JP5104107B2 - Strip-shaped workpiece exposure apparatus and focus adjustment method in strip-shaped workpiece exposure apparatus - Google Patents

Description

  The present invention relates to an exposure apparatus for forming a pattern on a long strip-shaped workpiece such as TAB (Tape Automated Bonding) or FPC (Flexible Printed Circuit), and a focus adjustment method in the exposure apparatus.

In a display panel such as a liquid crystal display, a mobile phone, a digital camera, and an IC card, a film circuit board in which an integrated circuit is mounted on a resin film such as polyester or polyimide having a thickness of about 25 μm to 125 μm is used. In the manufacturing process, the film circuit board is, for example, a strip-shaped workpiece having a width of 160 mm, a thickness of 100 μm, and a length of several hundreds of meters, and is usually wound on a reel.
Moreover, the conductor (for example, copper foil) is affixed on the said resin film in the film circuit board. The film circuit board is manufactured by repeating a resist coating process, an exposure process for transferring a desired circuit pattern, a resist developing process, an etching process for removing unnecessary conductors, etc., for example, 4 to 5 times. Done. In each step, the film circuit board is unwound from the reel, processed, and taken up on the reel again. Hereinafter, the film circuit board is referred to as a strip-shaped workpiece.
An exposure apparatus that transfers a circuit pattern to each exposure region while conveying the belt-like workpiece is disclosed in, for example, Patent Document 1 and the like.

FIG. 5 shows an example of the configuration of a belt-shaped workpiece exposure apparatus.
A belt-like workpiece W (hereinafter, also simply referred to as a workpiece W) is wound around the unwinding roll 1 in a roll shape so as to overlap with a spacer that protects the workpiece W. When pulling out from the unwinding roll 1, the spacer is wound around the spacer winding roll 1a.
The strip-shaped workpiece W that has come out of the unwinding roll 1 is sandwiched between the encoder roll R3 and the pressing roll R3 ′ through the slack portion A1 and the intermediate guide roll R2. The encoder roll R3 is a roll for confirming whether or not slip has occurred in a later-described transport roll during workpiece transport.
The strip-shaped workpiece W drawn out from the unwinding roll 1 passes through the exposure unit 3 and is held between the transport roll R4 and the pressing roll R4 ′. The work W is transported by a predetermined amount set by the rotation of the transport roll R4 and is sent onto the work stage 10 of the exposure unit 3.

On the exposure unit 3, a light irradiation unit 4 including a lamp 4a and a condenser mirror 4b, a mask M having a pattern (mask pattern) to be exposed on a workpiece, and a projection lens 5 are provided. The work stage 10 is mounted on the work stage drive mechanism 6, can be driven in the vertical and horizontal directions, and can be rotated about an axis perpendicular to the work stage surface.
In the exposure unit 3, the back surface side of the exposed area of the belt-like workpiece W is held on the surface of the work stage 10 by a holding means such as vacuum suction. This is to fix the exposure area of the workpiece W at the imaging position of the mask pattern projected by the projection lens 5 and prevent the workpiece W from moving in the optical axis direction or the conveyance direction during the exposure.

FIG. 6 is a perspective view showing the mask, projection lens, and work stage extracted from the exposure apparatus shown in FIG.
As shown in the figure, the mask M is formed with two alignment marks (mask marks) MAM, and the workpiece W has two alignment marks (work marks) corresponding to the number of mask marks MAM for each exposure region. ) WAM is formed. In this example, the work mark WAM is a through hole formed in the periphery of the belt-like workpiece W. However, when the belt-like workpiece W is light transmissive, a mark WAM is formed on the workpiece W. There may be.
Further, the work stage 10 is provided with notches 10a or through holes at positions (two locations) where the mask mark MAM is projected by the projection lens 5, and an alignment microscope (two units) 12 is disposed below the notches 10a. The
The alignment microscope 12 detects the mask mark MAM and the work mark WAM through the notch 10a or the through hole of the work stage 10.

