JP2011255292A - Positioning method, positioning device, droplet application method, liquid application apparatus, and reference plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely position a substrate even when the precise position of an alignment mark is unknown in the positioning of the substrate provided with the alignment mark.SOLUTION: A reference plate provided with an alignment mark positioned in the same position as that of the alignment mark in the substrate 2 is positioned. The position of the alignment mark in the positioned reference plate is measured and the substrate is positioned so that the alignment mark of the substrate is positioned in the same position as that of the measured alignment mark.

Description

  The present invention relates to a technique for positioning a substrate on a mounting table.

  In recent years, the droplet coating technique is expected to be used not only as a printer device for forming an image on a paper medium but also as a manufacturing device. In addition to the production of solar cells by using inkjet technology, the production of color filters such as liquid crystal display devices and organic EL display devices, and the production of various electronic devices and optical devices are performed. Considering such applied technology, in addition to the performance of the ink jet head itself, high accuracy is required for the posture adjustment of the sample to be processed, that is, the mechanism / method of alignment processing.

  In the alignment process, the posture is adjusted so that the alignment mark attached to the sample to be processed is at a predetermined position. Therefore, it is necessary to attach an alignment mark to the sample to be processed. When the sample to be processed is a solar cell, it is desirable to provide two alignment marks on the diagonal of the substrate of the solar cell that is the sample to be processed. In this case, compared with the case where three or more alignment marks are provided, the area for forming the alignment marks can be reduced, so that the area capable of generating power can be increased. Further, when positioned diagonally, the distance between the alignment marks can be increased, so that the substrate can be arranged with high accuracy and droplet application can be performed with high accuracy.

  As a general alignment technique, Patent Document 1 discloses a technique for easily and accurately calibrating the position of an alignment scope using a reference mask.

  FIG. 7 is a perspective view for explaining the outline of the printed circuit board manufacturing apparatus described in Patent Document 1. FIG.

  A pair of linear guides 103 is disposed on the upper surface of the base 101, and a feed screw 109 that is rotationally driven by a servo motor 107 is disposed between the linear guides 103. A drawing stage 105 is screwed to the feed screw 109 at its lower part. The drawing stage 105 includes a rotation mechanism (not shown) for rotating the mounting table 115 around the vertical z axis. The mounting table 115 is for mounting the printed circuit board S (processing object) on the top.

  A reference mask RM is disposed on the upper surface of the mounting table 115, and a suction table 117 is disposed thereon. On the upper surface of the reference mask RM, a grid-like reference pattern PR is formed over the entire surface.

  In the y direction (sub-scanning direction) in which the drawing stage 105 is moved by driving the servo motor 107, the drawing laser beam LB is deflected downward in the x direction (main scanning direction) at the processing position EP. An irradiation processing unit 121 is disposed. The processing unit 121 is disposed on the upper part of the base 101 with a portal frame, and the drawing stage 105 moves forward and backward with respect to the processing unit 121 when the servo motor 107 is driven.

  The base 101 is provided with an alignment scope unit (not shown) so as to cover the upper part of the drawing stage 105 at the standby position. The alignment scope unit includes four alignment scopes 133, 135, 137, and 139 that can move independently within a horizontal plane. Each alignment scope 133, 135, 137, 139 includes a CCD camera and a lens unit.

  The deviation between the field center of the field image captured by the CCD camera of the alignment scope and the intersection of the reference pattern PR at a predetermined position is obtained in the x direction (Δx) and the y direction (Δy). That is, even when the position of the alignment scope is displaced for some reason, the amount of displacement from that position is stored with reference to the reference pattern PR of the reference mask RM that is position-invariant in design. Therefore, if this “position shift amount” is read and corrected accordingly, the actual position at the center of the visual field of the alignment scope can be accurately determined.

  The printed circuit board S is placed on the placement table 115 by a loader (not shown), and the board S is sucked and held by vacuum suction. Each alignment scope 133, 135, 137, and 139 moves above the reference holes formed at the four corners based on the CAD data of the substrate S. The positions of the reference holes at the four corners are measured by image processing, the center of gravity is obtained to determine the mounting posture of the printed circuit board S, and the mounting table 115 is moved in the θ direction corresponding to the rotation direction around the z axis accordingly. After being rotated and parallel to the laser beam LB, a drawing process is performed at the processing position EP while moving toward the processing unit 121.

  The reference mask RM may be detachable instead of being disposed on the mounting table 115 at a fixed position.

