JP2003249540A - Work holder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simply constituted work holder which allows prevention of static charging at peeling and is applicable, both to plates are to be used singly with a substrate placed thereon and to stages constituting the substrate placement portion of a transfer robot or the like. <P>SOLUTION: The work holder is for holding plate-like workpieces and comprises plate-like bodies 2 and fluorocarbon resin films 1, covering the plate- like bodies. With respect to the surface of an organic conductive film, the arithmetic mean roughness Ra thereof is not smaller than 1.0 μm. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work holder capable of preventing peeling and electrification of a plate-like work such as a glass substrate. The present invention relates to a work holding table that is used as a member for mounting a plate-like work directly on the work holding table.

[0002]

2. Description of the Related Art Insulating substrates such as glass substrates are used for flat display panels such as liquid crystal display panels and plasma display devices. These insulating substrates can be used for alignment tables, adsorption tables, or SOG (Spin On Glas).
s) Placed on a hot plate for pre-baking the membrane,
Transfer and heat treatment are performed together with the hot plate. It is unavoidable that the insulating substrate and the mounting surface on which the insulating substrate is mounted rub against each other when the insulating substrate is received and delivered. It is well known that static electricity is generated and charges when insulating materials rub against each other. In particular, peeling electrification that occurs when the insulating substrate is sent out occurs. In particular, in the adsorption stage, a strong frictional force is generated and a large amount of charge is reached because the work is adsorbed on the mounting surface by drawing a vacuum from the air passage leading to the work mounting surface.

Along with peeling electrification, spark discharge may occur depending on the amount of electrification and the speed at which the substrate leaves the holder.
In addition, the characteristics of various semiconductor devices, for example, thin film transistors (TFTs) of liquid crystal display panels are affected. Therefore, various measures have been taken to prevent peeling electrification. For example, in the adsorption stage, in order to reduce the amount of charge, a method has been proposed in which an ionized gas of the opposite sign is circulated through the air passage when the vacuum in the air passage is broken to neutralize the charge (JP-A-11- 233599).

When an insulating substrate is mounted on an aluminum plate used alone, the surface of the aluminum plate is anodized to form a porous anodic oxide film, and then an antistatic fluororesin is applied. In addition, a structure in which the surface is grounded has been proposed (Japanese Patent Application No. 5-179087).

With the above structure, the amount of charge on the insulating substrate and its mounting device can be reduced, or static electricity can be prevented from accumulating on the surface of the insulating substrate and its mounting device.

[0006]

However, in order to effectively neutralize the gas on the mounting surface by causing a gas containing ions of opposite signs to flow in the air passage of the adsorption stage, a high level control technique for the fluid is required, It is difficult to realize with a simple device configuration.

[0007] Further, it takes a lot of man-hours to always ground the ground wiring by anodizing the aluminum plate and then impregnating the surface of the aluminum plate with an antistatic fluororesin to cover the surface with the ground wiring. It is necessary to secure it. In addition, it is difficult to keep the resistance value below a certain value.

Therefore, there has been a demand for the development of a work holder which can reliably prevent electrification and can be used as a plate used alone or as a substrate mounting stage of a transfer robot.

The present invention can effectively prevent peeling electrification with a simple structure, and can be applied to a plate used as a single unit on which an insulating substrate is mounted, and to a stage constituting a substrate mounting portion such as a transfer robot. It is an object of the present invention to provide a work holding table that can also be used.

[0010]

A work holding table of the present invention is a holding table for holding a plate-shaped work, comprising:
An organic conductive coating film that covers the plate-shaped body is provided, and the arithmetic average roughness Ra of the surface of the organic conductive coating film is 1.0 μm.
m or more (claim 1).

With this configuration, even if the plate-like work and the organic conductive coating are rubbed, if the arithmetic average roughness Ra is 1.0 μm or more, the contact area is small and the amount of static electricity generated is small. Since the amount of static electricity generated is small, it does not flow to other parts through the organic conductive film and is not charged.

The arithmetic mean roughness Ra specified in JIS B0601 may be 1.0 μm or more, for example, 5
When it exceeds 0 μm, when the plate-like work is sucked and held by vacuum suction from the back surface side of the work holding table, leakage occurs between the work holding table and the plate-shaped work and suction force is not generated. Therefore, it is desirable that the arithmetic average roughness Ra be 50 μm or less. In particular, the arithmetic mean roughness Ra is
It is desirable to be in the range of 1.5 μm to 15 μm.

