EP1242321A1

EP1242321A1 - Method and device for annealing flat bodies

Info

Publication number: EP1242321A1
Application number: EP00981280A
Authority: EP
Inventors: Ulrich Fotheringham; Hauke Esemann; Norbert Hildebrand; James M. Uhlik; Adam O'ryan
Original assignee: Carl Zeiss AG; Schott Glaswerke AG
Current assignee: Schott AG; Carl Zeiss AG
Priority date: 1999-11-25
Filing date: 2000-11-21
Publication date: 2002-09-25
Also published as: WO2001038241A1; AU1858301A; TW498057B; DE19956753A1

Abstract

The invention relates to a method for annealing flat bodies, especially flat bodies consisting of an amorphous, inorganic material, especially flat glass panes or glass ceramic panes. One or more of the flat bodies are subjected to a heat treatment within a temperature range between room temperature and the respective glass transition temperature. The invention is characterized in that said heat treatment is carried out in an annealing container and in that said annealing container is configured in such a way that it is closed sufficiently to prevent impurities from the environment surrounding the annealing container from coming into contact with the flat body.

Description

Method and device for tempering flat bodies

The invention relates to a method for tempering flat bodies such. B. from an amorphous, inorganic material, in particular flat glass panes, in which one or more flat glass panes within a tempering container of a heat treatment in the range between room temperature and the respective glass transition temperature, i.e. typically up to 1000 ° C, is subjected to and be a closed tempering vessel for tempering flat bodies z. B. those made of an amorphous, inorganic material, in particular

Flat glass panes and the use of such a container for heat treatment, for example tempering, of flat glass panes, in particular for display applications or of glass ceramic panes.

In the manufacture of flat bodies from an amorphous, inorganic

Material, preferably flat glass, it is necessary, particularly in the case of display glasses which are usually obtained by the drawing process, to subject the flat bodies or flat glass panes to a further heat treatment after their production. This need arises, for example, from special requirements for the flatness of the

Glass panes that may not be able to be set up directly in the hot forming process. In this case, the flatness can be subsequently improved by heating the flat glass pane on a flat surface to a temperature in the order of magnitude of the glass transition temperature, holding it at this temperature for a time, so that the glass adapts to the surface under its own weight, and finally slowly cools down again. The flatness of the glass panes that can be achieved in this way essentially depends only on the flatness of the base and the thickness distribution. Another, equally important reason for subjecting flat glass panes to subsequent heat treatment results from the special properties of the glass structure. Glass is structurally amorphous, although its amorphous structure is not solid, but is sensitive to the thermal history. It can still change after production, if the glass is reheated to temperatures at which relaxation processes are activated. Every change in the amorphous structure is associated with a change in the order in the glass and thus a change in density. For example, when the glass is cooled rapidly, the temperature is usually above the

When the glass transition temperature takes place, a relatively disordered structure is frozen so that the glass has a comparatively low density. With a subsequent temperature load, this structure can partially relax and assume a higher-order state, which is associated with an increase in density. However, this means that the vitreous body shrinks due to the subsequent heating. Conversely, depending on the previous cooling and the type of subsequent temperature load, it can also happen that the density drops and the vitreous body expands.

The size changes that occur in this way, depending on the temperature load and previous cooling, are typically of the order of magnitude of at most 0.1%, in many cases, however, due to the low temperature load (in the household, for example, usually below 100 ° C.), so that it is significantly lower Effect in most cases is not noticeable at all. This effect is significant in the production of flat screens, however, since structured layers, for example semiconductor layers, are usually applied to a flat glass pane in temperatures of typically 250-600 ° C. in several successive steps. A shrinkage or one that occurs

Expansion has the consequence that in the subsequent process step the mask no longer matches the structures already applied to the glass. This applies in particular to uneven shrinkage caused, for example, by temperature inhomogeneity, since, in contrast to uniform shrinkage, this cannot be compensated for by adapting the masks. In such an application, it is therefore necessary that the size change occurring at the relevant temperature load typically does not exceed an amount in the order of 10 ppm.

