JPH09255427A - Carbon heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stable and non-staining carbon heater little in the consumption of the carbon material also on the use of the heater for a long period and not causing a product-staining phenomenon accompanying the generation of carbon particles. SOLUTION: This carbon heat generator comprises a Si-containing glassy carbon material in which the Si atoms are dispersed in the glassy carbon tissue in an amount of 0.1-10wt.%. The Si-containing glassy material is obtained by subjecting a cured molded product which is crosslinked with groups of the formula: -O-Si-O- or a cured molded product to a calcination carbonization treatment. The cured molded product which is crosslinked with the groups of the formula: -O-Si-O- is obtained by stirring and mixing a thermosetting resin with the hydrolyzate of a Si alkoxide containing a single Si atom in the molecule and subsequently molding the mixture. The other cured molded product is obtained by dropwisely adding an aminosilane compound or epoxysilane compound containing a single Si atom in the molecule to a thermosetting resin, stirring and mixing the mixture and subsequently molding the mixture. The Si-containing glassy carbon material preferably has a tissue in which the Si atoms are homogeneously and continuously distributed in the glassy carbon tissue in the level of the atoms.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-polluting carbon heating element which is particularly useful as a heating source for various devices used in the semiconductor field and which is guaranteed to be used stably for a long period of time.

[0002]

2. Description of the Related Art Carbonaceous heating elements have characteristics such as good heat resistance and chemical stability, and a small coefficient of thermal expansion. Among these, heating elements made of graphite are particularly suitable in a non-oxidizing atmosphere. Since it is extremely stable even in a high temperature range exceeding 3000 ° C., it is useful as a heater member used under severe high temperature conditions.

Generally, a graphite heating element is formed by kneading and molding a powdered or granular material such as petroleum coke or pitch coke into an aggregate with a carbonizing binder such as tar or pitch, firing and carbonizing the molded body, and then graphitizing. It is manufactured by processing and then cutting into a predetermined heating element shape. However, the graphite heating element produced in this step usually contains a trace amount of metal components, and when heated by electric current, these metal impurities evaporate and volatilize from the tissue. It cannot be used as it is for a semiconductor single crystal pulling apparatus that does not like contamination by impurities. Therefore, a high-purity heating element obtained by treating a graphite material with a halogen-containing gas to vaporize and remove metal impurities as a halide is considered to be effective (JP-A-2-242579). However, since the graphite heating element does not have sufficient tissue cohesion and compactness, there are problems such as the fall of aggregate powder particles and the generation of built-in gas components during high-temperature heat generation. Even if it is applied, the safety against pollution cannot be secured.

Therefore, a carbonaceous heating element different from the above-mentioned ordinary graphite material has been proposed. For example, JP
JP-A-8-128686 discloses a carbon-based carbon-based coil resistance heat generation in which a mixture of an organic polymer substance, asphalt pitches, carbonized pitches and the like is formed into a linear body, and an organic linear body is formed into a coil and then carbonized. The body is disclosed. Further, in JP-A-5-135858, the main component is the specific resistance 1
A carbon heater made of a carbon material having a bending strength of 600 μΩcm or more and a bending strength of 500 kg / cm ² or more is disclosed. A spiral carbon made of a glassy carbon material (glassy carbon) produced by firing a resin as a material shape of the heater. A heater is illustrated.

Glassy carbon is a heterogeneous carbon material having a glassy and dense structure structure, and is gas impermeable, abrasion resistant, corrosion resistant, self-lubricating, and more carbonaceous than graphite materials and other carbon materials. It has excellent surface smoothness and toughness, and has very little degassing components from the internal structure under vacuum or when heat is generated. When it is used as a heating element, it is less likely to cause external contamination like graphite heating elements.

[0006]

However, the carbon heating element used for heating at a high temperature reacts with a small amount of oxygen and other gases present in the system even if the inside of the apparatus is kept in a non-oxidizing atmosphere. The material is gradually consumed. This phenomenon cannot be fully avoided even with a heating element made of glassy carbon, and stable use over a long period cannot be expected. Moreover, as the wear progresses, fine particles are easily generated from the tissue and the object to be heated is easily contaminated.

[0007] In the course of conducting multifaceted research on the improvement of the structure of the glassy carbon material, the present inventors have found that the chemical stability of a certain amount of Si uniformly contained in the structure of the glassy carbon material ( It has been confirmed that (oxidation resistance) is improved, that when it is used as a heating element, the service life is extended, and generation of particles can be effectively suppressed.

