JP4421597B2 - Substrate transfer device - Google Patents

Description

  The present invention relates to a substrate transport device, and more particularly to a substrate transport device having a function of removing the charge associated with roller transport of an insulating substrate constituting a liquid crystal display panel by soft X-ray irradiation.

A typical liquid crystal display device as a display device is configured by combining a liquid crystal display panel and peripheral devices such as a drive circuit and a backlight. The liquid crystal display panel is usually configured by sealing liquid crystal between one insulating substrate (active matrix substrate or thin film transistor substrate) and the other insulating substrate (counter substrate or color filter substrate). The insulating substrate includes a crystal plate and a resin plate in addition to the glass substrate , but a glass substrate that is generally widely used will be described below as an example.

  Such a glass substrate is transferred between a plurality of processing stations, such as a thin film transistor forming process or a color filter forming process, from a carry-in through a cleaning process, by a substrate transport apparatus called a so-called roller transport apparatus. Will be transferred between. The roller transport device is a conveyor in which a plurality of rollers (that is, rollers) are arranged in a plane, and the glass substrate is placed on the roller and transported in a predetermined direction at a predetermined speed by driving the roller.

  In such roller conveyance, the roller and the glass substrate are charged by repeating friction and contact peeling between the roller and the glass substrate. This charging may cause a discharge that destroys the wiring and circuit elements built in the glass substrate, or may cause various obstacles due to the adsorbing of surrounding dust by electrostatic force. In particular, in order to transfer the glass substrate to a cassette or a processing station or the like during transfer of the glass substrate to the cassette or a processing station during transfer, a large charge is generated when the glass substrate is lifted up (lifted up) from contact with the roller. This often occurs on the roller and the glass substrate, and this often causes discharge. In order to remove such charge, conventionally, soft X-rays have been irradiated from the lower surface of a glass substrate.

  FIG. 7 is an explanatory view of a conventional substrate transfer apparatus provided with a soft X-ray irradiation apparatus. The substrate transfer device SXU is configured by arranging a plurality of rollers RLR supported by a shaft SFT and rotating in a predetermined direction, usually in a horizontal plane. The glass substrate SUB is placed on the roller RLR and conveyed. The lower surface of the glass substrate SUB moves in the direction of arrow A while repeatedly contacting and peeling against the roller RLR. As a result, static electricity is charged and accumulated in the roller RLR and the glass substrate SUB.

FIG. 7 shows a transfer end portion that lifts up the glass substrate SUB and performs transfer for delivery to the next process. A soft X-ray irradiator SXU is installed at a position where the lower surface of the glass substrate SUB is desired upward in the conveyance end portion or in the middle of the conveyance. The soft X-ray irradiator SXU irradiates the lower surface of the glass substrate SUB with soft X-rays, and removes electric charges charged by contact with the roller RLR and peeling. Patent Documents 1 and 2 can be cited as examples of disclosing this type of static eliminator. Soft X-rays are X-rays having a wavelength of several to hundreds of millimeters (Iwanami Shoten RIKEN Dictionary).
JP 2004-299814 A Japanese Patent No. 2749202

  Since the static elimination performance due to the soft X-ray irradiation decreases in proportion to the distance to the object to be neutralized, the soft X-ray irradiation device SXU is installed at the conveyance end portion or at a position close to the roller RLR during the conveyance. . The roller RLR disposed on the lower surface of the glass substrate is made of an organic material such as Teflon (registered trademark) resin or polyethylene resin, and therefore deteriorates by irradiation with soft X-rays.

  Usually, a sufficient space cannot be secured around this type of substrate transfer apparatus, and the soft X-ray irradiation apparatus SXU is mounted on the substrate because the effect of removing static electricity from the soft X-rays decreases as the distance from the glass substrate increases. It must be placed in the immediate vicinity of the transport device. Therefore, as described above, the soft X-rays emitted from the soft X-ray irradiation device SXU directly hit the roller RLR. Deteriorated rollers generate particles and need to be replaced frequently. Discontinuation of processing associated with this replacement operation reduces throughput and is one of the obstacles to lowering product costs.

  An object of the present invention is to provide a substrate transfer device that suppresses deterioration of a roller due to soft X-ray irradiation from a soft X-ray irradiation device disposed in the immediate vicinity of the roller.

