JPH10120140A - Belt conveyor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveyor having high durability even under such environment (vacuum, high temperature and high cleanliness) as the inside of an etching chamber in a semiconductor manufacturing process. SOLUTION: A conveyor is provided with an endless spring belt 2 for conveying a semiconductor wafer 1, a roller 3 to be brought in contact with the belt 2, and a bearing part 6 for rotatably supporting the roller 3 to a fixed shaft 5. The roller 3 is formed of polymide or Copra (condensed polynuclear aromatic) resin into a ring body shape. The bearing 6 is a sliding bearing in which the inside diameter surface of the roller 3 and the outside diameter surface of the fixed shaft 5 are brought in contact with each other, and a crystalline PTFE lubricating coating is formed on the contact parts of both surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt conveyor which is operated in a vacuum and in an environment where it may come into contact with corrosive substances.

[0002]

2. Description of the Related Art For example, the interior of an etching chamber in a semiconductor manufacturing facility is maintained in a vacuum and with a high degree of cleanliness. In a transfer apparatus for inserting and removing a semiconductor wafer with such an etching apparatus, It may come into contact with corrosive etching gas when carrying in and carrying out.

FIGS. 3 to 5 show a transfer device used in such an environment. In this device, fixed shafts (15) protrude from both ends of a base (14), and a ring-shaped metal roller (13) is rotatable on both fixed shafts (15) via rolling bearings (16). And an endless belt (12: for example, a spring belt) is engaged with a groove (13a) provided on the outer peripheral surface of the roller member (13). As shown in FIG. 4, both sides of the conveyed object (11) are supported by belts (12) provided at both ends of the base (14). When a driving roller (not shown) is driven, the belt (12) rotates clockwise in FIG. 3, and the article (11) on the belt (12) is conveyed downstream.

[0004]

Considering that this type of transfer device is used in a vacuum, grease or lubricating oil is used as a lubricant for rollers and bearings for supporting the running of the belt. Fluid lubricants cannot be used. In addition, layered substances such as molybdenum disulfide, gold, silver,
A solid lubricant composed of a soft metal such as lead is not preferable in view of the dust generation and durability.

[0005] Under such circumstances, conventionally, members such as rollers, spring belts, and bearings are operated without lubrication, but this causes problems such as generation of dust due to wear of the contact portions and reduction in durability. In addition, since these members may come into contact with the etching gas, there is a problem that the durability is reduced due to corrosion.

Accordingly, the present invention provides a belt conveying apparatus which is operated in the above environment, in which the durability and operability of various members supporting the running of the belt are improved, and the generation of dust from the contact portion is improved. It aims at suppressing.

[0007]

In order to achieve the above object,
A belt transport device according to the present invention includes a belt that transports a transported object, a roller that comes into contact with the belt to support the belt, and a bearing that rotatably supports the roller with respect to a fixed shaft. Wherein the roller is formed of a resin material having self-lubricating properties.

[0008] The resin material is preferably a polyimide resin or a copna resin.

The bearing portion is preferably a sliding bearing in which the inner diameter surface of the roller contacts the outer diameter surface of the fixed shaft.

[0010] A coating made of crystalline polytetrafluoroethylene (PTFE) may be formed on at least one of a portion of the belt that contacts the roller and / or at least a portion of the roller that contacts the belt.

A coating made of crystalline polytetrafluoroethylene (PTFE) may be formed on at least one of the inner diameter surface of the roller constituting the sliding bearing and the outer diameter surface of the fixed shaft.

[0012] The bearing portion may include at least an inner / outer ring, a rolling element,
Further, the retainer may be a rolling bearing formed of stainless steel, and a coating made of crystalline polytetrafluoroethylene (PTFE) may be formed on at least a surface of the rolling bearing that generates rolling friction or sliding friction.

[0013] Further, the belt conveying device according to the present invention comprises:
A belt that conveys the conveyed object, a metal roller that comes into contact with the belt and supports the belt so that the belt can travel, and a bearing that rotatably supports the roller with respect to a fixed shaft, the belt comprising: And a coating made of crystalline polytetrafluoroethylene (PTFE) is formed on at least one of or both of the roller contacting portion and the roller contacting portion.

Further, the apparatus includes a belt for conveying the conveyed object, a metal roller for contacting the belt and supporting the belt so as to be able to travel, and a bearing for rotatably supporting the roller with respect to a fixed shaft. And at least the bearing portion
The outer ring, the rolling element, and the retainer are made of a rolling bearing made of stainless steel, and a film made of crystalline polytetrafluoroethylene (PTFE) is formed on at least the surface of the rolling bearing that generates rolling friction or sliding friction. Things.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the transport device according to the present invention comprises an endless belt (2) for transporting a transported object (1).
And a roller (3) that comes into contact with and supports the belt (2) so that it can run, and a fixed shaft (5) protruding from both sides of the roller (3) and the base (4). , Roller (3)
And a bearing part (6) for rotatably supporting the bearing. As the belt (2), a spring belt is used.

