KR102834815B1 - Double sided exposure apparatus and double sided exposure method - Google Patents

Abstract

In a double-sided exposure device that requires alignment of a substrate along with alignment of a pair of masks, the problem of the substrate being stationary with the substrate mark out of the camera's field of view is effectively solved.
A substrate (W) is intermittently transported and taken out from a roll by a transport system (1), and an exposure unit (2) irradiates light onto the substrate (W) through a pair of first and second masks (3, 4) arranged at a position interposed therebetween, thereby exposing the substrate (W). Prior to exposure, a camera (8) photographs an alignment mark (31) of the first mask (3), an alignment mark (41) of the second mask (4), and an alignment opening (Wm) of the substrate (W), and an alignment means performs alignment based on the photographed data. In a case where the camera (8) fails to photograph the alignment opening (Wm) when the transport system (1) stops the substrate (W), the substrate (W) is returned or transported so that the camera (8) photographs the alignment opening (Wm).

Description

{DOUBLE SIDED EXPOSURE APPARATUS AND DOUBLE SIDED EXPOSURE METHOD}

The present invention relates to a double-sided exposure device, such as a roll-to-roll method, used for manufacturing flexible printed circuit boards and the like.

The exposure device that exposes a target by irradiating it with light of a predetermined pattern is a core element technology of photolithography and is used for various purposes. There are various types of exposure devices, and one of them is known as a double-sided exposure device that exposes both sides of a long strip-shaped substrate.

For example, in the case of a device for exposing a soft substrate such as a flexible printed circuit board, a configuration is adopted in which exposure is performed while returning the substrate in a roll-to-roll manner. A pair of exposure units are arranged on both sides (usually upper and lower) of a substrate return line. The device includes a mask, and the exposure unit performs exposure by irradiating light of a predetermined pattern through each mask from both sides.

The return of the substrate taken out from the roll is intermittent, and among the substrates that have stopped after the return, light of a predetermined pattern is irradiated on both sides of a portion located between a pair of exposure units, so that both sides are exposed simultaneously.

Since these double-sided exposure devices are also a type of exposure device, alignment accuracy is a problem. In the case of a device that exposes a long strip-shaped substrate, such as a roll-to-roll device, the final product is obtained by cutting at an appropriate position in the longitudinal direction after photolithography is completed. Since the cutting position can be appropriately selected, alignment in the longitudinal direction in the exposure device has not been a problem in the past. On the other hand, the positional relationship between a pair of masks must be maintained with high accuracy. That is, if the accuracy of the positional relationship between a pair of masks is poor, the pattern on one side of the substrate and the pattern on the other side may be misaligned in the final product, which can easily lead to a product defect. For this reason, as in Patent Document 1 or Patent Document 2, a pair of masks are aligned with each other so that there is no misalignment in the patterns formed.

The conventional situation is as above, but recently, it is not enough to just align a pair of masks with each other, and positioning them on the substrate also needs to be performed with sufficiently high precision. One background to this is that, as products become more functional, they are increasingly having complex structures such as multilayer wiring.

For example, when assembling a complex structure such as a multilayer wiring on a flexible printed circuit board, in many cases, a pattern is already formed on a strip-shaped substrate, and additional resist is applied thereon and exposed. In the conventional case, a plurality of patterns are formed with intervals along the length direction of the strip-shaped substrate, and the portions where individual patterns are formed ultimately become individual products. In this case, in the additional exposure, it is necessary to expose with the necessary positional accuracy for the already formed pattern, and alignment with respect to the substrate is necessary.

In addition, depending on the product, there are cases where another flexible rectangular substrate is laminated on a portion where a pattern has already been formed, and exposure is performed to form a pattern on the other substrate (hereinafter referred to as an upper substrate). In this case as well, since the upper substrate is laminated in multiple portions with gaps in the longitudinal direction of the strip-shaped substrate, it is necessary to perform exposure in an aligned state for each upper substrate.

In this case, when alignment to the substrate is also required, after aligning a pair of masks with each other, it is necessary to align the pair of masks with the substrate while maintaining that state. For this reason, in patent document 2, a configuration is adopted in which alignment marks of both masks are photographed with a camera through alignment marks installed on the substrate.

Japanese Patent Publication No. 2000-155430 Japanese Patent Publication No. 2006-278648

As described above, Patent Document 2 proposes a configuration for achieving alignment with respect to a substrate in addition to positioning of a pair of masks.

However, according to the inventor's research, it is actually difficult to perform each alignment with the required precision using only the configuration disclosed in Patent Document 2. One of the reasons for this is the problem of the camera's field of view.

In order to perform alignment with high precision, the camera that captures each alignment mark must also have a high resolution. The reality is that a high resolution camera cannot see a wide field of view.

In this case, according to the inventor's research, in order to photograph the alignment mark of the substrate (hereinafter referred to as the substrate mark) and the alignment mark of the pair of masks by overlapping them, even if the substrate is stopped at a predetermined position with respect to the pair of masks, there are cases where the substrate is misaligned and stops due to the relationship between the accuracy of the formation position of the substrate mark and the accuracy of the substrate transport mechanism, and the substrate mark goes out of the field of view of the camera. In particular, in the case of a roll-to-roll type exposure device, the accuracy of the stop position of the roll transport mechanism is low compared to the high alignment accuracy required for exposure, and the substrate mark easily goes out of the field of view of the camera.

Neither Reference 1 nor Reference 2 take into account the fact that the substrate mark may be out of the camera's field of view, and these references are not helpful in resolving this issue.

The present invention has been made in consideration of the above points, and has as its object the effective resolution of the problem of a substrate being stopped in a state where the substrate mark is out of the field of view of a camera in a double-sided exposure device that requires alignment of a pair of masks as well as alignment of the substrate.

In order to solve the above problem, the invention described in claim 1 of the present application comprises a transport system for intermittently transporting a flexible substrate wound on a roll by taking it out,

A pair of first and second masks arranged at a position interposing the transferred substrate,

The return system is provided with an exposure unit that stops the substrate and, after alignment, irradiates light through each mask onto the substrate to expose both sides of the substrate.

The substrate has an alignment opening installed at a predetermined positional relationship with respect to the area to be exposed,

The first mask has a first mask mark, which is a mark for alignment.

The second mask has a second mask mark, which is a mark for alignment.

A camera capable of photographing the first mask mark, the second mask mark, and the alignment opening of the substrate is installed.

An alignment means is provided for positioning the first and second masks relative to the area of the substrate to be exposed by photographing data from a camera that photographs the first mask mark, the second mask mark, and the alignment opening.

The present invention has a configuration in which, when the camera fails to capture an alignment opening of the substrate when the return system stops the substrate, a control unit is provided to control the return system to return or transport the substrate so that the camera captures an alignment opening of the substrate.

In addition, in order to solve the above problem, the invention described in claim 2 has a configuration in which, in the configuration of claim 1, the alignment means includes a mask moving mechanism that moves the first and second masks in a direction parallel to the substrate.

In addition, in order to solve the above problem, the invention described in claim 3 has a configuration in which, in the configuration of claim 2, the mask moving mechanism is a mechanism capable of moving the first and second masks in a direction parallel to the surface of the substrate and perpendicular to the direction of transport by the transport system.