  The first means of the present invention for achieving the above object is to provide a shielding plate between the soft X-ray irradiation device and a roller disposed in the vicinity of the soft X-ray irradiation device, and the soft X-ray having high strength directly hits the roller. It is characterized by having suppressed. As the shielding plate, a SUS plate having a thickness of about 0.3 mm is desirable. Further, the second means of the present invention is such that the portion through which soft X-rays that irradiate the arrangement portion of the nearest roller pass between the soft X-ray irradiation device and the roller arranged in the soft X-ray irradiation device is an attenuation factor. The X-ray attenuating plate having a small attenuation factor is provided in a portion through which soft X-rays that irradiate a portion of a roller far from the soft X-ray irradiation apparatus are transmitted.

  By the 1st means, deterioration of the roller which a soft X ray with high intensity hits directly is controlled. The electrostatic capacity is increased by the shielding plate constituting the first means, and the potential due to the charged electric charge is lowered as compared with the case where the shielding plate is not provided, and a discharge preventing effect can be expected. Further, by grounding the shielding plate, a strong electric field is formed between the glass substrate and the concentration of ions generated by the soft X-rays is increased, so that the charge removal effect is improved.

  The second means suppresses the deterioration of the portion where the high-intensity soft X-rays are directly irradiated, and by appropriately selecting the attenuation rate of the soft X-ray attenuation member, The difference in the intensity of soft X-rays that irradiate a far site can be reduced, and the static elimination effect of the glass substrate can be made uniform.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings of the examples.

  1A and 1B are schematic diagrams for explaining a first embodiment of a substrate transfer apparatus according to the present invention. FIG. 1A is a side sectional view taken along an arrow A, and FIG. 1B is an arrow B in FIG. It is the principal part figure seen from the direction. The substrate transport apparatus includes a plurality of rollers RLR that are supported by the shaft SFT and rotate. Usually, the rollers RLR are arranged in a horizontal plane. The glass substrate SUB is placed on the roller RLR and conveyed in the direction of arrow A.

  In order to remove charges charged by contact with and peeling from the roller RLR by irradiating the lower surface (the surface in contact with the roller RLR) of the glass substrate SUB with a soft X-ray during the transfer terminal portion of the substrate transfer device or during the transfer. Soft X-ray irradiation device SXU. And the shielding board SHP which shields the direct irradiation of the soft X-ray SX radiate | emitted from the soft X-ray irradiation apparatus SXU was provided in the roller RLR arrange | positioned in the vicinity of the conveyance terminal part or the soft X-ray irradiation apparatus SXU in the middle of conveyance. The soft X-ray irradiation apparatus SXU is installed at a position where the roller RLR disposed at both ends of the transfer end portion or in the substrate transfer direction during transfer and at the transfer end portion or during transfer faces obliquely upward. The shielding plate SHP is formed of a metal plate having a thickness of about 0.3 mm, which is preferably SUS.

  By providing the shielding plate SHP, deterioration of the roller RLR directly hit by the high-intensity soft X-ray SX is suppressed. By providing this shielding plate SHP, the capacitance between the glass substrate SUB is increased, and the potential due to the charged charge is lowered compared with the case where the shielding plate is not provided, and an effect of preventing discharge can be expected. Furthermore, by grounding the shielding plate SHP, a strong electric field is formed between the glass substrate SUB, the ion concentration is increased, and the neutralization effect is improved.

  2A and 2B are diagrams for further explaining the first embodiment of the present invention, in which FIG. 2A is a side view and FIG. 2B is a top view of FIG. In FIG. 2, the same functional parts as those in FIG. The glass substrate SUB is placed on the roller RLR of the substrate transfer device and transferred in the direction of the arrow. In FIG. 2, the transfer operation is stopped at the position shown on the right side, and the glass substrate SUB is lifted up from the roller RLR by the arm of the transfer robot (not shown) and stored in the cassette.

  A soft X-ray irradiator SXU is installed at a position facing the roller RLR on which the glass substrate SUB is placed in the vicinity of both ends of the transfer terminal portion of the substrate transfer apparatus. Further, a shielding plate SHP that shields the roller RLR from the soft X-ray SX is attached to the roller RLR to which the soft X-ray SX of the soft X-ray irradiation device SXU is strongly irradiated. In FIG. 2, the shielding plates SHP are respectively attached to the two rows of rollers RLR from the transfer terminal end of the substrate transfer apparatus. However, the present invention is not limited to this, and the size of the glass substrate SUB and soft X-rays SX for static elimination are used. The roller RLR to which the shielding plate SHP is attached may be determined in accordance with the irradiation direction and the intensity thereof.

