JP5176631B2 - Substrate transfer device and substrate inspection device - Google Patents

Description

  The present invention relates to a substrate inspection apparatus for inspecting defects of a substrate for a flat panel display such as a liquid crystal display panel or a plasma display panel, and in particular for stably transporting a large substrate without vertical fluctuation due to vibration or the like. It relates to the device.

  With the recent increase in size and thickness of flat panel displays such as liquid crystal display panels and plasma display panels, as a substrate transport method in the manufacturing process, a conventional method using a roller has been mainly used. For example, various problems such as a substrate colliding with a roller due to bending due to the weight of the substrate being transported, vertical fluctuation during transport, and abrasion due to alignment have become apparent.

  In order to avoid such damage to the substrate, instead of conveyor conveyance using rollers for large substrates with large deflection due to the weight of the substrate and large vertical vibration during conveyance, the front surface of the substrate is lifted by air and made non-contact The technique to convey is used (patent documents 1, 2).

  In addition, in flat panel displays such as color filters, defects and the like are inspected in the manufacturing process. In recent years, screens have become higher in definition, and accordingly, inspection machines themselves are required to have high performance. It has been. For example, when inspecting defects of 5 μm or less, an inspection machine using an ultra-high resolution camera with a resolution of 3 μm or less has become essential from the viewpoint of quality assurance.

  However, the inspection 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 images for inspection, the substrate can be stably transported so as not to deviate from the depth of field. Desired. There is a problem in the substrate conveyance by the rollers that the vertical fluctuation during the conveyance of the substrate is large due to the unevenness of the roller itself and the installation situation due to the contact conveyance, and it is out of the depth of field of the high resolution inspection camera.

  Therefore, as described above, conveyance by air levitation that does not come into contact with the conveyance surface has been performed. The original non-contact air levitation transfer technology only lifted the substrate by blowing out air, so the floating accuracy of the substrate was large, and the vertical fluctuation of the substrate occurred due to the floating unevenness during transfer, and the inspection surface was There was a problem that it was out of the depth of field of the inspection camera. Therefore, as a solution to such a problem related to the floating of the substrate, there is a substrate floating mechanism that suppresses the vertical fluctuation of the floating by the suction force of the air by performing the suction simultaneously with the air blowing, as described in Patent Document 3. It has been developed. With this technology, even when the substrate is levitated with high precision, the non-uniformity of levitating during conveyance can be suppressed to 10 μm, and stable substrate conveyance can be performed.

  Since such a substrate floating mechanism is small, a large amount of the substrate floating mechanism must be used to stably transport a large substrate, and it does not deviate from the depth of field of the inspection camera. The height of the substrate levitation mechanism must be precisely aligned, and when assembling the substrate levitation mechanism into the device, the height is adjusted by inserting a shim or the like between the base plate and the substrate levitation mechanism, or The surface of the plate to be precisely polished is used. For example, if the floating amount of the substrate is 25 μm, the surface of the base plate is polished to about 10 μm and a plurality of substrate floating mechanisms are installed thereon. Has been.

JP 2004-279335 A JP 2006-258632 A JP 2008-7319 A

  However, in the conventional adjustment method, when adjusting the height by sandwiching the shim between the substrate floating mechanism and the base plate, it must be removed from the plate every time the height is adjusted. The problem comes out. Further, when polishing the base plate, there is a problem that the price of the entire apparatus including the processing cost for precise polishing becomes high.

  In view of this fact, the present invention considers such facts, and does not perform the adjustment method using the shim or precise polishing, but reduces the number of steps for assembling the substrate floating mechanism, and the price of the entire apparatus including precise processing. It is an object of the present invention to provide an attachment and height adjustment mechanism for a substrate floating mechanism that can reduce the above-described problem.

According to claim 1, a substrate floating mechanism for levitating a substrate installed in a plate conveying section, a substrate conveying mechanism for conveying the substrate, and a height adjusting mechanism for adjusting the height of the surface of the substrate floating mechanism. A substrate transfer apparatus comprising:
Wherein the substrate surface facing the substrate floating mechanism includes a vent made of a porous body, a suction hole formed as a plurality of holes in the entire area of said surface,
The height adjusting mechanism includes a movable plate that supports the levitation mechanism, a fixed plate installed under the movable plate, and a screw portion having a different pitch on the same axis formed on the two plates. An apparatus for transporting a substrate, comprising: an adjusting screw that is screwed to adjust a clearance between the two plates; and a sealing material that is sandwiched between the clearances.