When the work mark WAM is conveyed to the notch 10a of the work stage 10, that is, onto the alignment microscope 12, the work mark WAM is sucked and held on the work stage 10.
The alignment light illumination means 11 is inserted above the mask M by a moving mechanism (not shown). The alignment light illuminating means 11 irradiates the alignment light onto the mask mark MAM, and the projection lens 5 projects the mask mark image onto the alignment microscope 12 through the through hole as the work mark WAM.
The alignment microscope 12 detects the projected mask mark image. At the same time, an image of the edge of the through hole that is the work mark WAM is also detected.
The control unit 20 shown in FIG. 5 inputs the mask mark MAM image detected by the alignment microscope 12 and the edge image of the work mark WAM and performs image processing. Then, based on the positional information of the mask mark MAM and the work mark WAM, the work stage driving mechanism 6 is driven so that they are in a predetermined positional relationship, and the mask M and the work W formed with a mask pattern such as a circuit are formed. Align with the exposure area.

After the alignment is completed, the exposure light emitted from the light irradiation unit 4 is irradiated onto the workpiece W via the mask M and the projection lens 5, and the mask pattern is transferred to the workpiece W.
When the exposure is finished, the belt-like work W is held between the transport roll R4 and the pressing roll R4 ′, and transported and exposed so that the next exposure area is on the work stage 10.
In this way, the strip-shaped workpiece W is sequentially exposed and wound on the winding roll 2 through the guide roll R5 and the slack portion A2. At that time, the spacer is fed out from the spacer unwinding roll 2a, and the exposed belt-like workpiece W is wound up on the winding roll 2 together with the spacer.
The surface position of the work stage 10 is adjusted in advance to the focus position of the projection lens 5 by the work stage drive mechanism 6.
Japanese Patent No. 2886675

  Circuit patterns formed on film circuit boards are becoming more dense and finer as electronic devices become faster, more multifunctional, and smaller in size, and the exposure accuracy of exposure equipment is expected to increase year by year. It is becoming. Therefore, the projection lens of the exposure apparatus needs to have a higher resolution. However, when a high-resolution projection lens is mounted on the exposure apparatus, it has become necessary to perform focus adjustment, which was not necessary conventionally.

The reason will be described below. The focus adjustment is to adjust the focus of the mask pattern image projected on the work.
(1) The focus position of the projection lens changes with respect to the designed position due to a change in the refractive index of air between the lenses due to expansion and contraction of the lens due to a temperature change and a change in atmospheric pressure.
There is no problem as long as the change in the focus position is within the depth of focus of the projection lens. However, when the change in the focus position becomes larger than the depth of focus, the exposure accuracy decreases.
(2) In general, the projection lens tends to have a shallow depth of focus when the resolution is increased. For example, in a projection lens having a resolution of about 6 μm, the depth of focus is about 50 μm, but when the resolution is about 4 μm, the depth of focus is about 30 μm.
(3) Further, as the resolution of the projection lens increases, the number of lenses to be used increases, and in the lens barrel supporting the lens, the space between the lenses increases. The pressure in this space is difficult to follow the changes in the atmospheric pressure of the environment where the lens is placed. When the atmospheric pressure decreases, the lens is subjected to a force pushed outward from the lens barrel. The force pushed inside is working. For this reason, a high-resolution projection lens is easily affected by fluctuations in atmospheric pressure, and the change in focus position also increases.
(5) Conventionally, when the exposure apparatus is installed in the user's factory, the distance from the mask to the work (also referred to as the distance between the original images) is adjusted so that the projected image of the mask pattern is formed on the work. If the temperature of the room where the projector was installed was managed so as to be almost constant, the change in focus position could be kept within the depth of focus of the projection lens. That is, if the distance between the image original images is adjusted at the time of installation of the apparatus, it is not necessary to carry out again thereafter.
However, when the projection lens mounted on the exposure apparatus has a high resolution, a change in the focus position caused by a change in temperature or atmospheric pressure becomes larger than the depth of focus of the projection lens.

As described above, the cause of the change in the focus position is caused by the temperature change and the atmospheric pressure change, and the one that has a particularly large effect is the temperature change caused by the operation of the apparatus.
There are mainly the following three temperature changes caused by the operation of the apparatus.
(A) When exposure light passes through the projection lens, the lens absorbs light energy and the temperature rises. On the other hand, when the shutter is closed by exchanging the workpiece or the like, and the light does not pass through the lens, the temperature of the lens decreases. With this temperature change, the lens expands and contracts, and the focus position changes. (B) As the temperature of the lens changes, the temperature of the lens barrel that holds the lens also changes due to heat conduction and expands and contracts. As a result, the position of the lens changes and the focus position changes.
(C) The temperature change of the lens barrel and the heat of the light source unit that emits exposure light are transmitted to the housing of the apparatus, and the entire apparatus expands and contracts. Thereby, the distance from the mask stage to the work stage changes, and the focus position changes.
Therefore, in order to maintain the desired exposure accuracy, the focus position is confirmed periodically at a predetermined time or the number of exposures a plurality of times a day so that the projected image of the mask is formed on the workpiece. It is necessary to adjust (focus adjustment) the position of the mask and the workpiece (distance between the original images).

