KR20080033163A - Exposure apparatus and exposure method - Google Patents

Abstract

An exposure apparatus and an exposure method that can reliably perform imaging of an alignment mark of a photosensitive material placed on a stage. While the stage having the photosensitive material placed on it is moved along a predetermined conveyance route, a predetermined region including the alignment mark M of the photosensitive material is imaged by a first camera, and the position of a second camera having a higher magnification ratio than the first camera is adjusted based on the result of imaging by the first camera. Further, while the stage is moved along the predetermined conveyance route, the alignment mark M of the photosensitive material is imaged by the second camera, and image data corrected based on the imaging result is exposed on the photosensitive material by an exposure means.

Description

Exposure apparatus and exposure method {EXPOSURE APPARATUS AND EXPOSURE METHOD}

The present invention relates to an exposure apparatus and an exposure method for measuring the position of a photosensitive material such as a printed wiring board mounted on a stage and exposing a drawing region obtained according to the light beam modulated on the basis of image data to form an image. .

Conventionally, the laser exposure apparatus which forms a wiring pattern, for example in a printed wiring board (henceforth only a "substrate" or a "photosensitive material") etc. is known. This laser exposure apparatus is equipped with the exposure stage which mounted the printed wiring board which is an object of image exposure, and moves this exposure stage along a predetermined conveyance path | route.

Specifically, for example, as disclosed in Japanese Patent Laid-Open No. 2000-338432, the exposure stage on which the printed wiring board is mounted moves in the sub-scanning direction at a predetermined speed, and the print is performed at a predetermined reading position. For example, an alignment mark formed at the corner portion of the wiring board is photographed by the CCD camera. And the alignment process with respect to image data is performed by coordinate-converting a drawing object area | region in a drawing coordinate system according to the position of the printed wiring board obtained by this imaging | photography.

[Patent Document 1] Japanese Patent Application Laid-Open No. 6-305141

After performing the alignment process, the printed wiring board on the exposure stage is modulated based on the image data at a predetermined exposure position, and the photosensitive coating film formed on the surface by the laser beam deflected in the main scanning direction by the polygon mirror is scanned and exposed. do. As a result, an image (latent image) based on the image data (corresponding to the wiring pattern) is formed in a predetermined area (drawing area) on the printed wiring board.

The printed wiring board on which the image (latent image) is formed is taken out from the exposure stage after the exposure stage is moved back to the initial position, and the exposure stage from which the printed wiring board has been removed is shifted to the process of exposing the next printed wiring board.

In this way, in the laser exposure apparatus, in order to accurately match the exposure position with respect to the drawing area of a printed wiring board, the alignment mark which becomes a reference | standard of an exposure position is imaged, and an exposure position is appropriate | suited based on the measurement result of the position (reference position data). To match the position.

However, no matter what happens when the printed wiring board is mounted on the exposure stage, the mounting position is different from that of the previous board, or the alignment mark of the substrate is out of position for each lot or type even at the same size. There was a problem that the alignment mark deviated from the field of view of the CCD camera, and this imaging became impossible (an error occurred due to a poor detection of the alignment mark).

Therefore, in the past, when the alignment marks could not be detected (photographed), the substrate was relocated and coped again. However, since it is unclear at which position the substrate should be rearranged, it is practically rearranged properly to perform detection (photographing) again. Had to try. Therefore, depending on the case, it may be rearranged several times, causing the fall of processing efficiency.

The present invention obtains an exposure apparatus and an exposure method in which photographing of an alignment mark of a photosensitive material mounted on a stage can be reliably performed.

A first embodiment of the present invention provides a first camera for photographing a predetermined region including a stage on which a photosensitive material is mountable and movable along a predetermined conveyance path, and a photosensitive material alignment mark mounted on the stage; And a second camera that has a higher magnification than the first camera and is capable of adjusting the position of the photosensitive material based on the photographing result by the first camera, thereby photographing an alignment mark of the photosensitive material mounted on the stage. And exposure means for exposing the image data corrected on the basis of the photographing result by the second camera to the photosensitive material.

According to a second embodiment of the present invention, a predetermined area including an alignment mark of the photosensitive material is photographed by the first camera while the stage on which the photosensitive material is mounted is moved along a predetermined conveyance path. Based on the result, the position of the second camera, which is higher than the first camera, is adjusted, and the alignment mark of the photosensitive material is photographed by the second camera while the stage is moved along a predetermined conveyance path. It is an exposure method which exposes the corrected image data to the said photosensitive material by exposure means.