The present invention has been developed on the basis of the above findings, and its object to be solved is to reduce the consumption of materials even during long-term use, and to prevent the product from being contaminated due to the generation of particles. It is to provide a non-polluting carbon heating element.

[0009]

To achieve the above object, a carbon heating element according to the present invention is a Si-containing glassy material containing Si dispersed in a glassy carbon structure in an amount of 0.1 to 10% by weight. The structural feature is that it is made of a carbon material.

The Si-containing glassy carbon material constituting the present invention is preferably a composite structure in which the Si component dispersedly contained in the glassy carbon structure is distributed at the atomic level, and particularly -O-Si-O. Obtained by calcining and carbonizing a cured molded product of a thermosetting resin crosslinked with-, or a cured molded product of an aminosilane-containing resin composition or an epoxysilane-containing resin composition, and atomic level Si is present in the glassy carbon structure. An excellent effect is exhibited when it has a texture property that is distributed as a uniform continuous phase. Atomic-level Si is a texture property in which it is distributed as a uniform continuous phase in a glassy carbon structure. The grain boundary between Si and C does not substantially exist, and the Si component is observed by a transmission electron microscope (TEM). Indicates an organizational state that cannot be identified.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Si dispersed in a glassy carbon structure suppresses material consumption due to a reaction between a base carbon structure and a reactive gas such as oxygen and improves chemical stability. It is a component that functions to strengthen the brittle glassy carbon structure and prevent particles from falling off, and its content is 0.1 to 10% by weight, preferably 2
Set in the range of up to 8% by weight. This Si content is 0.1
If it is less than 10% by weight, sufficient chemical stability cannot be ensured for practical use, and if it exceeds 10% by weight, it is not possible to maintain the atomic level of Si dispersed state, which is a factor to increase the generation of particles.

The carbon heating element of the present invention comprising the Si-containing glassy carbon material having the above-mentioned texture is a thermosetting resin and a hydrolyzate of Si alkoxide having a single Si atom in one molecule, which is an organic solvent. It can be produced by a method in which the gelled product obtained by the cross-linking reaction is hard-molded by stirring and mixing in the interior, and then the molded product is subjected to firing carbonization treatment in a temperature range of 800 ° C. or higher in a non-oxidizing atmosphere. Alternatively, an aminosilane compound or an epoxysilane compound containing a single Si atom in one molecule is dropped into a thermosetting resin liquid, stirred and mixed, and produced by reacting an amino group or an epoxy group with a thermosetting resin. It is manufactured by a method in which an aminosilane-containing resin composition or an epoxysilane-containing resin composition is cured and molded, and then the molded body is subjected to firing and carbonization treatment in a temperature range of 800 ° C. or higher in a non-oxidizing atmosphere. The specific manufacturing process is as follows.

Examples of the thermosetting resin which is a raw material of the glassy carbon include phenol resin, furan resin,
Polyimide-based resins, polycarbodiimide-based resins, polyacrylonitrile-based resins, pyrene-phenanthrene-based resins, polyvinyl chloride-based resins, epoxy-based resins, and mixed resins thereof are used. In particular, a phenolic resin, a furan-based resin, or a mixed resin thereof having a residual carbon ratio of 45% by weight or more when the resin is fired at a temperature of 800 ° C. in a non-oxidizing atmosphere is preferably used.

Si alkoxides having a single Si atom in one molecule which are selectively used as the Si source have the general formula Si
(OR) _n or R _n Si (OR) _n (where R represents an alkyl group or an aryl group, and n represents an integer of 1 or more). Compounds such as polysilane, polysiloxane, and polysilazane to which Si atoms are bonded are not included. Examples of usable Si alkoxides having a single Si atom include methoxysilane, ethoxysilane, butoxysilane, propoxysilane, isopropoxysilane, diethoxysilane, dibutoxysilane, dipropoxysilane, trimethoxysilane, and triethoxysilane. , Tributoxysilane, tripropoxysilane, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, tetrapropoxysilane, trimethylmethoxysilane, trimethylethoxysilane, tri-n-propylmethoxysilane, tri-n-propylethoxysilane, tri -N-butylmethoxysilane, tri-iso-butylmethoxysilane, tricyclohexylmethoxysilane, tricyclohexylethoxysilane, bis (2-ethylhexyl)
Examples thereof include dimethoxysilane and bis (2-ethylhexyl) diethoxysilane. However, for the purpose of the present invention, low-reactivity tetramethoxysilane [Si (OCH ₃ ) ₄ ] or tetraethoxysilane [Si (OC
₂ H ₅ ) ₄ ] is preferable, and the latter tetraethoxysilane is particularly preferably used.