JP 2000-329523 (released on November 30, 2000)

  In the printed circuit board manufacturing apparatus described in Patent Document 1, if the position of the alignment mark (reference hole in Patent Document 1) is different from the position in the CAD data, an error occurs in alignment. In this case, even if the mounting table 115 is rotated based on the position of the alignment mark, the substrate (the printed circuit board S in Patent Document 1) is not parallel to the scanning direction of the laser beam LB and is in a misaligned state. Thus, the processing is performed.

  The present invention has been made in view of such circumstances, and a positioning method, a positioning device, and the positioning that accurately align a substrate even when the exact position of an alignment mark on the substrate is unknown. A reference plate provided for the method is provided.

  It is another object of the present invention to provide a droplet coating method and a droplet coating apparatus that perform droplet coating accurately on a desired position on a substrate.

  Further, when alignment marks are provided only at two diagonal points of the substrate, the linear direction connecting the two alignment marks does not coincide with the scanning direction of droplet application. When alignment marks are arranged in the scanning direction, the alignment camera (alignment scope in Patent Document 1) and the substrate are moved relative to each other in the scanning direction, and a plurality of alignment marks are sequentially captured at the center of the visual field of the alignment camera. Whether or not the deviation in the θ direction can be accurately detected. However, when there are alignment marks only at two diagonal points of the substrate, the above method cannot be used, and the deviation in the θ direction cannot be detected accurately.

  In order to solve the above-described problems, a positioning method of the present invention is a positioning method for positioning a substrate including an alignment mark, and positioning a reference plate including the alignment mark at the same position as the alignment mark on the substrate. Then, the position of the alignment mark on the positioned reference plate is measured, and the substrate is positioned so that the alignment mark of the substrate is positioned at the same position as the position of the measured alignment mark.

  The droplet coating method of the present invention is a droplet coating method for performing droplet coating on a substrate having an alignment mark, and positioning a reference plate having the alignment mark at the same position as the alignment mark on the substrate. And measuring the position of the alignment mark on the positioned reference plate, positioning the substrate so that the alignment mark of the substrate is positioned at the same position as the measured alignment mark, and positioning the substrate Applying droplets to the substrate.

  Further, the droplet application is a process performed by scanning a local application on the workpiece, and the positioning of the reference plate according to the droplet application method includes two feature points of the reference plate: Position them so that they line up in the scanning direction.

  The reference plate is positioned using an observation unit, and the observation unit from the position of the observation unit in the detection of the position of the first feature point to the position of the observation unit in the detection of the position of the second feature point. Is moved using the scanning means related to the scanning.

  The positioning device of the present invention is a positioning device for positioning a substrate having an alignment mark, the mounting table on which the substrate and the reference plate are mounted, the attitude adjusting unit for adjusting the orientation of the mounting table, and the substrate And an alignment camera that detects the position of the alignment mark provided on the reference plate, and an observation unit that detects the position of the feature point provided on the reference plate.

  The droplet coating apparatus of the present invention is a droplet coating apparatus that applies droplets to a substrate having an alignment mark, and adjusts the orientation of the mounting table on which the substrate and the reference plate are mounted, and the mounting table described above. An attitude adjustment unit, an alignment camera that detects the positions of alignment marks provided on the substrate and the reference plate, an observation unit that detects the positions of feature points provided on the reference plate, and a substrate placed on the mounting table. A droplet discharge unit that performs droplet application.

  Further, the reference plate of the present invention is a reference plate used in a droplet application method for applying droplets to a substrate provided with an alignment mark, and includes an alignment mark at the same position as the alignment mark provided in the substrate, And a reference pattern having two or more feature points.

  The substrate can be accurately positioned. Further, it is possible to accurately apply droplets to a desired position on the substrate.

FIG. 3 is a top view of the droplet applying apparatus according to the present embodiment. The side view of the droplet coating device which concerns on this Embodiment. The top view of the board | substrate which concerns on this Embodiment. The top view of the reference | standard board which concerns on this Embodiment. The processing flow figure concerning this Embodiment. The processing flow figure concerning this Embodiment. The perspective view with which it uses for outline | summary description of the printed circuit board manufacturing apparatus of a prior art.

  Hereinafter, embodiments for carrying out the present invention will be described in detail.

  The positioning device according to the present embodiment is a droplet coating device that is used in a production process for forming electrode wirings related to solar cells by droplet coating.

  FIG. 1 is a top view of the droplet applying apparatus according to the present embodiment.

