JP2010034382A - Substrate transport apparatus and substrate imaging pickup apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate transport apparatus with a substrate holding mechanism that can follow fluctuation in a vertical position caused by air surfacing without adjusting parallelism in a highly precise manner for installation so that distortion caused by a gradient between the substrate holding mechanism and the substrate may be not generated. <P>SOLUTION: The substrate transport apparatus is characterized by comprising a substrate holding mechanism and a substrate holding mechanism moving mechanism that can transport the substrate holding mechanism in the direction of transport. The substrate holding mechanism is composed of a plurality of substrate clipping sections, and each substrate clipping section can follow the vertical movement of the substrate independently. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a substrate imaging device for defect inspection of a substrate for a flat panel display such as a liquid crystal display panel or a plasma display panel, and a substrate transfer device used therefor, particularly for transferring a large substrate. The present invention relates to a substrate transfer device and a substrate imaging device for a substrate of the apparatus.

  As a method for transporting the substrate, conventionally, a method using a conveyor using a roller is mainly used, and the substrate is transported by bringing a roll conveyor directly into contact with 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. Techniques for inspecting a substrate by conveying the substrate by air levitation have already been described in Patent Documents 1 to 3.
In flat panel displays, for example, color filters are inspected for defects in the manufacturing process, but 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.

  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. Therefore, in order to capture an image for inspection, stable substrate transport is required so as not to deviate from the depth of field. It is done.

  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, in order to make the conveyance path not in contact with the conveyance surface, conveyance by air levitation has been performed. In the first non-contact air transfer technology, the substrate was only floated by blowing out the air, so the floating accuracy of the substrate was large, and vertical fluctuations occurred due to the floating unevenness during transfer. There was a problem of scratches such as contact with the surface, and a problem that the inspection surface deviated 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 movement of the substrate by the air suction force by performing suction at the same time as the air is blown out. With this technique, for those with high precision levitation, non-uniformity of levitation during conveyance can be suppressed to about 10 μm or less, and stable substrate conveyance 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 technique, the flying unevenness due to air conveyance is eliminated, and the substrate can be lifted with a stable flying accuracy. However, even if floating unevenness can be eliminated, if the air floating unit itself that is the foundation is not installed so as to have flatness with high accuracy, the position variation of the substrate height during transport will result. .

  It is technically difficult and expensive to manufacture such a large substrate that can be levitated by a single air levitation unit. Therefore, in the existing technology, a method is used in which air floating blocks of a size that can be manufactured relatively easily are arranged and used by the amount necessary for conveyance. When these air levitation blocks are arranged as many as necessary for substrate transport, the larger the number, the more difficult it is to install the levitation blocks with high accuracy without any difference in height.

  As a method of adjusting the height of each air levitation unit, there is a method of adjusting by placing a shim between the base on which the air levitation unit is installed and the air levitation unit. When this method is used, the flatness of the entire air bearing surface when all the air levitation units are arranged is about 20 μm. Even if the height of the air levitation unit is adjusted using shims, the air levitation unit The processing accuracy of itself cannot be adjusted.

  If the above-mentioned high-precision levitation fluctuation of about 10 μm is combined with the flatness error of about ± 20 μm when the air levitation unit is installed, the result will be a fluctuation of the substrate height position of about ± 30 μm or more during transportation. End up.

In this state, if the transport substrate is transported while being gripped at a fixed height position, a difference occurs between the substrate gripping position and the substrate floating height position due to fluctuations in the height position of the substrate being transported. The substrate will be distorted.
Further, if the substrate is held while being held at a certain fixed height, the parallelism between the substrate holding mechanism and the substrate must be set with high accuracy, and the substrate is distorted with a slight inclination.

  As a method for gripping a substrate, a method as described in Patent Document 4 is described as a technology for gripping a grip portion by moving it vertically or rotationally using a cylinder or the like using a fluid.

The patent literature is as follows.
International Publication Number WO2003 / 086917 JP 2004-279335 A JP 2006-258632 A JP 2008-78304 A

  However, with this method, if there is an inclination in the part where the substrate gripping mechanism comes into contact with the substrate, the inclination causes the substrate to be distorted, causing the vertical position of the substrate to fluctuate due to the distortion and contact the air levitation unit. Or out of the depth of field of the inspection camera, resulting in out-of-focus of the captured image and the like, making it impossible to perform a stable inspection.

  Therefore, the present invention does not require the parallelism to be adjusted and installed with high accuracy so as not to cause distortion due to the tilt between the substrate gripping mechanism and the substrate, and the substrate gripping mechanism is highly sensitive to fluctuations in the vertical position of the substrate due to air levitation. It is an object of the present invention to provide a substrate transfer apparatus that can follow the position.