Si alkoxide having a single Si atom in one molecule (hereinafter, simply referred to as "Si alkoxide")
Is added so as to have a concentration of 50% by volume or less with respect to the organic solvent, and an appropriate amount of water (1 to 1 with respect to the Si alkoxide) is added in advance.
2 mol equivalent amount) is added and hydrolyzed and mixed with the thermosetting resin in an organic solvent. It is preferable that the Si alkoxide and the thermosetting resin be added to an alcohol-based organic solvent from which water has been removed and sufficiently stirred, and then subjected to ultrasonic dispersion treatment and then mixed. By sequentially performing the dispersion treatment, the aggregated constituent molecules can be effectively disassembled. For this reason,
The reaction and aggregation of Si alkoxides in the subsequent operation stage are suppressed, and a stable monomolecular dispersed state is maintained.

The mixing of the Si alkoxide and the thermosetting resin is carried out by a method of gradually adding the hydrolyzed Si alkoxide solution to the thermosetting resin liquid while stirring.
At this time, the addition amount of the thermosetting resin is such that the Si content in the glassy carbon structure is 0.1 to 10% by weight.
Adjust to the amount ratio. At the time of mixing, if the solution is alkaline, polycondensation proceeds rapidly to form a spherical polymer. Therefore, it is preferable to adjust the pH of the solution to an acidic side by using an alcohol-soluble organic acid containing no water.

When the Si alkoxide solution and the thermosetting resin liquid are mixed, a crosslinking reaction occurs between the C-OH group in the thermosetting resin and the silanol group (Si-OH) of the hydrolyzed Si alkoxide, and the gel is gradually formed. Turn into. This cross-linking reaction is extremely faster than the dehydration condensation reaction between silanols, so that a gelled product of a thermosetting resin cross-linked with —O—Si—O— can be easily obtained. Therefore, the molded body is poured into a mold before the mixed solution of the Si alkoxide solution and the thermosetting resin liquid is gelled, vacuum defoaming treatment is performed if necessary, and then heated from room temperature to 70 ° C. It is preferably formed by a method of curing at the same time as curing. As the molding means, other suitable methods such as centrifugal molding, injection molding, transfer molding, compression molding, and laminated molding can be adopted, and the molding method is selected according to the desired shape of the heating element.

Further, as a Si source, a single Si in one molecule is used.
Aminosilane compounds containing atoms can also be used. The aminosilane compound containing a single Si atom in one molecule is represented by the following general formula (Formula 1) and is usually commercially available as an amine-based silane coupling agent. Aminosilane compounds containing a single Si atom in one molecule are selected and used because polysilane in which two or more Si atoms are bonded in one molecule causes an aggregation phenomenon at the mixing stage with the thermosetting resin liquid. It is easy, and since silane compounds having organic functional groups other than amino groups, such as methyl groups and vinyl groups, do not react directly with the thermosetting resin, separation, association, and multimerization (polymerization) occur during mixing. This makes it impossible to disperse Si at the atomic level.

[0019]

