JP5056339B2 - Substrate gripping mechanism for substrate transfer equipment - Google Patents

Description

  The present invention relates to a substrate gripping mechanism in a transport mechanism for stably transporting a substrate without a vertical fluctuation due to vibration or the like in a substrate inspection apparatus that performs defect inspection of a substrate for a flat panel display such as a liquid crystal display panel or a plasma display panel. It is about.

  Conventionally, as a method for transporting a substrate, a method using a conveyor using rollers is mainly used, and a substrate transport mechanism (chucking) transports a substrate by directly contacting a roll conveyor on the back surface of the substrate. However, due to the increase in size of the substrate, the substrate may collide with the rollers due to, for example, bending due to the weight of the substrate being transferred, vertical vibration during transfer, etc. Various problems occurred, such as scratches during transportation that occurred as a cause.

  Therefore, for a large-sized substrate having large deflection due to weight and large vertical vibration during conveyance, a non-contact conveyance technique in which the entire surface is floated by air and conveyed is used instead of conveyor conveyance using rollers.

  In flat panel displays, for example, color filters are inspected for defects in the manufacturing process. However, in recent years, screens have become higher in definition, and accordingly, inspection machines themselves are required to have high performance. ing. Specifically, an inspection machine using an ultra-high resolution camera with a resolution of 3 μm or less that inspects defects of 5 μm or less has become essential from the viewpoint of quality assurance.

  Techniques for inspecting a substrate by conveying the substrate by air levitation have already been described in Patent Documents 1 to 3 and the like.

International Publication Number W2003 / 086917 JP 2004-279335 A JP 2006-258632 A

  However, an inspection machine camera with a resolution of 5 μm or less has a shallow depth of focus and a narrow depth of field, and in order to capture an image for inspection, stable substrate transport is required so as not to deviate from the depth of field. .

  In the substrate conveyance by the roller, there is a problem that the vertical fluctuation during the conveyance of the substrate is severe due to the unevenness of the roller itself and the installation condition due to the contact conveyance, and it is deviated from the depth of field of the high resolution inspection camera. In addition, the substrate and the roller may collide with each other due to vibration caused by vertical fluctuations, which may damage the substrate.

  Therefore, the conveyance is performed in the air levitation that does not contact the conveyance surface. In the first non-contact air transfer technology, the substrate was only floated by blowing air, so the floating accuracy of the substrate was large, and the vertical fluctuation caused by the floating unevenness during transfer occurred, and the transfer by that There is a problem of scratches such as contact with the part, and a problem that the inspection surface deviates from the depth of field of the inspection camera due to vertical fluctuation due to vibration. Therefore, a technology has been developed to suppress the vertical fluctuation of the flying height by the air sucking force by performing air sucking and sucking in relation to the substrate floating. With this technology, the non-uniformity of the floating during transportation can be suppressed to 10 μm or less with respect to the highly precise floating, and stable substrate transportation can be performed. As a result, the inspection surface can be transported without departing from the depth of field, and the collision with the transport surface is eliminated.

With the above-described technology, the flying unevenness due to air conveyance is eliminated, and the substrate can be lifted with a stable flying accuracy.

  Although high-accuracy levitation can be achieved by air conveyance, a means for moving the substrate is required because rollers and conveyors are not used. In the conventional method, there is an example in which a driving unit such as a conveyor is provided outside the substrate and a suction cup or a chucking hand is installed on the conveyor. However, since the transport mechanism side is a reference, if the transport mechanism chucking height fluctuates, the substrate height is affected. For this purpose, the drive unit accuracy on the transport mechanism side and the suction pad and chucking hand mounting accuracy are required.

  In addition, since the flying height varies depending on the weight of the substrate in the air conveyance, it is necessary to adjust the height of the suction pad and the chucking hand on the conveyance mechanism side whenever the weight of the substrate changes.

  In addition, the air transport levitation mechanism is expensive due to the levitation accuracy (precise grade / normal grade), so it is necessary to use it depending on the usage conditions. Depending on the combination (normal grade → precision grade → normal grade) and clearance Variations in flying height occur.

Accordingly, an object of the present invention is to provide a transport mechanism for enabling substrate transport while ensuring high-accuracy levitation made possible by air transport.

