JP2001092530A - Device for correcting position of substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly precisely position a sheet-like substrate without being deflected. SOLUTION: Two position sensors 15, 16 are arranged at a prescribed interval along the side direction of the major side of a substrate 1, a position sensor 17 is arranged on the minor side of the substrate 1 and a difference between the position of the substrate 1 obtained on the basis of respective detection signals outputted from these sensors 15 to 17 and a reference position is found out. A correction variable operation part 23 calculates a correction variable for moving the substrate 1 to the reference position on the basis of the difference and a stage driving part 24 drives an XYθ stage 12 to position the substrate 1 always at the reference position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position of a substrate for holding a fixed position when inspecting various substrates such as a flat panel display such as a liquid crystal display and a plasma display and a printed circuit board used for electronic equipment. The present invention relates to a correction device.

[0002]

2. Description of the Related Art In a manufacturing process of a glass substrate used for a flat panel display such as a liquid crystal display or a plasma display, or a printed circuit board used for an electronic device, a pattern inspection and a defect inspection formed on a substrate surface are performed in a manufacturing process. Will be In these inspections, it is necessary to hold the substrate constant with respect to a preset reference position.

FIG. 7 is a configuration diagram of such a substrate positioning device. The substrate 1 is a printed circuit board for BGS in which die pads and ball pads are wired at high density, and is formed in a quadrilateral thin sheet shape.
The thickness is about 250 mm × 100 mm × 0.1 mm.

The two reference plates 2 and 3 position the substrate 1 at a position for pattern inspection or defect inspection.
The substrates 1 are arranged at predetermined positions so that two sides thereof come into contact with each other.

[0005] Two abutting cylinders 4 and 5 are provided opposite to the reference plates 2 and 3, respectively, and press the substrate 1 to apply the substrate 1 to the reference plates 2 and 3. .

With such a positioning device, the substrate 1 can be applied to each of the reference plates 2 and 3 by using the abutting cylinders 4 and 5, thereby enabling accurate positioning at the verification position.

As another positioning device, a plurality of pins for positioning the BGA printed circuit board 1 at positions for pattern inspection and defect inspection are provided, and these pins are provided with positioning holes formed in the substrate. There is something to set.

[0008]

However, in the above apparatus, since the substrate 1 is applied to each of the reference plates 2 and 3, the size of the printed circuit board 1 and each of the abutting cylinders 4 and 5 are set.
Depending on the magnitude of the contact force, the substrate 1 cannot be positioned at a position for pattern inspection or defect inspection with high precision because the substrate 1 is not applied to each of the reference plates 2 and 3, The substrate 1 may be deformed due to a strong force applied to the substrate 3.

In particular, a glass substrate used for a liquid crystal display or a printed circuit board used for an electronic device is extremely thin and is bent because it is formed in a sheet shape. If the substrate surface is held in a bent state as described above, there arises a problem that accurate inspection cannot be performed in various inspections. In addition, the glass substrate of a flat panel display has a large substrate area of 750 mm × 950 mm. In such a large substrate, the contact area and weight increase, so that the pressing method cannot cope with the pressing force and the pressing force is reduced. If it is strengthened, there is a problem that it is damaged by impact.

On the other hand, in an apparatus using a plurality of pins, since the position of each pin and the size of its diameter differ depending on the type of the printed board 1, another pin is prepared every time the type of the board 1 to be inspected is different. Must be done, and the setup is difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a substrate position correcting apparatus capable of positioning a sheet-like substrate with high accuracy without contact.

[0012]

According to the first aspect of the present invention,
Holding means for holding a quadrilateral substrate, position sensors for detecting at least three positions on two adjacent sides of the substrate, and correction for a reference position of the substrate based on the positions detected by the position sensors And a moving means for calculating the amount and moving the holding means in accordance with the correction amount.

According to a second aspect of the present invention, in the substrate position correcting apparatus of the first aspect, two position sensors are disposed on a long side of two adjacent sides of the substrate, and one position sensor is disposed on a short side.
One position sensor is arranged.

According to a third aspect of the present invention, in the substrate position correcting apparatus according to the first aspect, the position sensor is a line sensor.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a substrate position correcting device, and FIG. 2 is a configuration diagram of the device as viewed from the side. Substrate 1
Examples thereof include a glass substrate used for a flat panel display such as a liquid crystal display and a plasma display, or a printed substrate used for an electronic device. In this embodiment, an example will be described in which a thin seed-shaped printed circuit board such as a BGA printed circuit board in which a die pad and a ball pad are wired at high density is applied.