Such a low shrinkage or small expansion can be achieved if the flat glass panes used are subjected to an additional heat treatment in the range between room temperature and the glass transition temperature after hot forming, at which a strong pre-compression of the glass takes place. Such a precompression has the consequence that the possible size change in the subsequent

Temperature load turns out much smaller. In this regard, reference is made to G. W. Scherer, Relaxation in Glass and Composites, Wiley, 1986, pages 113-174.

What is essential for the success of this additional heat treatment is in addition to the

Selection of a suitable temperature program that this is carried out with a very homogeneous temperature distribution, i.e. Both the gradients within a glass pane and the temperature differences between the individual panes must be kept as low as possible, since otherwise the shrinkage or the expansion in the subsequent one

The temperature load turns out to be small, as desired, but fluctuates within a pane or between the individual panes, which cannot be compensated for, for example, even by adapting the mask. This requirement placed on the temperature homogeneity also applies to a temperament with regard to the homogeneity within a pane Improvement of the flatness, since temperature inhomogeneities always lead to stresses in the flat glass pane.

A method for the heat treatment of flat glass panes with high temperature homogeneity is known from DE 197 44 666 C1. Thereafter, the heat treatment is carried out in a radiation furnace in such a way that a flat glass pane or a stack of flat glass panes is located on a ceramic plate or between two ceramic plates of high thermal conductivity. By contact with the hochwärmeleiteπden ceramic plate, the influence of a prevailing in the furnace can be

Halve the temperature gradient on the glass in order of magnitude.

A disadvantage of this method is that very high demands must be placed on the cleanliness of the furnace used. Since the flat glass panes generally do not yet have optimal flatness at the start of the heat treatment, narrow air gaps are present between the individual panes, so that particles in the furnace can get between the panes and thus damage the surface. This is particularly dangerous when using a convection oven.

Another problem is that the application of the method known from DE 19744666 C1 is essentially limited to batch operation in the radiation furnace. Each passage of the described stack structure of ceramic plates and flat glass panes through a continuous furnace can easily lead to the formation of surface defects by slipping of the ceramic plates or flat glass panes. This is particularly true when using a convection oven, since the air currents in the oven promote slipping. A tempering container for tempering optical glass in a chamber furnace has become known from DD 158 938, but this container is not designed to be closed. Rather, air is introduced into the annealing container so that every point on the surface of the heat material is exposed to the air currents in order to achieve a high temperature homogeneity during the annealing process. This supplied furnace air in contact with the glass leads to undesirable damage to the surface of the material to be tempered due to the contamination introduced by the air flow.

JP 05330836 and JP 05339021 describe the use of glass ceramic plates as protection against particles originating from the furnace walls or heating elements. Although these offer a certain protection of the flat glass panes against contamination from the furnace, they cannot prevent contamination from dust from the environment, which is practically unavoidable in a production environment. Theoretically, the entire oven space known from JP 05330836 and JP 05339021, in which the glass ceramic plates are arranged, could be designed as a clean room in order to prevent damage to the glass surface, for example by dirt particles introduced into the oven, but this would be very complex, since this necessarily means Filtered oven air and the oven would have to be equipped with a lock system for loading and unloading.

Another possibility of protecting an annealing stack is shown in JP08151224. After this, the annealing stack is laterally delimited by quartz plates. A disadvantage of this method is that, due to the non-closed structure, the panes are not reliably protected against contamination either. In the construction according to JP 08151224, if the annealing is carried out as described in JP 08151224, N _{2 is} always fed into the furnace, with a gas flow of 500 l / hr, in order to prevent that paper inserted between the individual glass panes of the glass stack burns. In order to prevent contaminants from entering the furnace, the supplied N ₂ and all the components of the structure located inside the furnace would have to be cleaned in a complex manner. Furthermore, with this arrangement, slipping of the flat glass panes during the passage of a continuous furnace cannot be reliably prevented. Finally, the method known from JP08151224 is not sufficiently temperature-homogenized, since the thermal conductivity of the stainless steel hereafter used as the base and cover plate is low and no measures are taken to avoid vertical temperature gradients.

