TWI785149B - Mask pair, double-sided exposure apparatus, and mask exchange method - Google Patents

Abstract

It is designed so that alignment between exchanged reticles can be easily performed even when the substrate is left at the exposure work position. The first mask (1) mounted in the mask pair of the double-side exposure device for exposing both sides of the substrate (S) has a first mask mark (11) and a first auxiliary mask mark (12). The mask (2) has a second mask mark (21) and a second auxiliary mask mark (22). Superimpose the first auxiliary mask mark (12) and the second auxiliary mask mark (22) at a position away from the substrate (S) when the reticles (1, 2) are aligned with each other, and confirm this with the camera (8) state. When aligning the reticle (1, 2) of the substrate (S), the first reticle mark (11) and the second reticle mark (21) are superimposed, passing through the alignment opening (Sm) of the substrate (S) Shoot with camera (8).

Description

Mask pair, double-sided exposure apparatus, and mask exchange method

The present invention relates to a double-sided exposure apparatus such as a roll-to-roll method used in the manufacture of flexible printed circuit boards and the like.

An exposure device that irradiates an object with a predetermined pattern of light to expose it is used in various applications as a core technology of photolithography. There are various types of exposure apparatuses, but one of them is known as a double-side exposure apparatus for exposing both sides of a strip-shaped elongated substrate.

For example, in the case of an apparatus for exposing a flexible substrate such as a flexible printed circuit board, a configuration in which exposure is performed while conveying the substrate by roll-to-roll is employed. A pair of exposure units are arranged on both sides (normally, upper and lower sides) of the substrate transport path. Masks are provided on both sides of the transport path, and the exposure unit irradiates light of a predetermined pattern through each mask from both sides to perform exposure. The conveyance of the substrate pulled out from the reel is intermittent, and both surfaces of the portion located between the pair of exposure units among the substrates stopped after conveyance are irradiated with light of a predetermined pattern, and both surfaces are exposed at the same time.

Such a double-side exposure device is also a type of exposure device, and therefore alignment (alignment) accuracy becomes a problem. In the case of a roll-to-roll system that exposes a strip-shaped elongated substrate, after photolithography is completed, it is cut at an appropriate position in the longitudinal direction to obtain a final product. Since the cutting position can be appropriately selected, alignment in the longitudinal direction in the exposure apparatus has not been a big problem in the past. On the other hand, for a pair of masks, the mutual positional relationship must be maintained with high precision. That is, the reason is that if the accuracy of the positional relationship between the pair of photomasks is not good, the pattern on one side of the substrate and the pattern on the other side of the substrate will become misaligned in the final product, which will easily cause product defects. Therefore, as in Patent Document 1 or Patent Document 2, it is designed to calibrate a pair of photomasks to avoid misalignment of the formed patterns.

The previous situation was as above, but recently, it is not enough to align only a pair of photomasks with each other, and it is gradually required to perform the alignment of the substrate with a sufficiently high accuracy. One of the reasons behind this is that with the highly functionalization of products, more and more cases have complex structures such as multilayer wiring.

To illustrate an example, when a complex structure such as multilayer wiring is precisely produced on a flexible printed circuit board, it is often the case that a pattern is formed on a tape-shaped substrate, and a resist is further coated on it for exposure. . Existing patterns are formed in plural at intervals along the longitudinal direction of the strip-shaped substrate, and the portions where the respective patterns are formed eventually become individual products. In this case, in the further exposure, the already formed pattern must be exposed with the necessary positional accuracy, and calibration of the substrate is necessary.

In addition, depending on the product, another flexible square substrate may be laminated on top of the part where the pattern has been formed, and the other substrate (hereinafter referred to as the upper substrate) is exposed to form a pattern. situation. In this case as well, since a plurality of upper substrates are stacked at intervals along the longitudinal direction of the strip-shaped substrate, exposure must be performed in a state where the respective upper substrates are aligned.

In such a case where alignment with respect to the substrate is also required, after aligning a pair of photomasks with each other, it is necessary to align the pair of photomasks with respect to the substrate while maintaining this state. Therefore, in Patent Document 2, a configuration is adopted in which the alignment marks of the reticles on both sides are photographed by a camera through an opening (hereinafter referred to as an opening for alignment) provided on the substrate as an alignment mark. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2000-155430 [Patent Document 2] Japanese Patent Laid-Open No. 2006-278648

[Problem to be solved by the invention]

In the double-side exposure apparatus for exposing both sides of a strip-shaped elongated substrate as described above, if a pair of photomasks have different patterns to be formed, different ones are used. Therefore, it is necessary to replace the photomask according to the product. In this case, in the apparatus of the roll-to-roll transfer method, in which the substrate is pulled out from the roll and exposed, the type of product may be changed in the middle of the roll, and a pair of photomasks must be exchanged.

In this case, it is easier to exchange a pair of photomasks by rewinding the substrate for the time being so that there is no substrate at the exposure position. However, it is very cumbersome to take up the substrates that are processed in the longitudinal direction, and pull them out again after replacement to restore the original state, which may cause the problem that the operation of the device will stop for a long time. Therefore, if possible, it is preferable to design such that the substrate remains unchanged and only a pair of photomasks are exchanged.

However, according to the review of the inventors, in the case of conventional photomasks, the above-mentioned exchange method is a very laborious method due to the relationship with calibration. In view of this point, it is explained in detail below.

In order to align a pair of reticles with respect to the substrate with high precision, it is preferable to design the alignment mark of each reticle (hereinafter referred to as the reticle mark) and the alignment opening of the substrate to be perpendicular to each other as disclosed in Patent Document 2. They are aligned on the optical axis of the substrate, and the configuration of this state is confirmed by a camera. At this time, a plurality of mask marks are provided on each mask, and a plurality of alignment openings are also provided on the substrate in the same positional relationship. The positions of the reticles are adjusted so that the reticle marks and the openings for alignment are aligned on the optical axis, thereby performing alignment. In such an alignment structure as described above, of course, each mask mark in one mask falls within the range of the size of the substrate. That is, if the direction parallel to the board surface of the substrate and perpendicular to the longitudinal direction is defined as the substrate width direction, the distance between the substrate width direction of each mask mark in a mask will be greater than the width of the substrate. Still short.