Embedded image

Examples of the amine-based silane coupling agent containing an alkoxy group include 3-aminopropyltriethoxysilane (SiC ₉ H ₂₃ NO ₃ ), N- (2-aminoethyl) -3.
-Aminopropyltrimethoxysilane (SiC ₈ H ₂₂ N ₂ O ₃ ),
N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane (SiC ₈ H ₂₂ N ₂ O ₂ ), p- [N- (2-aminoethyl) aminomethyl] phenethyltrimethoxysilane (SiC ₁₄ H _{2 6} N ₂ O _3), 4- aminobutyl dimethylmethoxysilane _{(SiC 7 H 19 NO),} 4- aminobutyl triethoxysilane _{(SiC 10 H 2 5 NO 3} ), N- (2- aminoethyl) -3
-Aminopropyltris (2-ethylhexiso) silane
(SiC ₂₉ H _{6 4} N ₂ O ₃ ), p-aminophenyltrimethoxysilane (SiC ₉ H ₁₅ NO ₃ ), p-aminophenyltriethoxysilane (SiC ₉ H ₁₅ NO ₃ ), 3- (1-amino Propoxy) 3,3
-Dimethyl-1-propenyltrimethoxysilane (SiC ₁₁
H _{2 5} NO _4), 3- aminopropyl tris (methoxyethoxy) silane _{(SiC 18 H 4 1 NO 9} ), 3- aminopropyldimethylethoxysilane _{(SiC 7 H 19 NO),} 3- aminopropyl methyl diethoxy Silane (SiC ₈ H ₂₁ NO ₂ ), 3-aminopropyltrimethoxysilane (SiC ₉ H ₂₃ NO ₃ ), ω-aminoundecyltrimethoxysilane (SiC ₁₄ H _{3 3} NO ₃ ), 1-
Trimethoxysilyl-2- (p, m-aminomethyl) phenylethane (SiC ₁₂ H _{2 1} NO ₃ ), 6- (aminohexylaminopropyl) trimethoxysilane (SiC ₁₂ H _{3 0} N ₂ O ₃ ), N
- (triethoxysilylpropyl) urea (SiC ₁₀ H _{1 4} N
₂ O _4), trimethoxysilylpropyl diethylene triamine _{(SiC 10 H 2 7 N 3} O 3) , etc. are exemplified.

Examples of the amine-based silane coupling agent containing no alkoxy group include 3-aminopropyltrimethylsilane (SiC ₆ H ₁₇ N) and 3-aminopropyldiethylmethylsilane (SiC ₈ H ₂₁ N). To be

It is preferable to use those aminosilane compounds having a molecular weight as low as possible because organic components other than Si are thermally decomposed and volatilized during carbonization. Therefore, the most suitable amino group-containing silane compound for the present invention is 3
-Aminopropyltriethoxysilane.

The above-mentioned aminosilane compound containing a single Si atom in one molecule (hereinafter, simply referred to as "aminosilane compound").
Is dropped directly into the thermosetting resin liquid and stirred and mixed. The dropping amount of the aminosilane compound is such that the Si content in the glassy carbon structure is finally 0.1 to 10.
The weight is adjusted to be in the range of preferably 2.0 to 8% by weight. If the Si content is less than 0.1% by weight, the combined effects such as improvement in oxidation resistance will be insufficient, and 10
When the content is more than wt%, Si in the structure is granulated and grain boundaries are generated, and the continuous phase at the atomic level is destroyed, resulting in desorption of fine particles and reduction in mechanical strength.

When the drop mixing is promoted at this stage, the amino group in the aminosilane compound is bonded to the thermosetting resin in preference to the alkoxy group, and the dehydration condensation reaction proceeds. For example,
When 3-aminopropyltriethoxysilane is added dropwise to the phenolic resin liquid while stirring and mixing, a two-step reaction as shown in Chemical formulas 2 and 3 below proceeds.

[0025]

Embedded image

[0026]

Embedded image

Through the above reaction, the aminosilane compound becomes a solution having a homogeneous composition in which it is uniformly dispersed in the thermosetting resin. At this stage, the alkoxy group in the aminosilane compound scarcely reacts with the thermosetting resin, and the form in which the amino group is bonded to the resin component is relatively reactive due to the enormous molecule centering on Si. Will fall. For this reason, the reaction between the alkoxy group and the resin component is suppressed, and at the same time, the aggregation caused by the polymerization of aminosilanes is suppressed, so that the mixed solution exhibits an extremely homogeneous continuous phase containing no aggregated particles.

Since the aminosilane compound is heated in the process of mixing it with the thermosetting resin liquid, if the state is left as it is, the curing reaction proceeds and the heterogeneous composition is easily mixed and dispersed. In order to avoid such a phenomenon, it is preferable that the solution after mixing is cooled and stored to suppress the curing reaction, and then a slow flow is applied to enhance the homogeneity of the mixed state.

If necessary, the mixed solution is subjected to vacuum deaeration to remove air to be stored and then molded. The molding means is usually cast molding or centrifugal molding, but compression molding, extrusion molding, transfer molding or the like can be applied at the semi-cured stage. The molded body is 7
It is cured by heating to a temperature of 0 to 150 ° C.