The object of the invention is to overcome the disadvantages of the prior art and to provide a method which avoids damage to the surfaces of the flat glass panes, in particular due to contamination with particles. In particular, heat treatment of large batch sizes with high process stability is to be made possible.

According to the invention, this object is achieved in that the heat treatment is carried out in a closed annealing container. In this way, damage to the surface of the flat body to be tempered due to contamination from the environment of the tempering container can be avoided.

The advantages of the method according to the invention or of the invention

The device compared to the known tempering in a furnace are, in particular, the simple cleaning of the tempering container before use, for example using H ₂ O compared to cleaning and keeping a furnace clean, and the high temperature homogeneity which can be achieved in a simple manner in the tempering container. The tempering container is advantageously designed or mounted in such a way that the flat bodies, preferably the flat glass panes, are fixed in place during the heat treatment, in particular also in a continuous furnace. This has the advantage that the flat glass panes are secured against slipping, so that damage to the surface, for example when

Transport avoided.

In a particularly advantageous embodiment, the tempering container is mounted at an angle, so that at least two edges of the flat glass panes have at least one edge point on at least one side surface of the

Tempering vessel is present.

In a further advantageous embodiment of the invention, the heat treatment of one or more flat glass panes is carried out in a tempering container on a ceramic plate or between two ceramic plates of high thermal conductivity. A high lateral temperature homogeneity can be achieved in this way.

In a preferred embodiment, the closed tempering container comprises a cover surface and side surfaces which cover the upper part of the

Form tempering tank and a support surface that represents the lower part. Such a configuration makes it easier to load the container with ceramic plates and flat glass panes.

The annealing container can be made of aluminum, copper or another

Material have high thermal conductivity, which improves the temperature homogeneity within the glass. In an alternative embodiment, the side walls of the tempering container consist of a material with low thermal conductivity, which contributes to the reduction of lateral temperature gradients. According to the invention, both the flat glass panes and the ceramic plate can be secured against slipping through the side walls of the tempering container, so that jerky movements of the entire structure cannot damage the glass surfaces. This makes it possible to use a continuous furnace without any problems. In this case, the tempering container is preferably mounted obliquely, so that at least one edge point rests on at least one side surface of the tempering container on at least two edges of the flat glass panes.

The contact surface between the upper and lower part of the tempering container can advantageously be stepped, for example in the form of a labyrinth, in order to ensure optimum protection of the flat glass panes against soiling. As an alternative to this, a configuration similar to conventional UHV seals would include cutting on top and bottom

Lower part of the closed container and, for example, a metal seal in which they engage, are conceivable. The metal seal is preferably a Cu, Al or Au seal. The metal seal and the annealing container are particularly preferably made of the same material, for example aluminum, since the seal and the annealing container then have the same coefficient of thermal expansion σ. Other sealing materials are also conceivable.

With the seals described above - labyrinth seal and UHV seal - it is practically possible that within the tempering container

Clean room conditions prevail, while the closed container is exposed to harsh production conditions from the outside. For example, the tempering container loaded in a clean room can also be cleaned from the outside after completion of the heat treatment and opened again in the clean room in order to optimally process the flat glass panes to ensure clean conditions without the oven having to meet any special requirements.

In addition to the advantages mentioned above, the device according to the invention and the method according to the invention make a significant contribution to largely avoiding the formation of temperature gradients, in particular lateral gradients, within the flat glass pane or the stack of flat glass panes. This will be explained in more detail using an example.