When exchanging a pair of reticles as above, it is first necessary to align the reticles with each other. However, when each reticle is mounted, the markings on each reticle and the alignment openings on the substrate are not aligned in a straight line. The mask mark from the mask on the opposite side (backside of the substrate) will be hidden by the substrate. There are many cases where the substrate is light-shielding, and the state where the resist is coated is a typical example. In the state where the mask mark is hidden by the substrate, it is impossible to align the masks with each other. Therefore, the alignment opening of the substrate is first searched, and the mask mark of the mask on the opposite side is located at this position, and then the opposite side is aligned. It is very troublesome work that the mask mark of the mask on the side is located on a straight line. In particular, the operation of positioning the mask mark of the opposite mask in the alignment opening of the substrate has to be performed with the mask mark hidden, and thus becomes a very cumbersome operation.

As another method, it is also possible to pull out the mask to a position where the mask mark of the mask on the opposite side is not hidden by the substrate, and align the masks at this position. However, it is necessary to move the camera when the reticles are aligned with each other, and it must be returned to the original position after the alignment is completed. Then, the pair of reticles that have been calibrated must also be returned to the exposure operation position, but whether the pair of reticles are misaligned when returning must be confirmed by the camera. However, since there is a substrate at the returned position, the alignment mark of the opposite photomask cannot be captured by a camera, and it cannot be confirmed whether it remains in an aligned state. For confirmation, it is necessary to search for the alignment opening of the board and move each mask integrally so that each mask mark is located at the position. From such a fact, it is known that in the conventional configuration, exchanging the mask while leaving the substrate at the exposure operation position is a very laborious and troublesome operation due to the relationship with calibration.

The invention of this application was developed to solve such unsolved problems, and the purpose is to provide a pair of reticles that can be easily exchanged for alignment between reticles even when the substrate is left at the exposure work position. The configuration is designed so that the entire exchange operation can be completed in a short time by using such a mask pair. [Technical means to solve the problem]

In order to solve the above-mentioned problems to be solved, the invention described in item 1 of the scope of patent application of this case is a photomask pair composed of a first photomask and a second photomask mounted on a double-sided exposure device that exposes both sides of the substrate, and has the following advantages: The following constitutes, namely, The first reticle has a first reticle mark arranged for alignment of the substrate, and a first auxiliary reticle mark arranged for alignment of the second reticle, The second reticle has a second reticle mark for alignment of the substrate, and a second auxiliary reticle mark for alignment of the first reticle, The distance between the first mask mark and the second mask mark in the width direction of the substrate is less than or equal to the width of the substrate, The distance between the first auxiliary mask mark and the second auxiliary mask mark in the width direction of the substrate exceeds the width of the substrate. In addition, in order to solve the above-mentioned problems to be solved, the invention described in claim 2 has the following configuration, that is, it has a conveying system that pulls out the substrate rolled into a roll and feeds it intermittently; and A pair of photomasks as described in Item 1 of the scope of the patent application, arranged at a position sandwiching the substrate to be fed; and An exposure unit for exposing both sides of the substrate by irradiating light to the substrate through the first and second masks respectively after the transfer system stops the substrate for alignment; a substrate having alignment marks arranged in a defined positional relationship with respect to the areas to be exposed, It is provided with: a camera capable of photographing the aforementioned first mask mark, the aforementioned second mask mark and the alignment mark of the substrate; and a camera moving mechanism to move the camera; and The calibration means is to make the above-mentioned first and second reticles for the area to be exposed on the substrate by using the photographed data from the camera that has photographed the above-mentioned first reticle mark, the above-mentioned second reticle mark and the alignment mark of the substrate. Counterpoint; The camera moving mechanism is capable of photographing the substrate calibration position of the aforementioned first mask mark and the aforementioned second mask mark in order to align the aforementioned first and second mask with respect to the substrate, and for aligning the aforementioned first and second mask marks. A mechanism for moving the camera between the reticle alignment positions of the first auxiliary reticle mark and the second auxiliary reticle mark for alignment between reticles. In addition, in order to solve the above-mentioned problems to be solved, the invention described in claim 3 has the following configuration, that is, it has a conveying system that pulls out the substrate rolled into a roll and feeds it intermittently; and A pair of photomasks as described in Item 1 of the scope of the patent application, arranged at a position sandwiching the substrate to be fed; and An exposure unit for exposing both sides of the substrate by irradiating light to the substrate through the first and second masks after the transfer system stops the substrate for calibration; a substrate having alignment marks arranged in a defined positional relationship with respect to the areas to be exposed, It is provided with: a camera capable of photographing the aforementioned first mask mark, the aforementioned second mask mark and the alignment mark of the substrate; and The calibration means is to make the above-mentioned first and second reticles for the area to be exposed on the substrate by using the photographed data from the camera that has photographed the above-mentioned first reticle mark, the above-mentioned second reticle mark and the alignment mark of the substrate. Counterpoint; A camera arranged at a substrate alignment position for photographing the first mask mark and the second mask mark for aligning the first and second masks with respect to the substrate, and having a camera different from the camera , this other camera is disposed at a mask alignment position for photographing the first auxiliary mask mark and the second auxiliary mask mark in order to align the first and second masks with each other. In addition, in order to solve the above-mentioned problems to be solved, the invention described in item 4 of the scope of patent application is to pull out the flexible substrate rolled into a roll and feed it intermittently, and the two sides of the substrate to be fed In the double-sided exposure apparatus for exposing at the exposure operation position, the mask exchange method for exchanging the first and second masks by placing the sandwiched substrate at the exposure operation position has the following configuration, that is, It has: the exchanging step of exchanging at least one of the existing photomasks while leaving the substrate at the exposure operation position; and After the exchange step, the substrate is left in the exposure operation position and the first and second masks are aligned to each other for mask alignment; The first reticle has a first reticle mark arranged for alignment of the substrate, and a first auxiliary reticle mark arranged for alignment of the second reticle, The second reticle has a second reticle mark arranged for alignment of the substrate, and a second auxiliary reticle mark arranged for alignment of the first reticle, The distance between the first mask mark and the second mask mark in the width direction of the substrate is less than or equal to the width of the substrate, The distance between the first auxiliary mask mark and the second auxiliary mask mark in the width direction of the substrate exceeds the width of the substrate, In the mask alignment step, the first auxiliary mask mark and the second auxiliary mask mark are overlapped at a position away from the substrate, thereby aligning the first and second masks. [Efficacy of Invention]

