WO2012039252A1

WO2012039252A1 - Wafer inspecting apparatus

Info

Publication number: WO2012039252A1
Application number: PCT/JP2011/069869
Authority: WO
Inventors: 月本浩明; 佐藤裕史; 池田早人; 藤田大輔
Original assignee: タツモ株式会社
Priority date: 2010-09-21
Filing date: 2011-09-01
Publication date: 2012-03-29
Also published as: TW201214611A; JPWO2012039252A1

Abstract

A wafer inspecting apparatus (1) is mainly provided with a transfer mechanism, detecting mechanisms, and a sucking/rotating mechanism. The transfer mechanism transfers a rectangular wafer (10) by placing the wafer on transfer paths (2A, 2B). The detecting mechanisms (4A-4D) are provided in pairs with the transfer mechanism between the pairs, and detect the state of the wafer. The sucking/rotating mechanism (5) is provided with four suction chucks (52A-52D), sucks the wafer (10) between the two pairs of detecting mechanisms, said wafer being on the transfer paths (2A, 2B), and returns the wafer onto the transfer paths (2A, 2B) after turning the wafer 90°.

Description

Wafer inspection equipment

The present invention relates to an inspection apparatus for inspecting a wafer end face for defects.

Conventionally, a transfer mechanism for transferring a wafer to a predetermined position has been proposed in order to inspect the wafer and the like. For example, Patent Document 1 discloses a conveyance mechanism that includes a pair of conveyance belts that extend in parallel with a gap and a conveyance roller that rotationally drives the conveyance belt at the same speed.

In recent years, demand for solar cells has increased due to environmental considerations. As for the cell of a solar cell, what is formed on the wafer (glass substrate) cut out to the rectangle is common. A wafer may have a defect on the cut end surface. In order to improve the cell yield, it is desirable to inspect such a defect on the end surface of the wafer in advance to remove defective defective products.

FIG. 4 shows an example of a conventional apparatus that automates the inspection of defects on the wafer end face. This conventional wafer inspection apparatus 101 includes, as a transport mechanism, a pair of

transport belts

102A and 102B extending in parallel with a gap therebetween, and a plurality of transport rollers 103 that rotationally drive the

transport belts

102A and 102B at the same speed. Yes. When one of the transport rollers 103 is rotationally driven by a motor (not shown), the

transport belts

102A and 102B are rotated in the same direction, and the other transport rollers 103 are rotated following the rotation, whereby the

transport belts

102A and 102B are rotated. 102B moves. Thereby, the wafer 110 placed on the

transport belts

102A and 102B is transported in the direction of arrow X (hereinafter referred to as “transport direction”).

Since the wafer 110 is formed in a rectangular shape in plan view, the wafer 110 has

end faces

111, 112, 113, and 114 on four sides. The positional relationship between the end faces 111 to 114 is an arrangement in which two opposing end faces (hereinafter referred to as “end face pairs”) 111, 113 and 112, 114 are orthogonal to each other. In such an end face arrangement, the wafer 110 is arranged such that one

end face pair

112, 114 faces the transport direction X and the other

end face pair

111, 113 faces the direction orthogonal to the transport direction X. 102B is conveyed.

In addition, two pairs of image sensors (hereinafter referred to as “image sensor pairs”) 104A, 104B and 104C, 104D are disposed opposite to each other in the direction orthogonal to the transport direction X in the middle of the transport path. One

imaging element pair

104A, 104B and the other

imaging element pair

104C, 104D are installed with a gap in the transport direction X.

The operation of wafer inspection by the conventional wafer inspection apparatus 101 configured as described above will be described. First, the

imaging device pair

104A, 104B on the upstream side in the transport direction X is used to image each of the pair of

end faces

111, 113 of the wafer 110 that has been transported, and the end face images are displayed on a display device such as a monitor (not shown). indicate. The image is visually inspected for defects.

Thereafter, the transport mechanism (

transport belts

102A and 102B, transport roller 103) is temporarily stopped. Then, a suction stage (not shown) installed between the

transport belts

102A and 102B as viewed from above in the transport direction X is lifted and sucked, rotated by 90 ° as indicated by an arrow V, and the suction stage is lowered to lower the transport belt 102A. , 102B, move the transfer mechanism, and image the other

end face pair

111, 114 of the wafer 110 using the image

pickup element pair

104E, 104F on the upstream side in the transfer direction X, respectively. Perform the inspection.