  FIG. 2 is a side view of the droplet applying apparatus according to the present embodiment. The droplet applying apparatus according to the present embodiment includes a mounting table 5 for mounting a substrate 2 that is a solar battery cell, and a gantry 6 positioned above the mounting table 5. A guide rail 7 is fixed to the side surface of the gantry 6 with the Y direction as a longitudinal direction. The guide rail 7 is equipped with a droplet discharge unit 3 which is a droplet discharge unit and an alignment camera unit 8, and can move in the Y direction along the guide rail 7. The alignment camera unit 8 includes an alignment camera 9A, an alignment camera 9B, and an observation camera 9C as an observation unit. The observation camera 9C is configured to be movable in the X direction with respect to the alignment camera unit 8. In this embodiment, the height direction is expressed as the Z direction, the movement direction of the droplet discharge unit 3 and the alignment camera unit 8 is expressed as the Y direction, and the direction orthogonal to the Z direction and the Y direction is expressed as the X direction.

  The droplet applying apparatus according to this embodiment includes a substrate transfer robot (not shown) that places the substrate 2 on the mounting table 5.

  The mounting table 5 is installed on the attitude adjusting unit 5a. The attitude adjustment unit 5a can translate the mounting table 5 in the X direction or the Y direction, or perform θ rotation that is a rotational movement about an axis parallel to the Z axis. Further, the upper part of the mounting table 5 is a suction table 5b, which can fix the substrate 2 and a reference plate 20 (described later) by suction.

  The droplet discharge unit 3 includes a droplet discharge head 11. The droplet discharge unit 3 can discharge droplets from the droplet discharge head 11 and perform droplet application on the substrate 2. The droplet application of the present embodiment is a local application to the substrate 2, and a desired movement on the substrate 2 is performed by discharging the droplet by moving the droplet discharge unit 3 and the substrate 2 relatively. It is possible to apply accurately to the position. The movement is performed by moving the droplet discharge unit 3 along the guide rail 7 in the Y direction. In this specification, this movement is called “scanning”. The means for performing the scanning is referred to as “scanning means”. In this embodiment, the guide rail 7 or the like corresponds to the scanning unit.

  FIG. 3 is a top view of the substrate 2 before being processed by the droplet applying apparatus of this embodiment. In FIG. 3, the y direction indicates a direction to be arranged in parallel with the Y direction, which is the moving direction of the droplet discharge unit 3. The x direction is a direction orthogonal to the y direction in the top view. In the substrate 2, alignment marks 2a and 2b are formed in the vicinity of the two opposite corners. Although there may be more than two alignment marks, it is desirable that there are two diagonals as shown in FIG. In the case of two, since the area for forming the alignment mark can be reduced as compared with the case of three or more, in this embodiment in which the substrate 2 is a solar battery cell, the area capable of generating power is widened. can do. Further, when positioned diagonally, the distance between the alignment marks can be increased, so that the detection accuracy in the θ direction can be increased, the substrate 2 can be arranged with high accuracy, and droplet application can be performed with high accuracy. Can do.

  FIG. 4 is a top view of the reference plate 20. The y direction and x direction in FIG. 4 are the same as the y direction and x direction in FIG. The reference plate 20 includes an alignment mark 20a and an alignment mark 20b. The positions of the alignment marks 20a and 20b on the reference plate 20 are the same as the positions of the alignment marks 2a and 2b on the substrate 2. The reference plate 20 includes a reference pattern 20c having two or more feature points that can be observed by the observation camera 9C. The reference pattern 20c is a grid pattern. The feature point P1 and the feature point P2 are intersections in the reference pattern 20c, and are arranged side by side in the y direction. In addition, in order to make the position of alignment mark 20a and alignment mark 20b the same as the position of alignment mark 2a and alignment mark 2b, the formation method of alignment mark 20a and alignment mark 20b, and the formation method of alignment mark 2a and alignment mark 2b, Are preferably the same. Further, it is desirable that the reference plate 20 is made of the same material as the substrate 2.

  FIG. 5 is a process flow diagram of a droplet coating method that is a positioning method and a droplet coating method according to the present embodiment. The processing flow of the present embodiment will be described with reference to FIG.

  First, the substrate transfer robot places the reference plate 20 on the placement table 5 (S1). The reference plate 20 is preferably the same shape as the substrate 2. When the reference plate 20 has the same shape as the substrate 2, the reference plate 20 can be easily transported using the substrate transport robot that transports the substrate 2 and placed on the mounting table 5. The placed reference plate 20 is sucked and fixed by the suction stand 5b.

  Next, the reference plate 20 is positioned (S2). Specifically, the attitude adjustment unit 5a is operated, and the reference plate 20 is moved and positioned so that the scanning direction of droplet application by the droplet discharge unit 3 coincides with the coordinate axis direction in the reference pattern 20c.

  Next, the positions of the alignment marks 20a and 20b on the reference plate 20 are measured (S3). The measurement is performed using the alignment camera 9A and the alignment camera 9B.