According to the first aspect of the present invention, in the substrate transport apparatus including the substrate gripping mechanism and the substrate gripping mechanism moving mechanism capable of transporting the substrate gripping mechanism in the transport direction, the substrate gripping mechanism includes a plurality of substrate sandwiching portions. In addition, the present invention provides a substrate transfer apparatus comprising a mechanism in which each substrate sandwiching portion can independently follow the vertical movement of the substrate.

  According to a second aspect of the present invention, the mechanism in which each substrate sandwiching portion can independently follow the vertical movement of the substrate is a free rotation mechanism from the axis of the substrate gripping mechanism. The described substrate transfer apparatus is provided.

  According to a third aspect of the present invention, there is provided the substrate transfer apparatus according to the first or second aspect, wherein the entire substrate gripping mechanism includes a vertical movement control mechanism.

  According to a fourth aspect of the present invention, there is provided the substrate transport apparatus according to any one of the first to third aspects, wherein the substrate gripping mechanism is provided on the side of the transport path, and the transport path is provided with a substrate floating mechanism. Is.

  According to a fifth aspect of the present invention, there is provided the substrate transfer apparatus according to the fourth aspect, wherein the substrate floating mechanism comprises an air blowing mechanism.

  According to a sixth aspect of the present invention, there is provided the substrate transfer apparatus according to the fourth aspect, wherein the substrate floating mechanism includes an air blowing mechanism and an air suction mechanism.

  According to a seventh aspect of the present invention, there is provided a substrate imaging apparatus, wherein the imaging apparatus is provided on the conveyance path of the substrate conveyance apparatus according to any one of the fourth to sixth aspects.

  According to the first aspect of the present invention, since each of the substrate sandwiching portions can independently follow the vertical movement of the substrate, the degree of parallelism is set with high accuracy so as not to generate distortion due to the inclination of the substrate holding mechanism and the substrate. The height position of the substrate gripping mechanism can follow the change in the vertical position of the substrate due to air levitation without requiring adjustment and installation.

  According to the second aspect of the invention, since the mechanism in which each substrate sandwiching portion can independently follow the vertical movement of the substrate is a free rotation mechanism from the axis of the substrate gripping mechanism, complicated vertical movement control is possible. It is possible to follow the stable height position without providing a device for each substrate sandwiching portion.

  According to the invention of claim 3, stable weight cancellation can be performed as a whole. In addition, when the configuration of the substrate gripping mechanism is changed, even if the weight changes, the force that cancels the gravity can be easily changed by adjusting the pressing force of the cylinder.

  According to the fourth aspect of the present invention, stable conveyance can be performed not only when the substrate changes but also without depending on the substrate gripping mechanism or the substrate gripping mechanism moving mechanism.

  In this case, although one side may be sufficient, the effect of both sides is higher.

  According to the fifth aspect of the invention, not only the substrate sandwiching portion, but also the entire substrate can always be transferred by the same transfer path, and stable transfer can be performed.

  According to the sixth aspect of the present invention, it is possible to perform conveyance along the same conveyance path without considering parallelism with respect to the substrate, and stable conveyance can be performed.

  According to the seventh aspect of the present invention, it is possible to obtain an accurate imaging result, for example, the inspection of the substrate, without being transported without departing from the depth of field of the imaging surface. Inspection accuracy such as defect inspection can be improved.

  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 imaging device used in a substrate inspection device.

  The substrate transfer apparatus 1 according to the present invention includes a substrate floating mechanism 3 that keeps the substrate 2 floating at a certain height by blowing and sucking air, and one side portion of the substrate 2 that protrudes from one side of the substrate floating mechanism 3. A substrate transport mechanism 5 that is provided adjacent to one side surface of the substrate gripping mechanism 4 that fixes and holds the substrate and that transports the substrate 2 in the direction along the transport direction X via the substrate gripping mechanism 4 in the previous period. And a floating control unit A that supplies air to the substrate floating mechanism 3 and sucks air from the substrate floating mechanism 3, and an inspection unit B that performs imaging of the substrate 2 and performs defect inspection from the captured image. .

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

  The substrate floating mechanism 3 in the substrate transfer apparatus 1 of the present invention is a rectangular hollow structure, and the surface 3a facing the substrate 2 has a plate-like substance with numerous fine holes (for example, porous carbon or Metal sintered body). By applying compressed air to the surface 3a through a pipe 9p connected to the internal hollow space 9, a uniform upward air flow 12 can be formed over the entire surface 3a. This upward air flow 12 makes it possible to slightly lift the substrate 2.