An epoxysilane compound containing a single Si atom in one molecule is represented by the following general formula (4) (wherein R ₁ is a saturated or cyclic carbon chain containing one oxygen, R ₂ or R ₃ And R ₄ is an alkyl group or an alkoxy group having 1 to 3 carbon atoms.).

[0031]

Embedded image

Examples of such epoxysilane compounds include 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyldimethylmethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3
-Glycidoxypropyldimethylethoxysilane, 3-
Glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldiisopropenoxysilane,
Examples thereof include 3-glycidoxypropyldiisopropylethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. However, 3-glycidoxypropylmethyldimethoxysilane is most preferably used for the purposes of the present invention. The reason for this is that the 3-glycidoxypropylmethyldimethoxysilane has a low molecular weight, and therefore has a relatively small amount of volatile components during carbonization, which is advantageous in that material distortion due to shrinkage does not occur.

The above-mentioned epoxysilane compound containing a single Si atom in one molecule (hereinafter, simply referred to as "epoxysilane compound") is dropped into the thermosetting resin liquid. The thermosetting resin liquid serves as a carbon source that is converted into glassy carbon by firing and carbonizing treatment, and for example, liquid phenol resin, furan resin, polyimide resin, polycarbodiimide resin, polyacrylonitrile resin, pyrene- A phenanthrene-based resin, a polyvinyl chloride-based resin, an epoxy-based resin, a mixed resin thereof, or the like can be used. In particular, an initial condensate of a phenolic resin or a furan resin having a high residual carbon rate remaining when the resin is fired at a temperature of 800 ° C. in a non-oxidizing atmosphere, or a mixed resin liquid thereof is preferably used.

The dropping of the epoxysilane compound into the thermosetting resin liquid is carried out under sufficient stirring conditions. At this time, since the reaction between the epoxysilane compound and the thermosetting resin does not occur, reaction troubles such as heat generation and thickening of the mixed resin composition do not occur. Therefore, it is not particularly necessary to perform complicated reaction suppressing operations such as cooling, sufficient fluidity can be ensured even when a large amount of epoxysilane compound is dropped, and air entrained during mixing can be easily degassed, so that voids It becomes possible to mold without leaving. Even when a silane compound having an alkoxy group is used, the reaction between the alkoxy group and the resin hardly occurs at this point, so that the phenomenon of deterioration of workability due to gelation does not occur.

The epoxysilane-containing resin composition obtained by the dropping operation is preferably stored in a fluid state for one day or more in order to further improve the uniformity of mixing and promote the dispersion at the atomic level. Mixtures stored in a low-viscosity liquid form have a very homogeneous composition in which Si is dispersed at the atomic level, and separation of silane compounds that occurs when mixing silane compounds having only hydrophobic groups such as methyl groups Does not occur.

The epoxysilane-containing resin composition is then vacuum deaerated, if necessary, to remove the stored air, and then molded into a predetermined shape. The molding means is usually cast molding or centrifugal molding, but it is also possible to apply compression molding, extrusion molding, transfer molding, etc. at the semi-cured stage. The molded body thus molded is heated to a temperature of 70 to 150 ° C. and hardened to obtain a glassy carbon precursor.

The epoxysilane compound that has not reacted with the thermosetting resin during the room temperature mixing process undergoes a ring-opening reaction of the epoxy group at the heating stage during molding and curing to start the reaction with the resin component. Therefore, by controlling the heating temperature in the molding process, the epoxysilane compound slowly reacts with the resin component while maintaining a uniform dispersion state, and the curing reaction of the resin and the reaction of the epoxy group and the resin component occur at the same time during the curing process. proceed. By this action, the curing reaction of the resin proceeds at a slow rate, so that the occurrence of strain due to the reaction between the epoxysilane compound and the resin component is effectively suppressed.

For example, the reaction between the epoxysilane compound and the phenol resin is presumed to proceed according to the reaction formula shown in the following chemical formula 5.

[0039]

Embedded image

The cured molded product thus obtained is packed in a graphite crucible or sandwiched between graphite plates and then packed in an electric furnace kept in an inert atmosphere of nitrogen, argon or the like, or a lead hammer furnace. The thermosetting resin component is converted into glassy carbon by firing carbonization treatment in a temperature range of 800 ° C. or higher, preferably in a temperature range of 1000 to 2500 ° C.
In this firing carbonization stage, the deoxidation reaction proceeds, and Si becomes 0.1
Within the range of from 10 to 10% by weight, the glassy carbon structure has a texture property that it is distributed as a uniform continuous phase at the atomic level.