The simplest way to adjust the focus is to expose the pattern for focus adjustment on the workpiece while actually changing the distance between the original images. From the development result, the pattern between the original images is located at the position where the pattern is formed with the highest accuracy. Is to set the distance. However, this method has the following problems.
Since it is necessary to repeat exposure and development, it takes time to make adjustment settings, and it is not practical to perform adjustments several times a day.
Assuming that the focus adjustment is performed by the above method, consider the case where the focus adjustment is performed in the middle of the exposure process (in the middle of the lot). If the workpiece is a single wafer, when the exposure processing of a certain workpiece is completed and the workpiece is unloaded, the loading of the next workpiece is temporarily stopped. Then, the mask and workpiece are exchanged for focus adjustment, and focus adjustment is performed.
However, when the work is in the form of a band, there is no break in the middle of the work, so it is difficult to exchange the mask and the work. Accordingly, focus adjustment cannot be performed during the exposure process (in the middle of the lot).

As a method of adjusting the focus without performing exposure and development, the mask pattern is projected through the projection lens, the projected pattern image is detected, and the distance between the original images is adjusted so that the focus is achieved. It is possible to do.
However, this also has the following problems.
When focus adjustment is performed using a projection image, a focus adjustment pattern is formed somewhere on the mask. Further, an illumination unit that illuminates the focus adjustment pattern and an image receiving unit that detects and receives the projected pattern image are required. However, providing illumination means and image receiving means for focus adjustment leads to an increase in the cost of the apparatus.

Therefore, it is conceivable to perform focus adjustment using a mask mark formed for alignment (the mask alignment mark is also used as a focus adjustment pattern). Since the mask mark is projected onto the alignment microscope by the alignment illumination system, it is not necessary to newly provide illumination means and image receiving means if the focus adjustment can be performed using the mask mark.
However, there is a problem with this method as described below.
The alignment accuracy required in the current strip-shaped workpiece exposure apparatus is about ± 5 μm, and the size of the mask mark for achieving this accuracy is, for example, a circle having a diameter of about 0.5 mm (work mark). The diameter of the through hole is about 1 mm).
On the other hand, for example, when adjusting the focus of a projection lens having a resolution of 4 μm, it is determined by checking whether a pattern image equivalent to the projection lens looks in focus or not. Therefore, the pattern for focus adjustment needs to be a line and space (L & S) pattern of several μm (for example, 6 μm). Therefore, the mask mark is too large to be used for focus adjustment.
In addition, the alignment microscope is provided with a lens for forming a projected image on the image receiving surface. For this reason, in the alignment microscope, as in the projection lens, the focus position changes due to changes in temperature and pressure. Therefore, when the focus adjustment is performed by causing the alignment microscope to receive the focus adjustment pattern, it is necessary to correct the change in the focus position of the alignment microscope, but the method has not been established.

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to perform exposure processing in the middle of a strip-shaped workpiece exposure apparatus even when the workpiece is strip-shaped. It is possible to perform focus adjustment in a short time, and to perform focus adjustment in a short time without adding illumination means or image receiving means dedicated to focus adjustment and without increasing the cost of the apparatus.