As shown in FIG. 4, the

image sensor pair

104E, 104F facing the transport direction A is provided, and after the

image sensor pair

104A, 104B images one

end face pair

112, 114 as described above, the transport mechanism (

Conveyor belts

102A and 102B, Conveyor roller 103) are temporarily stopped, image

pickup element pairs

104E and 104F are moved to positions indicated by dotted lines in FIG. 4, and image pickup of

end face pairs

112 and 114 is performed without rotating wafer 110. There was also something to do.

Japanese Unexamined Patent Publication No. 2000-12652

However, the conventional wafer inspection apparatus 101 described above has a problem that the number of wafers processed per unit time is reduced because the transport mechanism must be temporarily stopped in order to inspect the end surface defects on the four sides of the wafer. It was.

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an inspection apparatus capable of detecting the state of a wafer by changing the posture of the wafer without stopping the transfer mechanism.

In order to achieve the above object, the wafer inspection apparatus according to the present invention mainly includes a transfer mechanism, a detection mechanism, and a suction rotation mechanism.

The transfer mechanism is configured to transfer the wafer on the transfer path.

The detection mechanism is configured to detect the state of the wafer.

The suction rotation mechanism is configured to suck and rotate the wafer from the transfer path and then return it to the transfer path again.

According to the wafer inspection apparatus configured as described above, the posture of the wafer is changed by the suction rotation mechanism while the wafer is transferred by the transfer mechanism.

According to the present invention, the wafer state can be detected by changing the posture of the wafer without stopping the transfer mechanism. Accordingly, the number of processed wafers per unit time increases, and the unit price of the product can be reduced accordingly.

1 is a schematic plan view showing a wafer inspection apparatus according to an embodiment of the present invention. It is a schematic sectional drawing which shows a wafer inspection apparatus same as the above. It is a schematic plan view explaining the test | inspection operation | movement by a wafer test | inspection apparatus same as the above. It is a schematic plan view which shows the wafer inspection apparatus which concerns on a prior art example.

A schematic configuration of a wafer inspection apparatus according to an embodiment of the present invention will be described with reference to FIGS. The wafer inspection apparatus 1 shown in FIG. 1 and FIG. 2 mainly includes a transport mechanism, two

image sensor pairs

4A, 4B and 4C, 4D, and an adsorption rotation mechanism 5.

The transfer mechanism is configured to transfer the wafer 10 on a transfer path (referred to as an area sandwiched between the

transfer belts

2A and 2B). Specifically, the transport mechanism includes a pair of

transport belts

2A and 2B extending in parallel with a gap therebetween, and a plurality of transport rollers 3 that rotationally drive the

transport belts

2A and 2B at the same speed. When one of the transport rollers 3 is rotationally driven by a motor (not shown), the

transport belts

2A and 2B are rotated in the same direction, and the other transport rollers 3 are rotated following the rotation, whereby the

transport belts

2A and 2B are rotated. 2B moves. Thereby, the wafer 10 placed on the

transport belts

2A and 2B is transported in the direction of the arrow X (hereinafter referred to as “transport direction”). FIG. 1 shows a state in which two wafers 10-1 and 10-2 are continuously transferred. As described above, the wafer is continuously transferred at a predetermined interval without stopping the transfer mechanism.

The wafer 10 has a planar shape cut out into a rectangle, and is used, for example, for a glass substrate of a solar battery cell. Since the wafer 10 is formed in a rectangular shape in plan view, the wafer 10 has

end faces

11, 12, 13, and 14 on four sides. The positional relationship between the end faces 11 to 14 is such that two opposing pair of end faces (hereinafter referred to as “end face pairs”) 11, 13 and 12, 14 are orthogonal to each other. In such an end face arrangement, the wafer 10 is transported upstream from the suction rotation mechanism 5 described later, and one

end face pair

12, 14 faces the transport direction X, and the other

end face pair

11, 13 is transported on the transport path so as to face the direction orthogonal to the transport direction X.

The two image sensor pairs 4A, 4B and 4C, 4D face each other in the direction orthogonal to the transfer direction X, are spaced apart from each other in the transfer direction X, and end face pairs of the wafer 10 (direction orthogonal to the transfer direction X) The pair of end faces facing each other) is imaged.

The suction rotation mechanism 5 is installed between the two

imaging element pairs

4A, 4B and 4C, 4D in the transport direction X, and is configured to suck the wafer 10 from the transport path, rotate it 90 °, and then return it to the transport path again. Is done.

Specifically, as shown in FIG. 2, the suction rotation mechanism 5 mainly includes a rotary plate 51, a stepping motor 57, an encoder 58, suction chucks 52A to 52D, and a suction device.