According to the first aspect of the present invention, the apparatus includes the substrate floating mechanism that floats the substrate installed in the substrate transport unit, the gripping unit that grips one or both ends of the substrate, and the gripping transport unit that moves the gripping unit. In the substrate transfer device characterized in that
The gripping means includes an upper block and a lower block that sandwich a substrate end portion by a substrate sandwiching portion;
A support for supporting the upper block and the lower block and aligning the movement axis;
A chuck opening and closing tube disposed outside the substrate sandwiching portion of the upper block and the lower block;
Fluid supply / discharge means for supplying and discharging fluid to and from the chuck opening and closing tube;
A repulsion spring disposed between the upper block and the lower block;
A support beam and a support spring that support the upper block and the lower block,
When a fluid is supplied to the inside of the chuck opening / closing tube to expand the chuck opening / closing tube, the substrate sandwiching portions of the upper block and the lower block operate to sandwich the substrate end, and when the fluid is discharged from the inside of the chuck opening / closing tube A gap is formed between the substrate sandwiching portions of the upper block and the lower block by the repulsion spring to perform an operation of opening the substrate end.
A gripping mechanism for a substrate transport apparatus, comprising the gripping and transporting means for reciprocating at least one gripping means.

  According to a second aspect of the present invention, in the substrate transport apparatus gripping mechanism according to the first aspect of the present invention, an adsorbing portion is disposed in either of the upper and lower blocks of the substrate gripping means.

  According to the first aspect of the present invention, even when the floating height of the substrate fluctuates due to changes in the substrate specifications (weight and thickness) to be transferred, the chucking height of the gripping mechanism does not need to be adjusted and the substrate is chucked. Adjustment can be performed on the basis of the substrate. Further, it is possible to follow the fluctuation of the flying height of the substrate even after chucking.

  According to the second aspect of the present invention, it is possible to stabilize the holding of the substrate by disposing the adsorbing portion on the substrate holding portion of either the upper block or the lower block of the substrate holding means.

  Hereinafter, a substrate gripping mechanism in a substrate transfer apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a substrate transfer device applied to a substrate inspection apparatus.

  The substrate transport apparatus 1 according to the present invention includes a levitation mechanism 3 that transports the substrate 2 while floating the substrate 2 by blowing air, a levitation mechanism 4 that transports the substrate 2 while precisely floating the substrate by blowing and sucking air, and the substrate A substrate gripping mechanism 5 for fixing one end and both ends of the substrate 2 protruding from the side surfaces of the levitation mechanism 3 and the substrate levitation mechanism 4, and a side surface of the substrate levitation mechanism 3 and the substrate levitation mechanism 4; From the substrate transport mechanism 6 that transports the substrate 2 in the direction along the transport direction X via the substrate fixing mechanism 5, the supply of air to the substrate floating mechanism 3 and the substrate holding mechanism 4, and the substrate floating mechanism 4 A levitation control unit A that sucks the air and an inspection unit B that performs surface inspection of the substrate 2.

  Next, the structure of the substrate floating mechanism 3 and the substrate floating mechanism 4 will be described with reference to FIG. 2 is a schematic cross-sectional view of the substrate floating mechanism 3 and the substrate floating mechanism 4, and the thickness and the floating amount of the substrate 2 are exaggerated for easy understanding.

  The substrate levitation mechanism 4 in the substrate transfer apparatus 1 of the present invention is a rectangular hollow structure, and the surfaces 3a and 4a facing the substrate 2 are plate-like substances having countless fine holes (for example, porous Carbon or sintered metal). The surfaces 3a and 4a are adjacent to the internal hollow spaces 10 and 12, and the surface 3a and the surface 3a and 4a are applied by applying pressure from the levitation controller A through the pipes 10p and 12p connected to the hollow spaces 10 and 12. A uniform upward air flow 13 and 14 can be formed over the entire area 4a. This upward air flow makes it possible to slightly lift the substrate 2.

  In the substrate levitation mechanism 4, suction holes 8 having a diameter of about 0.5 to 2 mm are provided on the entire surface 4 a other than the region in a range of about 10 to 50 mm at regular intervals or irregular intervals. The suction hole 8 is not electrically connected to the hollow space 10 provided in the substrate floating mechanism 3 and is connected to the hollow space 11 provided separately. The suction hole 8 is hollowed by the floating control unit A through the pipe 11v. By reducing the internal pressure of the space 11, air can be sucked from the suction hole 8.