According to claim 2, wherein the movable plate and the fixed plate is a substrate transfer apparatus according to claim 1, characterized by comprising a vent hole for discharging air from the intake hole of the substrate floating mechanism.

According to claim 3, wherein the sealing material is a substrate transfer apparatus according to claim 2, wherein the an elastic member of rings provided coaxially with the vent hole.

According to claim 4, wherein the movable plate and the fixed plate in the substrate transfer apparatus to 3 according claims 2, characterized in that it comprises a vent hole for supplying air to the vent hole of the substrate floating mechanism is there.

According to a fifth aspect of the present invention, there is provided a substrate inspection apparatus comprising: the substrate conveyance device according to any one of the first to fourth aspects; and a camera for imaging a substrate installed in a substrate conveyance unit of the substrate conveyance device. It is.

  By adopting the above configuration in the present invention, it is possible to reduce the number of steps for assembling the substrate floating mechanism, to improve maintenance by attaching the substrate floating mechanism individually, and to precisely adjust the height independently of the base plate to be mounted. This makes it possible to reduce the price of the entire system, including the processing costs for precision polishing of the base plate.

    FIG. 1 is a configuration diagram of a substrate transfer apparatus of the present invention applied to a substrate inspection apparatus. The substrate transfer apparatus 1 according to the present invention includes a base levitating mechanism 3 that keeps the substrate 2 levitating and maintaining at a constant height by blowing and sucking air, and a height position adjustment that individually adjusts the height of the substrate levitating mechanism 3. A mechanism 4, a substrate gripping mechanism 5 for fixing and holding one end of the substrate 2 protruding from one side surface of the substrate floating mechanism 3, and a side surface of the substrate floating mechanism 3; A substrate transport mechanism 6 that transports the substrate 2 in a direction along the transport direction X, and a levitation controller A that supplies air to the substrate levitation mechanism 3 and sucks air from the substrate levitation mechanism 3. The inspection unit B that performs surface inspection of the substrate 2 is provided.

  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 is a plate-like substance having numerous fine holes, such as porous carbon or It is formed of a metal sintered body or the like. By applying compressed air to the surface 3a through a pipe 10p connected to the internal hollow space 10, a uniform upward air flow 13 can be formed over the entire surface 3a. The upward air flow 13 makes it possible to slightly lift the substrate 2.

  In the substrate levitation mechanism 3, the surface 3a is provided with suction holes 9 having a diameter of about 0.5 to 2 mm at equal intervals or irregular intervals in the range of about 10 to 50 mm. The suction hole 9 is not electrically connected to the hollow space 10 provided in the substrate floating mechanism 3 and is connected to a separately provided hollow space 11, and the internal pressure of the hollow space 11 is reduced through a pipe 11 v. By lowering, air can be sucked from the suction hole 9.

  The air can be blown from the entire surface 3a, and at the same time, the air can be sucked from the suction holes 9 to maintain the flying height of the substrate 2 with high accuracy.

  As shown in FIG. 1, the substrate gripping mechanism 5 in the substrate transport apparatus 1 of the present invention operates at least two block-shaped members in a direction perpendicular to the substrate 2 by an air actuator or the like to clamp and fix the substrate 2. Alternatively, two or more gripping portions 7 are provided for sucking and fixing the substrate by suction pads embedded in a block-shaped member. The substrate gripping mechanism 5 is fixed to a base plate 8 that is an operating part of the substrate transport mechanism 6.

  As shown in FIG. 1, the substrate transport mechanism 6 in the substrate transport apparatus 1 of the present invention is provided adjacent to one side surface of the substrate floating mechanism 3, and moves the substrate 2 along the substrate transport direction X at a constant speed without unevenness. It is a uniaxial transport mechanism for transporting. For example, a combination of a linear motor and a linear guide whose speed fluctuation is small compared to a combination of a servo motor and a ball screw is suitable. However, in the future, when the required accuracy of inspection will increase and this transport mechanism will be applied to an ultra-high resolution inspection machine, it may be possible to combine an air levitation guide with a coreless type linear motor.

  As shown in FIG. 1, the levitation control unit A in the substrate transfer apparatus 1 of the present invention has a compressed air path 25 for supplying compressed air into the substrate levitation mechanism 3 and an exhaust path for sucking and exhausting air from the substrate levitation mechanism 3. 26. In FIG. 1, the levitation control unit A is disposed in the machine-side space of the substrate transfer apparatus 1 for the sake of explanation, but the arrangement position is not particularly limited. Actually, for example, it can be stored under the substrate transfer device or in a separate housing.