As explained below, according to the mask pair of claim 1 of the present application, the mask can be exchanged while maintaining the substrate at the exposure operation position, and the alignment between the exchanged masks can be performed while maintaining the substrate at the exposure operation position. , so there is no problem of stopping the operation of the device for a long time. At this time, the mask pair has auxiliary mask marks, and the distance between the first auxiliary mask mark and the second auxiliary mask mark in the width direction of the substrate exceeds the width of the substrate, so that the two images can be captured at a position far away from the substrate. Auxiliary reticle marking on the side enables alignment of reticles with each other. Therefore, after the alignment of the reticles is completed, there is no need to move the reticle to its original position, and the alignment of the reticles can be performed very simply and in a short time. In addition, according to the invention described in item 2 of the patent application scope of this application, in addition to the above-mentioned effects, the camera can be used for both the calibration of the reticle and the calibration of the reticle pair to the substrate, so the number of cameras only needs to be small. This will reduce the cost. In addition, according to the invention described in item 3 of the scope of patent application of this application, in addition to the above-mentioned effects, a camera different from the camera used for calibration of the substrate for the pair of reticles is used when calibrating the reticles, so in terms of structure It becomes simple and saves the time required for moving the camera. In addition, according to the invention of claim 4 of the scope of patent application of this application, the mask is exchanged while maintaining the substrate at the exposure operation position, and the alignment between the exchanged masks is performed while maintaining the substrate at the exposure operation position, so there is no damage to the device. The problem of long-term stoppage of operation. At this time, the mask pair has auxiliary mask marks, and the distance between the first auxiliary mask mark and the second auxiliary mask mark in the width direction of the substrate is greater than the width of the substrate, and the two sides will be captured at a position far away from the substrate. Auxiliary reticle marks for reticle alignment. Therefore, after the alignment of the reticles is completed, there is no need to move the reticle to its original position, and the alignment of the reticles can be performed very simply and in a short time.

Next, an embodiment (embodiment) of the present invention will be described. First, an embodiment of the invention of the mask pair will be described. FIG. 1 is a perspective schematic view of a photomask pair according to the embodiment. The so-called "reticle pair" means a group of a pair of reticles. The mask pair consists of a first mask 1 and a second mask 2 mounted on a double-side exposure device that exposes both sides of a substrate. Each photomask 1, 2 is plate-shaped, and it is square in this embodiment. Since it is used for exposure, a pattern to be transferred is drawn on each mask 1, 2. In each photomask 1, 2, the area|region in which a pattern was drawn is called a pattern area, and is shown by P in FIG.

As shown in FIG. 1 , in the state of being mounted on the device, the first photomask 1 and the second photomask 2 are in a horizontal posture, so they are parallel to each other. The first photomask 1 and the second photomask 2 also have the same posture in the direction of rotation around the vertical axis, and the facing sides of the square face the same direction with respect to the first photomask 1 and the second photomask 2 . As shown in FIG. 1 , the substrate S is also in a horizontal posture at the exposure operation position. In the case of performing contact exposure, each mask 1 and 2 will move toward the substrate S from the state shown in FIG. 1 , and be in close contact with the substrate S. FIG. Light is irradiated and exposed through each photomask 1 and 2 in a close contact state.

As mentioned above, in a double-sided exposure apparatus, alignment of a mask pair with respect to the board|substrate S is performed. Therefore, each mask 1, 2 is provided with marks 11, 21 for this calibration. Hereinafter, the alignment mark 11 provided in the 1st mask 1 is called a 1st mask mark, and the alignment mark 21 provided in the 2nd mask 2 is called a 2nd mask mark. As shown in FIG. 1 , in this embodiment, the first mask mark 11 has a circular shape, and the second mask mark 21 is a circular dot smaller than the first mask mark 11 .

As shown in FIG. 1 , for alignment, an alignment opening Sm is also formed on the substrate S as an alignment mark. In the present embodiment, the opening Sm for alignment has a circular shape. In this embodiment, the 1st mask mark 11 and the 2nd mask mark 21 are smaller than the opening Sm for alignment. As will be described later, when aligning the substrate S, the first and second mask marks 11 and 21 are located in the opening Sm for alignment.

Moreover, in the mask alignment of the embodiment with such a structure, other alignment marks 12, 22 are provided in addition to the above-mentioned mask marks 11, 21 for alignment with respect to the board|substrate S. FIG. Hereinafter, among these other alignment marks 12 and 22, those provided on the first reticle 1 are referred to as first auxiliary reticle marks, and those provided on the second reticle 2 are referred to as second auxiliary reticle marks. These auxiliary mask marks 12, 22 are specially provided for aligning the masks 1, 2 with each other. In this example, two auxiliary mask marks 12 , 22 are provided on each mask 1 , 2 .

Moreover, each auxiliary mask mark 12,22 is provided outside the 1st and 2nd mask mark 11,21 in the width direction of the board|substrate S. As shown in FIG. To describe it more specifically, in the embodiment, the substrate S is assumed to be long and strip-shaped. The width direction of the substrate S is a direction along the surface of the substrate S and a direction perpendicular to the longitudinal direction. Hereinafter, this direction is referred to as the substrate width direction.

As shown in FIG. 1 , the first mask mark 11 is formed outside the pattern area P in the width direction of the substrate. However, the distance between the four first mask marks 11 in the substrate width direction is shorter than the width of the substrate S (indicated by Sw in FIG. 1 ). Therefore, when the first mask 1 is closely attached to the substrate S, the four first mask marks 11 will be located within the surface of the substrate 1 . The four second mask marks 21 are also formed at a distance shorter than the width Sw of the substrate S on the outside of the pattern P in the substrate width direction. Therefore, when the second mask 2 is closely attached to the substrate S, the four second mask marks 21 will be located within the surface of the substrate 1 .

On the other hand, the distance between the two first auxiliary mask marks 12 in the substrate width direction is longer than the substrate S width Sw as shown in FIG. 1 . The distance between the two second auxiliary mask marks 22 in the width direction of the substrate is also longer than the width Sw of the substrate S. In addition, in this embodiment, the direction connecting the two first auxiliary mask marks 12 is equal to the width direction of the substrate, and the direction connecting the two second auxiliary mask marks 22 is also equal to the width direction of the substrate. In addition, the distance between the two first auxiliary mask marks 12 is equal to the distance between the two second auxiliary mask marks 22 . Such first and second auxiliary mask marks 12 and 22 are used when aligning the reticles 1 and 2 as will be described later.

In addition, each mask 1, 2 is basically transparent outside the pattern area P. As shown in FIG. In the transparent part, for example, each mask mark 11, 12, 21, 22 is formed as a black pattern. Therefore, each mask mark 11 , 12 , 21 , 22 can be recognized with sufficient contrast by the camera 2 .