  By blowing air from the entire area of the surface 4a and simultaneously sucking air from the suction hole 8, the flying height of the substrate 2 can be maintained with high accuracy.

  The substrate gripping mechanism 5 of the present invention grips the edge of one or both sides of the substrate 2 in order to move the substrate floating on the substrate floating mechanism 4 in a predetermined direction. For comparison, first, a technique of a conventional substrate gripping mechanism will be described with reference to FIGS.

  FIG. 3 shows a conventional substrate gripping mechanism. In the conveyance by a roller roll (conveyor) or the like, the roller roll itself rotates to convey the substrate. Therefore, the substrate is held by holding the substrate end surface with the substrate gripping pins 25. The feeding is performed by a conveyor, and the substrate gripping pins 25 are used as auxiliary and positioning.

  FIG. 4 shows details of a conventional substrate gripping mechanism. The substrate gripping pin 25 installed on the base plate 24 is not touching the substrate 2 when the substrate is loaded as shown in FIG. 4A, and the pin 25 moves in the direction of the substrate 2 after the alignment shown in FIG. 4B. Fix the substrate. This method does not hold from the upper and lower surfaces of the substrate 2 but only serves to assist the roller conveyance.

  Next, the structure of the substrate gripping mechanism 5 in the substrate transfer apparatus 1 of the present invention will be described with reference to FIG. 5 is a cross-sectional view of the substrate gripping mechanism 5 taken along the width direction of the substrate 2 in FIG.

  The substrate gripping mechanism 5 includes an upper block 26, a lower block 27, a repulsion spring 28, a chuck portion opening / closing tube 29, and a support column 30. The support column 30 supports the upper block 26 and the lower block 27 so that the driving directions for gripping the substrate can be aligned.

  A fluid supply / discharge means (not shown) is connected to the chuck portion opening / closing tube 29, and supplies or discharges fluid to / from the chuck portion opening / closing tube 29. Various gases and liquids can be selected as the fluid supplied into the tube 1.

  In this way, the chuck portion opening / closing tube 29 expands in the diametrical direction when a fluid is supplied to the inside thereof, and is crushed in the diametrical direction when the fluid is discharged from the inside. When the chuck portion opening / closing tube 29 swells, the substrate sandwiching portion of the upper block 26 and the lower block 27 can grip the substrate 2 (substrate chuck state), and the gripping force is the air pressure inside the chuck opening / closing tube 29. And the force of the repulsion spring 28.

  When the fluid is discharged from the inside of the chuck opening / closing tube 29, a gap is formed between the substrate sandwiching portions of the upper block 26 and the lower block 27 by the force of the repulsion spring 28, and the substrate 2 can be released without being gripped. Yes (substrate unchucked state).

  FIG. 5A shows the case of the gripping mechanism alone. At this time, the upper block 26 and the lower block 27 are opened evenly with respect to the substrate 2 in the unchucked state, but the chucking position may be lowered downward due to the weight of the gripping mechanism portion when the substrate 2 is chucked. Accordingly, the floating position of the substrate 2 and the height position of the gripping mechanism 5 may be shifted, and the substrate 2 may bend.

  Therefore, in the gripping mechanism of the present invention shown in FIG. 5B, in order to cancel the weight of the gripping mechanism 5, the support beam 40 and the support spring 31 are installed, and the substrate 2 is kept at the height of the substrate 2 even after chucking. It is possible to follow.

The operation of the gripping mechanism of the present invention shown in FIG. 5 (B) is as follows.
When compressed air is introduced into the tube 29 from the unchucked state, the tube 29 expands, the upper block 26 moves down, and the lower block 27 moves up to chuck the substrate 2.

  The spring 31 is disposed through a fixing bolt installed on the support beam 40 extending from the support column 30 and further fixed to a female screw provided on the lower block 27 with a bolt. The weights of the upper and lower blocks 26 and 27 are lifted by a force transmitted from the fixing bolt to the spring 31 and the spring returning. The lifting amount can be adjusted by the pressing amount of the fixing bolt (the crushed amount of the spring 31).