In addition, in order to solve the above problem, the invention described in claim 4 has a configuration in which, in any one of the configurations of claims 1 to 3, the control unit controls the transfer system to first return the substrate to change the position of the substrate when the camera fails to capture the alignment opening of the substrate when the transfer system stops the substrate, and to transport the substrate when the camera fails to capture the alignment opening of the substrate even at that position.

In addition, in order to solve the above problem, the invention described in claim 5 has a configuration in which, in any one of the configurations of claims 1 to 3, when the return system stops the substrate and the camera fails to capture the alignment opening of the substrate, the stroke of the return or transfer is shorter than the length of the direction of the stroke of the field of view of the camera.

In addition, in order to solve the above problem, the invention described in claim 6 is a double-sided exposure method in which a flexible substrate wound on a roll is taken out by a conveying system and intermittently transported, and light is irradiated to both sides of the substrate by an exposure unit through a pair of first and second masks arranged with the substrate interposed therebetween, thereby exposing the substrate.

The substrate has an alignment opening installed at a predetermined positional relationship with respect to the area to be exposed.

The first mask has a first mask mark, which is a mark for alignment.

The second mask has a second mask mark, which is a mark for alignment.

A method of performing alignment by photographing a first mask mark, a second mask mark, and an opening for alignment of a substrate with a camera prior to exposure, and aligning the first and second masks with respect to an area of the substrate to be exposed based on the photographed data obtained.

In the case where the camera fails to capture an alignment opening in the substrate when the return system stops the substrate during alignment, the return system is controlled to return or transport the substrate so that the camera captures an alignment opening in the substrate.

As described below, according to the invention described in claim 1 or 6 of the present application, when the camera fails to capture the alignment opening of the substrate during alignment, the substrate is returned or transported so that the camera captures the alignment opening. Therefore, even when the precision of the formation position of the alignment opening is low or the precision of the intermittent transport of the substrate is low, alignment does not become impossible, and the problem of reduced productivity due to abnormal stoppage of the device is prevented. In addition, since the substrate is moved to bring the alignment opening into the field of view of the camera, a large-scale and expensive mask moving mechanism is unnecessary, and in this respect, it is very practical.

In addition, according to the invention described in claim 2, in addition to the above effect, since alignment is performed by a return system, it becomes unnecessary, and therefore, the structure of the return system can be avoided from becoming complicated.

In addition, according to the invention described in claim 3, in addition to the above effects, it is suitable because it can easily cope with cases where the substrate is skewed or the alignment opening is formed misaligned in the width direction of the substrate.

In addition, according to the invention described in claim 4, in addition to the above effects, since the position of the substrate is changed by first returning the substrate, the amount of returning the substrate to find an opening for alignment can be reduced, and a complicated and expensive mechanism for suppressing meandering even when the amount of returning is large becomes unnecessary.

In addition, according to the invention described in claim 5, in addition to the above effect, since the stroke of returning or transferring is shorter than the length of the direction of the stroke of the field of view of the camera, even in the case where the center of the alignment opening is located at the boundary line of the field of view of the camera, after returning or transferring, the alignment opening is captured by the camera in an amount greater than half. Therefore, the possibility of an error in judging whether or not the alignment opening has been captured is reduced.

Fig. 1 is a front cross-sectional schematic diagram of a double-sided exposure device of the embodiment.
Figure 2 is a schematic diagram showing the alignment marks required for alignment.
Figure 3 is a flow chart schematically illustrating an extraction of a part related to alignment from the main sequence program.
Figure 4 is a schematic plan view showing the determination of the presence or absence of an alignment opening by the opening presence or absence determination program.
Figure 5 is a flow chart schematically illustrating an aperture search program.
Figure 6 is a planar schematic diagram showing the transfer and return of the substrate by the aperture search program.
Figure 7 is a schematic diagram illustrating an example of how an opening for alignment of a substrate is found by an opening search program.
Figure 8 is a planar schematic diagram showing the determination of a missing hole in an alignment opening by an opening missing determination program and the resolution of the missing hole by an opening missing resolution program.
Figure 9 is a schematic plan view showing a mark obscuration judgment and a temporary alignment program by a mark obscuration judgment program.
Figure 10 is a schematic diagram showing a mark omission judgment program and a mark omission resolution program.
Figure 11 is a schematic plan view showing the alignment by this alignment program.
Figure 12 is a schematic diagram showing the relationship between the length of the search stroke and the opening for alignment.

Next, a form for implementing the present invention (hereinafter, “embodiment”) will be described.

Fig. 1 is a schematic front cross-sectional view of a double-sided exposure device of an embodiment. The device of the embodiment is a device that exposes a strip-shaped substrate (W) with a soft material such as polyimide. As shown in Fig. 1, the double-sided exposure device is equipped with a transport system (1) and an exposure unit (2).

The return system (1) is a mechanism that intermittently feeds out a flexible substrate (W) wound on a roll. “Flexible” means having flexibility that allows it to be wound on a roll, and an example of this is a substrate for a flexible printed circuit board.

In this embodiment, the transport system (1) is a mechanism that horizontally takes out the substrate (W) and transports it in a horizontal position. Specifically, the transport system (1) is provided with a delivery-side core roller (11) on which an unexposed substrate (W) is wound, a delivery-side pinch roller (12) that takes out the substrate (W) from the delivery-side core roller (11), a take-up-side core roller (13) on which the exposed substrate (W) is wound, and a take-up-side pinch roller (14) that takes out the exposed substrate (W) and winds it on the take-up-side core roller (13). In addition, the transport direction of the substrate (W) by the transport system (1) is set to the X direction, and the horizontal direction perpendicular thereto is set to the Y direction. The Y direction is the width direction of the substrate (W). The direction perpendicular to the XY plane is set to the Z direction.

An exposure work position is set between the sending-side pinch roller (12) and the taking-up-side pinch roller (14). The exposure work position is a position where exposure is performed simultaneously on both sides of the substrate (W) by the exposure unit (2).

As shown in Fig. 1, a pair of masks (3, 4) are placed with a substrate (W) interposed at an exposure work position. Hereinafter, the upper mask (3) is called the first mask, and the lower mask (4) is called the second mask. Each mask (3, 4) is in a horizontal position.

The exposure unit (2) is also installed in two units corresponding to the masks (3, 4). The exposure unit (2) that exposes through the first mask (3) is installed above the first mask (3) and exposes by irradiating light downward. The exposure unit (2) that exposes through the second mask (4) is installed below the second mask (4) and exposes by irradiating light upward.

The two exposure units (2) are arranged symmetrically vertically and are structurally identical. That is, each exposure unit (2) is equipped with a light source (21) and an optical system (22) that irradiates light from the light source (21) to the masks (3, 4), etc. As described below, the device of this embodiment is a device that performs contact exposure, and each exposure unit (2) is a unit that irradiates parallel light to each mask (3, 4). Therefore, the optical system (22) includes a collimator lens.

The return system (1) includes buffer areas (101, 102) on the upstream and downstream sides of the exposure work position. The return system (1) includes a first drive roller (15) arranged on the upstream side of the exposure work position and a second drive roller (16) arranged on the downstream side of the exposure work position. Each of the drive rollers (15, 16) is a pinch roller.

