JP3606473B2 - Pyrolytic boron nitride container - Google Patents

Description

[0001]
[Industrial application fields]
In the present invention, the temperature distribution of the pyrolytic boron nitride container, in particular, the container heated by external heating becomes uniform, and the support substrate and the radiation absorbing layer, and the radiation absorbing layer and the insulating layer or the protective layer are pressurized and heated. The present invention relates to a pyrolytic boron nitride container that does not peel even upon impact.
[0002]
[Prior art]
A pyrolytic boron nitride (hereinafter abbreviated as PBN) molded product is obtained by using NH ₃ and BF ₃ as raw materials, which are converted to PBN by a thermal CVD method at a temperature of 1,700 ° C., for example, and coated on the substrate. It is well known that it is made, and it is also known that the PBN molded article thus produced has excellent heat resistance and thermal shock resistance.
[0003]
This PBN molded article does not have a melting point, is highly pure, and emits very little impurity gas at high temperatures. Therefore, it is considered useful as a container for dissolution in a high vacuum. For the PBN container, a carbon film having a high infrared absorption rate is applied to all or a part of the outer surface and / or the inner surface to provide a radiation absorption layer in order to improve the heating efficiency and overall temperature uniformity. It has been proposed (see JP-A-2-204391).
[0004]
[Problems to be solved by the invention]
However, when this radiation absorption layer is provided, impurities are mixed into the product due to the scattering of the radiation absorption layer, and since these are generally conductive, there is a heater for heating and this. In order to solve these disadvantages, it has been proposed to provide an insulating layer or a protective layer on the outermost surface and / or the innermost surface (Japanese Patent Application Laid-Open No. Hei 4). No. 231459, Japanese Patent Laid-Open No. 4-285086), the adhesion between the PBN container and the radiation absorbing layer and / or between the radiation absorbing layer and the insulating layer or protective layer is not necessarily high. There was a problem that when any impact or thermal shock due to heating was applied during handling, they were easily peeled off.
[0005]
[Means for Solving the Problems]
The present invention relates to a PBN container in which such disadvantages and problems are solved, and this is provided with a radiation absorbing layer on the whole or a part of the outer surface and / or inner surface of a support substrate made of PBN, and the outermost surface and / or Te PBN container odor formed by providing an insulating layer or a protective layer on the innermost surface, the thickness of the radiation absorber layer is not more than 0.025mm or 0.010, the thickness of the insulating layer or the protective layer and at 0.02mm or more 0.050mm or less, and, characterized in that the surface roughness Ra of the support substrate and radiant light absorbing layer of this and 1μm or 5μm or less, the Rmax as 10μm or 30μm or less Oh Ru. The radiation absorbing layer is preferably made of carbon, and the insulating layer is preferably made of pyrolytic boron nitride, silicon nitride, aluminum nitride or aluminum oxide.
[0006]
That is, as a result of various studies to develop a PBN container in which the disadvantages of the conventionally known PBN containers have been solved, the present inventors have provided a radiation absorbing layer on the supporting substrate of the PBN container, and an insulating layer or It is assumed that a protective layer is provided, and the support substrate and the radiation absorbing layer have a surface roughness Ra of 1 μm to 5 μm and an Rmax of 10 μm to 30 μm. The physical bonding force between the light absorption layer and the insulating layer or the protective layer is increased by the anchor effect, and the internal stress of the radiation light absorption layer is relieved, and therefore, it is found that peeling at this bonding portion does not occur. According to this, it was confirmed that this PBN container can have a long life having high thermal shock resistance, and the present invention was completed.
[0007]
[Action]