  Here, by adjusting the pushing amount of the spring 31, the position at the time of chucking (chuck position height) can be adjusted by suspending the weight of the upper and lower blocks 26, 27, and the upper and lower blocks 26 can be adjusted. 27, the weight of the upper and lower blocks 26, 27 is not applied to the substrate 2 and can follow the vertical movement of the substrate 2.

  Further, in the gripping mechanism of the present invention shown in FIG. 5C, a constant load winding spring 32 is used as a support spring for canceling the weight of the gripping mechanism 5. Since the constant load winding spring 32 is a spring that can obtain a constant load regardless of the expansion and contraction of the winding spring, it is possible to always support the gripping mechanism 5 with a constant force.

  Furthermore, as shown in FIG. 5D, it is possible to stabilize the holding of the substrate 2 by installing the suction portion 34 in the lower block 27.

  In the substrate gripping mechanism 5 of the present invention described above, one end or both end portions of the substrate 2 are sandwiched and fixed from the upper and lower surfaces of the substrate 2, and the floating is movable in a direction perpendicular to the substrate 2. Two or more places are installed on the base plate 7 which is an operation part of the substrate transport mechanism 6 through the structure (see FIG. 1). As a result, it is possible to absorb the deviation between the vertical position of the substrate 2 being transferred and the vertical position of the substrate transfer mechanism 6, and the substrate 2 can be transferred with high accuracy.

  As shown in FIG. 1, the substrate transfer mechanism 6 in the substrate transfer apparatus 1 of the present invention is provided adjacent to one side or both sides of the substrate floating mechanism 3 and moves the substrate 2 along the substrate transfer direction X at a constant speed. It is a uniaxial transport mechanism that transports by. For example, a combination of a linear motor and a linear guide whose speed fluctuation is smaller than a combination of a servo motor and a ball screw is suitable. However, when the required accuracy of inspection increases in the future and this transfer device is applied to an ultra-high resolution inspection machine or the like, it may be possible to combine an air levitation guide with a coreless type linear motor.

  As shown in FIG. 1, the levitation controller A in the substrate transfer apparatus 1 of the present invention sucks air from the substrate levitation mechanism 3 and the compressed air path 21 for supplying compressed air to the substrate levitation mechanism 4 and the substrate levitation mechanism 4. An exhaust path 18 for exhausting is provided. In FIG. 1, the levitation control unit A is disposed in the machine-side space of the substrate transport apparatus 1 for the sake of explanation, but actually, it is housed under the substrate transport apparatus 1 or in a separate housing.

  On the upstream side of the compressed air path 21, there are provided a pressure regulating valve 19 that adjusts the supply pressure, and a manifold 20 that branches the piping and distributes the compressed air to the substrate floating mechanism 3 and the substrate floating mechanism 4. A blower pump 15 serving as a power source for air suction and a ball valve 16 for adjusting the suction flow rate and pressure are provided on the upstream side of the exhaust path 18. By adjusting the supply pressure and the suction flow rate, the floating accuracy of the substrate 2 on the transport surface of the substrate floating mechanism 4 can be increased.

  As shown in FIG. 1, the inspection unit B in the substrate transport apparatus 1 of the present invention is installed so as to straddle the substrate transport mechanism 6, the substrate floating mechanism 3, and the substrate floating mechanism 4 in the width direction perpendicular to the transport direction X. A beam-like member is provided at a predetermined height position from the upper surface of the substrate levitation mechanism 4, and is provided below the upper surface of the substrate levitation mechanism 4 by a camera device 22 that images the upper surface of the substrate 2 and an attachment member (not shown). A light source 9 for irradiating light in the light guide direction of the camera device 22 is provided. Further, the camera device 22 is fixed to the beam-like member via an alignment stage in which the position in the direction perpendicular to the transport surface and the angle around the rotation axis parallel to the transport direction X can be adjusted.

  Finally, a specific floating state of the substrate 2 being transferred will be described with reference to FIG. FIG. 6 exaggerates the thickness of the substrate 2 and the gap between the substrate floating mechanism 3 and the substrate floating mechanism 4 for explanation.