As shown in Fig. 1, the area between the delivery-side pinch roller (12) and the first drive roller (15) is a delivery-side buffer area (101). In addition, the area between the second drive roller (16) and the take-up-side pinch roller (14) is a take-up-side buffer area (102).

The first drive roller (15) and the second drive roller (16) are elements that perform intermittent transport of the substrate (W) through the exposure work position. That is, the first drive roller (15) and the second drive roller (16) are rollers that operate synchronously and are configured to transport the substrate (W) with a set predetermined stroke. This stroke is the distance that the substrate (W) is transported during one intermittent transport, and is hereinafter referred to as a transport stroke.

Meanwhile, the delivery-side shim roller (11) and the delivery-side pinch roller (12) are driven synchronously according to the amount of looseness of the substrate (W) in the delivery-side buffer area (101). A sensor (not shown) is arranged in the delivery-side buffer area (101), and when the amount of looseness decreases, the delivery-side shim roller (11) and the delivery-side pinch roller (12) operate synchronously and deliver the substrate (W) until the amount of looseness reaches the set maximum value.

The same applies to the winding-side buffer area (102), where a sensor (not shown) is placed. When the amount of looseness increases to a limit according to a signal from the sensor, the winding-side pinch roller (14) and the winding-side core roller (13) operate synchronously, and the substrate (W) is wound so that the amount of looseness decreases to a set minimum value.

In the intermittent transport of the above-described return system (1), both sides of the substrate (W) are exposed by each exposure unit (2) while the substrate (W) is stopped after transport in the transport stroke, and prior to this, an alignment means for performing alignment is installed. The major characteristic points of the double-sided exposure device of the embodiment are included in the configuration of the alignment means and each part for alignment. Hereinafter, the configuration for alignment will be described.

In this embodiment, alignment is ultimately performed by positioning a pair of masks (3, 4) relative to an area to be exposed on a substrate (W). Therefore, as illustrated in FIG. 1, the pair of masks (3, 4) are provided with a mask moving mechanism (5), and the mask moving mechanism (5) is included in the alignment means. The mask moving mechanism (5) is a mechanism that moves each mask (3, 4) in the XY direction to change its position. The mask moving mechanism (5) is a mechanism that can independently move the first mask (3) and the second mask (4), and can also move the two masks (3, 4) as one unit. Such a mechanism can be easily manufactured, for example, by fixing a mechanism for moving the first mask (3) in the XY direction to the first base plate, fixing a mechanism for moving the second mask (4) in the XY direction to the second base plate, and further installing a mechanism for moving the first and second base plates together in the XY direction.

In addition, each mask (3, 4) is provided with a Z-direction movement mechanism (not shown). The Z-direction movement mechanism is a mechanism for moving each mask (3, 4) toward the substrate (W) for contact exposure and bringing it into close contact with the substrate (W).

As illustrated in Fig. 1, the device has a main controller (6) that controls each part, including the return system (1) and the mask moving mechanism (5). A main sequence program (7) that controls each part of the device to operate in a predetermined order is implemented in the main controller (6). That is, the main sequence program (7) is stored in the memory unit (60) of the main controller (6) and is executable by a processor (not illustrated) of the main controller (6). In addition, the main controller (6) has a display (61) that displays errors, etc.

For alignment, a mark to be displayed is required. Fig. 2 is a perspective schematic diagram showing alignment marks required for alignment. As shown in Fig. 2, alignment marks (31, 41) are formed on each mask (3, 4). Hereinafter, the alignment mark (31) installed on the first mask (3) is referred to as the first mask mark, and the alignment mark (41) installed on the second mask (4) is referred to as the second mask mark. As shown in Fig. 2, in this embodiment, the first mask mark (31) is cylindrical, and the second mask mark (41) is a circular point smaller than the first mask mark (31).

As shown in Fig. 2, an alignment mark (Wm) is formed on the substrate (W) for alignment. The alignment mark (Wn) on the substrate (W) is formed as an opening. Hereinafter, this is called an alignment opening. In this embodiment, the alignment opening (Wm) is formed in a circular shape.

As described above, alignment is an operation of aligning a pair of masks with each other and aligning a pair of masks with respect to a substrate. To this end, it is easy to perform alignment based on the state in which a pair of mask marks and alignment marks of the substrate overlap, and assuming that this state is an ideal state (standard for precision). The "overlapping state" is typically the case in which the centers of each mark (31, 41, Wm) are positioned on a straight line (on a straight line perpendicular to the substrate (W)), as illustrated in Fig. 2, but there are also cases in which another state is used as the standard for precision.

In this embodiment, in order to enable alignment to be easily performed with high precision, the alignment opening (Wm) is larger than the first mask mark (31) and larger than the second mask mark (41). That is, in a state where alignment is achieved, two mask marks (31, 41) are visible within the alignment opening (Wm) when viewed in a direction perpendicular to the substrate (W).

As shown in Fig. 1, the device is equipped with a camera (8) that photographs each alignment mark (31, 41, Wm). The camera (8) is connected to the main controller (6), and the photographing data of the camera (8) is sent to the main controller (6).

As shown in Fig. 2, in this embodiment, four first mask marks (31) and four second mask marks (41) are installed. Four cameras (8) are also installed to match these. The first mask marks (31) and the second mask marks (41) are installed at positions corresponding to corners of a square, and the cameras (8) are also installed at positions corresponding to corners of a square.

Each camera (8) is positioned so that its optical axis (optical axis of the built-in lens) (A) is vertical and is mounted in a posture for shooting downward. A camera movement mechanism (81) for changing the position of the camera (8) in the XY direction is installed on the stand on which each camera (8) is fixed.

The first mask mark (31) and the second mask mark (41) are installed at positions corresponding to the corners of a square having the same dimension and shape. These positions are already known as design information, and the four cameras (8) are installed in a state where they are adjusted to have the same positional relationship in the horizontal direction. However, it is not essential that the optical axes (A) of the four cameras (8) are coaxial with the centers of the respective mask marks (31, 41), and it is sufficient that each mask mark (31, 41) is within the range of the field of view of each camera (8).

The alignment opening (Wm) of the substrate (W) is a mark indicating the position of an area to be exposed (hereinafter referred to as a target exposure area), and is installed at a predetermined positional relationship with respect to the target exposure area. The target exposure area is an area to which the pattern of each mask (3, 4) is to be transferred, and is indicated by a dotted line in Fig. 2. The alignment opening (Wm) is formed on the outside of the target exposure area (R), and is formed at a position corresponding to a corner of a square having the same dimensions and shape as the first and second mask marks (41).

In addition, the target exposure area (R) corresponds to a portion of the substrate (W) used when producing one product. Therefore, as illustrated in Fig. 2, a plurality of target exposure areas (R) are set at intervals along the longitudinal direction of the strip-shaped substrate (W). The alignment aperture (Wm) is also designed to have the same positional relationship for each target exposure area (R). In addition, the pitch of each target exposure area (R) corresponds to the transfer stroke (indicated by Lf in Fig. 2) by the aforementioned transport system (1).