It is assumed that to carry out the heat treatment, a stack of flat glass panes is stored on a 6 mm thick plate made of silicon-filtered SiC, which due to its high thermal conductivity (approx. 100 W / mK at 200 ° C) alone makes a certain contribution to temperature homogenization , as stated in DE 197 44 666 C1. If this SiC plate is in turn on a 16 mm thick copper plate, which represents the bottom or the contact surface of an annealing container according to the invention, an increase results from the thermal conductivity of the copper (373 W / mK at 200 ° C) and the other data mentioned above the temperature-homogenizing effect by a factor of 10. The same

Effect is obtained on the top of the stack, provided that the tempering container is dimensioned such that its lid is in contact with the upper SiC plate. The copper plate mentioned above can also be provided with a coating against scaling.

In the event of contact between the upper SiC plate and the lid or cover surface of the tempering container, the method according to the invention has the further advantage that when using highly thermally conductive side walls of the tempering container, the upper and lower ceramic plates are thermally short-circuited, so that the effects are not only horizontal but also also vertical temperature gradients prevailing in the furnace on the Flat glass pane can be largely eliminated. In an advantageous embodiment of the invention, it can be provided that in the case of a tempering vessel which consists entirely of a material with high thermal conductivity, the side walls are additionally surrounded by a material with low thermal conductivity in order to improve the lateral temperature homogeneity.

If the method according to the invention is carried out in a radiation oven or in an oven in which the heat is transported at least partially by radiation, it is advantageous if heat exchange by radiation can take place between the tempering vessel and its surroundings. In the case of a highly reflective metal surface, this is only possible to a very limited extent.

According to a development of the invention, the heat exchange by radiation can be optimized by providing the tempering container with a coating which has a high emissivity in the infrared range. For example, ceramic coatings based on aluminum titanate can be used for this purpose. If the heat transfer is to take place preferably over the top and bottom of the tempering container, which again

To improve the lateral temperature homogeneity, the coating with high emissivity can be limited to these areas.

The method and the device according to the invention are to be described by way of example with reference to the figures and the explanations below.

Show it:

1 shows an inventive construction of an annealing container for

Implementation of the method according to the invention characters

2a to 2c different embodiments of a labyrinth seal

Figure 3 shows a UHV seal

FIG. 4 shows an open structure for carrying out the method according to the invention.

FIG. 1 shows an annealing container 1 according to the invention for carrying out the method according to the invention. The tempering container 1 is made in two parts and consists of an upper part 3 and a lower part 5. The upper part 3 comprises the cover surface 4 and the side surfaces 6.1, 6.2, the

Lower part 5 the bottom or the supporting surface 8 of the tempering container 1 according to the invention. The material of the upper and lower part of the tempering container 1 is preferably a metal, for example. In a further developed embodiment, the metal surface of the tempering container 1, which faces the furnace, can be designed with a coating, not shown, which has a high emissivity in the infrared.

The contact surface between the upper part 3 and lower part 5 of the tempering vessel is designed with a step 7. With such a configuration, the stack 9 is made of flat glass pane 1 1 inside the

Tempering container 1 optimally protected against the ingress of dirt. According to the invention, the stack 9 of flat glass panes 11 is located between two ceramic plates 13, 15 arranged in the interior of the container 1, which in turn are in contact with the cover or support surface. Advantageously, ceramic plates are used with a thickness such that the ratio of the total thickness of the ceramic plates to the height of the entire stack 9 made of glass pane is at least 1 / λ -40 W / (m -K), where λ is the thermal conductivity of the ceramic material in the range of the heat treatment temperature is. FIG. 2a shows a first embodiment of a baby seal according to the invention. The contact surface between upper part 3 and lower part 5, which is designed as step 7, can be clearly seen

When the upper part 3 and lower part 5 are assembled, upper part 3 and

Lower part 5, for example at points 20 and 22. The stepped design reliably prevents contamination from penetrating from the outside of the container into the inside of the container. In addition to an embodiment with only one step according to FIG. 2a, there are also multi-stage embodiments, such as in FIG. 2b illustrated conceivable The contact surface between the upper part 3 and lower part 5 comprises two stages 7 1 and 7 2 in the example shown in FIG. 2b. If the two containers are connected to one another, at least at points 20, 22 and 24 there is a circumferential contact between the upper part and lower part ensured. 2c shows an alternative embodiment of a