The roller (3) is made of a resin material having a self-lubricating property and excellent in chemical resistance and low dust generation, such as a polyimide resin or a copna resin, in a ring shape. Such a roller (3) made of resin is formed by machining a resin molding material or by injection molding a resin material.

Here, "copna resin" refers to naphthalene,
It is a thermosetting resin obtained by crosslinking polycyclic aromatic hydrocarbons such as anthracene, phenanthrene, pyrene and coal tar pitch with p-xylylene glycol using an acid catalyst. The reaction proceeds in electrophilic substitution involving dehydration, condensed polycyclic aromatic nucleus is a number linked structure Penjiru type bond, a condensed polycyclic polynuclear aromatic resin "Co ndensed P oly n uclear
As A romatic Resin "it is designated. Abbreviation, attracted underlined called" COPNA resin ". Copna resin has excellent heat resistance, sliding properties, mechanical properties, chemical resistance, and electrical insulation, and also has easy moldability and cost performance. In particular, since the roller (3) is excellent in injection moldability, the cost can be reduced by forming the roller (3) by injection molding of copna resin. Copna resin is currently marketed by Sumikin Kako Co., Ltd. under the trade name "SK Resin".

Polyimide and copna resin have low outgassing and excellent properties such as corrosion resistance and self-lubricating property, and can be used in a vacuum and in an environment where they can come into contact with corrosive gas such as in an etching chamber. Also have excellent durability.

The bearing (6) is a sliding bearing in which the inner diameter surface of the roller (3) is brought into contact with the outer diameter surface of the fixed shaft (5).
When the bearing (6) is a sliding bearing in this way, the roller (3) can be used as compared with a conventional case using a rolling bearing.
The bearing and the bearing (6) can be formed as an integrated structure, and the structure can be simplified. Further, since the roller (3) is formed of a resin material having self-lubricating properties, lubrication between the roller (3) and the fixed shaft (5) and between the roller (3) and the belt (2). Well done. Therefore, the durability can be improved as compared with the conventional device.

Further, a portion of the bearing portion (6) where sliding friction occurs, specifically, the inner diameter surface of the roller (3) and the fixed shaft (5)
A lubricating coating (7: shown in black) made of crystalline PTFE (polytetrafluoroethylene: average molecular weight is preferably 5000 or less), if necessary, on at least one of its outer diameter surfaces. May be formed. here,
The “lubricating film made of crystalline PTFE” refers to a film in which the crystal structure (molecular structure) of PTFE is not subdivided, such as a so-called sputtering film.
It can be formed by spraying the treatment liquid of E (such as the above-mentioned PTFE powder dispersed in a solvent) on the object to be treated, or by immersing the object to be treated in the treatment liquid. The PTFE coating (7) has a lubricating effect on the surface where sliding friction occurs and also has a function of protecting the base material surface from reactive gases and the like, so that the durability of the apparatus can be further improved. Further, in the PTFE coating (7) formed by spraying or dipping as described above, the structure of PTFE is not subdivided and the PTFE crystal structure is left intact as compared with the sputtering film or the like. Shows excellent lubricity inherent in PTFE.

The above-mentioned PTFE coating (7) is used not only between the roller (3) and the fixed shaft (5) but also in the bearing (6).
In the above, a portion that generates sliding friction, for example, between the side plate (8) made of, for example, resin inserted into the fixed shaft (5) and the fixed shaft (5), and between the side plate (8) and the roller (3) Alternatively, it may be formed between a roller (3) and a locking member (9) made of, for example, resin, which is attached to the tip of the shaft (5). In each case, P is applied to both surfaces of the two members that generate sliding friction.
In addition to forming a TFE film, PT
An FE coating may be formed.

Further, if a PTFE film (7 ') is formed at the contact portion between the roller (3) and the belt (2), wear due to relative movement between the two can be prevented, and dust generation from this portion is suppressed. be able to. In this case, the PTFE coating (7 ')
It suffices if it exists at least between the belt (2) and the roller (3), and it may be provided only on the belt (2), or may be provided only on the groove (3a) of the roller (3). May be provided on both the belt (2) and the roller (3). In the case where the PTFE film (7 ') is formed on the belt (2), if the transfer of the PTFE film to the conveyed article (1) is concerned, only the contact portion with the roller (3), for example, the belt (2). The coating may be formed only on the inner peripheral side of ()).

If the bearing (6) is a plain bearing as described above, and there is a concern that the rotational torque of the roller (3) will increase, as shown in FIG. PTFE coated stainless steel (for example, SU
S440C) rolling bearing (deep groove ball bearing or the like) may be used. That is, at least the inner and outer rings (6a) (6
b), the rolling element (6c) and the retainer (not shown) are formed of stainless steel, and a surface on which sliding friction or rolling friction occurs in the bearing, for example, the surface of the rolling element (6c: ball)
The rolling bearing on which the TFE film (7) is formed is used. The PTFE coating (7) may be formed on at least one of the friction generating portions in the bearing, and may be formed on the raceway surfaces of the inner and outer rings (6a) (6b) in addition to the surface of the ball (6c). May be. Further, other parts other than the above bearing components, for example, a shield plate (6d) for sealing may be made of stainless steel.