The rotating plate 51 is formed in a cross-shaped planar shape including four equal-length arms 511 to 514 that are equally spaced by 90 ° as viewed from above. The rotating plate 51 is rotatably disposed above the

conveyor belts

2A and 2B. The rotation center of the rotating plate 51 is positioned so that the tip ends of the two arms (511 and 512 in the example of FIG. 1) are positioned just above the conveyance path.

Each of the four

chucks

52A, 52B, 52C, 52D is attached to the lower surface of the tip of each

arm

511, 512, 513, 514. As a result, as shown in FIG. 1, the chucks 52A to 52D for suction are provided in an arrangement that is equally spaced by 90 ° when the rotary plate 51 is viewed from above, and two chucks for suction (in the example of FIG. 1, 52A and 52B.) Are located immediately above the conveyance path. When the rotating plate 51 rotates, the chucks 52A to 52D for suction rotate on a circumferential path.

The motor 57 is configured to rotationally drive the rotary plate 51 using a drive shaft 571. The motor 57 is installed below the rotating plate 51. The motor 57 is fixed in the motor housing 16 with bolts. Further, the motor housing 16 is fixed to a fixing base (not shown) by a bolt 25 with bolts. As a result, vibration generated when the motor 25 is driven can be absorbed.

As a specific example of the motor 57, a stepping motor can be suitably used. The drive shaft 571 of the motor 57 is connected to the bearing 7 via the coupling 6A. The bearing 7 is fixed to the center portion of the lower surface of the rotating plate 51. The bearing 7 is attached to the frame 23. The frame 23 is fixed to the flange 25 by a flange 24 with bolts. As a result, vibration generated when the motor 25 is driven can be absorbed.

The encoder 58 is configured to control the motor 57 so that the rotation angle of the rotating plate 51 is 90 °. For example, the motor 57 is controlled so as to regulate the number of steps of the stepping motor. The encoder 58 is attached to the lower end of the motor 57 using a coupling 6B so as to be coaxial with the drive shaft 571.

The suction device has an electric blower 56, intake pipes 53A to 53D, 54A to 54D, and an intake duct 55.

As the electric blower 56, a known one that generates air for suction can be used.

The

intake pipes

53A, 53B, 53C, 53D are arranged radially from the center of the rotating plate 51. The

intake pipes

53A, 53B, 53C, and 53D are installed along the longitudinal direction on the

arms

511, 512, 513, and 514, respectively.

The intake pipes 54 </ b> A, 54 </ b> B, 54 </ b> C, 54 </ b> D are vertically installed at the center of the rotating plate 51. A disk-shaped support base 26 is fixed to the center of the upper surface of the rotating plate 51, and the

intake pipes

54A, 54B, 54C, 54D are arranged at 90 ° intervals when the rotating plate 51 is viewed from above. It is fixed with.

The inner ends of the

intake pipes

53A, 53B, 53C, and 53D are connected to the lower ends of the

intake pipes

54A, 54B, 54C, and 54D using joints. The outer ends of the

intake pipes

53A, 53B, 53C, 53D are bent downward by 90 ° and connected to the suction chucks 52A, 52B, 52C, 52D using joints.

2, what is denoted by reference numeral 21 is an L-shaped support member that is fixed to a fixing base (not shown) with a bolt and extends to above the center of the rotating plate 51. A rotating disk 22 is rotatably supported at the tip of the support member 21.

The intake duct 55 is inserted into the support member 21. One end of the intake duct is connected to the electric blower 56 described above.

The upper ends of the above-described

intake pipes

54A, 54B, 54C, 54D are connected, and are connected to the other end of the intake duct 55 via a seal member so as to be rotatable via a turntable 22. When the rotating plate 51 rotates, the intake pipes 53A to 53D and 54A to 54D also rotate.

Next, the wafer inspection operation of wafer inspection apparatus 1 according to the present embodiment configured as described above will be described with reference to FIG. First, one

end face pair

11 and 13 of the wafer 10 is imaged by the upstream

imaging element pair

4A and 4B in the transport direction X while the wafer 10 is transported by the transport mechanism.

Thereafter, the electric blower 56 is driven, and suction air is generated in the suction chucks 52A to 52D through the intake duct 55, the intake pipes 54A to 54D, and 53A to 53D, as indicated by an arrow S in FIG. Therefore, by generating this suction air, the wafer 10 is sucked from the transport path by the chucking chuck 52A.