Labyrinth seal shown, in which the upper part 3 comprises a nose 26 which engages in the groove 28 of the lower part 5 If the upper part 3 and lower part 5 are closed, the upper part 3 and lower part 5 touch at least three points 20, 22 and 24

FIG. 3 shows an alternative embodiment of a gas-tight connection and thus also a leak-proof connection for all particles. The upper part 3 and the lower part 5 comprise cutting edges 30, 32 arranged in the area of the contact surfaces and a metal seal 34 inserted between the upper part and the lower part , Upper and lower parts can be clamped together. The cutting edges 30, 32 then engage in the metal seal and effect the particle-tight connection. The metal seal can, for example, be made of copper, aluminum or gold. The same material is preferably used for the metal seal as for the closed one Tempering container, so that

Overall system no different coefficients of thermal expansion having. The preferred material for the metal seal and thus for the entire closed container are aluminum and copper. Other materials are also conceivable.

FIG. 4 shows an overall system for carrying out a method according to the invention. The overall system comprises, for example, a continuous furnace 100, which can be designed as a circulating air furnace, in which individual tempering containers 1 are transported through the furnace on a circulating belt 102.

The containers are loaded in a clean room 104. The tempering containers are loaded and closed there under clean room conditions. The tempering containers 1 are then transported through a lock 106 into the continuous furnace 100 and annealed in this furnace, for example as a convection oven. It does not matter how polluted the air in the

Convection oven.

After tempering and cleaning, the tempering containers are transported from outside to clean room 110 via lock 108. The tempered glass panes can then be removed again in clean room 110 under clean room conditions.

The implementation of a method according to the invention with an annealing container 1 is described below:

A stack 9 of ten disks 11 of glass D263 (Schott DESAG AG, Grünenplan) cleaned in an ultrasonic cleaning system is formed in the format 340 x 320 x 1, 1 mm ³ without the use of a release agent and between two equally large, 6 mm thick plane-ground ceramic plates 13, 15 positioned from silicon infiltrated SiC. This structure is placed in a tempering container 1 made of aluminum (Alimex ACP 5080) appropriate Inneπabmessungeπ introduced, the ceiling and side walls have a wall thickness of 20 mm, while the thickness of the bottom is 35 mm. The tempering container is closed during the tempering.

A convection oven with 48 zones is used to carry out the heat treatment, in which a temperature profile in the range between room temperature and 500 ° C. is set. The feed rate is selected so that the heat treatment takes a total of 14 hours.

To determine the temperature homogeneity, seven type K thermocouples calibrated with an accuracy of ± 1 ° C are used, which are additionally introduced into the aluminum box in such a way that the temperatures can be measured on all six sides and in the middle of the stack during the heat treatment. The measurement is in the form of a

Drag measurement carried out using correspondingly long, temperature-insensitive cables and all temperatures registered at intervals of five minutes.

The result of the heat treatment described in this way is one

Temperature deviation within the cooling phase, i.e. in the relevant part of the tempering program, typically around 2 K. This corresponds to the accuracy of the thermocouples used, so that temperature gradients cannot be detected. The inspection of the flat glass panes after the heat treatment shows that neither surface defects due to

Sliding of the panes can still be detected by contamination from particles coming from the oven or the environment.

The invention thus for the first time specifies a method and a device for tempering a large number of flat bodies, in particular flat glass panes, in which damage occurs, for example, due to in the furnace Any contamination or transport through a continuous furnace can be safely avoided. Furthermore, a high temperature homogeneity within the flat body is guaranteed.

Claims

claims

1. A method for tempering flat bodies, in particular made of an amorphous, inorganic material, in particular flat glass panes or glass ceramic panes, one or more of the flat ones

Bodies are subjected to a heat treatment in the temperature range between room temperature and the respective glass transition temperature, characterized in that the heat treatment is carried out in a tempering container and the tempering container is designed such that

Contamination of the environment of the tempering container does not come into contact with the flat body.