The plate-like work may be any plate-like work. Examples thereof include glass substrates and resin substrates (flat panel substrates) for insulating liquid crystal display panels and plasma display panels, and color filters.

The above-mentioned organic electroconductive coating may cover at least the surface of the plate-like body with which the plate-like work is in contact, and the back side may or may not be covered. Used when the organic conductive coating coats at least the surface on which the plate-shaped work is in contact, for example, when the insulating plate-shaped work is a glass substrate, the glass substrate is coated with the SOG film paint and baked. The work holder of the present invention can be formed on a hot plate or the like. This hot plate can be used as one independent consumable part. Also, if all surfaces of the hot plate are covered with an organic conductive film, it is possible to avoid that the part of the plate not covered with the organic conductive film rubs against other parts to generate metal powder. it can.

Another work holding table of the present invention is a holding table for holding a plate-shaped work, comprising a plate-shaped body and an organic conductive coating film disposed on the plate-shaped body. The uniform coating has a nonuniform thickness, including zero thickness, on the plate-like work (claim 2).

With this structure, the plate-shaped work is supported by a point,
It is supported by a supporting portion corresponding to the pattern shape of the thick portion of the organic conductive coating, such as spot-shaped support, linear support, plate-shaped support, and the like. Therefore, even if the plate-like work and the organic conductive coating rub against each other, the amount of static electricity generated is small. Since the generated static electricity is small in amount, it does not flow to other parts through the organic conductive film and become charged.

The plate-like body may have a portion not covered with the organic conductive film. The pattern shape of the thick portion may be any shape having a non-uniform thickness distribution such as a dot shape, a patch shape, a cross shape, a grid pattern, or three or more simple protrusions that are not on a straight line.

In any of the work holders according to the present invention, the organic conductive film may contain a filler (claim 3).

By including a large size filler in the resin, the surface roughness can be increased. Further, by using a hard filler, it is difficult for the plate-shaped work to be pushed and flattened by the weight of the plate-like work due to long-term use.
Also, when used in a suction stage with strong vacuum suction,
Alternatively, when it is used after being heated to a high temperature of 60 ° C. or higher, it is possible to secure the durability for maintaining the surface roughness for a long period of time.

In any of the work holders of the present invention, the surface of the plate-like body may be subjected to at least one of roughening treatment and surface irregularity forming treatment (claim 4).

As described above, when the underlayer of the organic conductive film is roughened or has surface irregularities, the organic resin layer is simply formed on the organic conductive film by a usual method, and the organic conductive layer film is formed. Can be roughened and the thickness distribution of the organic conductive coating can be made non-uniform.

The roughening treatment is a treatment for uniformly roughening the surface in a macroscopically planar manner while mixing the convex portions and the concave portions. Further, the surface unevenness forming process is a process of forming a concave portion and a convex portion on the surface regardless of macro planarity and uniformity. Generally, the smaller the size of the convex portion or the concave portion is the surface subjected to the roughening treatment, and the larger size is the surface subjected to the surface irregularity forming treatment, but the division between the two is not so clear.

In the work holding table of the present invention in which the organic conductive coating having a non-uniform thickness distribution is arranged, the organic conductive coating is
It can be formed by an organic resin pattern layer forming means (claim 5).

By arranging the organic conductive film using a screen printing method or a dispenser which is an organic resin pattern layer forming means, it is possible to inexpensively and efficiently without arranging the organic conductive material in an unnecessary portion. An organic conductive coating can be formed on the surface.

Examples of means for forming the organic resin pattern layer include the above-mentioned screen printing method, use of a dispenser, exposure to a photosensitive resin and patterning by development.

In the work holder according to the present invention, the organic conductive film may be a fluororesin film (claim 6).

Since the fluororesin is smooth and has a small friction coefficient, the amount of static electricity generated is small even when the fluororesin rubs against the insulating plate-like work. Moreover, since it has conductivity, even if static electricity is generated, it flows to another member through the conductive strength holding portion, so that the amount of charge can be significantly reduced. The above-mentioned fluororesin coating is used for the holding base, for example, 200 ° C to 500 ° C.
It can be formed by heating to ° C and coating with a fluororesin.