In order to solve the above problems, in the present invention, a light transmission member is provided on the through hole or notch of the work stage, a focus adjustment pattern for an alignment microscope is formed on the light transmission member, and a projection lens is provided on the mask. A focus adjustment pattern is formed, the projection microscope focus adjustment pattern and the alignment microscope focus adjustment pattern are detected by the alignment microscope, and focus adjustment is performed.
That is, focus adjustment is performed as follows.
(1) A light irradiation unit that irradiates exposure light, a mask stage that supports a mask on which a pattern and a mask alignment mark are formed, and a long belt-like work on which a work alignment mark is formed are held and cut or penetrated. A work stage in which a hole is formed; a projection lens that projects the pattern formed on the mask onto the work; a light transmissive member disposed on a through hole or notch in the work stage; and the light transmissive member. An exposure apparatus for a strip-shaped workpiece, comprising: an alignment microscope provided below a member; and a control unit that detects the mask alignment mark and the workpiece alignment mark by the alignment microscope and aligns the mask. A focus adjustment pattern for a projection lens is formed on the light transmission member, and Imento forming a focus adjustment pattern for a microscope. The mask alignment mark formed on the mask is annular, and the projection lens focus adjustment pattern formed on the mask is a line-and-space pattern formed inside the ring of the mask alignment mark. , focus adjustment pattern alignment microscope that is formed on the light-transmitting member is formed in a projected image inside the mask marks of the wheel ring, said control unit, by the alignment microscope, the focus adjusting said projection lens The focus adjustment is performed by detecting the pattern and the focus adjustment pattern for the alignment microscope.
(2) In the above (1), the alignment microscope includes a first image receiving unit that detects an image at a low magnification and a second image receiving unit that receives an image at a high magnification, and aligns a mask and a workpiece. At this time, the alignment mark is detected by the first image receiving unit, and the focus adjustment pattern is detected by the second image receiving unit when the focus adjustment is performed.
(3) In the above (1) and (2), the work alignment mark is a through hole formed in the belt-like work.
(4) A focus adjustment method in the exposure apparatus for the strip-shaped workpiece according to (1) to (3) above, wherein the alignment microscope focus adjustment pattern is received by the alignment microscope, and the workpiece is adjusted so that the pattern is in focus. The first step of moving the stage in the optical axis direction (Z direction) and the projection lens focus adjustment pattern are received, and the mask stage is moved in the optical axis direction (Z direction) so that the pattern is in focus. And the mask stage and the work stage so that the work stage and the mask stage are equal to the projection lens while maintaining the distance from the mask stage to the work stage at the end of the process. And a third step of moving.

In the present invention, the following effects can be obtained.
(1) Since a pattern for focus adjustment is formed on the mask, the projected image is detected and picked up by an alignment microscope, and the distance between the image original images is adjusted so as to be in focus, without actually exposing and developing the pattern, Focus adjustment can be performed in a short time.
(2) Since the focus adjustment pattern formed on the mask is formed inside the alignment mark formed on the mask in an annular shape, even if it is a strip-shaped workpiece with no gap in the middle of the workpiece, exposure processing is performed. Focus adjustment can be performed in the middle of the lot (in the middle of the lot).
(3) Furthermore, by aligning the mask and the workpiece, the pattern for focus adjustment can be aligned within the field of view of the alignment microscope. Therefore, if the mask and the workpiece are aligned, it is possible to immediately move to the focus adjustment work, and even if the focus adjustment is performed in the middle of the lot, it is possible to prevent a decrease in throughput as much as possible.
(4) Since a pattern for adjusting the focus of the alignment microscope is provided on the work stage, a change in the focus position of the alignment microscope can be corrected when adjusting the distance between the image original images.

FIG. 1 and FIG. 2 show the apparatus configuration of an embodiment of the present invention. FIG. 1 shows the overall configuration of the belt-shaped workpiece exposure apparatus of this embodiment, and FIG. 2 shows the alignment light illumination means, mask stage, projection lens, work stage, and alignment microscope extracted from the apparatus shown in FIG. It is a figure.
1 and 2, the mask stage 13 is moved at least in the Z direction (optical axis direction, vertical direction in the drawing) by the mask stage moving mechanism 14.
The work stage 10 is also moved in the optical axis direction (Z direction, vertical direction in the drawing) by the work stage moving mechanism 6.
The mask stage 13 and the work stage 10 move the position of the focal length (design value) of the projection lens 5 as the origin position in the Z direction (optical axis direction) of each stage. The control unit 20 stores the origin position and the movement origin in the Z direction (optical axis direction) of each of the stages 14 and 10.
The work stage 10 is provided with a notch 10a or a through-hole, and an alignment microscope 12 is disposed under the notch 10a or a through-hole. The alignment microscope 12 is independent of the movement of the work stage 10.