2. The method according to claim 1, characterized in that the tempering container is designed or stored such that the flat

Body or the flat body is fixed in place during the heat treatment.

3. The method according to any one of claims 1 to 2, characterized. that at least one ceramic plate is provided in the interior of the tempering container.

4. The method according to claim 3, characterized in that the ceramic plate (s) is or are arranged between the support surface and / or the cover surface and the flat body or bodies.

5. The method according to any one of claims 3 or 4, characterized in that the ceramic plate or ceramic plates with a high thermal conductivity, preferably greater than 50 W / mK Room temperature, particularly preferably greater than 80 W / mK at room temperature.

6. The method according to any one of claims 3 to 5, characterized in that the ceramic plates have such a thickness that the

The ratio of the total thickness of the ceramic plates to the height of the glass stack is at least 1 / λ -40 W / (m -K), where λ is the thermal conductivity of the ceramic material in the range of the heat treatment temperature.

7. The method according to any one of claims 3 to 6, characterized in that the ceramic plate or ceramic plates has or have a high flatness, preferably better than 100 microns, particularly preferably better than 50 microns, very particularly preferably better than 20 microns.

8. The method according to any one of claims 3 to 7, characterized in that the ceramic plates have a roughness R _tm <10 microns, preferably <1 microns.

9. The method according to any one of claims 3 to 8, characterized in that the ceramic plate or ceramic plates comprises silicon carbide, preferably silicon-infiltrated SiC.

10. The method according to any one of claims 1 to 9, characterized in that the tempering container is a material with high or all or part

Thermal conductivity, preferably greater than 200 W / mK at room temperature, particularly preferably greater than 350 W / mK at room temperature.

11. The method according to any one of claims 1 to 10, characterized in that the Seitenπwäπde completely or partially a material low thermal conductivity, preferably <20 W / mK, particularly preferably <5 W / mK, particularly preferably <2 W / mK, very particularly preferably <1 W / mK.

12. The method according to any one of claims 1 to 11, characterized in that the material of the annealing container comprises aluminum or an aluminum alloy.

13. The method according to any one of claims 1 to 12, characterized in that the material of the annealing container comprises copper or a copper alloy.

14. The method according to any one of claims 1 to 13, characterized in that the side surfaces of the tempering vessel are firmly connected to the cover surface resulting in an upper part, and the

Contact surface represents a second, separate lower part.

15. The method according to any one of claims 1 to 14, characterized in that the contact surfaces between the upper and lower part of the tempering vessel are designed in stages, preferably with two stages, particularly preferably with three stages.

16. The method according to any one of claims 1 to 15, characterized in that in the region of the contact surfaces of the upper and lower part blades (30, 32) are arranged which engage in a sealing ring which is preferably metallic, particularly preferably Cu, Al or Au includes.

17. The method according to claim 16, characterized in that the seal and the closed container comprise the same material.

18. The method according to any one of claims 1 to 17, characterized in that the loading of the tempering container is carried out under clean room conditions.

19. The method according to any one of claims 1 to 18, characterized in that the unloading of the tempering container takes place under clean room conditions.

20. The method according to any one of claims 1 to 19, characterized in that the tempering container completely or partially a

Coating which has a high emissivity in the infrared region, preferably greater than 0.5, particularly preferably greater than 0.8, in contrast, again preferably greater than 0.9.

21. The method according to claim 20, characterized in that the

Coating comprises a ceramic layer.

22. The method according to any one of claims 20 to 21, characterized in that the coating aluminum titanate, a mixture of aluminum oxide and titanium oxide or a mixture of

Zirconia and chromium (III) oxide.

23. Tempering container for tempering flat bodies, in particular made of an amorphous, inorganic material, in particular flat glass or glass ceramic disks (11), in a temperature range between

Room temperature and the glass transition temperature of the substance to be tempered, characterized in that the tempering heater is designed in such a closed manner that contamination of the environment of the tempering container does not come into contact with the flat body.