The alignment means is composed of each hardware installed in the above-mentioned device and software including a main sequence program (7) installed in the main controller (6). Hereinafter, the alignment means, including the configuration of the software, will be described in detail. First, the entire alignment will be described briefly. Fig. 3 is a flow chart schematically showing a portion related to alignment extracted from the main sequence program (7).

Alignment is an operation performed after the intermittent transport of the substrate (W) by the return system (1) is completed. The main sequence program (7) has, for alignment, an aperture presence/absence judgment step S1 for judging whether all alignment apertures (Wm) have been photographed, as roughly illustrated in FIG. 3, an aperture missing judgment step S2 for judging whether all alignment apertures (Wm) are recognized without missing, a mark obscuration judgment step S3 for judging whether each mask mark (31, 41) is not obscured by the substrate (W) in the case where all alignment apertures (Wm) are recognized without missing, a mark missing judgment step S4 for judging whether the mask mark (31, 41) is not photographed because it is missing in the case where it is judged that each mask mark (31, 41) is not obscured, and a main alignment step S5 for performing the main alignment in the case where it is judged that all mask marks (31, 41) are not missing.

And, in the main controller (6), as sub-programs called and executed from the main sequence program (7), an opening presence/absence judgment program (71), an opening search program (72), an opening missing judgment program (73), an opening missing resolution program (74), a mark obscuration judgment program (75), a temporary alignment program (76), a mark missing judgment program (77), a mark missing resolution program (78), and a main alignment program (79) are implemented.

The opening presence/absence judgment step S1 is a step of executing the opening presence/absence judgment program (71) and acquiring its return value. The opening search program (72) is a program executed when it is determined that at least one alignment opening (Wm) is not in the field of view of the camera (8).

The aperture omission judgment step S2 is a step of executing the aperture omission judgment program (73) and obtaining its return value. The aperture omission resolution program (74) is a program executed when it is determined that there is an omission for at least one alignment aperture (Wm).

The mark obscuration determination step S3 is a step of executing the mark obscuration determination program (75) and obtaining its return value. The temporary alignment program (76) is a program that is executed when it is determined that the mask mark is obscured by the substrate (W) in image data from at least one camera (8).

Mark judgment step S4 is a step of executing a mark omission judgment program (77) and obtaining its return value.

This alignment program (79) is a program that is executed when it is determined that all mask marks (31, 41) are not covered by the substrate (W) and can be aligned.

Next, the configuration of each step and each subprogram will be sequentially explained. First, the opening presence/absence judgment step S1 and the opening presence/absence judgment program (71) will be explained.

As shown in Fig. 3, the main sequence program (7) executes the opening presence/absence judgment program (71) after the intermittent transfer is completed. The return value of the opening presence/absence judgment program (71) is a normal value if all the alignment openings (Wm) are photographed, and an abnormal value if not.

Fig. 4 is a schematic plan view showing the judgment of the presence or absence of an alignment opening by the opening presence or absence judgment program (71). In Fig. 4, the fields of view of four cameras (8) are represented as V1 to V4. Fig. 4 (A) shows a case where all alignment openings (Wm) are in the fields of view (V1 to V4) of the cameras (8), and normal values are returned. Fig. 4 (B) shows a case where, for example, three alignment openings (Wm) are out of the fields of view (V3, V4) of the cameras (8), and abnormal values are returned.

The aperture presence/absence judgment program (71) is programmed to process image data from each camera (8) and to judge whether an image of an alignment aperture (Wm) is included by pattern matching. In this embodiment, the alignment aperture (Wm) is circular, and its diameter is already known as design information. Therefore, the aperture presence/absence judgment program (71) searches for one that can be judged to be an alignment aperture (Wm) among those that appear circular at the boundary between light and dark. If there is nothing that appears to be an alignment aperture (Wm) for at least one image data, an abnormal value is returned, and otherwise a normal value is returned.

As illustrated in FIG. 3, the main sequence program (7) is programmed to execute the aperture search program (72) when the return value of the aperture presence/absence judgment program (71) is an abnormal value. FIG. 5 is a flow chart schematically illustrating the aperture search program (72). In addition, FIG. 6 is a planar schematic diagram illustrating the transport and return of the substrate (W) by the aperture search program (72), and FIG. 7 is a perspective schematic diagram exemplarily illustrating a state in which an aperture (Wm) for alignment of the substrate (W) is found by the aperture search program (72).

A major feature of this device is that, when the alignment aperture (Wm) is not captured, the substrate (W), not the camera (8), is moved to bring the alignment aperture (Wm) into the field of view of the camera (8). That is, the aperture search program (72) is programmed to output a control signal for aperture search to the return system (1). At this time, the aperture search program (72) is programmed to first output a return signal (hereinafter, “aperture search return signal”) in consideration of the characteristics of the return system (1), and then output a transfer signal (hereinafter, “aperture search transfer signal”) when the alignment aperture (Wm) cannot be completely captured with that.

More specifically, in Fig. 6, a field of view (V) of one camera (8) and one alignment aperture (Wm) to be found are shown. The alignment aperture (Wm) is installed at a predetermined positional relationship with respect to the target exposure area (R).

In Fig. 6, the displacement of the field of view (V) relative to the substrate (W) by the feed signal for aperture search and the return signal for aperture search is depicted. In reality, the substrate (W) moves and the field of view (V) does not move, but the relative displacement of the field of view (V) is depicted for understanding.

The numbers in the field of view (V) surrounded by the dotted line indicate the displacement order of the relative field of view (V). The displacement of the relative field of view (V) is according to the feed signal for aperture search or the return signal for aperture search, but the stroke of the displacement is the same. Hereinafter, this stroke is called a search stroke and is indicated by Ls in Fig. 6.

As illustrated in Fig. 6, the search stroke (Ls) is slightly shorter than the length (length in the X direction) (Lc) of the field of view (V) of the camera (8). Therefore, when the substrate (W) moves by the length of the search stroke (Ls), the field of view (V) after the movement partially overlaps with the original field of view (V) (the camera (8) recognizes the same area).

The aperture search program (72) moves the substrate (W) (relative displacement of the field of view (V)) in the order of priorities indicated by numbers in Fig. 6 until an alignment opening (Wm) is found. That is, as illustrated in Fig. 6, the aperture search program (72) initially outputs a search return signal for returning the substrate (W) by the length of the search stroke (Ls). As a result, the field of view (V) is displaced as indicated by the arrow of the number 1 with ○ in Fig. 6. After a time lag until the movement of the substrate (W) is completed, the aperture presence/absence judgment program (71) is called and executed to determine whether the alignment opening (Wm) has entered the field of view (V). If it has entered the field of view (V), the program is terminated at that point, but if it has not entered, a search return signal for returning the substrate (W) by the length of the search stroke (Ls) is output once more. As a result, the field of view (V) is displaced as indicated by the number 2 with ○ in Fig. 6. Similarly, after the time lag, the opening presence/absence judgment program (71) is executed, and if the alignment opening (Wm) is photographed, it is terminated, and if not photographed, a search transport signal is output to transport the substrate (W) by three times the length of the search stroke (Ls).