The present invention relates to a PBN container, and as described above, in a PBN container in which a radiation absorbing layer is provided on a support base material made of PBN and an insulating layer or a protective layer is provided on the support base material. The surface roughness Ra of the radiation absorbing layer is 1 μm or more and 5 μm or less, and Rmax is 10 μm or more and 30 μm or less. According to this, the support substrate, the radiation absorbing layer, and the radiation absorbing layer The bonding force between the insulating layer and the protective layer is increased by the anchor effect due to the surface roughness, so that they do not peel off between the supporting substrate and the radiation absorbing layer and between the radiation absorbing layer and the insulating layer or protective layer. This PBN container is advantageous in that it can be used stably for a long period of time.
[0008]
The PBN container of the present invention is made by coating a substrate with PBN produced by a thermal CVD method of NH ₃ and BF ₃ by a known method. The PBN layer as a supporting substrate is formed on the PBN layer. The radiation-absorbing layer is provided on all or a part of the outer surface and / or the inner surface, and the outermost surface and / or the innermost surface of the radiation-absorbing layer is provided with an insulating layer or a protective layer.
[0009]
This radiation-absorbing layer may be a well-known layer, which may be made of carbon such as pyrolytic graphite obtained by thermally decomposing methane gas at a high temperature under vacuum. The thickness is preferably 0.010 μm or more and 0.025 mm or less in order to relieve internal stress in the dependent layer.
The insulating layer or protective layer prevents contact between the radiation absorbing layer and the heater, and the insulating layer or protective layer is made of PBN, silicon nitride, aluminum nitride, or aluminum oxide. The film thickness may be 0.020 mm or more and 0.050 mm or less.
[0010]
In the PBN container of the present invention, the surface of the support base and the radiation absorbing layer has a surface roughness Ra of 1 μm or more and 5 μm or less, and Rmax of 10 μm or more and 30 μm or less. What is necessary is just to process the surface of a support base material and a radiation light absorption layer, for example by the sandblasting method.
Since the surface of the supporting substrate and the radiation absorbing layer treated in this way has the roughness as described above, the supporting substrate and the radiation absorbing layer and the radiation absorbing layer and the insulating layer or Since the bonding force between the protective layers is increased by the anchor effect due to the surface roughness, the thickness of the radiation absorbing layer is 0.010 mm or more and 0.025 mm or less, and the internal stress in the layer is relaxed. The PBN container can be used stably for a long period of time without peeling between the support substrate and the radiation absorbing layer, or between the radiation absorbing layer and the insulating layer or protective layer even if there is a thermal shock due to external pressure or heating. The advantage of being able to do so is given.
[0011]
Also, this PBN container is provided with a radiation absorbing layer as described above. When a heater is used for heating, the radiation from the heater is absorbed by this absorbing layer, so that the heating efficiency is improved. So that the temperature distribution in the PBN container can be increased and the temperature distribution of the radiation absorption layer can be increased for a long time if it is provided at a specific part such as the bottom, opening, center, or one side of the PBN container. The advantage is that it can be provided stably over time.
[0012]
Next, a method for producing the PBN container of the present invention will be described with reference to the drawings.
FIGS. 1A to 1D are longitudinal sectional views of a PBN container prepared in the order of the manufacturing process of the PBN container of the present invention. FIG. 1A is a diagram illustrating a process in which NH ₃ and BF ₃ are evacuated. A PBN container 1 having an opening 2 obtained by coating PBN reacted at a high temperature on a carbon material or the like is shown below, and this is then subjected to sandblasting as shown in the drawing. Thus, the surface roughness Ra is set to 1 μm or more and 5 μm or less, and Rmax is set to 10 μm or more and 30 μm or less.
[0013]
Next, as shown in FIG. 1B, the PBN container 1 is provided with a radiation absorbing layer 3 made of pyrolytic graphite obtained by pyrolysis by high-temperature treatment of methane gas in vacuum. As shown in FIG. 1 (c), the absorbing layer 3 is subjected to a sandblast treatment so that the surface thereof has a surface roughness Ra of 1 μm to 5 μm and a Rmax of 10 μm to 30 μm. 4.
[0014]
Further, for this PBN container, as shown in FIG. 1 (d), NH ₃ and BF ₃ were treated at high temperature under vacuum on the entire surface of the radiation-absorbing layer 4 that had been roughened. By covering the obtained PBN and forming the insulating layer 5, the PBN container 6 of the present invention can be obtained.