The carbon heating element obtained from the Si-containing glassy carbon material thus obtained is finally commercialized by buffing or diamond lapping the surface, if necessary, to improve the surface smoothness. In the case of manufacturing a heating element having a complicated shape such as a spiral shape or a comb shape, for example, the molded body before firing and carbonization is processed or die-molded in consideration of the dimensional shrinkage ratio at the time of carbonization, or the carbon body after firing. It can be machined in any way.

The carbon heating element according to the present invention has a composite composition in which Si in the glassy carbon structure is dispersed and contained in the range of 0.1 to 10% by weight, and Si at the atomic level is uniform in the glassy carbon structure. It has a texture that is distributed as a continuous phase. This structure characteristic is different from the structure in which the Si component is dispersed in the state of fine particles, and exhibits an alloy-like continuous solid solution phase in which there is no grain boundary between Si and C in the structure. Substantially no difference from the single structure is recognized, but microscopically, a part of C in the glassy carbon structure is replaced by Si and has a continuous phase bonded by -C-Si-C-. It has a unique composite form.

The above-mentioned texture property effectively suppresses the reaction with a trace amount of oxygen and other reactive gases existing in the heating system when the heating element is heated to a high temperature, and long-term chemical stability. And, at the same time, it becomes possible to use it for a long time in a state where particles are not generated.

[0044]

EXAMPLES Examples of the present invention will be specifically described below in comparison with comparative examples. However, the scope of the invention is not limited to these examples.

Examples 1 to 5 and Comparative Examples 1 to 3 Tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] was dissolved in water-free ethanol to a concentration of 50% by volume, and stirred with a stirrer for 30 minutes. After stirring, dispersion treatment was performed for 2 hours by an ultrasonic vibration device. To this solution, 0.03 mol of acetic acid containing no water and 1 mol of water were added dropwise with respect to 1 mol of tetraethoxysilane, and stirred and mixed with a stirrer for 1 hour to hydrolyze tetraethoxysilane. . Then, while stirring the hydrolyzed tetraethoxysilane, it was dissolved in ethanol containing no water in advance, stirred with a stirrer for 30 minutes, and then stirred with an ultrasonic vibrator.
The phenol resin solution that had been subjected to the time dispersion treatment was gradually added, and subsequently stirred with a stirrer for 1 hour and mixed until uniform. The mixed solution was poured into a mold, defoamed in a vacuum device, and heated from room temperature to 70 ° C. to harden a gel formed by the crosslinking reaction. The obtained cured molded body is transferred to a heating furnace kept in a nitrogen atmosphere, and the temperature is 10 ° C./h.
It was heated to 2000 ° C. at a heating rate of r and carbonized by firing.
In this way, Si-containing glassy carbon materials having different Si contents (200 mm in length and width, 4 mm in thickness) were manufactured. The physical properties of each of the obtained Si-containing glassy carbon materials were measured and are shown in Table 1.

Each of the plate-shaped Si-containing glassy carbon materials produced was machined into a disc-shaped heating element shape as shown in FIG. In FIG. 1, 1 is a heating element body (diameter 146 mm), 2 is a slit portion (width 2 mm) installed in the heating element body 1, and 3 is a terminal portion. Then, the surface thereof was subjected to smooth buffing using an abrasive having a grain size of # 800 to obtain a carbon heating element. The carbon heating element was mounted in a chamber whose pressure was reduced to 10 Torr, and heat was generated by energization so that the central heating portion reached 1600 ° C. In this way, the weight reduction rate of the carbon heating element after heat generation by energization for 300 hours and the number of generated particles of 0.3 μm or more dropped in the chamber were measured, and the results are shown in Table 2.