  Further, on the upstream side of the compressed air path 25, a pressure adjusting valve 23 for adjusting the supply pressure and a manifold 24 that branches the piping and distributes and supplies the compressed air to the substrate floating mechanism 3 are provided. The exhaust path 26 is provided with a blower pump 21 serving as a power source for air suction and a ball valve 22 for adjusting the suction flow rate on the upstream side. Further, the exhaust path 26 is provided with a chamber 29 having a volume between the ball valve 22 and the substrate floating mechanism, thereby reducing the pressure fluctuation in the substrate floating mechanism. By adjusting the supply pressure and the suction flow rate, the floating accuracy of the substrate on the substrate floating mechanism 3 can be increased.

  As shown in FIG. 1, the inspection section B in the substrate transport apparatus 1 of the present invention includes a beam-shaped member 40 installed so as to straddle the substrate transport mechanism 6 and the substrate floating mechanism 3 in the width direction perpendicular to the transport direction X. The camera device 41 is installed at a predetermined height position from the upper surface of the substrate floating mechanism 3 and irradiates light in the light guide direction of the camera device 41 below the upper surface of the camera floating mechanism 3 and the camera device 41 that images the upper surface of the substrate 2. A light source 42 is provided. Further, the camera device 41 is fixed to the beam-like member 40 via an alignment stage 43 capable of adjusting the position in the direction perpendicular to the substrate transfer surface and adjusting the angle around the rotation axis parallel to the transfer direction X.

  Next, the height position adjusting mechanism 4 will be described with reference to FIGS.

  First, the substrate floating mechanism 3 in the substrate transport apparatus 1 of the present invention includes at least two through-spotted holes 52 that are not electrically connected to the hollow space 10 and the hollow space 11 on the surface 3a thereof. The through screw hole 52 is fixed to the female screw part 51 a of the movable plate 51 by an attachment screw 53. The movable plate supports the substrate floating mechanism and controls the height of the movable substrate by controlling the height of the movable plate. The movable plate 51 has a taper screw portion 51b for attaching a pipe joint 54 for supplying compressed air from the compressed air path 25 to the hollow space 10 in the substrate floating mechanism 3 and between the hollow space 11 in the substrate floating mechanism 3 and the chamber 29. A vent hole 51c is provided to allow the air to pass therethrough. The movable plate 51 is provided with a screw portion 51d for adjusting the height of the upper surface of the substrate floating mechanism 3. Here, as an example, the height and flatness of the substrate floating mechanism 3 are adjusted by three-point support including three screw portions.

  In the height position adjusting mechanism 4, the fixed plate 50 is provided with a screw portion 50 d having a different pitch from the screw portion 51 d on the same axis as the height adjusting screw portion 51 d of the movable plate 51. A hole 50b through which a pipe joint 54 for supplying compressed air to the hollow space 10 in the levitation mechanism 3 is passed, and a vent hole 50c for passing air between the hollow space 11 in the substrate levitation mechanism 3 and the chamber 29 are provided. A hole (not shown) for attaching the fixing plate 50 to the substrate transport apparatus 1 or the chamber 29 is provided.

  In the height position adjusting mechanism 4, an adjustment screw 56 having a male screw portion that is screwed into the screw portion 51 d of the movable plate 51 and the screw portion 50 d of the fixed plate 50 is provided. Here, the female screw portion of the movable plate 51 and the fixed plate 50 and the male screw portion of the adjustment screw 56 are unified as either a right screw or a left screw. In addition, a spring 57, for example, a compression spring, is provided on the adjustment screw 56 between the plates so as to prevent the adjustment screw 56 from loosening due to vibrations of the substrate transfer apparatus 1 between the plates.

  In the height position adjusting mechanism 4, the clearance between both plates is set to block leakage of air sucked from the upper surface 3 a of the substrate floating mechanism coaxially with the vent hole 51 c of the movable plate 51 and the vent hole 50 c of the fixed plate 50. Is provided with a sealing material 58 for forming an air suction path. Specifically, it is a ring-shaped elastic material provided so as to relay both the air holes. Since the air exhausted from the intake hole of the levitation mechanism does not leak between the movable plate and the fixed plate by the sealing material, the suction force of the levitation mechanism can be maintained and conveyance with stable height accuracy is possible. .

  Next, the operation principle of the height position adjusting mechanism 4 in the substrate transfer apparatus 1 of the present invention will be described with reference to FIG. 4 is a schematic cross-sectional view of the height position adjusting mechanism, and the clearance between the movable plate 51 and the fixed plate 50 is exaggerated for easy understanding.