Although the embodiment in which the roller (3) is made of resin has been described above, similar to the conventional embodiment shown in FIG.
Even if the metal roller (13) is rotatably supported on the fixed shaft (15), the belt (2) and the roller (3)
Or a PTFE coating (7 ') is formed on the contact portion with the PTFE coating (7'), or the bearing portion (16) is made of a stainless steel rolling bearing, and at least the surface of the bearing that generates rolling friction or sliding friction has the PTFE coating (7 '). 7) may be formed.

[0026]

As described above, if the roller is formed of a resin material having self-lubricating properties, the lubrication between the roller and the fixed shaft is sufficiently achieved, so that the durability is improved as compared with the conventional apparatus. be able to.

If the resin material is formed of a polyimide resin or a copna resin, the durability can be further improved due to the excellent chemical resistance and low dust generation.

If the bearing portion is a slide bearing in which the inner diameter surface of the roller is in contact with the outer diameter surface of the fixed shaft, the roller and the bearing portion can be integrated as compared with the case where a rolling bearing is used. Thus, the structure can be simplified.

If a crystalline PTFE film is formed on at least one or both of a portion of the belt that comes into contact with the roller and at least one of the portion of the roller that comes into contact with the belt, the PTFE film will not function as a lubricant. At the same time, since the surface of the base material is protected from the reactive gas, it is possible to suppress the generation of dust from the contact portion between the roller and the belt and to improve the durability of this portion.

If a crystalline PTFE film is formed on at least one of the inner diameter surface of the roller and the outer diameter surface of the fixed shaft, the durability of the bearing portion can be reduced while suppressing the generation of dust from the sliding bearing portion. Can be improved.

The bearing portion includes at least an inner / outer ring, a rolling element,
If the cage is a rolling bearing made of stainless steel, and a crystalline PTFE film is formed on at least the surface of the rolling bearing where rolling friction or sliding friction occurs, dust generation can be prevented while avoiding an increase in rotational torque. And the durability can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the present invention.

FIG. 3 is a side view of a conventional transport device.

FIG. 4 is a cross-sectional view in a direction orthogonal to the transport direction of the transport device shown in FIG.

FIG. 5 is an enlarged sectional view of the transfer device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conveyed object 2 Belt 3 Roller 4 Base 5 Fixed shaft 6 Bearing part 7 PTFE coating

Claims (8)

[Claims] 1. A vehicle comprising: a belt that conveys a conveyed object; a roller that comes into contact with the belt and supports the belt so that the belt can travel; and a bearing that rotatably supports the roller with respect to a fixed shaft. A belt transport device in which the rollers are formed of a self-lubricating resin material. 2. The belt conveying device according to claim 1, wherein the resin material is a polyimide resin or a copna resin. 3. The belt conveying device according to claim 1, wherein the bearing portion is a sliding bearing in which an inner diameter surface of the roller is in contact with an outer diameter surface of the fixed shaft. 4. A coating comprising crystalline polytetrafluoroethylene (PTFE) formed on at least one or both of a portion of the belt that contacts the roller and at least one of the portion of the roller that contacts the belt. Item 2. The belt conveying device according to Item 1. 5. A film made of crystalline polytetrafluoroethylene (PTFE) is formed on at least one of the inner diameter surface of the roller and the outer diameter surface of the fixed shaft.
The belt conveying device according to claim 1. 6. The bearing portion is a rolling bearing in which at least an inner / outer ring, a rolling element, and a retainer are formed of stainless steel, and at least a surface of the rolling bearing that generates rolling friction or sliding friction has crystallinity. The belt conveying device according to claim 1, wherein a coating made of polytetrafluoroethylene (PTFE) is formed. 7. A belt comprising a belt for conveying a conveyed object, a metal roller for contacting and supporting the belt so as to be able to travel, and a bearing for rotatably supporting the roller with respect to a fixed shaft. Wherein at least one or both of a portion of the belt that contacts the roller and at least one of the portions of the roller that contact the belt are made of crystalline polytetrafluoroethylene (PTF).
A belt transport device on which a coating comprising E) is formed. 8. A belt comprising: a belt for conveying a conveyed object; a metal roller for contacting and supporting the belt so as to be able to travel; and a bearing for rotatably supporting the roller with respect to a fixed shaft. Wherein the bearing portion is a rolling bearing in which at least the inner and outer races, rolling elements, and the retainer are formed of stainless steel, and at least a surface of the rolling bearing that generates rolling friction or sliding friction has a crystalline polycrystalline polymer. Tetrafluoroethylene (PT
A belt transport device on which a coating made of FE) is formed.