The vacuum plate 10 has a suction mechanism, and is provided on an XYθ stage 12 via a hollow rotary shaft 11. A plurality of suction holes are formed in the vacuum plate 10, and these suction holes communicate with the hollow holes 13. This hollow hole 13 is connected to a suction device 14. The XYθ stage 12 moves the vacuum plate 10 on the XY plane and rotates in the θ direction as is well known, and includes an X drive motor, a Y drive motor, and a θ drive motor.

The three position sensors 15 to 17 have a function of detecting the position of each adjacent side of the substrate 1 adsorbed on the vacuum plate 10 and outputting a detection signal. Two of the position sensors 15 to 17 are arranged at predetermined intervals along the long side of the substrate 1. Other position sensors 17
It is arranged on the short side of the substrate 1. FIG. 2 shows only the position sensor 16 because of the illustrated relationship.

Each of the position sensors 15 to 17 has a structure in which a light projecting unit 18 and a light receiving unit 19 are arranged opposite to each other as shown in FIG. The light projecting unit 18 is provided with, for example, a semiconductor laser 20 as a light source.
The laser light output from 0 is shaped into parallel light by the lens 21 and emitted. The light receiving section 19 is C
A line sensor 22 in which CDs (solid-state imaging devices) are arranged is provided. This line sensor 22 is arranged in a direction substantially perpendicular to the side direction of the substrate 1. Therefore, these position sensors 15 to 17 detect digitally values where laser light is shielded by the substrate 1 as side positions of the substrate 1.

It is needless to say that if the distance between the position sensors 15 and 16 on the long side with respect to the substrate 1 is set as wide as possible, the position of the long side of the substrate 1 can be detected with high accuracy.

The correction amount calculating section 23 includes the position sensors 15 to
Each of the detection signals output from 17 is input, and the position of the substrate 1 adsorbed on the vacuum plate 10 is obtained from the positions of the long side and the short side of the substrate 1 adjacent to each other obtained from these detection signals. It has a function of calculating a difference between the position of the substrate 1 and a reference position to be sucked in the pattern inspection or the defect inspection of the substrate 1 and calculating a correction amount for moving the substrate 1 to the reference position from the difference. .

The stage driving unit 24 includes a correction amount calculating unit 23
Has the function of driving the X drive motor, the Y drive motor, and the θ drive motor of the XYθ stage 12 according to the correction amount.

Next, the operation of the device configured as described above will be described.

For example, in the manufacturing process of the BGA printed board 1, the board 1 is set on the vacuum plate 10, and the suction device 14 starts a suction operation.

Due to the suction operation of the suction device 14, air is supplied from the plurality of suction holes of the vacuum plate 10 to the rotary shaft 1.
Air is vented through one hollow hole 13. As a result, the substrate 1 is sucked on the vacuum plate 10.

Each of the position sensors 15 to 17 is provided on each side of the substrate 1 adsorbed on the vacuum plate 10.
That is, the two position sensors 15 and 16 detect the position of the long side of the substrate 1 and output their respective detection signals, and the other position sensors 17 detect the position of the short side of the substrate 1 and detect each of them. Output a signal.

The correction amount calculating section 23 includes the position sensors 15 to
The position of the substrate 1 adsorbed on the vacuum plate 10 is determined from the positions of the long side and the short side of the substrate 1 adjacent to each other, which are obtained from these detection signals. A difference from the reference position recorded in the correction amount calculating section 23 is obtained, and a correction amount for moving the substrate 1 to the reference position is calculated from the difference.

The stage driving section 24 includes a correction amount calculating section 23
, The X drive motor, the Y drive motor, and the θ drive motor of the XYθ stage 12 are driven in accordance with the correction amount to adjust the substrate 1 to the reference position.

As a result, the substrate 1 is always held at the reference position, and in this state, a pattern inspection or a defect inspection on the BGA printed board is performed.

As described above, in one embodiment,
Two position sensors 15 and 16 are arranged at a predetermined interval along the long side of the substrate 1 and a position sensor 17 is arranged on the short side of the substrate 1.
Substrate 1 obtained based on each detection signal output from 7
Is calculated from the difference between the reference position and the reference position, and the correction amount for moving the substrate 1 to the reference position is calculated by the correction amount calculation unit 23 from the difference to drive the XYθ stage 12.
In particular, the thin sheet-like substrate 1 having a thickness of about 0.1 mm can always be positioned with high precision, for example, about 5 μm with respect to a reference position without deformation. Thereby, a pattern inspection, a defect inspection, and the like can be performed with high accuracy in the manufacturing process of the substrate 1.

Further, when positioning the substrate 1, since no human hand touches the substrate 1, any sheet-like substrate 1 can be positioned with high accuracy.

The substrate 1 is sucked by the vacuum plate 10 and detected by the position sensors 15 to 17.
XYθ stage 12 based on the difference between the position of
Is feedback-controlled to correct the position of the substrate 1, so that the substrate 1 can be automatically corrected to the reference position without contact.