Next, a double-sided exposure apparatus of an embodiment in which such a mask pair is mounted will be described. Fig. 2 is a schematic front view of a double-side exposure device according to the embodiment. As shown in FIG. 2 , the double-sided exposure apparatus includes a transport system 3 and an exposure unit 4 . The double-side exposure apparatus of the embodiment is an apparatus for exposing a tape-shaped substrate as described above. Such a substrate is, for example, made of polyimide, for example, a substrate for a flexible printed circuit board.

The transport system 3 is a mechanism for intermittently sending out the substrate S wound into a roll. The transport system 3 is a mechanism that draws out the substrate S horizontally and transports it in a horizontal posture. Specifically, the transport system 3 includes: a delivery-side core roller 31 around which an unexposed substrate S is wound; a delivery-side pinch roller 32 that pulls the substrate S out from the delivery-side core roller 31; and The winding-side core roller 33 on which the exposed substrate S is wound, and the winding-side pinch roller 34 which pulls out the exposed substrate S and winds the winding-side core roller 33 . In addition, the feeding direction of the substrate S by the transfer system 3 is defined as the X direction, and the horizontal direction perpendicular thereto is defined as the Y direction. The Y direction is the width direction of the substrate. The direction perpendicular to the XY plane is defined as the Z direction. An exposure work position is set between the sending-side pinch roller 32 and the take-up-side pinch roller 34 . The exposure work position is a position where both surfaces of the substrate S are simultaneously exposed by the exposure unit 4 .

Moreover, the mask pair is mounted in this exposure work position. As shown in FIG. 2 , in the mask pairing, the first mask 1 is arranged on the upper side of the substrate S, and the second mask 2 is arranged on the lower side of the substrate S. As shown in FIG. That is, it becomes the state which sandwiched the board|substrate S by a photomask pair. The first mask 1 is mounted on the first mask stage 10 , and the second mask 2 is mounted on the second mask stage 20 . Each mask stage 10, 20 is a square frame shape, and it is a shape which does not obstruct the light irradiation which passes each mask 1, 2.

In addition, a mask moving mechanism 5 for moving the masks 1 and 2 is attached to the mask pair. In the present embodiment, the mask moving mechanism 5 is a mechanism capable of independently moving the first mask 1 and the second mask 2 and also capable of moving the two masks 1 and 2 integrally. For example, by fixing the mechanism for moving the first mask platform 10 in the XY direction to the first base plate, fixing the mechanism for moving the second mask platform 20 in the XY direction on the second base plate, and then setting the first It is realized by the mechanism that the two bottom plates move in the XY direction integrally.

In addition, the mask moving mechanism 5 is a mechanism that is automatically controlled by the main controller 6, but the main controller 6 has a manual operation part not shown in the figure, and is a mechanism that can also be manually operated. In addition, Z direction movement mechanism which is not shown in figure is provided in each mask 1,2. The Z-direction moving mechanism is used for contact exposure, and is used to move the masks 1 and 2 toward the substrate S so as to be in close contact with the substrate S.

The exposure unit 4 also employs a pair so that both sides of the substrate S can be exposed by light irradiation through such a pair of masks 1 , 2 each. The exposure unit 4 which exposes through the 1st mask 1 is provided in the upper side of the 1st mask 1, and irradiates light downward and exposes. The exposure unit 4 which exposes through the 2nd photomask 2 is provided in the lower side of the 2nd photomask 2, and irradiates light upwards and exposes.

The two exposure units 4 are vertically symmetrical and identical in structure. That is, each exposure unit 4 is equipped with the light source 41, the optical system 42 which irradiates the light from the light source 41 to the reticle 1, 2, etc. As will be described later, the apparatus of this embodiment is an apparatus that performs contact exposure, and each exposure unit 4 is a unit that irradiates parallel light to each mask 1 , 2 . Therefore, the optical system 42 includes a collimating lens.

The transport system 3 includes buffer zones 301 and 302 on the upstream and downstream sides of the exposure work position. The transport system 3 includes a first drive roller 35 arranged upstream of the exposure work position, and a second drive roller 36 arranged downstream of the exposure work position. Each drive roller 35,36 is a pinch roller. As shown in FIG. 2 , a delivery-side buffer zone 301 is formed between the delivery-side pinch roller 32 and the first driving roller 35 . In addition, a winding-side buffer zone 302 is formed between the second driving roller 36 and the winding-side pinch roller 34 .

The first driving roller 35 and the second driving roller 36 are elements for performing intermittent feeding of the substrate S passing through the exposure work position. That is to say, the first driving roller 35 and the second driving roller 36 are synchronously acting rollers, and are configured to feed the substrate S by a predetermined stroke. This stroke is the distance that the substrate S is fed during one batch of intermittent feeding, hereinafter referred to as the feeding stroke, represented by Lf in FIG. 1 .

On the other hand, the sending-side core roller 31 and the sending-side pinch roller 32 are synchronously driven in accordance with the slack of the substrate S in the sending-side buffer zone 301 . A sensor (not shown) is arranged in the sending-side buffer zone 301, and when the amount of slack decreases, the sending-side core roller 31 and the sending-side pinch roller 32 will operate synchronously, and the substrate S will be sent out until the slack reaches the set maximum value. up to the amount. The same is true for the take-up side buffer 302, and a sensor not shown is disposed therein. According to the signal from the sensor, if the amount of slack increases to the limit, the pinch roller 34 on the take-up side and the core roller 33 on the take-up side will act synchronously to wind up the substrate S until the amount of slack is reduced to the set minimum value. .

In the intermittent feeding of the conveyance system 3 described above, both sides of the substrate S are exposed by the exposure units 4 during the stop of the substrate S after the feeding by the feed stroke Lf, but before that, they are exposed by the calibration means. to calibrate. The calibration means is a means of aligning the area to be exposed on the substrate S in order to move the first and second masks 1 and 2 . Therefore, the aforementioned mask moving mechanism 5 is included in the calibration means.

As shown in FIG. 2 , the apparatus includes a main controller 6 for controlling each part including the transport system 3 and the above-mentioned mask moving mechanism 5 . In the main controller 6, a main sequence program (main sequence program) 7 for controlling each part of the device to operate in a predetermined procedure is installed. That is, the main sequence program 7 is stored in the storage unit 60 of the main controller 6 and can be executed by a processor (not shown) of the main controller 6 . The main sequence program 7 constitutes a calibration means for performing the aforementioned calibration. In addition, the main controller 6 includes a display 61 for displaying errors and the like.