  In the substrate levitation mechanism 4, the surface 3a is provided with suction holes 8 having a diameter of about 0.5 to 2 mm at regular intervals or irregular intervals in the range of about 10 to 50 mm. The suction hole 8 is not electrically connected to the hollow space 9 provided in the interior of the substrate floating mechanism 3 and is connected to the hollow space 10 provided separately, and is connected to the hollow space 10 through the pipe 10v. By reducing the internal pressure, air can be sucked from the suction hole 8. Further, by blowing air from the entire surface 3a and simultaneously sucking air from the suction holes 8, the flying height of the substrate 2 can be maintained with high accuracy.

  The structure of the substrate gripping mechanism 4 in the substrate transfer apparatus 1 of the present invention will be described with reference to FIG. 3 is a cross-sectional view of the substrate gripping mechanism 4 taken in the width direction in FIG. The substrate gripping mechanism 4 includes a shaft 50, an upper block 51 and a lower block 52 that are rotatable about the shaft 50, a gripper opening / closing tube 53, a tension spring 54, and a bearing 55 that connects the shaft 50 and the upper and lower blocks. The substrate sandwiching part 6 is composed of

  A hemispherical protrusion is provided at the portion where the upper block 51 and the lower block 52 are in contact with the substrate 2 so that the upper and lower blocks can hold the substrate 2 at any rotation angle. 56 is configured.

  The gripper opening / closing tube 53 is connected to a fluid supply / exhaust main body (not shown), and supplies or discharges fluid to / from the gripper opening / closing tube 53. You can choose a liquid.

  The inside of the gripper opening / closing tube 53 expands in the diametrical direction by supplying the fluid, and is shaped to be crushed in the diametrical direction when the fluid is discharged from the inside. When the gripper opening / closing tube 53 is crushed, the substrate sandwiching portion 6 of the upper block 51 and the lower block 52 can grip the substrate 2 (substrate chuck state), and the gripping force is determined by the restoring force of the tension spring. .

When a fluid is supplied to the inside of the holding part opening / closing tube, a gap is formed between the board sandwiching parts of the upper block 51 and the lower block 52 by the air pressure inside the tube, and the board 2 can be released without being held. (Substrate unchucked state)
Next, the behavior of the substrate gripping mechanism 4 of the present invention during substrate transfer is shown in FIGS. 4 and 5 are schematic cross-sectional views, and exaggerate the thickness, flying height, and flying variation of the substrate 2 for easy understanding. In FIG. 4, the substrate 2 is transported in the transport direction X and the substrate floating mechanism 3 is being transferred. At this time, the end portion of the substrate 2 does not reach the suction hole 8 of the substrate floating mechanism 3, and the flying height varies due to the compressed air from the surface 3a. With respect to the floating fluctuation amount of the substrate 2, the substrate sandwiching portion 6 of the substrate gripping mechanism 4 rotates and moves the upper block 51 and the lower block 52 around the shaft 54, so that the substrate holding height is the same as the floating variation amount of the substrate 2. The holding part 56 moves up and down by the amount. In FIG. 5, the end of the substrate 2 reaches the suction hole 8 of the substrate floating mechanism 3, and the flying height of the substrate 2 attempts to return to the set flying height by blowing in air. At this time, the upper and lower blocks 51 and 52 also rotate around the axis 50 of the substrate gripping mechanism 4 so that the gripper 56 follows the flying height of the substrate 2.

  By attaching a plurality of substrate sandwiching portions 6 to the substrate gripping mechanism 4, the gripping portions 56 of the individual substrate sandwiching portions 6 of the substrates follow different substrate heights, and the substrate 2 is not distorted. Accurate levitation can be achieved. Here, the smaller the thickness of the upper and lower blocks of the substrate sandwiching portion 6 is, the better the greater the number of substrate sandwiching portions 6 is.

  Only the substrate gripping mechanism 4 causes distortion of the substrate due to the weight of the gripping mechanism itself. Therefore, it is necessary to cancel the own weight in order to offset the weight of the substrate gripping mechanism 4.

  Here, the dead weight cancellation will be described. A self-weight canceling mechanism is shown in FIG. In FIG. 6, the shaft 50 of the substrate gripping mechanism 4 is supported by a column 61, and the column 61 is attached to a column base 62. One of the leaf springs 63 is attached to the attachment part of the support 61 and the support base 62 so that the other end is attached to the substrate gripping mechanism support base 64. A cylinder 65 is installed below the support base 62.