  First, as shown in FIG. 6A, the substrate 2 is levitated and conveyed over the area of the substrate levitating mechanism 3. Next, as shown in FIG. 6B, the tip of the substrate 2 that has reached the region of the substrate floating mechanism 4 has a large floating amount due to the air blowing from the substrate floating mechanism 3 and the adsorption effect of the substrate floating mechanism 4. . Actually, the tip of the substrate 2 is slightly bent downward.

Thus, the height fluctuation due to the connection between the substrate floating mechanism 3 and the substrate floating mechanism 4 cannot be absorbed by the substrate gripping mechanism of the conventional method, and the substrate 2 is bent. Since the deflection has a non-negligible effect in the high-precision inspection, the inspection cannot be performed normally. However, according to the substrate gripping mechanism of the present invention, it is possible to carry the substrate 2 while following the flying height variation of the substrate 2 well, and therefore it is possible to carry out a highly accurate inspection without any problem.

The schematic perspective view which shows the Example of the board | substrate conveyance apparatus which uses the board | substrate holding | grip mechanism of this invention. The cross-sectional schematic diagram of the board | substrate floating mechanism of a board | substrate conveyance apparatus same as the above. The board | substrate conveyance by the conventional method and a board | substrate holding | gripping method schematic perspective view. Cross-sectional schematic diagram of substrate transport and substrate gripping method by conventional method The cross-sectional schematic diagram of the board | substrate holding | grip mechanism of this invention. The schematic diagram of the substrate floating state in a substrate conveyance apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate conveyance apparatus 2 ... Substrate 3 ... Substrate floating mechanism 3a ... Surface (substrate floating mechanism)
4 ... Substrate levitation mechanism 4a ... Surface (substrate levitation mechanism)
5 ... Substrate gripping mechanism 6 ... Substrate transport mechanism 7 ... Base plate 8 ... Suction hole (Substrate floating mechanism)
9. Illumination for transmission inspection 10. Hollow space (substrate floating mechanism: blowing up)
10p ... Piping (substrate floating mechanism: blowing up)
11 ... Hollow space (substrate floating mechanism: suction)
11v ... Piping (substrate floating mechanism: suction)
12 ... Hollow space (base floating mechanism: blowing up)
12p ... Piping (base levitation mechanism: blowing up)
13 ... Air flow (substrate floating mechanism: blowing up)
14 ... Air flow (substrate floating mechanism: blowing up)
15 ... Blower pump (suction)
16 ... Ball valve 17 ... Chamber 18 ... Exhaust path 19 ... Pressure regulating valve 20 ... Manifold 21 ... Pressure air path 22 ... Camera device 23 ... Roller roll (for conveyance)
24 ... Base plate 25 ... Substrate gripping pin 26 ... Upper block 27 ... Lower block 28 ... Repulsion spring 29 ... Chuck opening / closing tube 30 ... Post 31 ... Support spring 32 ... Constant load winding spring 33 ... Exhaust pressure 34 ... Adsorption part 40 ... Support Beam

Claims (2)

A substrate transportation system comprising: a substrate floating mechanism that floats a substrate installed in the substrate transportation unit; a gripping unit that grips one or both ends of the substrate; and a gripping transport unit that moves the gripping unit. In the device
The gripping means includes an upper block and a lower block that sandwich a substrate end portion by a substrate sandwiching portion;
A support for supporting the upper block and the lower block and aligning the movement axis;
A chuck opening and closing tube disposed outside the substrate sandwiching portion of the upper block and the lower block;
Fluid supply / discharge means for supplying and discharging fluid to and from the chuck opening and closing tube;
A repulsion spring disposed between the upper block and the lower block;
A support beam and a support spring that support the upper block and the lower block,
When a fluid is supplied to the inside of the chuck opening / closing tube to expand the chuck opening / closing tube, the substrate sandwiching portions of the upper block and the lower block operate to sandwich the substrate end, and when the fluid is discharged from the inside of the chuck opening / closing tube A gap is formed between the substrate sandwiching portions of the upper block and the lower block by the repulsion spring to perform an operation of opening the substrate end.
A holding mechanism for a substrate transfer apparatus, comprising: the holding and transferring means for reciprocating at least one of the holding means. 2. The gripping mechanism for a substrate transport apparatus according to claim 1, wherein a suction part is arranged in either of the upper and lower blocks of the substrate gripping means.

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