Thereafter, when the motor 57 is driven, the rotating plate 51 rotates, so that the wafer 10 sucked by the chucking chuck 52A can be moved in the rotating direction of the rotating plate 51 along a circumferential path. Since the encoder 58 regulates the rotation angle of the rotating plate 51 to 90 °, as shown by an arrow T in FIG. 3A, the wafer 10 is counterclockwise so as to draw a 90 ° arc. Moving. That is, as shown in FIG. 3B, the wafer 10 moves to the place where the chuck 52B for the suction originally existed and is positioned on the transfer path again. At this time, the orientation of the wafer 10 is also inverted by 90 °, and the other

end face pair

12, 14 is opposed to the direction orthogonal to the transport direction X.

Thereafter, when the electric blower 56 is stopped, the suction air that has adsorbed the wafer 10 does not work, and the wafer 10 falls on the transfer path by its own weight. The wafer 10 is transferred on the transfer path as it is.

Then, the other end face pairs 12 and 14 of the wafer 10 are imaged by the imaging element pairs 4C and 4D on the downstream side in the transport direction X. Since the captured end face image is displayed on a display device such as a monitor (not shown), the image is visually confirmed to check for defects.

Therefore, according to the wafer inspection apparatus 1 according to the present embodiment, it is possible to inspect defects on the four end faces of the wafer 10 without stopping the transfer mechanism. Therefore, the number of wafers processed per unit time increases, and the unit price of the solar battery cell can be reduced accordingly.

In the above embodiment, suction air is generated from all the suction chucks 52A to 52D, but only the necessary suction chuck is provided by providing an electromagnetic valve in each suction pipe connected to each suction chuck. The opening and closing of the electromagnetic valve may be controlled so that suction air is generated from the air.

In the control of driving / stopping the electric blower 56 and the motor 57, since the transport speed of the

transport belts

2A and 2B is always constant, the interval between the wafers 10 to be transported one after another is made constant by the automatic delivery mechanism. May be intermittent driving using a timer. In addition, a position sensor that detects the position of the wafer 10 may be provided in the transfer path, and control may be performed based on the position information of the wafer 10. In this case, line malfunctions are reduced and productivity is improved.

In the above-described embodiment, image diagnosis using an image sensor is used to detect the state of the end face of the wafer. However, contact inspection such as probe inspection may be used.

The description of the above-described embodiment is an example in all respects, and should be considered as not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

1-

wafer inspection apparatus

2A, 2B-conveying belt 3-conveying

roller

4A, 4B, 4C, 4D-imaging device 5-adsorption rotating mechanism 51-rotating

plate

52A, 52B, 52C, 52D-

adsorption chuck

53A, 53B, 53C , 53D-

Suction pipe

54A, 54B, 54C, 54D-Suction pipe 55-Suction duct 56-Electric blower 57-Motor 58-Encoder

Claims

A transport mechanism for transporting a wafer whose plane shape is cut into a rectangular shape on the transport path;
A detection mechanism for detecting the state of the wafer;
An adsorption rotation mechanism for adsorbing and rotating the wafer from the conveyance path and returning it to the conveyance path again;
A wafer inspection apparatus comprising:
A transport mechanism for transporting a wafer whose plane shape is cut into a rectangular shape on the transport path;
Two imaging element pairs facing each other in a direction perpendicular to the transport direction and spaced apart from each other in the transport direction, and imaging each of the pair of end faces of the wafer;
An adsorption rotation mechanism that is installed between the two image sensor pairs in the conveyance direction, adsorbs the wafer from the conveyance path, rotates the wafer by 90 °, and returns the wafer to the conveyance path again;
The image pickup device pair on the upstream side in the transfer direction images each of the one end face pair of the wafer while the wafer is transferred by the transfer mechanism, and then the wafer is rotated by 90 ° by the suction rotation mechanism. A wafer inspection apparatus characterized in that each of the other pair of end faces of the wafer is imaged by the imaging element pair on the downstream side in the transport direction.
The adsorption rotation mechanism is
A rotating plate rotatably disposed above the conveying path;
A motor for rotating the rotating plate;
An encoder that controls the motor so that the rotation angle of the rotating plate is 90 °;
Four suction chucks equally spaced 90 ° on the lower surface of the rotating plate and sucking the wafer;
A suction device for sucking air through the chuck for suction;
The wafer inspection apparatus according to claim 2, further comprising:
The wafer inspection apparatus according to claim 3, wherein two of the chucks for suction are located immediately above the transfer path.
The said rotary plate is formed in the cross shape provided with the four arms equally distributed at 90 degrees, and each of the said 4 chuck | sucking chucks was attached to the front-end | tip part of each arm. Wafer inspection equipment.
6. The wafer inspection apparatus according to claim 1, wherein the wafer is a glass substrate for a solar battery cell.