The calibration performed by the calibration means is further described in detail with reference to FIG. 2 and FIG. 3 . Fig. 3 is a schematic perspective view showing alignment in the double-side exposure apparatus according to the embodiment. As shown in FIG. 2 and FIG. 3 , the device includes a camera 8 for calibration. In the present embodiment, four first mask marks 11 and four second mask marks 21 are respectively provided as described above, so four cameras 8 are provided in conjunction with these. As shown in FIG. 3, four cameras are installed at positions corresponding to corners of a square.

As mentioned above, there are two types of calibration, one is the calibration between the reticle 1 and 2, and the other is the calibration of the reticle pair with respect to the substrate S. Among them, FIG. 3(1) shows the alignment of the reticles 1 and 2, and FIG. 3(2) shows the alignment of the reticle pair with respect to the substrate S.

As shown in FIG. 2 and FIG. 3 , each camera 8 is arranged so that the optical axis (optical axis of the built-in lens) A becomes vertical, and is installed in a downward posture. A camera moving mechanism 81 for changing the position of the camera 8 in the XY direction is provided on the base where each camera 8 is fixed. In addition, as shown in FIG. 2 , each camera 8 is connected to the main controller 6 , and the shooting data of the cameras 8 will be sent to the main controller 6 . The camera moving mechanism 81 is also controlled by the main controller 6 .

First, alignment between the reticles 1 and 2 will be described. Alignment between the reticles 1 and 2 is performed when the respective reticles 1 and 2 are mounted on the device for the first time or when the reticles 1 and 2 are exchanged as described later. For the mutual calibration of the reticles 1, 2, two cameras on both sides of the four cameras 8 are used. For example, of the four cameras 8 shown in FIG. 3 , the two cameras on the left are used for the calibration of the reticles 1 and 2 . Hereinafter, these two cameras 8 are called dual-purpose cameras.

When aligning the reticles 1 and 2, the camera moving mechanism 8 moves the combined camera 8 to a position where the reticles 1 and 2 are aligned (hereinafter referred to as a mask alignment position). The reticle alignment position is the position where each of the first and second auxiliary reticle marks 12 and 22 of the reticle 1 and 2 will fall into the field of view. In other words, each mask 1, 2 is arranged so that each of the first and second auxiliary mask marks 12, 22 falls into the field of view of the dual-purpose camera 8 arranged at the mask alignment position. This configuration work is mostly manual work. In addition, the moving direction to the mask calibration position is consistent with the Y direction.

The images of the auxiliary mask marks 12 and 22 captured by the dual-purpose camera 8 are displayed on the display 61 through the main controller 6 . Therefore, the operator manually operates the mask moving mechanism 5 while looking at the image on the display 61 so that the first auxiliary mask marks 12 and the second auxiliary mask marks 22 overlap on the same straight line. In this way, as shown in FIG. 3(1), a pair of photomasks 1 and 2 are aligned with each other. For example, the position of the 1st mask 1 is maintained fixed, and the 2nd mask 2 is moved so that each 2nd auxiliary mask mark 22 and each 1st auxiliary mask mark 12 may become the same straight line. In this embodiment, each first auxiliary mask mark 12 is circular, and each second auxiliary mask mark 22 is a circle smaller than the first auxiliary mask mark 12, so each second auxiliary mask mark 22 will Located in each first auxiliary mask mark 12 . Then, if the center of each second auxiliary mask mark 22 and the center of each first auxiliary mask mark 12 coincide within a necessary accuracy range, the two masks 1 and 2 are aligned with each other.

Next, the alignment of the mask pair with respect to the substrate S will be described. When the above-mentioned alignment between the reticles 1 and 2 is performed, the dual-purpose camera 8 returns to its original position. The original position is a position set as an arrangement position of the camera 8 when calibration with respect to the board|substrate S is performed. Hereinafter, this position is referred to as a substrate calibration position.

The substrate calibration position is a position corresponding to a corner of a square whose sides extend in the XY direction. The relationship of the board calibration positions of the four cameras 8 is consistent with the design positional relationship of the calibration openings Sm of the board S. As shown in FIG. Therefore, when the calibration openings Sm are correctly formed as designed and the transfer system 3 performs intermittent feeding between the feeding strokes Lf without errors, the calibration openings Sm are located on the optical axes A of the cameras 8 . Actually, each calibration opening Sm deviates from the optical axis A when the intermittent feeding is completed due to the deviation of the forming positions of the calibration openings Sm or the accuracy limit of the intermittent feeding of the transport system 3 . Each camera 8 uses something with a sufficiently large field of view so that the calibration openings Sm fall into the field of view of each camera 8 even in this situation.

The calibration of the substrate S is carried out by the automatic control of the main controller 6 . Specifically, it is executed by the main sequence program 7 built in the main controller 6 and several subroutines called out from the main sequence program 7 to execute. In the main controller 6, as subroutines called out from the main sequence program 7 and executed, there are opening presence/absence determination program 71, opening search program 72, opening lack judgment program 73, opening lack elimination program 74, mark concealment determination Program 75 , provisional calibration program 76 , mark lack judgment program 77 , mark lack elimination program 78 , formal calibration program 79 .

The final calibration is the formal calibration program 79, but the main sequence program 7, before the formal calibration, will execute the opening presence or absence determination program 71 to make it judge whether each calibration opening Sm is photographed by the camera 8, if not photographed, Then the opening search program 72 is executed. The opening search program 72 sends a control signal to the conveyance system 3 to slightly reverse or feed the substrate S so that each calibration opening Sm falls into the field of view of each camera 8 .

In addition, the main sequence program 7 executes the opening defect determination program 73 to determine whether any of the calibration openings Sm is missing. If it is lacking and is photographed, then execute the opening lack elimination program 74 . The opening defect elimination program uses the camera moving mechanism 81 to move the camera 8 to eliminate the defect.

In addition, the main sequence program 7 executes the mark concealment determination program 75 to determine whether each of the first and second mask marks 11 and 21 is concealed on the substrate S, and if concealed, executes the tentative calibration procedure 76 . The provisional calibration program 76 is based on the position of each mask mark 11, 21 when the calibration of the previous exposure is completed, and calculates the amount of movement to eliminate the concealment, and sends it to the mask moving mechanism 5 so that each mask 1, 21 2 Move, thereby eliminating concealment.