By this, the field of view (V) is displaced as indicated by the arrow of number 3 with a circle around it in Fig. 6. The aperture search program (72) executes the aperture presence/absence judgment program (71) after the time lag, and ends when the alignment aperture (Wm) is photographed. If it is not photographed, a search transport signal is additionally output to transport the substrate (W) by the length of the search stroke (Ls). By this, the field of view (V) is displaced as indicated by the arrow of number 4 with a circle around it in Fig. 6. The aperture search program (72) executes the aperture presence/absence judgment program (71) after the time lag, and ends when the alignment aperture (Wm) is photographed, and if it is not photographed here either, it ends with the abnormal value as the return value. That is, the return value when the alignment aperture (Wm) is photographed is the normal value, and the return value when it is not photographed until the end is the abnormal value. In addition, Fig. 7 shows an example in which, by sending a control signal to the return system (1), the field of view (V) is relatively displaced as shown in (1)→(2)→(3)→(4)→(5), and the alignment opening (Wm) is captured by the camera (8) by the output of the last search return signal.

As shown in Fig. 3, the main sequence program (7) is programmed to obtain a return value from the aperture search program (72), and if the return value is an abnormal value, error processing is performed and the program is stopped because the alignment aperture (Wm) is not found. The error processing includes an operation of displaying on the display (61) of the main controller (6) that the alignment aperture (Wm) could not be photographed.

As shown in Fig. 3, when the return value of the aperture search program (72) is a normal value or when a normal value is returned in the execution of the first aperture presence/absence judgment program (71), the main sequence program (7) executes the aperture missing judgment program (73). Fig. 8 is a planar schematic diagram showing the missing judgment of the alignment aperture (Wm) by the aperture missing judgment program (73) and the missing resolution by the aperture missing resolution program.

When the intermittent transport of the substrate (W) by the return system (1) is completed or when the aperture search program (72) is terminated normally, the alignment aperture (Wm) may be completely within the field of view of the camera (8), but may be partially missing and not within the field of view. An example of a missing state is shown in (1) of Fig. 8. The aperture missing judgment program (73) processes the image data from each camera (8) and determines whether or not the alignment aperture (Wm) has been captured without missing any image data. If it has been captured without missing any image data, the normal value is returned to the main sequence program (7), and if it is determined that there is missing for image data from one or more cameras (8), an abnormal value is returned.

As illustrated in Fig. 3, the main sequence program (7) calls and executes the aperture omission elimination program (74) when an abnormal value is returned from the aperture omission judgment program (73) (when it is determined that there is a omission). The aperture omission elimination program (74) processes image data from each camera (8) to calculate the movement amount (direction and distance) of the substrate (W) or the camera (8) required to eliminate the omission. Then, the aperture omission elimination program (74) is programmed to send the calculated movement amount to the return system (1) and/or the camera movement mechanism (81) and move the substrate (W) and/or the camera (8). At this time, for the movement in the X direction, either the substrate (W) or the camera (8) may be moved, but in this embodiment, the substrate (W) is moved. In addition, the camera (8) is moved in the Y direction. That is, the aperture gap resolution program (74) is programmed to send the amount of movement (direction and distance) in the X direction for gap resolution to the return system (1) and the movement distance in the Y direction to the camera movement mechanism (81).

In any case, when the aperture gap correction program (74) is executed, as shown in (2) of Fig. 8, the four alignment apertures (Wm) are photographed with the gaps corrected. In addition, since the amount of the gap is usually different in each image data, the image data with the largest gap in the alignment aperture (Wm) is identified among the image data from the four cameras (8), and the movement amount for correcting the gap in that image data is sent to the return system (1) and/or the camera movement mechanism (81).

As shown in Fig. 3, the main sequence program (7) is programmed to execute the mark obscuration judgment program (75) after executing the aperture omission resolution program (74). Fig. 9 is a planar schematic diagram showing the mark obscuration judgment and temporary alignment program (76) by the mark obscuration judgment program (75).

When the normal value is returned in the aperture omission judgment program (73) or the aperture omission resolution program (74) is terminated, the alignment aperture (Wm) is photographed without omission from each camera (8), but there are cases where a pair of mask marks (31, 41) is not located within each alignment aperture (Wm) and is obscured by the substrate (W). An example of a situation where such obscuration of a pair of mask marks (31, 41) occurs is shown in (1) of Fig. 9.

The mark occlusion judgment program (75) is a program that processes image data from each camera (8) to determine whether an image of a pair of mask marks (31, 41) exists within each alignment opening (Wm). In this embodiment, since the first mask mark (31) is a circle smaller than the alignment opening (Wm) and the second mask mark (41) is a circular point smaller than the second mask mark (41), it is determined by pattern matching whether these exist within each alignment opening (Wm). The mark occlusion judgment program (75) is programmed so that if they exist, a normal value is returned to the main sequence program (7), and if they do not exist, an abnormal value is returned.

As shown in Fig. 3, the main sequence program (7) executes a temporary alignment program (76) when an abnormal value is returned from the mark obscuration judgment program (75). The temporary alignment program (76) is a program that performs temporary alignment based on the positions of a pair of mask marks (31, 41) at the time of the previous exposure (exposure of the previous target exposure area (R)).

As described below, the main sequence program (7) has a step of storing the center positions (positions in XY coordinates) of a pair of mask marks (31, 41) in the memory (60) when the alignment is completed. The temporary alignment program (76) is a program that reads out this information from the memory (60) and uses it. Specifically, the temporary alignment program (76) reads out this center position from the memory (60) and calculates the misalignment with the center of the alignment opening (Wm). Then, it corrects this misalignment and calculates the amount of movement (amount of total movement) of the pair of masks (3, 4) so that the centers of the pair of mask marks (31, 41) coincide with the center of the alignment opening (Wm). Here again, the amount of movement is the direction and distance of movement. And, the temporary alignment program (76) sends the calculated movement amount to the mask movement mechanism (5) and moves the pair of masks (3, 4) as one. That is, the temporary alignment program (76) assumes that the pair of masks (3, 4) will continue to be positioned at the positions finally positioned by the alignment during the previous exposure, and causes the pair of masks (3, 4) to move to resolve mark obscuration based on that position. In this way, as shown in (2) of Fig. 9, the mark obscuration is resolved. In addition, as described later, the pair of masks (3, 4) move in the Z direction by a Z-direction movement mechanism (not shown) to come into close contact with the substrate (W), and after the end of exposure, move in the opposite Z direction to separate from the substrate (W). During this Z-direction movement, each mask (3, 4) may be slightly displaced in the XY direction, but it may be said that almost the same position is maintained in the XY direction.

As shown in Fig. 3, the main sequence program (7) executes the mark obscuration judgment program (75) once more when the temporary alignment program (76) is executed to determine whether or not there is a mark obscuration. Then, if it is confirmed that the normal value is returned, the main sequence program (7) performs the mark omission judgment program (77) step. Fig. 10 is a planar schematic diagram showing the mark omission judgment program (77) and the mark omission resolution program (78).