FIG. 3 is a diagram for explaining an example of the result of measuring the relationship between the irradiation distance and the ion concentration in the irradiation region of the soft X-ray SX. The irradiation distance (cm) on the horizontal axis is the distance from the soft X-ray SX emission part of the soft X-ray irradiation apparatus SXU to the equidistant spherical surface, and is the ion concentration (ions · cm ⁻³ ) on the vertical axis. Soft X-rays have a large distance attenuation. For example, in the case of 30 cm and 80 cm, the soft X-ray intensity at the irradiation site is reduced by an order of magnitude. And as FIG. 3 showed, the intensity | strength of a soft X-ray has the relationship of a substantially inverse proportion to distance. Therefore, as described above, it is necessary to arrange the soft X-ray irradiation apparatus SXU as close as possible to the lower surface of the glass substrate SUB. This means that the deterioration of the roller that is close to the soft X-ray irradiation device SXU and is directly hit by the soft X-ray is extremely large compared to other rollers.

  However, according to the first embodiment of the present invention, the roller directly irradiated with soft X-rays is protected by the shielding plate SHP, and the progress of deterioration is prevented. Further, since the ions generated by the irradiation with the soft X-ray SX wrap around the inside of the shielding plate SHP, the charged charges on the glass substrate SUB are sufficiently removed.

  FIG. 4 is a schematic diagram for explaining Example 2 of the substrate transfer apparatus according to the present invention, and is a side sectional view similar to FIG. Similarly to the first embodiment, the substrate transport apparatus according to the second embodiment has a plurality of rollers RLR arranged in the transport direction, and the lower surface of the glass substrate SUB for configuring the liquid crystal display panel is placed on the rollers RLR. In addition, the glass substrate SUB is lifted up during transfer or at the middle of transfer, and transferred for delivery to the next process.

  A soft X-ray irradiation device SXU is provided for irradiating the lower surface of the glass substrate SUB with soft X-rays at the end of transfer or in the middle of transfer to remove charges charged by contact with and peeling from the roller RLR. In addition, the attenuation rate of the transmission part of the soft X-ray that irradiates the nearest roller is large in the vicinity of the transfer end part or the soft X-ray irradiation apparatus SXU in the middle of the transfer, and the distance from the soft X-ray irradiation apparatus SXU is long. A soft X-ray attenuating member ATN is provided in which the attenuation rate of the soft X-ray transmission site that irradiates the roller becomes gradually smaller.

  The soft X-ray irradiator SXU is installed at both ends of the substrate transfer direction indicated by the arrow A during transfer or at the transfer end, and at a position facing the roller RLR arranged at the transfer end or in the transfer diagonally upward. Yes. The soft X-ray attenuation member ATN uses a metal mesh whose aperture ratio changes stepwise, a metal plate whose thickness changes gradually, a resin plate whose thickness changes gradually, or a resin plate with a metal vapor deposition film whose slit width changes gradually . When using a metal mesh, a metal plate whose thickness gradually changes, or a resin plate with a metal vapor deposition film whose slit width gradually changes, it is desirable to ground this.

  FIG. 5 is an explanatory diagram of the attenuation characteristics of the soft X-ray attenuation member ATN set in the second embodiment of the present invention. An arrow E indicates a conveyance end portion, a solid line a indicates a characteristic in which the attenuation amount at the conveyance end portion E is large and the attenuation amount decreases rapidly as the distance from the soft X-ray irradiation apparatus SXU increases, and a dotted line b indicates conveyance. The attenuation at the end E is not so large, and the attenuation gradually decreases as the distance from the soft X-ray irradiation apparatus SXU increases.

  FIG. 6 is a diagram illustrating how the soft X-ray intensity distribution on the lower surface of the glass substrate SUB varies depending on the presence / absence of the soft X-ray attenuation member ATN. A broken line c 'in FIG. 6 shows a soft X-ray intensity distribution on the lower surface of the glass substrate when the soft X-ray attenuation member is not installed. On the other hand, the solid line a ′ in FIG. 6 shows the soft X-ray intensity distribution on the lower surface of the glass substrate when the soft X-ray attenuation member having the characteristics of the solid line a in FIG. It is. Thus, by appropriately selecting the attenuation rate of each part of the soft X-ray attenuation member, the difference in irradiation intensity due to the distance from the soft X-ray irradiation apparatus can be reduced, and a wide area on the lower surface of the glass substrate. A uniform charge eliminating effect can be obtained. 6 shows the soft X-ray intensity distribution on the lower surface of the glass substrate when the soft X-ray attenuation member having the characteristics of the dotted line b in FIG. 5 is installed. Although slightly higher, the strength is lower than in the case where the soft X-ray attenuation member indicated by the broken line c ′ in FIG. 6 is not installed. Therefore, it can be seen that the soft X-ray attenuation member is effective in reducing the deterioration of the roller, regardless of the soft X-ray attenuation member having any of the characteristics shown in FIG.