24. Tempering container according to claim 23, characterized in that the tempering container (1) comprises means which are designed such that the flat body or the flat bodies is or are fixed in place during the heat treatment.

25. Tempering container according to claim 24, characterized in that the means for fixing the flat bodies during the heat treatment are side surfaces (6.1, 6.2).

26. Tempering container according to one of claims 23 to 25, characterized in that the side surfaces (6.1, 6.2) of the tempering container are firmly connected to a cover surface (4) resulting in an upper part and the support surface (8) is a second separate lower part (5) ,

27. Tempering container according to one of claims 23 to 26, characterized in that the contact surfaces between the upper and lower part (3,5) of the tempering container (1) are designed in stages, preferably with two stages (7), particularly preferably with three stages.

28. Tempering container according to one of claims 23 to 27, characterized in that in the region of the contact surfaces of the upper and lower part (3, 5) blades (30, 32) are arranged which engage in a seal (34), which is preferably metallic , iπsbersoπdere preferably comprises Cu, Al or Au.

29. Tempering container according to claim 28, characterized in that the sealing ring and the closed container comprise the same material.

30. Tempering container according to one of claims 23 to 29, characterized in that it is designed such that inside the

Tempering container ceramic plates can be arranged.

31. Tempering container according to claim 30, characterized in that the ceramic plate (s) is or are arranged between the support surface and / or the cover surface and the flat body or the flat bodies.

32. Tempering container according to one of claims 30 to 31, characterized in that the ceramic plate or ceramic plates (13, 15) has a high thermal conductivity, preferably greater than 50 W / mK at room temperature, particularly preferably greater than 80 W / mK at room temperature or have.

33. Tempering container according to one of claims 30 to 32, characterized in that the ceramic plates have such a thickness that the ratio of the total thickness of the ceramic plates to the glass stack height is at least 1 / λ -40 W / (m-K), where λ is the

Thermal conductivity of the ceramic material is in the range of the heat treatment temperature.

34. Tempering container according to one of claims 30 to 33, characterized in that the ceramic plate or ceramic plates (13, 15) has a high flatness, preferably better than 100 μm, particularly preferably better than 50 μm, very particularly preferably better than 20 μm or . exhibit.

35. Tempering container according to one of claims 30 to 34, characterized in that the ceramic plates have a roughness R _tm <10μm, preferably <1 μm.

36. Tempering container according to one of claims 30 to 35, characterized in that the ceramic plate or the ceramic plates Silicon carbide, preferably silicon infiltrated SiC comprises or comprise.

37. Tempering container according to one of claims 23 to 36, characterized in that the tempering container in whole or in part

Material with high thermal conductivity, preferably greater than 200 W / mK at room temperature, particularly preferably greater than 350 W / mK at room temperature.

38. Temper container according to one of claims 23 to 37, characterized in that the side walls completely or partially a material of low thermal conductivity, preferably <20 W / mK; particularly preferably comprise <5W / mK, particularly preferably <2W / mK, very particularly preferably <1W / mK.

39. Tempering container according to one of claims 23 to 38, characterized in that the tempering container completely or partially comprises a coating which has a high emissivity in the infrared, preferably greater than 0.5, particularly preferably greater than 0.8, in contrast, again preferably greater than 0.9.

40. Tempering container according to claim 39, characterized in that the coating comprises a ceramic layer.

41. Tempering container according to one of claims 39 to 40, characterized in that the coating comprises aluminum titanate, a mixture of aluminum oxide and titanium oxide or a mixture of zirconium oxide and chromium (III) oxide.

42. Tempering container according to one of claims 23 to 41, characterized in that the material of the tempering container comprises aluminum or an aluminum alloy.

43. Tempering container according to one of claims 23 to 42, characterized in that the material of the tempering container comprises copper or a copper alloy.

44. Use of a tempering container according to one of claims 23 to 43, for the tempering of one or more of the following

Materials: - flat glass paneπ

- display glasses

- glass ceramic plates