carbide.

Instead of silicon, however, it is also possible in principle to choose any material which, in combination with carbon, makes it possible to produce a carbide structure.

A crucible made in this way 100 allows in particular the inclusion of liquid silicon for the production of silicon crystals for the semiconductor industry.

By the downwardly tapered structure of the crucible 100 and by the choice of material, especially when using C / C-SiC for the design of the side wall elements 106 , the floor wall elements 108 and / or the receiving device 104 , allows the crucible 100 an easy removal of in the crucible 100 solidified material, such as solidified silicon, so that the crucible 100 preferably can be used again.

In particular, if fiber-ceramic material, for example C / C-SiC, as a material for the crucible 100 is used, the solidified material by the differential thermal expansion of the crucible 100 on the one hand and the solidified material on the other hand automatically cools down from the crucible 100 to solve. The melting pot 100 is then preferably reusable.

The material of the crucible 100 preferably has in particular a smaller thermal expansion coefficient than the material to be solidified therein, for example as silicon.

LIST OF REFERENCE NUMBERS

100

 melting pot

102

 kit

104

 cradle

106

 Side wall member

108

 Bottom wall member

110

 frame device

112

 edge element

114

 lower edge

116

 square picture

118

 corner

120

 lateral edge

122

 The direction of gravity

124

 Trapezoidal recording

126

 bottom wall

128

 Side wall

130

 top end

B

 width

H

 height

L

 length

α

 tilt angle

Claims (20)

Kit ( 102 ) for a carbide-ceramic crucible ( 100 ) comprising at least one bottom wall element ( 108 ) for forming a bottom wall ( 126 ) of the crucible ( 100 ) and at least one sidewall element ( 106 ) for forming a side wall ( 128 ) of the crucible ( 100 ), wherein the at least one bottom wall element ( 108 ) and / or the at least one sidewall element ( 106 ) is a fiber ceramic body or a preform body for a fiber ceramic body. Kit ( 102 ) according to claim 1, characterized in that the kit ( 102 ) at least one edge element ( 112 ) for reinforcing at least one edge ( 114 . 120 ) of the crucible ( 100 ). Kit ( 102 ) according to claim 2, characterized in that the at least one edge element ( 112 ) has an at least approximately L-shaped cross-section. Kit ( 102 ) according to one of claims 2 or 3, characterized in that a plurality of interconnected and / or interconnectable edge elements ( 112 ) are provided, which a receiving device ( 104 ) for receiving the at least one bottom wall element ( 108 ) and / or the at least one sidewall element ( 106 ) form. Kit ( 102 ) according to one of claims 1 to 4, characterized in that the at least one bottom wall element ( 108 ) and / or the at least one sidewall element ( 106 ) Comprises fibers which are at least approximately parallel to one in the assembled state of the crucible ( 100 ) an interior of the crucible ( 100 ) facing surface of the at least one bottom wall element ( 108 ) and / or the at least one sidewall element ( 106 ). Kit ( 102 ) according to one of claims 1 to 5, characterized in that the at least one bottom wall element ( 108 ) and / or the at least one sidewall element ( 106 ) Comprises fibers which extend at least approximately over an entire width (B) of the at least one bottom wall element (FIG. 108 ) or the at least one side wall element ( 106 ). Kit ( 102 ) according to one of claims 1 to 6, characterized in that the at least one bottom wall element ( 108 ) and / or the at least one sidewall element ( 106 ) Comprises fibers which extend at least approximately over an entire length (L) of the at least one bottom wall element (FIG. 108 ) or over an entire height (H) of the at least one side wall element ( 106 ). Kit ( 102 ) according to one of claims 1 to 7, characterized in that the fibers of the fiber ceramic body or of the preform for the fiber ceramic body comprise carbon fibers and / or carbide fibers. Carbide ceramic crucible ( 100 ), which consists of a kit ( 102 ) is formed according to one of claims 1 to 8. Crucible ( 100 ) according to claim 9, characterized in that an angle which of a bottom wall ( 126 ) and a side wall ( 128 ) of the crucible ( 100 ) is greater than 90 °. Crucible ( 100 ) according to one of claims 9 or 10, characterized in that an angle which of two adjacent side walls ( 128 ) of the crucible ( 100 ) is greater than 90 °. Crucible ( 100 ) according to one of claims 9 to 11, characterized in that the crucible ( 100 ) is wrapped at least in sections with a fiber. Use of a kit ( 102 ) according to one of claims 1 to 8 for the production of a carbide-ceramic crucible ( 100 ). Method for producing a carbide-ceramic crucible ( 100 ), comprising: - producing at least one bottom wall element ( 108 ) and at least four sidewall elements ( 106 ), wherein at least one bottom wall element ( 108 ) and / or at least one sidewall element ( 106 ) is a fiber ceramic body or a precursor body for the fiber ceramic body; Connecting the at least one bottom wall element ( 108 ) and the at least four sidewall elements ( 106 ) together. Method according to claim 14, characterized in that at least one edge element ( 112 ) for reinforcing at least one edge ( 114 . 120 ) of the crucible ( 100 ) in an edge region on two adjoining side wall elements ( 106 ) and / or in an edge region on a bottom wall element ( 108 ) and an adjacent side wall element ( 106 ) is arranged. Method according to one of claims 14 or 15, characterized in that a plurality of edge elements ( 112 ) of the crucible ( 100 ) a receiving device ( 104 ) for receiving the at least one bottom wall element ( 108 ) and / or the at least one sidewall element ( 106 ) is formed. A method according to claim 16, characterized in that the at least one bottom wall element ( 108 ) and / or the at least one Sidewall element ( 106 ) in the receiving device ( 104 ) to be ordered. Method according to one of claims 14 to 17, characterized in that at least one bottom wall element ( 108 ), at least one sidewall element ( 106 ) and / or at least one edge element ( 112 ) are wrapped with a fiber. Method according to one of claims 14 to 18, characterized in that the at least one bottom wall element ( 108 ) and the at least four sidewall elements ( 106 ) are joined together to form a fluid-tight shell. A method according to claim 19, characterized in that the fluid-tight shell is wrapped with a fiber.

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