The mark missing judgment program (77) is a step for judging whether each mask mark (31, 41) is completely within the alignment opening (Wm). Similarly, it is a step for judging whether the image of each mask mark (31, 41) is acquired within the alignment opening (Wm) by pattern matching. As shown in (1) of Fig. 10, if it is judged that a pair of mask marks (31, 41) is missing in the image data from at least one camera (8), the mark missing judgment program (77) returns an abnormal value, otherwise it returns a normal value.

The mark missing resolution program (78) calculates the movement amount (direction and distance) required to resolve the mask mark missing for the shooting data in which the mark missing judgment program (77) indicates that a mark was missing. In this embodiment, since the first mask mark (31) is large, the mark missing resolution program (78) specifies an arc judged to be a part of the first mask mark (31) and obtains the center of the arc. Then, the program obtains the shortest movement amount (distance and direction) required for the obtained center to be separated from the outline of the alignment opening (Wm) by a radius (the radius of the arc of the first mask mark (31)) or more. Then, the mark missing resolution program (78) is programmed to send a control signal for moving a pair of masks (3, 4) by this movement amount to the mask moving mechanism (5). When there is a mark omission in image data from two or more cameras (8), the mark omission elimination program (78) calculates the movement amount for elimination of each image data and calculates the average of these. Since the movement amount is a distance and a direction, the average distance and the average direction are calculated. Then, the calculated average movement amount is sent to the mask movement mechanism (5).

The main sequence program (7) executes the mark omission elimination program (78), executes the mark omission judgment program (77) once more to determine whether or not there is any omission of the mask mark, and if it confirms that the normal value has been returned, executes the main alignment program (79). Fig. 11 is a schematic diagram showing the main alignment by the main alignment program (79).

This alignment program (79) processes the shooting data from each camera (8) in a state where this alignment is possible. This alignment program (79) first obtains the center of the first mask mark (31) and the center of the second mask mark (41) in a coordinate system whose origin is a point on the optical axis (A). Then, it determines whether the center of the first mask mark (31) and the center of the second mask mark (41) match with the required precision, and if they do not match, it sends a signal to the mask moving mechanism (5) to move one or both masks to match them. Normally, since the two are matched during the previous exposure, they match.

After confirming that the center of the first mask mark (31) and the center of the second mask mark (41) coincide within the range of the required precision, this alignment program (79) finds the midpoint of these centers. Then, this alignment program (79) finds the center of the alignment opening (Wm) of the substrate (W), finds the misalignment with the midpoint of the centers of a pair of mask marks (31, 41), and calculates the movement direction and distance of each mask (3, 4) to eliminate the misalignment.

This alignment program (79) performs the above data processing on the shooting data from each camera (8) and calculates the movement direction and distance of each mask (3, 4) for resolving the misalignment. Then, the average is calculated for the movement direction and distance obtained from each shooting data, and this is used as the final movement command for each mask (3, 4) for this alignment, and this is returned to the main sequence program (7). Since the movement direction and distance are identified as each vector (indicated by an arrow in Fig. 11), the direction of each vector is synthesized and the average is taken for the length.

The main sequence program (7) sends a movement command, which is a return value, to the mask movement mechanism (5), and moves a pair of masks (3, 4) as one unit so that their respective centers are aligned in a straight line with the required precision. This completes the alignment. In addition, although not shown in Fig. 3, the main sequence program (7) stores the center coordinates of each mask mark (31, 41) at the time of completion of the alignment in the memory unit (60), for alignment during exposure of the next target exposure area (R).

By thus finally executing the alignment program (79), a pair of masks (3, 4) are aligned with each other and a pair of masks (3, 4) are aligned to the substrate (W). The main sequence program (7) is programmed to perform alignment while performing each judgment step as described above and executing each sub-program as necessary.

Next, the overall operation of the double-sided exposure device according to the embodiment of the above configuration will be described in brief. The following description is also a description of an embodiment of the invention of the double-sided exposure method. In addition, the invention of the double-sided exposure method can be said to be an invention of a method for manufacturing an object called a substrate exposed on both sides.

A pair of masks (3, 4) are positioned at a standby position away from the substrate (W) in the Z direction. This position is a position where an XY plane exists on which alignment of each mask (3, 4) is performed.

From the main controller (6) where the main sequence program (7) is being executed, a control signal is sent to the return system (1) to transport the substrate (W) by the transport stroke (Lf). As a result, the first drive roller (15) and the second drive roller (16) operate synchronously, and the substrate (W) is transported forward (to the winding side) in the X direction by the transport stroke (Lf).

When the transfer completion signal is returned from the return system (1) to the main controller (6), the main sequence program (7) performs the series of alignment operations described above. That is, it determines whether there is an alignment aperture (Wm) within the field of view of each camera (8), and if not, it executes an aperture search program (72), and then determines whether there is an aperture omission. Then, if any of the alignment apertures (Wm) is missing, it executes an aperture omission elimination program (74), and then determines whether there is a mark obscuration. Then, if there is a mark obscuration in any of the shooting data, it executes a temporary alignment program (76). Furthermore, if the mask mark (31, 41) is missing and photographed, it executes a mark omission elimination elimination program (78). Then, the main sequence program (7) executes this alignment program (79). As a result, the alignment is completed.

Thereafter, the main sequence program (7) sends a control signal to a Z-direction movement mechanism that is not shown, and moves a pair of masks (3, 4) in the Z direction to bring each mask (3, 4) into close contact with the substrate (W). In this state, the main sequence program (7) acquires shooting data from each camera (8) and determines whether the alignment state is maintained (whether the centers of each mark (31, 41, Wm) match with the required precision). If maintained, the main sequence program (7) sends a control signal to each exposure unit (2) and causes exposure to be performed.

After exposure for a predetermined time for the required exposure amount, each exposure unit (2) stops irradiating the light. Thereafter, the main sequence program (7) sends a control signal to a Z-direction movement mechanism (not shown) to move a pair of masks (3, 4) away from the substrate (W) and return them to the initial standby position.

When it is confirmed that each mask (3, 4) has returned to the standby position, the main sequence program (7) sends a control signal to the return system (1) and moves the substrate (W) forward in the X direction by the amount of the transfer stroke (Lf). Thereafter, the operation is as described above, and the operation of performing alignment and then exposure between the intermittent transfers of the substrate (W) of the transfer stroke (Lf) is repeated.

When the operation is repeated, if the amount of looseness of the substrate (W) in the sending-side buffer area (101) decreases, the sending-side shim roller (11) and the sending-side pinch roller (12) operate synchronously and send the substrate (W) to the sending-side buffer area (101). In addition, if the amount of looseness of the substrate (W) in the taking-up side buffer area (102) increases, the taking-up side shim roller (13) and the taking-up side pinch roller (14) operate synchronously and wind the substrate (W) on the taking-up side shim roller (13).

According to the double-sided exposure device of the embodiment regarding the configuration and operation, when alignment is performed after completion of intermittent transport, it is determined whether the alignment opening (Wm) of the substrate (W) is within the field of view of the camera (8), and if not, the substrate (W) is moved so that the alignment opening (Wm) is within the field of view of the camera (8), so that an alignment error (impossible alignment) due to the inability to photograph the alignment opening (Wm) is prevented. For this reason, even when the precision of the formation position of the alignment opening (Wm) is low or the precision of the intermittent transport of the substrate (W) is low, alignment does not become impossible, and the problem of reduced productivity due to abnormal stoppage of the device is prevented.