In addition, the main sequence program 7 executes the mark missing judgment program 77 to judge whether or not each mask mark 11, 21 is missing and photographed. If it is lacking and is photographed, the mark lacking elimination program 78 is executed. The marking defect elimination program 78 calculates the amount of movement for eliminating the defect, and sends it to the mask moving mechanism 5 to move the masks 1 and 2 to eliminate the defect.

In this way, once each calibration opening Sm is photographed in a state without defects, and each mask mark 11, 21 is located in each calibration opening Sm in a state without defects, it becomes a state that can be calibrated, and the main sequence program 7 will execute the formal calibration routine 79. FIG. 4 is a schematic plan view showing the formal calibration procedure 79 .

The formal calibration program 79 first calculates the center of the first mask mark 11 and the center of the second mask mark 21 in the coordinate system with the point on the optical axis A as the origin. Then, it is judged whether the center of the first mask mark 11 and the center of the second mask mark 21 are consistent with the necessary accuracy, if not, a signal is sent to the mask moving mechanism 5 to make one of the mask 1, 2 Or both sides move to make it consistent. Usually, the previous exposure would bring the two together to the necessary precision, and that state would be maintained. After confirming that the center of the first mask mark 11 and the center of the second mask mark 21 coincide with the required precision, the program 79 is formally calibrated to find the middle point of these centers. Then, the formal calibration program 79 finds the center of the calibration opening Sm of the substrate S, finds the deviation from the middle point of the center of the pair of mask marks 11, 21, and calculates the mask used to eliminate the deviation. The direction and distance of the movement of 1 and 2.

The calibration program performs the above-mentioned data processing on the shooting data from each camera 8, and calculates the moving direction and distance of each mask 1, 2 to eliminate the deviation. Afterwards, the moving directions and distances obtained from each photographed data are averaged to serve as the movement commands of the masks 1 and 2 for the final main calibration, and are sent back to the main sequence program 7 . The direction and distance of movement are grasped as the vectors of each (shown by arrows in FIG. 4 ), so the direction of each vector is synthesized, and the length is averaged.

The main sequence program 7 sends the return value, that is, the movement command, to the mask moving mechanism 5, so that the pair of masks 1, 2 are moved integrally, so that the centers of the mask marks 11, 21 are aligned at the required precision. Straight line. At this point, the formal calibration is over. Thereafter, the main sequence program 7 stores the coordinates of the centers of the mask marks 11 and 21 at the point in time when the official calibration is completed in the memory unit 61 for calibration during exposure of the next target exposure region R. The main sequence program 7 and the subroutines 71 to 79 are written to perform the above-mentioned operations.

Next, the overall operation of the double-side exposure apparatus according to the embodiment configured as described above will be schematically described. A pair of photomasks 1 and 2 are located at a standby position away from the substrate S in the Z direction. This position is a position where the XY plane for alignment of the mask pair with respect to the substrate S exists. A control signal is sent from the main controller 6 which is executing the main sequence program 7 to the conveying system 3, so as to feed the substrate S by just the amount of the feeding stroke Lf. In this way, the first driving roller 35 and the second driving roller 36 will act synchronously, and the substrate S will be fed toward the front side (winding side) in the X direction just at the feeding stroke Lf.

Once the signal that has been fed is returned from the conveying system 3 to the main controller 6, the main sequence program 7 performs the above-mentioned series of calibration operations. That is, if the calibration opening Sm is not within the field of view of each camera 8, the opening search program 72 is executed, and if any calibration opening Sm is missing, the opening lack elimination program 74 is executed. In addition, if there is a hidden mark, the temporary calibration program 76 is executed, and if one of the first and second mask marks 11 and 21 is defective, the mark-deficient elimination program 78 is executed. Thereafter, the main sequence program 7 executes the formal calibration program 79 . In this way, the calibration is complete.

Thereafter, the main sequence program 7 sends a control signal to the Z-direction moving mechanism not shown to move the pair of masks 1 and 2 in the Z direction so that the respective masks 1 and 2 are brought into close contact with the substrate S. In this state, the main sequence program 7 obtains the shooting data from each camera 8, and judges whether to maintain the calibrated state (whether the centers of the marks 11, 21, Sm coincide with the necessary accuracy). If maintained, the main sequence program 7 sends a control signal to each exposure unit 4 to make it perform exposure.

After exposure for a predetermined time with a necessary exposure amount, each exposure unit 4 stops light irradiation. Thereafter, the main sequence program 7 sends a control signal to the Z-direction moving mechanism not shown, so that the pair of masks 1 and 2 are separated from the substrate S and return to the original standby position. Once it is confirmed that each photomask 1, 2 has returned to the standby position, the main sequence program 7 sends a control signal to the conveying system 3, so that the substrate S is fed toward the front side in the X direction by just the portion of the feeding stroke Lf. Thereafter, for the same operation as above, the operation of performing calibration and exposure is repeated during the pause of the intermittent feeding during the feeding stroke Lf of the substrate S.

When the operation is repeated, if the slack of the substrate S in the delivery-side buffer zone 301 decreases, the delivery-side core roller 31 and the delivery-side pinch roller 32 will operate synchronously to send the substrate S to the delivery-side buffer zone 301 . In addition, when the slack of the substrate S in the winding-side buffer zone 302 increases, the winding-side core roller 33 and the winding-side pinch roller 34 operate synchronously to wind the substrate S onto the winding-side core roller 33 .

After repeating such operations, it is necessary to exchange masks 1 and 2 when exposing products of different types. The exchange operation here also has great features, so it will be described in detail below. As mentioned above, when the photomasks 1 and 2 are exchanged, it is very troublesome to temporarily wind up the substrate S that is processed in the middle of the longitudinal direction, and then pull it out after the exchange to restore the original state. Therefore, in the device of the embodiment, the substrate S S will remain still and exchange masks 1 and 2. That is, the first photomask 1 is detached from the first photomask stage 10 , and another first photomask 1 is mounted on the first photomask stage 10 . In addition, the second photomask 2 is detached from the second photomask stage 20 , and another second photomask 2 is mounted on the second photomask stage 20 .

Thereafter, re-align the reticles 1 and 2 with each other. This is because when the photomasks 1 and 2 are exchanged, the photomask stages 10 and 20 may be slightly misaligned, or the mounting positions of the photomasks 1 and 2 may be slightly misaligned. In addition, depending on the type, the size of the reticle 1 and 2 or the shape of the auxiliary reticle marks 12 and 22 may be different, and recalibration is necessary.