Although there are many types of fluororesins, soft fluororesins tend to be flattened by pressing the irregularities on the roughened surface or the irregularities of the surface waviness. Therefore, when importance is attached to the durability of the unevenness, it is desirable to use a hard fluororesin such as crosslinkable PTFE.

A binder resin having a high coating hardness may be used together. In the work holder of the present invention, the plate-shaped body can be made of a conductive material (claim 7).

With this configuration, the plate-like body covered with the organic conductive film can also serve as a route for the outflow of static electricity, which is effective for further reducing the charge amount.

In the work holder of the present invention, the plate-shaped body can be formed of either iron or aluminum (claim 8).

Here, iron and aluminum may contain iron and aluminum as a main component, and may form an alloy with another metal or the like.

The work holding table of the present invention constitutes a surface layer portion of the adsorption stage for adsorbing the plate-like work, and the organic conductive coating can contact the plate-like work at the adsorption stage (claim 9).

With this configuration, the suction stage is constituted by the work holding table, and peeling electrification does not occur.
It is possible to position and transfer a glass substrate or the like.

The work holding table of the present invention constitutes the surface layer portion of the plate-like work mounting portion of any one of the alignment table, the substrate holder of the processing apparatus and the marking table, and the organic conductive film is in contact with the plate-like work. It is possible (claim 10).

With this structure, a portion on which a plate-like work is placed and peeling charge may occur can be formed by the structure of the work holder of the present invention. As a result, it becomes possible to prevent the plate-like work from being charged.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view showing a hot plate (work holding table) in which the entire surface of an aluminum alloy plate is coated with a fluororesin and the coating is roughened. FIG. 2 is a sectional view taken along line II-II. The hot plate 10 is used to hold the color filter in a furnace when the color filter is heated when manufacturing the color filter used in the liquid crystal display panel. The atmosphere in the furnace is evenly distributed to all parts of the hot plate, and the through holes 3 are used as holes for sucking from the back surface when sucking at the suction stage.

FIG. 3 is an enlarged view of the surface of the hot plate shown in FIG. The fluororesin film 1 covering the aluminum alloy plate 2 is made of heat-resistant fluororesin. As shown in FIG. 3, the surface of the fluorine resin is roughened to have an arithmetic average surface roughness Ra of 1.0 μm or more. FIG. 4 is a diagram showing a state in which a plate-shaped work such as a color filter is placed on the plate and heated, and the peaks of the roughened surface are pushed by the weight of the plate-shaped work so that the peaks 1t are lowered. When a soft fluororesin is used, such flattening of the peaks proceeds, and eventually flattening. When the surface is flattened, the contact area between the fluororesin film 1 and the work increases, and the amount of peeling charge increases. In order to prevent such flattening due to pushing of the work, it is desirable to use crosslinkable PTFE having high hardness and excellent heat resistance as the fluororesin. By using the crosslinkable PTFE, it is possible to maintain a roughened surface state even when the fluororesin coating film is heated to 60 ° C. or higher or repeatedly heat-treated.

Conventionally, before the hot plate 10 was used, peeling electrification occurred and troubles occurred at a frequency of 5 to 10 cases / hour, but the hot plate of the present invention is used. As a result, no trouble has occurred. Therefore, the liquid crystal display panel can be efficiently manufactured, and the manufacturing cost can be significantly reduced.

(Second Embodiment) FIGS. 5 and 6 are views showing a work holder according to a second embodiment of the present invention. 5 is a plan view of the work holding table, and FIG. 6 is a sectional view taken along line VI-VI of FIG. The present embodiment is characterized in that the pattern of the organic conductive film is arranged on the aluminum alloy plate 2 by the screen printing method. Further, in the present embodiment, since the vacuum suction is performed by the suction stage, the suction holes 3
In order to ensure the airtightness of the space drawn from the suction hole and the suction hole, an edge peripheral wall 4 is provided along the edge circumference. The work holding table 10 on which the plate-shaped work is mounted is evacuated through the through hole 3 from the space surrounded by the peripheral wall 4, the plate-shaped body 2, and the plate-shaped work, and is vacuumed.