A glass plate 10b made of a material through which exposure wavelength light passes is fitted into a notch or a through-hole (hereinafter, mainly described as a notch) 10a of the work stage 10. The glass plate 10 b is prevented from jumping above the surface of the work stage 10.
The alignment microscope 12 is disposed under the glass plate 10b. Similar to the conventional example, the alignment microscope 12 is provided at a position where the alignment mark MAM is formed according to the number of alignment microscopes MAM. In the present embodiment, since the alignment marks MAM are formed in two places, two alignment microscopes 12 are also provided in accordance therewith.
Each alignment microscope 12 includes two CCD cameras for receiving images. One is for low magnification and the other is for high magnification. The magnification is changed by switching the optical path. A low magnification (for example, 1.5 times) is used to detect the mask mark and the work mark when aligning the mask and the work. On the other hand, a high magnification (for example, 10 times) is used to detect a focus adjustment pattern during focus adjustment.

The configuration other than the above is basically the same as that in FIG. 5, and the strip-shaped workpiece W that has come out of the unwinding roll 1 is sandwiched between the encoder roll R3 and the pressing roll R3 ′ via the slack portion A1 and the intermediate guide roll R2. Then, after passing through the exposure unit 3, it is nipped and transported by the transport roll R4 and the pressing roll R4 ′. The work W is transported by a predetermined amount set by the rotation of the transport roll R4 and is sent onto the work stage 10 of the exposure unit 3.
On the exposure unit 3, a light irradiation unit 4 including a lamp 4a and a condenser mirror 4b, a mask M having a pattern (mask pattern) to be exposed on a workpiece, and a projection lens 5 are provided. The work stage 10 is mounted on the work stage drive mechanism 6, can be driven in the vertical and horizontal directions, and can be rotated about an axis perpendicular to the work stage surface.
The strip-shaped workpiece W is aligned by the exposure unit 3 and then exposed, and the exposed strip-shaped workpiece W is wound around the winding roll 2 through the guide roll R5 and the slack portion A2.

Here, the focus adjustment pattern for the projection lens and the focus adjustment pattern for the alignment microscope will be described.
As described above, the size of the mask mark (for example, 0.5 mm in diameter) is different from the size of the focus adjustment pattern (for example, L & S of 6 μm). Using this difference in size, a focus adjustment pattern is formed inside the mask mark.
That is, as shown in FIGS. 3A and 3B, the mask mark MAM has a ring shape (ring shape) having an outer shape of, for example, φ0.5 mm and an inner diameter of φ0.3 mm. Then, for example, a 6 μm L & S focus adjustment pattern (hereinafter referred to as a focus pattern FP) is formed inside the inner diameter of φ0.3 mm. Therefore, when the mask M and the workpiece W are aligned, when the mask mark MAM is projected onto the alignment microscope, the focus pattern FP is also projected onto the alignment microscope 12 at the same time. 3A shows a projected image of the mask mark MAM and the focus pattern FP, the edge of the through hole (work mark WAM), and the focus adjustment pattern AP of the alignment microscope formed on the glass plate, FIG. (B) is an enlarged view of the mask mark and focus patterns FP and AP of (a).
The focus adjustment pattern AP for the alignment microscope is formed on the glass plate 10b fitted into the cutout or the through hole of the work stage 10.
The position where the pattern AP is formed is a position that does not overlap when the mask mark MAM or the focus pattern FP is projected, and is within the field of view of the alignment microscope 12. For example, as shown in FIG. 3B, it is inside the annular mask mark image and next to the focus pattern FP image.

Next, a procedure for aligning the mask M and the workpiece W and adjusting the focus of the projection lens and alignment microscope will be described.
(1) The workpiece W is conveyed by a preset distance by the rotation of the conveyance roll R4, and the through hole as the workpiece mark WAM stops on the alignment microscope 12. Through holes are formed in the work W at a predetermined pitch for each exposure area, and the transport roll R4 rotates by a distance corresponding to the pitch. The workpiece W is held on the workpiece stage 10.
(2) The alignment light illumination means 11 is inserted above the mask M (between the mask M and the light irradiation unit 4) by the alignment light illumination means moving mechanism 11a.
The alignment light illuminating unit 11 irradiates the alignment light to the mask mark MAM and the focus pattern FP formed therein. Here, the wavelength of the alignment light is the same as that of the exposure light irradiated from the light irradiation unit 4.