At this time, the mask pair of the embodiment has the auxiliary alignment marks 12, 22 in addition to the first and second mask marks 11, 21, so it is used. That is, as shown in FIG. 3(1), the dual-use camera 8 is positioned at the mask calibration position by the camera moving mechanism 81 . Then, each auxiliary alignment mark 12, 22 is photographed by each dual-purpose camera 8, and the image is displayed on the display 61, and the operator operates the reticle moving mechanism 5 while looking at the display 61 to perform mutual reticle 1, 2. calibration. Once the alignment of the photomasks 1 and 2 is completed, preparations for exposure through the photomasks 1 and 2 are completed, so the above-mentioned operations are repeated thereafter.

In this way, according to the mask exchange method of the embodiment, the masks 1 and 2 are exchanged while maintaining the substrate S at the exposure work position, and the masks 1 and 2 are exchanged while maintaining the substrate S at the exposure work position. the calibration. Therefore, there is no problem of stopping the operation of the device for a long time. In addition, the mask pair of the embodiment has auxiliary mask marks 12, 22, and the distance between the first auxiliary mask mark 12 and the second auxiliary mask mark 22 in the width direction of the substrate exceeds the width Sw of the substrate S. Therefore, the camera 8 can be used to photograph the auxiliary mask marks 12 and 22 on both sides at a position far away from the substrate S, so that the reticles 1 and 2 can be calibrated. Therefore, there is no need to move the masks 1 and 2 to their original positions after the alignment of the masks 1 and 2 is completed, and the alignment of the masks 1 and 2 can be performed very simply and in a short time.

The double-sided exposure apparatus of the above-mentioned embodiment is configured to move the dual-purpose camera 8 to the mask alignment position by the camera moving mechanism 81 when the masks 1 and 2 are aligned with each other. camera. Since the number of cameras increases, the cost increases, but there are advantages of simplifying the configuration of the camera moving mechanism 81 and saving time for moving the dual-use camera 8 . In addition, in the above-mentioned embodiment, although the alignment of the reticle 1 and 2 when the reticle 1 and 2 are exchanged is a manual operation, the reticle 1 is also performed in the alignment operation before exposure that is repeated every time the intermittent feeding is performed. , 2 In the case of mutual calibration, this is the automatic control made by the main controller 6. In addition, although the alignment between the reticle 1 and 2 at the time of reticle exchange was described as a manual operation, it may be performed by automatic control by the main controller 6 .

In addition, in the above-mentioned embodiment, the conveyance system 3 conveys the object of the board|substrate S roll-to-roll, but it is also possible to adopt the structure which only the delivery side is a roll type. That is, the double-side exposure apparatus of the present invention can also be used in the process of cutting the exposed substrate S at a predetermined position and performing subsequent processing. In addition, as the conveyance system 3, the feeding direction of the board|substrate S may also be a vertical direction. In this case, both surfaces of the board|substrate S of a vertical posture are exposed through a photomask, and the exposure unit 4 is arrange|positioned on the left and right.

In addition, in the said embodiment, although the alignment mark of the board|substrate S is the opening Sm for alignment, it does not necessarily have to be an opening. In the substrate S, there may be a transparent region outside the target exposure region R, and a circumferential mark may be formed in this region as an alignment mark, for example. In addition, a shape cut from the edge of the substrate S may also be formed as an alignment mark. In addition, as the shape of the alignment mark of the board|substrate S, other shapes, such as a square or a triangle, may be sufficient.

For the first mask mark 11 and the second mask mark 21 , a shape other than a circumferential shape or a circle may also be employed. For example, one side may be circular and the other side may be cross-shaped. In addition, there are cases where calibration is performed in a state where the first mask mark 11 enters the inside of the second mask mark 21 . This point also applies to the first auxiliary mask mark 12 and the second auxiliary mask mark 22 . In addition, the distance between the two first mask marks 11 in the substrate width direction or the distance between the two second mask marks 21 may coincide with the width Sw of the substrate S. For example, when the alignment marks of the substrate S are arranged on both sides of the substrate S, or in the case of gaps arranged on the two sides, there will be a distance between the two first mask marks 11 in the width direction of the substrate and The width of the substrate S and the distance between the two second mask marks 21 in the width direction of the substrate are consistent with the width of the substrate S.

Also, since the mask mark (in the above example, the first mask mark 11 ) closer to the substrate S with respect to the camera 8 is not blocked by the substrate S, it may be larger than the alignment opening Sm. However, when the contrast between the substrate S and the photomask is small, there is a problem that processing of image data becomes difficult. If the alignment is performed with the pair of mask marks 11, 21 located in the alignment opening Sm, the contrast between the substrate S and the mask marks 11, 21 will not become a problem, which is preferable. .

In addition, in the above-mentioned embodiment, although the number of auxiliary mask marks 12, 22 in one mask 1, 2 is two, it may be three or more, and one case is also possible. For example, if the photomask stages 10 and 20 are capable of holding the photomasks 1 and 2 without deviation around the axis in the Z direction, only one calibration mark is required for each photomask 1 and 2. One bit is enough, and such a configuration may also be adopted. In addition, in the description of the embodiment of the mask exchange method, although both the masks 1 and 2 were exchanged, there may be a case where only one of the masks 1 and 2 is exchanged. In this case, it is also necessary to align the reticles 1 and 2 after exchange, and the configuration having the above-mentioned auxiliary mask marks 12 and 22 contributes to the simplification of alignment.

Although the device of the above-mentioned embodiment is exposed by a contact method, the effect of the above-mentioned alignment configuration is similarly exerted even by a proximity method or a projection method, so these methods may also be used. In addition, in the case of the proximity method or the projection exposure method, it is not necessary to bring a pair of masks into close contact with the substrate, so there may be no mechanism for moving the mask in the Z direction.