  As described above, according to the present invention, by installing the soft X-ray shielding member or the soft X-ray attenuation member, the deterioration of the rollers can be suppressed and the replacement frequency of the rollers can be kept low, thereby improving the throughput. Can be achieved. Further, in order to further enhance the effect of the present invention, it goes without saying that a structure that can be easily replaced with a soft X-ray including a roller is provided.

It is a schematic diagram explaining Example 1 of the board | substrate conveyance apparatus by this invention. It is a figure which further demonstrates Example 1 of this invention. It is a figure explaining an example of the result of having measured the relationship between irradiation distance and ion concentration in the irradiation area | region of soft X-ray SX. It is a schematic diagram explaining Example 2 of the board | substrate conveyance apparatus by this invention. It is explanatory drawing of the attenuation | damping characteristic of the soft X-ray attenuation member set in Example 2 of this invention. It is a figure explaining the soft X-ray intensity distribution in the lower surface of the glass substrate by the presence or absence of a soft X-ray attenuation member. It is explanatory drawing of the conventional board | substrate conveyance apparatus provided with the soft X-ray irradiation apparatus.

Explanation of symbols

  SUB ... insulating substrate (glass substrate), RLR ... roller (roller), SXU ... soft X-ray irradiation device, SX ... soft X-ray, SHP ... shielding plate, ATN ... soft X-ray attenuation member.

Claims (12)

It has a plurality of rollers arranged in the transport direction and transports the lower surface of the glass substrate for constituting the liquid crystal display panel placed on the roller, and transports the glass substrate in the transport end portion or in the middle of transport. A substrate transfer device that lifts up and transfers to transfer to the next process,
A soft X-ray irradiator for irradiating the lower surface of the glass substrate with soft X-rays in the transfer termination portion or in the middle of transfer, and removing the charges of the roller and the glass substrate charged by contact and peeling with the roller. Prepared,
The roller disposed in the vicinity of the transfer end portion or the soft X-ray irradiation device in the middle of transfer is provided with a shielding plate that blocks direct soft X-rays emitted from the soft X-ray irradiation device. Substrate transport device. In claim 1,
The soft X-ray irradiator is installed at a position facing the upper end of the transfer or the both ends of the substrate transfer direction in the middle of transfer and the roller disposed in the transfer end or in the middle of the transfer obliquely upward. Substrate transport device. In claim 1,
The substrate transfer apparatus, wherein the shielding plate is made of metal. In claim 3,
The substrate transfer apparatus, wherein the shielding plate is grounded. It has a plurality of rollers arranged in the transport direction and transports the lower surface of the glass substrate for constituting the liquid crystal display panel placed on the roller, and transports the glass substrate in the transport end portion or in the middle of transport. A substrate transfer device that lifts up and transfers to transfer to the next process,
A soft X-ray irradiation apparatus for irradiating the lower surface of the glass substrate with soft X-rays in the transfer termination portion or in the middle of transfer, and removing the charges of the roller and the glass substrate charged by contact with the roller and detachment peeling. With
A roller that has a large attenuation factor of a soft X-ray transmission part that irradiates the nearest roller near the end of transfer or the soft X-ray irradiation device in the middle of transfer, and the distance from the soft X-ray irradiation device is long. A soft X-ray attenuating member is provided in which the attenuation rate of the transmission part of soft X-rays that irradiates is gradually reduced. In claim 5 ,
The soft X-ray irradiator is installed at a position facing the upper end of the transfer or the both ends of the substrate transfer direction in the middle of transfer and the roller disposed in the transfer end or in the middle of the transfer obliquely upward. Substrate transport device. In claim 5 ,
The substrate transfer apparatus, wherein the soft X-ray attenuation member is a metal mesh whose aperture ratio changes stepwise. In claim 5 ,
The substrate transfer apparatus, wherein the soft X-ray attenuation member is a metal plate whose thickness gradually changes. In claim 5 ,
The substrate transfer apparatus, wherein the soft X-ray attenuation member is a resin plate whose thickness gradually changes. In claim 5 ,
The substrate transfer apparatus, wherein the soft X-ray attenuation member is a resin plate with a metal vapor deposition film whose slit width gradually changes. In claim 7,
The substrate transfer apparatus, wherein the metal mesh is grounded. In claim 10,
The substrate transfer apparatus, wherein the metal deposition film is grounded.

Images