  Next, the reference plate 20 is carried out (S4). Unloading is performed by the substrate transfer robot.

  Next, the board | substrate 2 is carried in and it mounts on the mounting base 5 (S5). Loading and placing are performed by a substrate transfer robot. The placed substrate 2 is sucked and fixed by the suction stand 5b.

  Next, the substrate 2 is positioned (S6). Specifically, the posture adjusting unit 5a is operated, and the substrate 2 is placed so that the positions of the alignment marks 2a and 2b of the substrate 2 are the same as the positions of the alignment marks 20a and 20b measured in S3. Move.

  Next, the droplet discharge unit 3 discharges droplets and applies droplets to the substrate 2 (S7).

  Next, the substrate transport robot unloads the substrate 2 (S8). In addition, when performing droplet application | coating with respect to the some board | substrate 2, what is necessary is just to repeat the process of S5-S8.

  The positioning of the reference plate 20 in S2 will be described in detail using the processing flow of FIG. First, the observation camera 9C is moved to a position where the feature point P1 can be imaged, the reference plate 20 is imaged by the observation camera 9C, and features in the captured image are obtained by image processing such as binarization and edge detection. The position of the point P1 is detected (S21). In addition, a display unit such as a display that displays the captured image, and an input unit such as a mouse that acquires position information in the image displayed on the display unit. An arbitrary position in the image displayed on the screen may be input from the input unit as the position of the feature point P1. Further, when the feature point P1 is not captured in the captured image, the feature point P1 may be searched by moving the observation camera 9C and capturing another position.

  Next, the alignment camera unit 8 is moved along the guide rail 7 (S22). The movement distance is the distance between the feature point P1 and the feature point P2.

  At this point, the observation camera 9C has moved to a position where the feature point P2 can be imaged. The reference camera 20 is imaged by the observation camera 9C, and the position of the feature point P2 in the captured image is detected by image processing or the like (S23).

  It is determined whether or not the position of the detected feature point P1 and the position of the detected feature point P2 are within an allowable range (S24). If it is within the allowable range, step S2 is terminated.

  When the allowable range is exceeded, a positioning amount is calculated using the position of the feature point P1 and the position of the feature point P2, and the posture adjustment unit 5a is operated according to the positioning amount, and the mounting table 5 is moved. (S25).

  Specifically, the angle formed by the straight line P1-P2 and the Y axis is calculated, and the mounting table 5 is rotated by θ by the angle. Next, the position after θ rotation is calculated with respect to the midpoint between the feature point P1 and the feature point P2, and the mounting table 5 is translated by the difference between the position and the desired position.

  According to the process of S25, the positioning should ideally be completed, but in reality, an error that cannot be allowed after S25 due to the movement distance error of the alignment camera unit 8 in S22 and the movement error of the mounting table 5 in S25. May exist. In that case, it returns to S21 and repeats the process of S21-S25 until it determines with the tolerance | permissible_range in S24.

  As described above, according to the processing flow of S21 to S25, the mounting table 5 is moved, and the reference plate 20 is moved so that the scanning direction of droplet application by the droplet discharge unit 3 coincides with the coordinate axis direction in the reference pattern 20c. Can be positioned. Accordingly, the error of the droplet application position due to the fact that the orientation of the grid of the reference pattern 20c and the scanning direction of the droplet application do not coincide with each other is within an allowable range, and is accurately set at a desired position on the substrate 2. Droplets can be applied.

  Further, according to the processing flow of S21 to S25, when the observation camera 9C is moved from the position at the time of detecting the position of the feature point P1 to the position at the time of detecting the position of the feature point P2 in the steps of S22 and S23, Without moving the camera 9 </ b> C with respect to the alignment camera unit 8, the guide rail 7 which is a scanning unit used for scanning the droplet discharge unit 3 is used. Therefore, in the movement from the feature point P1 to the feature point P2, an error due to the movement of the observation camera 9C with respect to the alignment camera unit 8 does not occur, so that accurate positioning is possible.

  In addition, after the process of S25, since there is a high probability that the observation camera 9C is at a position where the vicinity of the feature point P2 can be imaged, in the next processing loop, the imaging order of the feature point P1 and the feature point P2 is switched. First, the feature point P2 is imaged first (S23), then the alignment camera unit 8 is moved (S22, but in the reverse direction), and the feature point P1 is imaged (S21). Can be processed in a short time.

  Even when the exact positions of the alignment marks 2a and 2b on the substrate 2 are unknown, positioning is performed based on the positions of the alignment marks 20a and 20b having the same positions as the alignment marks 2a and 2b. As a result, the substrate 2 can be positioned accurately and droplet application can be performed accurately.