In the case where the alignment opening (Wm) does not enter the field of view of the camera (8), a response may be considered in which the camera (8), rather than the substrate (W), is moved to place the alignment opening (Wm) in the field of view. However, this configuration is not very practical. This is because alignment is ultimately an operation to align a pair of mask marks (31, 41) and the alignment opening (Wm) of the substrate (W) with the required precision, and it is necessary to confirm this state with the camera (8). Therefore, when the camera (8) is moved to change the position of the field of view, it is also necessary to move the pair of masks (3, 4). In this case, the problem that the alignment opening (Wm) of the substrate (W) deviates from the field of view of the camera (8) is due to the misalignment of the formation position of the alignment opening or the precision of the intermittent transfer of the substrate (W), so the movement distance for placing the alignment opening (Wm) in the field of view is relatively long. Meanwhile, the mask moving mechanism (5) for moving a pair of masks (3, 4) is a mechanism for performing alignment with the required precision, and a high-precision micro-movement mechanism with a small error is adopted. Such a mechanism has a short maximum movement distance, and therefore it is very difficult to use the mask moving mechanism (5) to bring the alignment opening (Wm) into the field of view. Even if it is possible, a micro-movement mechanism capable of moving a long distance is required, and a very large-scale and expensive mechanism is required. According to the configuration of the embodiment, since the substrate (W) is moved to bring the alignment opening (Wm) into the field of view of the camera (8), a large-scale and expensive mask moving mechanism (5) is unnecessary, and in this respect, it is very practical.

When finding an opening (Wm) for alignment of the substrate (W), the substrate (W) is first returned (moved in the opposite direction to the intermittent transfer) and then, if it is still not found, transferred (moved in the same direction as the intermittent transfer), which is a configuration suitable for the relationship with the characteristics of the return system (1) that performs intermittent transfer.

In a double-sided exposure device using a conveying system (1) that intermittently conveys a substrate (W) wound on a roll, it is important to conduct conveyance that minimizes the meandering of the substrate (W). This is because if meandering occurs, positional misalignment in the width direction (Y direction) of the substrate (W) occurs, and if this becomes large, alignment can easily become impossible.

In this case, the return system (1) is equipped with a high-precision transfer mechanism or sensor to prevent meandering when transferring forward, but the mechanism to prevent meandering when transferring backward (returning) is often simplified. This is because there are few situations where the substrate (W) is returned. In other words, if a mechanism to prevent meandering to the same extent is configured when transferring backward, the mechanism becomes unnecessarily large and expensive.

In the configuration of the above-described aperture search, since the movement of the substrate (W) is to bring the alignment opening (Wm) into the field of view of the camera (8), it is necessary to move it back and forth at least the length of the field of view of the camera (8) (length in the direction of movement). For example, let's say that it moves back and forth by the length of one field of view of the camera (8). In this case, if the movement (movement) of one field of view is initially performed forward, if the alignment opening (Wm) is not found there, a movement (return) of two fields of view is required backward. In contrast, if the movement (return) is initially performed backward, if the alignment opening (Wm) is not found there, a movement (transfer) of two fields of view is made forward.

That is, the configuration that performs the return of the substrate (W) at the beginning during the opening search has the significance of minimizing the return distance of the substrate (W) as much as possible and suppressing the occurrence of meandering of the substrate (W) at the opening search as much as possible. In other words, the configuration that performs the return of the substrate (W) at the beginning has the significance of making unnecessary a complicated and expensive mechanism that suppresses meandering even when performing the return over a long distance.

In addition, as described above, in the configuration of the aperture search, the search stroke is slightly shorter than the length of the field of view of the camera (8), and the fields of view overlap before and after the movement of the search stroke. This configuration contributes to increasing the accuracy when determining that the alignment aperture (Wm) has been found. This point will be explained with reference to Fig. 12. Fig. 12 is a schematic diagram showing the relationship between the length of the search stroke (Ls) and the alignment aperture (Wm).

If the intermittent transfer is completed, it is assumed that the center of the alignment opening (Wm) is located on the boundary line of the field of view of the camera (8) as illustrated in (A) of Fig. 12. In this case, if the length (Lc) of the search stroke (Ls) and the field of view of the camera (8) are the same, it is assumed that the search stroke (Ls) is moved and the field of view is relatively displaced as indicated by the dotted line in (A) of Fig. 12. In this case, as can be seen from (A) of Fig. 12, the amount (area) of the alignment opening (Wm) captured by the camera (8) does not change even after the search stroke (Ls) is moved. That is, the presence or absence of the alignment opening (Wm) in the field of view (V) is judged based on the half of the alignment opening (Wm), and an error easily occurs in which a non-alignment opening (Wm) is mistakenly judged to be the alignment opening (Wm).

Meanwhile, as in the embodiment, if the search stroke (Ls) is made shorter than the length (Lc) of the field of view, even if the center of the alignment opening (Wm) is located on the boundary of the field of view (V), after the search stroke (Ls) is moved, the alignment opening (Wm) is recognized by the camera (8) by an amount greater than half, as indicated by the dotted line in (B) of Fig. 12. Therefore, the possibility of error is reduced. The difference between the search stroke (Ls) and the length (Lc) of the field of view (V) (indicated by d in (B) of Fig. 12) is about 5 to 20% of the length (diameter in this example) of the movement direction of the alignment opening (Wm).

In addition, if the difference (d) between the length (Lc) of the search stroke (Ls) and the alignment opening (Wm) is made half or more of the length of the alignment opening (Wm), even if the center of the alignment opening (Wm) is located on the boundary line of the field of view (V), the alignment opening (Wm) is entirely included in the field of view (V) after the search stroke (Ls) moves. In this configuration, the above-described aperture missing judgment or missing resolution program may be made unnecessary. However, if the alignment opening (Wm) is missing in the width direction of the substrate (W), missing resolution by movement of the camera (8) is required.

In addition, in the configuration of the above embodiment, if there is a misalignment in the alignment opening (Wm) of the substrate (W), the alignment is performed after the misalignment is resolved, so that the alignment is performed with the complete alignment opening (Wm) introduced into the image data, which has the effect of further increasing the alignment precision.

A configuration in which temporary alignment is performed first when the mask mark on the opposite side is covered by the substrate (W) saves the effort of finding the mask mark and has the effect of reducing the overall time required for alignment.

Furthermore, the configuration of performing alignment by determining whether a mark is missing and, if missing, resolving the missing state, performs alignment after introducing a complete image of a pair of mask marks (31, 41), thus having the effect of further increasing alignment precision in this respect.

In the above-described embodiment, the return system (1) is configured to return the substrate (W) in a roll-to-roll manner, but there may also be cases where a configuration in which only the delivery side is a roll-type configuration is adopted. That is, there may also be cases where the double-sided exposure device of the present invention is adopted in a process of cutting the substrate (W) after exposure at a predetermined position and performing subsequent processing.

In addition, as a return system (1), there are cases where the transport direction of the substrate (W) is up and down. In this case, exposure is performed on both sides of the substrate (W) in a vertical position through a mask, and exposure units (2) are arranged on the left and right.