In addition, since the positioning can be corrected without contact while the substrate 1 is attracted onto the vacuum plate 10, it can be used not only for a lightweight substrate such as a BGA printed circuit board but also for a liquid crystal display or a plasma display.
It is also applicable to PD substrates. When applied to an FPD substrate, the size of this substrate has become extremely large, 750 mm × 950 mm, and the weight has increased accordingly. Vacuum plate 1
Since it is becoming difficult to slide the slider on the zero, it can be easily realized by non-contact positioning correction as in the present invention.

The present invention is not limited to the above embodiment, but may be modified as follows.

For example, the three position sensors 15 to 17
As shown in FIG. 4, the arrangement position may be changed according to the size (size) of the substrate 1. For example, the substrate 1 includes a plurality of types having different sizes such as sizes Q1, Q2, and Q3. For the substrate 1 of size Q1, each position sensor 15
Numerals 16 are the common arrangement positions described above. For the substrate 1 having a size Q2 larger than the size Q1, for example, the position sensor 15 is changed from the position P1 to the position P2, and for the substrate 1 having a larger size Q3, the position sensor 1 is changed.
5 is changed from the position P1 to the position P3. Position P
2, the position sensor may be fixed to P3.

Further, as shown in FIG.
The position of the substrate 1 may be detected by 5 and 16. In this case, the position sensors 15 and 16 are respectively disposed on the long side and the short side of the substrate 1, and the position sensor 15 on the long side is provided movably in the long side direction of the substrate 1.
The movement of the position sensor 15 can be realized by providing the movement mechanism 30.

With such a configuration, the position sensor 15
Is moved from the position P10 to the position P11 to detect two predetermined long sides of the substrate 1 and the position sensor 17
It is sufficient to detect one point on the short side of. In this case, if the movement of the position sensor 15 is set according to the size of the substrate, it is possible to cope with substrates of many sizes.

Further, as shown in FIG. 6, in the substrate manufacturing process, it is possible to detect the positions of the long side and the short side of the substrate 1 using the two position sensors 15 and 17 during the transfer of the substrate 1. Good. In this case, the transport position of the substrate 1 being transported is detected by the detection timing unit 31, and when the substrate reaches the transport position S1 as shown in FIG. 6B, the position of the long side and the short side of the substrate 1 are detected by the position sensors 15 and 17 when the substrate is transported and reaches the transport position S2 as shown in FIG. 6B. Becomes Also in this case, by adjusting the detection timing of the position sensor 15 according to the substrate size, it is possible to cope with substrates of various sizes.

As a substrate, any glass substrate used for a flat panel display such as a liquid crystal display or a plasma display, or a substrate requiring high-precision positioning, such as a printed circuit board used for an electronic device, can be used. it can.

[0040]

As described above in detail, according to the present invention, it is possible to provide a substrate position correcting apparatus capable of accurately positioning a sheet-like substrate without bending.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a substrate position correcting apparatus according to the present invention.

FIG. 2 is a side view of a configuration of a substrate position correcting apparatus according to an embodiment of the present invention.

FIG. 3 is a configuration diagram of a position sensor in one embodiment of the substrate position correction device according to the present invention.

FIG. 4 is a diagram showing an arrangement position of a position sensor according to a size of a substrate in another embodiment of the substrate position correcting apparatus according to the present invention.

FIG. 5 is a diagram showing an operation of detecting a position of a substrate when two position sensors are used in another embodiment of the device for correcting the position of a substrate according to the present invention.

FIG. 6 is a diagram showing an operation of detecting the position of a substrate during conveyance in another embodiment of the substrate position correcting apparatus according to the present invention.

FIG. 7 is a configuration diagram of a conventional substrate positioning device.

[Explanation of symbols]

 1: substrate, 10: vacuum plate, 11: rotary shaft, 12: XYθ stage, 13: hollow hole, 14: suction device, 15 to 17: position sensor, 18: light emitting part, 19: light receiving part, 20: semiconductor Laser, 21: lens, 22: line sensor, 23: correction amount calculation unit, 24: stage drive unit, 30: moving mechanism, 31: detection timing unit.

Claims (3)

[Claims] 1. A holding means for holding a quadrilateral substrate; a position sensor for detecting at least three positions on two adjacent sides of the substrate; and a position sensor based on each position detected by the position sensor. Moving means for obtaining a correction amount for a reference position of the substrate and moving the holding means in accordance with the correction amount; 2. The device according to claim 1, wherein two position sensors are arranged on a long side of two adjacent sides of the substrate, and one position sensor is arranged on a short side. Substrate position correction device. 3. The substrate position correcting device according to claim 1, wherein said position sensor is a line sensor.