1‧‧‧The first mask 11‧‧‧First mask mark 12‧‧‧The first auxiliary mask mark 2‧‧‧Second mask 21‧‧‧Second Mask Marking 22‧‧‧Second Auxiliary Mask Marking 3‧‧‧Transportation system 4‧‧‧Exposure unit 41‧‧‧Light source 42‧‧‧Optical system 5‧‧‧Reticle moving mechanism 6‧‧‧Main controller 61‧‧‧memory department 7‧‧‧Main sequence program 71‧‧‧Determination program for presence or absence of opening 72‧‧‧Open search program 73‧‧‧Determination program for lack of opening 74‧‧‧Mouth gap elimination program 75‧‧‧Mark Concealment Judgment Program 76‧‧‧Temporary Calibration Program 77‧‧‧Determination program for mark deficiency 78‧‧‧Mark deficiency elimination program 79‧‧‧Formal calibration procedure 8‧‧‧Camera 81‧‧‧Camera moving mechanism S‧‧‧substrate Sm‧‧‧calibration opening

[ Fig. 1 ] A perspective schematic view of a mask pair according to the embodiment. [ Fig. 2 ] A schematic front cross-sectional view of a double-side exposure device according to the embodiment. [ Fig. 3 ] A schematic perspective view showing alignment in a double-side exposure device according to the embodiment. [Fig. 4] A schematic plan view revealing the formal calibration procedure.

1‧‧‧The first mask

2‧‧‧Second mask

8‧‧‧Camera

11‧‧‧First mask mark

12‧‧‧The first auxiliary mask mark

21‧‧‧Second Mask Marking

22‧‧‧Second Auxiliary Mask Marking

A‧‧‧optical axis

S‧‧‧substrate

R‧‧‧Target exposure area

Lf‧‧‧Feed Itinerary

Sm‧‧‧calibration opening

Sw‧‧‧Substrate S width

Claims (4)

A pair of photomasks is a pair of photomasks composed of a first photomask and a second photomask mounted on a double-side exposure device that exposes both sides of a substrate. It is characterized in that the aforementioned first photomask has a 2 first mask marks provided for calibration of the substrate, and 2 first auxiliary mask marks provided for calibration of the aforementioned second mask. 2 second mask marks for calibration, and 2 second auxiliary mask marks for calibration of the first mask, the 2 first mask marks in the width direction of the substrate and the distance between the two aforementioned second mask marks in the width direction of the aforementioned substrate is less than or equal to the width of the aforementioned substrate, and the two aforementioned first auxiliary mask marks are placed between the aforementioned The distance in the width direction of the substrate exceeds the width of the substrate, and the distance between the two second auxiliary mask marks in the width direction of the substrate exceeds the width of the substrate, and the two first auxiliary lights The mask mark and the two first mask marks are aligned on the same straight line, and the direction of the same straight line is the same direction as the width direction of the substrate when mounted on the double-sided exposure device, and the two second auxiliary masks are The mark and the two aforementioned second mask marks are arranged side by side on the same straight line, and the direction of the same straight line is the same as that carried on the aforementioned two-sided exposure In the case of an optical device, the direction coincides with the width direction of the aforementioned substrate. A double-side exposure device characterized by comprising: a conveying system that pulls out a flexible substrate rolled into a roll and intermittently feeds it; The pair of photomasks described in claim 1 of the scope of patents; and after the transfer system stops the aforementioned substrate and performs alignment, each of the first and second photomasks irradiates the aforementioned substrate with light to expose both sides of the aforementioned substrate Unit; the substrate having two calibration marks arranged in a predetermined positional relationship with respect to the area to be exposed, and a camera capable of photographing each of the aforementioned first mask marks, each of the aforementioned second mask marks, and the aforementioned substrate each of the aforementioned calibration marks; and a camera moving mechanism that moves the aforementioned camera; For the shooting data of the camera, align the aforementioned first and second photomasks with respect to the area to be exposed on the aforementioned substrate; Calibrate and photograph the substrate alignment positions of each of the aforementioned first reticle marks and each of the aforementioned second reticle marks, and photograph each of the aforementioned first auxiliary reticle marks and each of the aforementioned first reticle marks in order to align the aforementioned first and second reticles with each other 2. A mechanism for moving the aforementioned camera between the mask alignment positions of the auxiliary mask marks. A double-side exposure device characterized by comprising: a conveying system that pulls out a flexible substrate rolled into a roll and intermittently feeds it; The pair of photomasks described in claim 1 of the scope of patents; and after the transfer system stops the aforementioned substrate and performs alignment, each of the first and second photomasks irradiates the aforementioned substrate with light to expose both sides of the aforementioned substrate Unit; the substrate having two calibration marks arranged in a predetermined positional relationship with respect to the area to be exposed, and a camera capable of photographing each of the aforementioned first mask marks, each of the aforementioned second mask marks, and the aforementioned substrate each of the aforementioned calibration marks; and the calibration means, by taking the photographed data from the aforementioned camera of each of the aforementioned first mask marks, each of the aforementioned second mask marks, and each of the aforementioned calibration marks of the aforementioned substrate, the aforementioned first, second The two photomasks are aligned for the area to be exposed on the aforementioned substrate; the aforementioned camera is configured to photograph each of the aforementioned first photomask marks and each of the aforementioned photomasks in order to align the aforementioned first and second photomasks with respect to the aforementioned substrate. The substrate alignment position of the second reticle mark, and a camera different from the aforementioned camera is provided, and the aforementioned other camera is configured to photograph each of the aforementioned first auxiliary reticles in order to align the aforementioned first and second reticles with each other The reticle alignment position of the mark and each of the aforementioned second auxiliary reticle marks. A method for exchanging a photomask, in a double-sided exposure device that pulls out a flexible substrate rolled into a roll and feeds it intermittently, and exposes both sides of the fed substrate at an exposure work position, The method of exchanging the first and second photomasks in which the exposure operation position is arranged so as to sandwich the aforementioned substrate is characterized in that the first and second photomasks are exchanged while the aforementioned substrate is left in the aforementioned exposure operation position. The step of exchanging the photomask of at least one side of the mask; and after the aforementioned exchanging step, the step of aligning the aforementioned first and second photomasks by leaving the aforementioned substrate at the aforementioned exposure operation position; the aforementioned first photomask A mask having two first mask marks for alignment of the substrate and two first auxiliary mask marks for alignment of the second mask, the second mask, There are 2 second mask marks set for calibration of the aforementioned substrate, 2 second auxiliary mask marks set for calibration of the aforementioned first mask, and 2 aforementioned first mask marks The distance apart in the width direction of the substrate is not more than the width of the substrate, and the distance between the two second mask marks in the width direction of the substrate is not more than the width of the substrate, and the two second mask marks The distance between one auxiliary mask mark in the width direction of the substrate exceeds the width of the substrate, and the distance between the two second auxiliary mask marks in the width direction of the substrate exceeds the width of the substrate, In the aforementioned photomask alignment step, each front The first auxiliary mask marks overlap with each of the second auxiliary mask marks, thereby aligning the first and second masks.

Images