In addition, in the above embodiment, the alignment opening (Wm) is circular, but this is merely an example, and may have other shapes such as a square or a triangle. In addition, it does not have to form a complete peripheral edge, such as a shape cut from the side edge of the substrate (W).

Furthermore, the term "opening" means that light passes through it. This assumes that the substrate (W) is light-blocking, and a typical example is when resist is applied. Since it is an opening that means that light passes through it, it may be blocked by a light-transmitting member rather than a through hole. In other words, it means that the layer that blocks light is open there.

For the first mask mark (31) and the second mask mark (41), there are cases where shapes other than a cylindrical shape or a circle are adopted. For example, one side may be circular and the other side may be cross-shaped. Also, there are cases where the alignment is performed with the first mask mark (31) inside the second mask mark (41).

Furthermore, since the mask mark on the side closer to the camera (8) than the substrate (W) is not blocked by the substrate (W), it may be larger than the alignment opening (Wm). However, if the contrast between the substrate (W) and the mask is small, there is a problem that processing of image data becomes difficult. In a configuration where alignment is performed with a pair of mask marks positioned within the alignment opening, the contrast between the substrate (W) and the mask mark does not become a problem, and is suitable in this respect.

In addition, in the above embodiment, the mask moving mechanism (5) is not necessarily essential. If the substrate (W) is transported without any deviation and there is no particular misalignment of the Y-direction position of the alignment opening (Wm), movement in the Y-direction is unnecessary during alignment, and movement in the X-direction is sufficient. In this case, alignment can also be performed by moving the substrate (W) in the X-direction, and in this case, the mask moving mechanism (5) is unnecessary, and the alignment means is mechanically composed only of the transport system (1).

However, if there is a mask moving mechanism, it can also respond to cases where the substrate (W) is misaligned in the Y direction or the alignment opening (Wm) is formed so as to be misaligned, and it is suitable in this respect. In addition, if the mask moving mechanism can also move a pair of masks (3, 4) in the X direction, the mask moving mechanism can be used instead of the transport system when performing alignment in the X direction. The transport system (1) is a mechanism for intermittent transport of the substrate (W), and if alignment in the X direction is also attempted, the structure tends to become complicated. If alignment in the X direction is performed by the mask moving mechanism, the structure of the transport system (1) can be avoided from becoming complicated.

Although the device of the above embodiment performs exposure in a contact manner, the configuration of the alignment is equally effective in exposure in a proximity manner or projection manner, so there may be cases where these methods are adopted.

In addition, in the case of the proximity method or projection exposure method, it is unnecessary to attach a pair of masks to the substrate, so in some cases, a mechanism for moving the mask in the Z direction is not installed.

In addition, although the main controller (6) is an example of a control unit, there may be other configurations. For example, a control unit may be installed separately from the main controller (6), or a part within the main controller (6) may correspond to a control unit.

1 Return system
2 exposure units
21 light source
22 Optical System
3. Mask 1
31 1st mask mark
4. Second Mask
41 2nd mask mark
5 Mask moving mechanism
6 Main Controller
61 Memory
7 Main Sequence Program
71 Opening Presence/Aboutness Determination Program
72 Opening Search Program
73 Opening Missing Decision Program
74 Opening Missing Relief Program
75 Mark Coverage Determination Program
76 Temporary Alignment Program
77 Mark Missing Decision Program
78 Mark Missing Remedy Program
79 Bone Alignment Program
8 cameras
81 Camera Movement Mechanism
W substrate
Aperture for Wm alignment
V view

Claims (4)

A return system that intermittently transports a flexible substrate wound on a roll by pulling it out,
A pair of first and second masks arranged at positions interposed between intermittently transferred substrates,
The return system is provided with an exposure unit that stops the substrate and, after alignment, irradiates light through each mask onto the substrate to expose both sides of the substrate.
The substrate has an alignment opening installed at a predetermined positional relationship with respect to the area to be exposed,
The first mask has a first mask mark, which is a mark for alignment.
The second mask has a second mask mark, which is a mark for alignment.
A camera capable of photographing the first mask mark, the second mask mark, and the alignment opening of the substrate is installed.
An alignment means is provided for positioning the first and second masks relative to the area of the substrate to be exposed by photographing data from a camera that photographs the first mask mark, the second mask mark, and the alignment opening.
The alignment means is a means for performing an aperture search by moving the substrate or the camera so that the camera is photographing the alignment aperture of the substrate when the camera in the operating state is not photographing the alignment aperture of the substrate when the return system intermittently transports the substrate and stops the substrate.
The alignment means is a means for performing an aperture search so that the camera is in a state of photographing an alignment aperture of the substrate, and when a first mask mark or a second mask mark is photographed while not completely within the alignment aperture being photographed and is missing, moving the first mask in the case where the first mask mark is missing and being photographed, or the second mask in the case where the second mask mark is missing and being photographed, or moving the substrate, to resolve mark missing so that the first mask mark and the second mask mark are completely within the alignment aperture.
A double-sided exposure device characterized in that the alignment means is a means for performing this alignment by moving the first mask and the second mask so as to align the centers of the first mask mark and the second mask mark after eliminating mark omission, and to eliminate misalignment between their centers and the center of the alignment opening. In claim 1,
A double-sided exposure device characterized in that the alignment means includes a mask moving mechanism that moves the first and second masks in a direction parallel to the substrate, and the mask moving mechanism is a mechanism that can move the first and second masks in a direction parallel to the surface of the substrate and perpendicular to the direction of transport by the transport system. A double-sided exposure method in which a flexible substrate wound on a roll is intermittently transported by a transport system by taking it out, and then, with respect to the transported and stopped substrate, light is irradiated by an exposure unit through a pair of first and second masks arranged with the substrate interposed therebetween to expose both sides of the substrate,
The substrate has an alignment opening installed at a predetermined positional relationship with respect to the area to be exposed.
The first mask has a first mask mark, which is a mark for alignment.
The second mask has a second mask mark, which is a mark for alignment.
A method of aligning the first and second masks with respect to the area of the substrate to be exposed by photographing the first mask mark, the second mask mark, and the alignment opening of the substrate with a camera prior to exposure, using the obtained photographing data.
When the return system intermittently transports the substrate and the substrate is stopped, if the camera in the operating state is not photographing the alignment opening of the substrate, an aperture search is performed by moving the substrate or the camera so that the camera photographs the alignment opening of the substrate.
After performing an aperture search, if the first mask mark or the second mask mark is not completely within the alignment aperture being photographed and is missing, the first mask in the case where the first mask mark is missing and is being photographed or the second mask in the case where the second mask mark is missing and is being photographed is moved, or the substrate is moved, thereby eliminating mark missing so that the first mask mark and the second mask mark are completely within the alignment aperture.
A double-sided exposure method characterized in that, after removing mark omission, the first mask and the second mask are moved to align the centers of the first mask mark and the second mask mark and remove any misalignment between their centers and the center of the alignment opening. In claim 3,
A double-sided exposure method, characterized in that the above alignment includes an operation of moving the first and second masks by a mask moving mechanism in a direction parallel to the surface of the substrate and perpendicular to the direction of transport by the transport system.