The conductive resin film on the work holding table can be very easily arranged on the aluminum alloy plate by screen printing with a height difference higher than that of the peaks in the roughening treatment. . Therefore, regardless of the hardness of the conductive resin coating, it is possible to maintain a state in which peeling charge is prevented for a long period of time. In this case, the plate
By using a conductor such as an aluminum alloy as described above, even a slight amount of peeling charge can be easily released to the ground.

FIG. 7 and FIG. 8 are modifications of this embodiment. 7 is a plan view, and FIG. 8 is VI of FIG.
It is sectional drawing which follows the II-VIII line. Also in the case of this work holding base, the conductive resin pattern was arranged on the aluminum alloy plate by the screen printing method. Since the conductive resin pattern of FIG. 7 has a larger area than that of FIG. 5, it can support a heavier plate-shaped work.

(Third Embodiment) FIG. 9 is a view showing a work holding base in the third embodiment of the present invention. The present embodiment is characterized in that the fluororesin film contains the filler 5 as shown in FIG. As the filler, a particularly hard fluororesin such as crosslinkable PTFE can be used.

By using the above-mentioned filler, a surface having a large height difference corresponding to the diameter of the filler can be formed. Therefore, prevention of peeling electrification can be suppressed for a long period of time. Also, as the material of the filler,
The service life can be further extended by using a special hard material.

Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. Not limited. The scope of the present invention is shown by the description of the claims, and includes the meaning equivalent to the description of the claims and all modifications within the scope.

[0047]

By using the work holding table of the present invention, it is possible to effectively prevent peeling charge for a long period of time with a simple structure. The work holding table of the present invention is
For example, it can be used as a stand-alone plate on which an insulating substrate such as a glass substrate is placed, or as a stage that constitutes the part on which the insulating substrate is placed in a transfer robot etc. Becomes

[Brief description of drawings]

FIG. 1 is a perspective view showing a hot plate on which a work holding table according to a first embodiment of the present invention is formed.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged view of the surface of the fluororesin coating of FIG.

FIG. 4 is an enlarged view of the fluororesin coating after the plate-shaped work is mounted on the hot plate shown in FIG.

FIG. 5 is a plan view of a work holding table according to the second embodiment of the present invention.

FIG. 6 is a VI-VI sectional view of the work holding table in FIG.

FIG. 7 is a plan view of a modification of the work holding table according to the second embodiment of the present invention.

8 is a work holding table VIII-VI in FIG.
It is a II sectional view.

FIG. 9 is a sectional view of a work holding table according to a third embodiment of the present invention.

[Explanation of symbols]

1 fluororesin coating, 2 aluminum alloy plate, 3 through holes,
4 peripheral wall, 5 filler.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5F031 CA05 HA02 HA03 HA08 HA10                       HA13 MA26 MA30 PA21

Claims (10)

[Claims] 1. A holding table for holding a plate-shaped work, comprising: a plate-shaped body; and an organic conductive coating film that coats the plate-shaped body. Ra
Is 1.0 μm or more, the work holding table. 2. A holding table for holding a plate-shaped work, comprising: a plate-shaped body; and an organic conductive film disposed on the plate-shaped body, wherein the organic conductive film is the plate-shaped body. A work holder that has a non-uniform thickness, including zero thickness, on the work. 3. The work holder according to claim 1, wherein the organic conductive coating contains a filler. 4. The work holder according to claim 1, wherein at least one of a roughening treatment and a surface unevenness forming treatment is performed on a surface of the plate-shaped body. 5. The work holder according to claim 2, wherein the organic conductive film is formed by an organic resin pattern layer forming means. 6. The work holder according to claim 1, wherein the organic conductive film is a fluororesin film. 7. The work holding table according to claim 1, wherein the plate-shaped body is made of a conductive material. 8. The work holder according to claim 1, wherein the plate-shaped body is made of iron or aluminum. 9. The work holding table constitutes a surface layer portion of an adsorption stage for adsorbing the plate-like work, and the organic conductive coating is in contact with the plate-like work at the adsorption stage. 8. The work holder according to any one of 8. 10. The work holding table constitutes a surface layer part of a mounting part of the plate-like work, which is one of an alignment table, a substrate holder of a processing apparatus, and a marking table, and the organic conductive film is provided on the adsorption stage. The work holder according to any one of claims 1 to 8, which is in contact with the plate-shaped work.