Examples 6 and 7 3-aminopropyltriethoxysilane (A0750 manufactured by Chisso Corporation) and 3-glycidoxypropylmethyldimethoxysilane (Toray Dow Corning Silicone) so that the Si content was 5 wt%. AY43-0 manufactured by Co., Ltd.
26] is a phenol resin [PR9 manufactured by Sumitomo Dures Co., Ltd.
40] and then mixed with stirring for 1 hour. In addition,
The resin solution to which 3-aminopropyltriethoxysilane was added was once placed in a refrigerator at 2 ° C. to suppress heat generation, and then 24
Stirring and mixing were performed more gently over time. Further, the phenol resin solution to which 3-glycidoxypropylmethyldimethoxysilane was added was gently stirred and mixed for 24 hours. Next, these mixed solutions were poured into a mold, defoamed in a vacuum apparatus, and then heat-cured from room temperature to 70 ° C. to obtain a resin molded plate. The obtained cured molded article was treated in the same manner as in Example 1 in a nitrogen atmosphere at 10 ° C./hr.
Is heated to 2000 ° C at a heating rate of
A contained glassy carbon material (200 mm in length and width, 4 mm in thickness) was manufactured. The physical properties of the obtained Si-containing glassy carbon material were measured, and the results are also shown in Table 1.

The Si-containing glassy carbon material produced in this manner was machined and buffed by the same method as in Example 1 to produce a carbon heating element having the shape shown in FIG. This carbon heating element was subjected to an electric heating test under the same conditions as in Example 1, the weight reduction rate and the number of particles generated after the heating test were measured, and the results are also shown in Table 2.

Comparative Example 4 A SiC sintered body was machined to produce a heating element having the shape shown in FIG. 1, and an energization heating test was conducted under the same conditions as in Example 1. The physical properties of the SiC heating element in this case are shown in Table 1, and the weight loss rate and the number of particles generated after the heating test are shown in Table 2.
It is listed in each.

Comparative Example 5 An isotropic graphite material [G347 manufactured by Tokai Carbon Co., Ltd.] was machined to produce a heating element having the shape shown in FIG. 1, and an energization heat generation test was conducted under the same conditions as in Example 1. It was The physical properties of the graphite heating element in this case are shown in Table 1, and the weight reduction rate after the heat generation test and the number of particles generated are also shown in Table 2.

[0051]

[Table 1]

[0052]

[Table 2]

As is clear from consideration of the results shown in Tables 1 and 2, the carbon heating element made of the Si-containing glassy carbon material according to the example is suitable as a heating element despite containing the Si component. It has physical properties, has a low weight loss rate after an electric heat generation test, and has very few particles generated. On the other hand, in Comparative Example 1 in which the Si content is less than 0.1% by weight and Comparative Example 3 in which no Si component is contained, the weight reduction rate and the number of particles generated increase, and S
In Comparative Example 2 in which the i content exceeds 10% by weight, although the weight reduction rate is small, the number of particles generated is large, and it can be seen that both have problems in long-term stability and non-staining property.
Further, both the heating element of Comparative Example 4 made of a SiC sintered body and the heating element of Comparative Example 5 made of an isotropic graphite material both generate particles remarkably, which causes a problem of reduction in yield due to contamination.

[0054]

As described above, according to the present invention, by selecting the Si-containing glassy carbon material in which a certain amount of Si is dispersedly contained in the glassy carbon structure, the consumption is small even at high temperature heat generation and the structure is small. It is possible to provide a high-performance carbon heating element in which the generation of particles is extremely small. Therefore, it is expected to be useful as a heating element of a semiconductor device which requires stable use for a long period of time and non-polluting property.

[Brief description of drawings]

FIG. 1 is a plan view showing a shape of a heating element produced in an example of the present invention.

[Explanation of symbols]

 1 Heating element body 2 Slit part 3 Terminal part

Claims (2)

[Claims] 1. A glassy carbon structure containing 0.1% of Si.
A carbon heating element comprising an Si-containing glassy carbon material dispersedly contained in the range of 10 to 10% by weight. 2. A Si-containing glassy carbon material, a thermosetting resin, and a hydrolyzate of a Si alkoxide containing a single Si atom in one molecule are stirred and mixed in an organic solvent to obtain —O—S.
a cured molded product crosslinked with i-O-, or a cured molded product obtained by dropping an aminosilane compound or an epoxysilane compound containing a single Si atom in one molecule into a thermosetting resin liquid and stirring and mixing the molded product. The carbon heating element according to claim 1, wherein the carbon heating element has a texture property in which Si at an atomic level is obtained by firing and carbonizing and is distributed as a uniform continuous phase in a glassy carbon structure.