  In the height position adjusting mechanism 4, the height of the movable plate 51 can be adjusted by a pitch difference between the screw portion 50 d of the fixed plate 50 and the screw portion 51 d of the movable plate 51 by rotating the adjustment screw 56 once. it can. For example, when the screw portion 51d of the movable plate 51 is M6 fine pitch 0.75mm and the screw portion 50d of the fixed plate 50 is coarse pitch 0.8mm, the height of the movable plate 51 is adjusted per rotation of the adjusting screw 56. Adjustment with high accuracy of 0.05 mm is possible. For example, by adjusting the height of the three points of the movable plate 51 with the adjusting screw 56 while using a measuring instrument such as a laser displacement meter or a level, the height and level of the upper surface of the substrate plate floating mechanism 3 can be adjusted with high accuracy. And it becomes possible to adjust easily. Further, since the movable plate 51 is always pushed upward by the force of the spring 57, it is not necessary to lock it with a double nut after adjusting the height, and it is possible to always maintain a high positional accuracy. Become.

  As described above, the height position adjusting mechanism 4 is used to reduce the number of assembling steps when attaching the substrate floating mechanism 3 to the substrate transport apparatus 1, for example, every time the height is adjusted unlike when adjusting with a shim or the like. It is possible to unify tools used for adjustment and unify the approach without having to remove the substrate floating mechanism 3 from the apparatus. In addition, since the individual height adjustment can be easily performed by using the height adjusting mechanism 4, the surface accuracy of the base plate 50 to which the substrate floating mechanism 3 is attached is not necessary. That is, it is not necessary to perform a precise polishing process or the like on the base plate 50, and the overall price of the substrate transfer apparatus 1 can be reduced.

The schematic perspective view which shows the Example of the board | substrate conveyance apparatus by this invention Cross-sectional schematic diagram of substrate floating mechanism of substrate transfer device Schematic diagram of the height adjustment mechanism of the substrate transfer device Cross-sectional schematic diagram of the height adjustment mechanism of the substrate transfer device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate conveyance apparatus 2 ... Substrate 3 ... Substrate levitation mechanism 3a ... Surface (substrate levitation mechanism)
4 ... Height position adjustment mechanism 5 ... Substrate gripping mechanism 6 ... Substrate transport mechanism 7 ... Grasping part (Substrate gripping mechanism)
8 ... Base plate 9 ... Suction hole (substrate floating mechanism)
10 ... Hollow space (Substrate levitation mechanism: blowing up)
10p ... Piping (substrate floating mechanism: blowing up)
11 ... Hollow space (substrate floating mechanism: suction)
11v ... Piping (substrate floating mechanism: suction)
13 ... Air flow (substrate floating mechanism: blowing up)
21 ... Blower pump 22 ... Ball valve 23 ... Pressure regulating 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 ... Fixed plate 50b ... Vent hole (pressure air path)
50c ... Vent hole (suction path)
50d ... Screw part 51 ... Movable plate 51a ... Female screw part (attachment of substrate floating mechanism)
51b ... Taper screw part 51c ... Vent hole (suction path)
51d ... Female thread part 52 ... Through counterbore hole (substrate floating mechanism)
53 ... Installation screw 54 ... Pipe joint 56 ... Adjustment screw 57 ... Spring 58 ... Elastic material (seal material)

Claims (5)

A substrate transfer apparatus comprising: a substrate floating mechanism for levitating a substrate installed in a substrate transfer unit; a substrate transfer mechanism for transferring the substrate; and a height adjusting mechanism for adjusting the height of the surface of the substrate floating mechanism. And
Wherein the substrate surface facing the substrate floating mechanism includes a vent made of a porous body, a suction hole formed as a plurality of holes in the entire area of said surface,
The height adjusting mechanism includes a movable plate that supports the levitation mechanism, a fixed plate installed under the movable plate, and a screw portion having a different pitch on the same axis formed on the two plates. An apparatus for transporting a substrate, comprising: an adjusting screw that is screwed to adjust a clearance between the two plates; and a sealing material sandwiched between the clearances.   The substrate transfer apparatus according to claim 1, wherein the movable plate and the fixed plate include a vent hole for discharging air from an intake hole of the substrate floating mechanism.   3. The substrate transfer apparatus according to claim 2, wherein the sealing material is a ring-shaped elastic material provided coaxially with the vent hole.   4. The substrate transfer apparatus according to claim 2, wherein the movable plate and the fixed plate include a vent hole for supplying air to a vent hole of the substrate floating mechanism.   5. A substrate inspection apparatus comprising: the substrate transfer apparatus according to claim 1; and a camera for imaging a substrate installed in a substrate transfer unit of the substrate transfer apparatus.

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