However, in this case, in order to prevent the temperature of the opening from being lowered, as shown in FIG. 2, the roughened surface radiation absorbing layer 4 extends from the opening 2 of the PBN container 6 to 1/3 of the total length of the container. May be provided.
[0015]
【Example】
Next, examples and comparative examples of the present invention will be given.
Example NH ₃ and BF ₃ were reacted at 1,800 ° C. under a vacuum of 2 Torr, and this was coated on a carbon substrate at a thickness of 1 mm to prepare a PBN container. The surface was sandblasted and the surface roughness Ra was 1.0 μm and Rmax was 10 μm.
Next, the surface of this container was coated with pyrolytic graphite obtained by pyrolyzing methane gas at 1,650 ° C. under a vacuum of 5 Torr to a thickness of 25 μm, and after that, a radiation absorbing layer was produced, and then this surface was sandblasted The surface roughness Ra was 1 μm and Rmax was 10 μm.
[0016]
Next, the outermost surface of the radiation absorbing layer is coated with a PBN layer obtained by reacting NH ₃ and BF ₃ at 1,800 ° C. under a vacuum of 2 Torr at a thickness of 50 μm to form an insulating layer. The PBN container of the present invention was manufactured, and for this PBN container, a cycle of raising the temperature from 700 ° C. from 25 ° C. water to 1 minute and then lowering the temperature to 25 ° C. water was repeated 100 times. However, no peeling occurred at these joints.
[0017]
Comparative Example 1
A PBN container was produced in the same manner as in the example. At this time, the surface roughness Ra of the PBN layer on the container surface was 1.0 μm, but Rmax was 7 μm. In the same heating / cooling cycle as in the example, peeling occurred at the joint in only 7 times.
[0018]
Comparative Example 2
A PBN container was prepared in the same manner as in the example. However, when the same cycle test as in the example was performed on a PBN container in which the thickness of the pyrolytic graphite layer as the radiation absorbing layer was 35 μm, this was 10 times. Separation occurred at the joint in the cycle.
[0019]
【The invention's effect】
The PBN container of the present invention is provided with a radiation absorbing layer on the surface of a support substrate made of PBN, and an insulating layer or a protective layer is provided on the surface, and the surface roughness Ra of the surfaces of the support substrate and the radiation absorbing layer is 1 μm. The PBN container has excellent thermal shock properties, and the temperature distribution of the container heated by external heating becomes uniform, and the support substrate and the radiation are uniform. Since the bonding force between the light absorption layer and between the radiation absorption layer and the insulating layer or the protective layer is increased by the anchor effect, there is an advantage that it does not peel off even by pressure or thermal shock.
[Brief description of the drawings]
FIGS. 1A to 1D are longitudinal sectional views of PBN containers manufactured in the order of the manufacturing process of the PBN container of the present invention.
FIG. 2 is a longitudinal sectional view of a PBN container of the present invention provided with a pyrolytic graphite layer for preventing the opening from being lowered in temperature.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... PBN support base material 2 ... Opening part 3 ... Radiation light absorption layer 4 ... Rough surface processing Radiation light absorption layer 5 ... Insulating layer 6 ... PBN container

Claims (3)

Heat obtained by providing a radiation absorbing layer on all or part of the outer surface and / or inner surface of a support substrate made of pyrolytic boron nitride, and providing an insulating layer or protective layer on the outermost surface and / or innermost surface thereof decomposition boron nitride container odor Te, not more than該輻Shako thickness of the absorbing layer is more than 0.010 0.025 mm, the thickness of the insulating layer or the protective layer is not more than 0.050mm than 0.02 mm, In addition, the pyrolytic boron nitride container is characterized in that the surface roughness Ra of the surface of the supporting substrate and the radiation absorbing layer is 1 μm or more and 5 μm or less and Rmax is 10 μm or more and 30 μm or less. The pyrolytic boron nitride container according to claim 1, wherein the radiation absorbing layer is made of carbon. 2. The pyrolytic boron nitride container according to claim 1, wherein the insulating layer is made of pyrolytic boron nitride, silicon nitride, aluminum nitride or aluminum oxide.

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