  Regarding the self-weight cancellation, a method is used in which the weight of the substrate gripping mechanism is canceled by the force of the cylinder 65 by the fluid, but in this description, the fluid is generally used air. Therefore, a regulator 66 for adjusting the air pressure for operating the cylinder 65 is provided. The regulator 66 supplies air from the direction of the arrow 67 and is directly connected to the cylinder 65 by an air pipe 68. The regulator 66 is preferably a high-resolution type capable of fine adjustment of air.

  In general, sliding resistance is generated in the air cylinder, so that there is a problem that the air cylinder does not move smoothly when the height position of the substrate changes. However, the air cylinder 65 used in this case is By maintaining the rod in a non-contact state in the manner of an air bearing, the rod can be operated with almost no sliding resistance. This cylinder has almost no sliding resistance and is already an existing technology.

  Since the substrate transport apparatus of FIG. 1 transports the substrate while gripping, the self-weight cancellation itself also moves. However, it is possible to cancel a part of the substrate's own weight by the restoring force of the leaf spring 63 installed to serve as a guide for the vertical movement of the substrate gripping mechanism. The relative position with can be kept constant.

  Further, it is possible to cancel the dead weight by installing the position of the air cylinder on the upper part of the substrate gripping mechanism and suspending the substrate gripping mechanism from the upper part. In this case, the performance itself such as the followability of the height position does not change only by changing the above explanation and the direction of the force.

  As described above, according to the substrate gripping mechanism of the present invention, it is possible to carry the substrate 2 without causing distortion of the substrate while following the flying height variation of the substrate 2 well. Can be implemented without any problem.

It is a schematic perspective view which shows the Example of the board | substrate conveyance apparatus using the board | substrate holding | grip mechanism of this invention. It is a cross-sectional schematic diagram of the board | substrate floating mechanism of a board | substrate conveyance apparatus same as the above. It is a cross-sectional schematic diagram of a board | substrate holding | grip mechanism. It is a cross-sectional schematic diagram which shows the behavior of a board | substrate holding | grip mechanism. It is a cross-sectional schematic diagram which shows the behavior of a board | substrate holding | grip mechanism. It is a schematic perspective view which shows the Example of the dead weight cancellation method of a board | substrate holding | grip mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate conveyance apparatus 2 ... Substrate 3 ... Substrate floating mechanism 3a ... Surface (substrate floating mechanism)
4 ... Substrate gripping mechanism 5 ... Substrate transport mechanism 6 ... Substrate clamping part 8 ... Suction hole (Substrate floating mechanism)
9 ... Hollow space (substrate floating mechanism: blowing up)
9p ... Piping (substrate floating mechanism: blowing up)
10 ... Hollow space (substrate floating mechanism: suction)
10v ... Piping (substrate floating mechanism: suction)
12 ... Air flow (substrate floating mechanism: blowing up)
21 ... Blower pump 22 ... Ball valve 23 ... Pressure adjustment valve 24 ... Manifold 25 ... Pressure air passage 26 ... Exhaust passage 29 ... Chamber 40 ... Beam-like member 41. ..Camera device 42 ... Light source 43 ... Alignment stage 50 ... Axis 51 ... Upper block 52 ... Lower block 53 ... Chuck opening / closing tube 54 ... Tension spring 56 ... Grasping part 61 ... Stand 62 ... Stand base 63 ... Plate spring 64 ... Substrate gripping mechanism support 65 ... Cylinder 66 ... Regulator 67 ... Air inlet

Claims (7)

  In a substrate transport apparatus including a substrate gripping mechanism and a substrate gripping mechanism moving mechanism capable of transporting the substrate gripping mechanism in a transport direction, the substrate gripping mechanism includes a plurality of substrate sandwiching portions, and each substrate sandwiching portion is independent. And a mechanism that can follow the vertical movement of the substrate.   2. The substrate transfer apparatus according to claim 1, wherein the mechanism in which each of the substrate sandwiching portions can independently follow the vertical movement of the substrate is a free rotation mechanism from the axis of the substrate gripping mechanism.   3. The substrate transfer apparatus according to claim 1, wherein the entire substrate gripping mechanism includes a vertical movement control mechanism.   4. The substrate transfer apparatus according to claim 1, wherein a substrate gripping mechanism is provided on a side of the transfer path, and a substrate floating mechanism is provided in the transfer path.   5. The substrate transfer apparatus according to claim 4, wherein the substrate floating mechanism comprises an air blowing mechanism.   5. The substrate transfer apparatus according to claim 4, wherein the substrate floating mechanism includes an air blowing mechanism and an air suction mechanism.   7. A substrate imaging apparatus, wherein an imaging apparatus is provided on a conveyance path of the substrate conveyance apparatus according to claim 4.

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