  Therefore, the droplet applying apparatus and the droplet applying method according to the present embodiment can accurately position the solar cells, thereby suppressing the area loss of the electrode wiring and improving the yield.

  The reference pattern 20c according to the present embodiment only needs to be able to specify the positions of the feature point P1 and the feature point P2. Therefore, the reference pattern 20c does not have to be a square pattern and specifies the positions of the feature point P1 and the feature point P2. It may be a pattern including a cross, a dot, a circle or the like.

  Further, the positioning method and the reference plate 20 of the present embodiment have the scanning direction of the droplet discharge unit 3 with respect to the substrate 2, the alignment marks 2a and 2b, and the like when there are alignment marks only at two diagonal points shown in FIG. This is particularly useful when the direction of the straight line connecting is different. This is because when the straight line connecting the alignment marks 2a and 2b coincides with the scanning direction of the droplet discharge unit 3 with respect to the substrate 2, the alignment marks 2a and 2b on the substrate 2 are not used without using the reference plate 20. This is because the substrate 2 can be positioned if the processes of S21 to S25 are performed assuming that the feature point P1 and the feature point P2 are the same, but the scanning direction of the droplet discharge unit 3 with respect to the substrate 2 and alignment are performed. This is because the processing is impossible when the linear direction connecting the marks 2a and 2b is different.

  Alternatively, the droplet discharge unit 3 and the alignment camera unit 8 may be integrally moved along the guide rail 7 in the Y direction. In this case, an error related to the movement of the alignment camera unit 8 in the Y direction with respect to the droplet discharge unit 3 does not occur, which is more preferable.

    The positioning method, droplet coating method, positioning device, droplet coating device, and reference plate of the present invention can be used not only for solar cell manufacturing but also for liquid crystal manufacturing, IC pattern manufacturing, and the like. Further, the present invention is not limited to droplet application, and can be used in processing that involves scanning, such as when laser light is irradiated while scanning.

DESCRIPTION OF SYMBOLS 3 Droplet discharge unit 5 Mounting stand 5a Attitude adjustment part 5b Suction stand 6 Gantry 7 Guide rail 8 Alignment camera unit 9A Alignment camera 9B Alignment camera 9C Observation camera 11 Droplet discharge head 20 Reference plate 20a Alignment mark 20b Alignment mark 20c Reference pattern

Claims (7)

A positioning method for positioning a substrate having an alignment mark,
Positioning a reference plate having an alignment mark at the same position as the alignment mark on the substrate,
Measure the position of the alignment mark on the positioned reference plate,
A positioning method comprising positioning the substrate so that the alignment mark of the substrate is positioned at the same position as the measured position of the alignment mark. A droplet application method for applying droplets to a substrate having an alignment mark,
Positioning a reference plate having an alignment mark at the same position as the alignment mark on the substrate,
Measure the position of the alignment mark on the positioned reference plate,
Positioning the substrate so that the alignment mark of the substrate is located at the same position as the position of the alignment mark measured;
A droplet coating method, wherein droplet coating is performed on the positioned substrate. The droplet application is a process performed by scanning a local application on the substrate,
The droplet applying method according to claim 2, wherein the reference plate is positioned such that two characteristic points of the reference plate are aligned in the scanning direction. The positioning of the reference plate is performed using an observation unit,
The movement of the observation unit from the position of the observation unit in the detection of the position of the first feature point to the position of the observation unit in the detection of the position of the second feature point is performed using the scanning unit related to the scanning. The droplet coating method according to claim 3. A positioning device for positioning a substrate having an alignment mark,
A mounting table for mounting the substrate and the reference plate;
A posture adjusting unit for adjusting the orientation of the mounting table,
An alignment camera for detecting a position of an alignment mark provided on the substrate and the reference plate;
An observation unit for detecting a position of a feature point included in the reference plate;
A positioning device comprising: A droplet coating apparatus that performs droplet coating on a substrate having an alignment mark,
A mounting table for mounting the substrate and the reference plate;
A posture adjusting unit for adjusting the orientation of the mounting table,
An alignment camera for detecting a position of an alignment mark provided on the substrate and the reference plate;
An observation unit for detecting a position of a feature point included in the reference plate;
A droplet coating apparatus comprising: a droplet discharge unit that performs droplet coating on a substrate placed on the mounting table. A reference plate used in a droplet application method for applying droplets to a substrate having an alignment mark,
A reference plate comprising an alignment mark at the same position as the alignment mark provided on the substrate and a reference pattern having two or more feature points.