(3) The image of the mask mark MAM and the focus pattern FP illuminated by the alignment light is projected onto the glass plate 10b provided in the notch or the through hole of the work stage 10.
As shown in FIG. 3A, the alignment microscope is used to adjust the focus of the alignment microscope formed on the projection image of the mask mark MAM and the focus pattern FP, the edge of the through hole that is the work mark WAM, and the glass plate. The pattern AP is received.
(4) The alignment of the mask M and the workpiece W is performed so that the annular mask mark MAM and the edge of the through hole that is the mask mark WAM have a preset positional relationship. At this time, the mask mark MAM and the mask mark WAM are detected using a low magnification of the alignment microscope. The control unit 20 performs alignment based on the position information of the mask mark MAM and the work mark WAM.
By aligning the mask M and the workpiece W, the annular mask mark MAM and the through-hole workpiece mark WAM have a predetermined positional relationship. Thus, the projection lens focus pattern FP formed inside the annular mask mark MAM and the alignment microscope focus pattern AP formed on the glass plate of the work stage are aligned in the field of view of the alignment microscope. Will be placed. Thereby, the following focus adjustment operations are possible.

(5) The focus adjustment of the projection lens 5 and the focus adjustment of the alignment microscope 12 are performed according to the following procedure. At this time, the focus patterns FP and AP are detected using a high magnification of the alignment microscope.
FIGS. 4A to 4D are views for explaining the movement of the mask and the workpiece during the force adjustment. The focus adjustment procedure of this embodiment will be described with reference to FIG.
(A) As shown to Fig.4 (a), the alignment microscope 12 is the projection lens focus adjustment pattern FP projected on the glass plate 10b, and the alignment microscope focus adjustment formed on the glass plate 10b. The pattern AP is received simultaneously. The received image signal is sent to the control unit 20.
The control unit 20 performs image processing on the received image of the projection lens focus pattern FP and the alignment microscope focus pattern AP.
Here, the mask stage 13 and the work stage 10 are at the origin position. The origin position is the position of the focal length (design value) of the projection lens 5 as described above.
(B) Adjust the focus of the alignment microscope. That is, as shown in FIG. 4B, the control unit 20 moves the work stage 10 in the vertical direction (optical axis direction / Z direction) so that the pattern AP is focused. If the pattern AP is in focus, the control unit 20 stops the movement of the work stage 10 and stores the movement distance A from the origin position.

(C) As shown in FIG. 4C, the control unit 20 moves the mask stage 14 in the vertical direction (optical axis direction / Z direction) so that the pattern FP is in focus. If the pattern FP is in focus, the control unit 20 stops the movement of the mask stage 14 and stores the movement distance B from the origin position. The movement distance B of the mask stage is always greater than the movement distance A of the work stage 10.
The focus adjustment of the alignment microscope 12 and the focus adjustment of the projection lens 5 may be performed in the reverse order or simultaneously.
In this state, the alignment microscope is focused on the glass 10b of the work stage 10, and the focus pattern FP image is projected on the glass of the work stage 10 in a focused state. The distance from the mask stage 14 to the work stage 10 in this state is the distance D between image original images with which the exposure apparatus is focused in the current environment.
Here, since it is in focus, it is not so that exposure processing can be performed in this state. In this state, the distance from the mask M to the projection lens 5 is usually not equal to the distance from the projection lens 5 to the work stage 10. If the distance between the two is not the same, distortion due to aberration occurs in the projected image.
For this reason, the mask stage 14 and the work stage 10 are set so that the distance from the mask M to the projection lens 5 and the distance from the projection lens 5 to the work stage 10 are equal to each other while the distance D between the original images is maintained. Must be moved.

(D) Therefore, as shown in FIG. 4D, the movement distance A of the work stage 10 is subtracted from the movement distance B of the mask stage 14 stored above, and the value is divided by two. This value is C. Then, the mask stage 14 is moved upward from the origin position to the position of the distance C, and the work stage 10 is moved downward from the origin position to the position of the distance C. In this way, the distance from the mask M to the projection lens 5 and the distance from the projection lens 5 to the work stage 10 can be made equal while keeping the distance D between the image originals that are in focus.
This completes the focus adjustment of the projection lens and the alignment microscope.

As described above, when the alignment and focus between the mask M and the workpiece W are completed, the exposure operation is resumed in this state.
A projected image of the focused mask pattern is obtained on the work. In this state, the exposure light emitted from the light irradiation unit 4 is irradiated onto the workpiece W through the mask M and the projection lens 5, and the mask pattern is transferred to the workpiece W.
When the exposure is finished, the belt-like work W is held between the transport roll R4 and the pressing roll R4 ′, and transported and exposed so that the next exposure area is on the work stage 10.
As described above, the exposed belt-like workpiece W is wound around the winding roll 2 through the guide roll R5 and the slack portion A2. At that time, the spacer is fed out from the spacer unwinding roll 2a, and the exposed belt-like workpiece W is wound up on the winding roll 2 together with the spacer.

In the above embodiment, the case where the work mark is a through hole formed in the peripheral part of the belt-like workpiece has been described. However, when the belt-like workpiece is light transmissive, the mark is not on the through hole but on the workpiece. May be formed.
Recently, in order to improve the alignment accuracy between the mask and the workpiece, alignment marks may be formed at two or more places, for example, four places. In that case, four alignment microscopes are provided according to the number of alignment marks. If four alignment microscopes are provided, the tilt amount of the work stage can also be detected.

It is a figure which shows the whole structure of the exposure apparatus of the strip | belt-shaped workpiece | work of the Example of this invention. It is the perspective view which extracted and showed the part of alignment light illumination means, a mask stage, a projection lens, a work stage, and an alignment microscope in the apparatus shown in FIG. FIG. 5 is an enlarged view of a mask mark MAM, a projected image of a focus adjustment pattern FP, a focus adjustment pattern AP, and a work mark WAM. It is a figure explaining the movement of a mask and a workpiece | work at the time of force adjustment. It is a figure which shows an example of a structure of the exposure apparatus of a strip | belt-shaped workpiece | work. It is the perspective view which extracted and showed the part of the mask of the exposure apparatus of FIG. 5, a projection lens, and a work stage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Unwinding roll 2 Winding roll 3 Exposure part 4 Light irradiation part 5 Projection lens 6 Work stage drive mechanism 10 Work stage 10a Notch (through-hole)
DESCRIPTION OF SYMBOLS 10b Glass plate 11 Alignment light illumination means 12 Alignment microscope 13 Mask stage 14 Mask stage moving mechanism 20 Control part M Mask W Band-shaped work MAM Mask mark WAM Work mark FP Projection lens focus adjustment pattern AP Alignment microscope focus adjustment pattern

Claims (4)

A light irradiation unit for irradiating exposure light;
A mask stage for supporting a mask on which a pattern and a mask alignment mark are formed;
A work stage that holds a long band-shaped work on which a work alignment mark is formed and has a notch or a through hole, and
A projection lens that projects the pattern formed on the mask onto the workpiece;
A light transmissive member disposed on the through hole or notch of the work stage;
An alignment microscope provided below the light transmitting member;
In an exposure apparatus for a strip-shaped workpiece, which includes the control unit that detects the mask alignment mark and the workpiece alignment mark by the alignment microscope and aligns the mask.
The mask has a focus adjustment pattern for the projection lens,
In addition, a focus adjustment pattern for an alignment microscope is formed on each of the light transmission members,
The mask alignment mark formed on the mask is annular,
The projection lens focus adjustment pattern formed on the mask is a line-and-space pattern formed on the inner side of the ring of the mask alignment mark,
Focus adjustment pattern for alignment microscope that is formed on the light-transmitting member is formed in a projected image inside the mask marks of the wheel ring,
The strip-shaped workpiece exposure apparatus, wherein the control unit detects the projection lens focus adjustment pattern and the alignment microscope focus adjustment pattern by the alignment microscope, and performs focus adjustment. The alignment microscope
A first image receiving unit that detects an image at a low magnification and a second image receiving unit that receives an image at a high magnification. When aligning a mask and a workpiece, an alignment mark is placed on the first image receiving unit. Detect
2. The apparatus for exposing a belt-like workpiece according to claim 1, wherein when performing focus adjustment, the second image receiving unit detects a focus adjustment pattern. 3. The exposure apparatus for a strip-shaped workpiece according to claim 1, wherein the workpiece alignment mark is a through-hole formed in the strip-shaped workpiece. A focus adjustment method in the exposure apparatus for a strip-shaped workpiece according to claim 1, 2 or 3,
A first step of receiving the alignment adjustment pattern for the alignment microscope by the alignment microscope and moving the work stage in the optical axis direction so that the pattern is in focus;
A second step of receiving the projection lens focus adjustment pattern and moving the mask stage in the optical axis direction so that the pattern is in focus;
While maintaining the distance from the mask stage to the work stage at the end of the above process,
A focus adjustment method in an exposure apparatus for a strip-shaped workpiece, comprising: a third step of moving the mask stage and the work stage so that the work stage and the mask stage have an equal distance from the projection lens.

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