According to each said embodiment, first, the 1st camera image | photographs the predetermined area | region containing an alignment mark, and the 2nd in which magnification is higher than this, and the position with respect to the photosensitive material was adjusted based on this imaging result. Shoot the alignment mark with the camera. Therefore, even if the mounting position of the photosensitive material differs with respect to the stage, or a position difference occurs in the alignment mark of the photosensitive material for each lot and for each kind, the alignment mark can be surely photographed by the second camera. Therefore, since it exposes to the said photosensitive material based on the image data correct | amended based on the imaging result by a 2nd camera, reliable exposure can be performed.

In each of the above embodiments, the photographing in the first camera is performed during the moving direction of the stage, with the movement along the predetermined conveying path of the stage being a reciprocating motion, and the photographing in the second camera and the exposure means. Exposure may be performed while moving to the ear of the stage.

According to the above embodiment, first, the predetermined area including the alignment mark is photographed by the first camera during the movement of the stage, and then the magnification is higher than that of the first camera during the movement of the stage. The alignment mark is photographed with a second camera whose position with respect to the photosensitive material is adjusted. Thereby, even if the mounting position of the photosensitive material is shifted with respect to a stage, or a position difference arises in the alignment mark of the photosensitive material for every lot, for every kind, an alignment mark can be imaged surely with a 2nd camera. Therefore, since it exposes to the said photosensitive material based on the image data correct | amended based on the imaging result by a 2nd camera, reliable exposure can be performed. In addition, since the stage is configured to reciprocate, space saving of the exposure apparatus installation space can be achieved.

In each said embodiment, you may shorten at least the illumination light of the said 2nd camera.

According to the said embodiment, this imaging | resolution shooting can be improved at the time of imaging | photography with the 2nd camera which needs at least precision.

In each said embodiment, you may make the speed at the time of the movement of the said stage back and forth faster than the speed at the time of moving to the ear of the said stage.

According to the said embodiment, since the speed can be raised at the time of imaging with the 1st camera which does not require a large precision, the processing efficiency (productivity) can be improved.

In each said embodiment, the space | interval in the movement direction of the said stage of the some alignment mark in the photosensitive material in which the space | interval of the said 2nd camera and the said exposure means in the movement direction of the said stage was mounted in the said stage The above may be sufficient.

According to the said embodiment, even if the exposure means and a 2nd camera approach and are arrange | positioned, exposure process by an exposure means can be performed, image | photographing an alignment mark with a 2nd camera every interval of the alignment mark in the moving direction of a stage. Therefore, the processing efficiency (productivity) can be improved and the space saving of the exposure apparatus installation space can be achieved.

Effect of the Invention

As described above, according to the present invention, it is possible to provide an exposure apparatus and an exposure method capable of reliably photographing an alignment mark of a photosensitive material mounted on a stage.

1 is a schematic perspective view showing an exposure apparatus.

2 is a schematic side view showing an exposure apparatus.

3 is a schematic plan view of the exposure apparatus.

4 is a schematic perspective view showing an exposure stage.

5 is a schematic perspective view of the exposure head unit.

Fig. 6A is a schematic plan view of the exposure area by the exposure head unit.

Fig. 6B is a schematic plan view showing the arrangement pattern of the head assembly.

7 is a schematic plan view showing an arrangement state of a dot pattern in a single head assembly.

8 is a schematic perspective view showing an alignment unit.

9 is a control flowchart showing an exposure start timing correction routine.

10 (A) is an explanatory diagram showing the time of measurement of the alignment mark.

10B is an explanatory diagram showing a time of measuring alignment marks.

10C is an explanatory diagram showing a time of measuring alignment marks.

11 is a schematic perspective view showing a modification of the exposure apparatus.

It is a schematic side view which shows the modification of an exposure apparatus.

It is a schematic top view which shows the modification of an exposure apparatus.

[Description of the code]

10: exposure apparatus

20: exposure stage (stage)

28: exposure head unit (exposure means)

30: alignment unit

36: low magnification camera portion (first camera)

38: high magnification camera portion (second camera)

50: controller

60: photosensitive material

EMBODIMENT OF THE INVENTION Hereinafter, 1st Embodiment of this invention is described in detail based on the Example shown in drawing. 1 is a schematic perspective view of an exposure apparatus according to the present invention, FIG. 2 is a schematic side view of an exposure apparatus, and FIG. 3 is a schematic plan view of an exposure apparatus. 3, the arrow X is made into the width direction, and the arrow Y is made into the moving direction or the scanning direction. In addition, in FIG. 2, the arrow YA is made into the backward direction, and the arrow YB is made into the return direction.

[Configuration of Exposure Device]

As shown in Figs. 1 to 3, the exposure apparatus 10 is configured by accommodating each part in a rectangular frame 12 formed by attaching a rod-shaped square pipe in a frame shape. Is attached to a panel not shown. Accordingly, the exposure apparatus 10 is configured to be cut off from the outside.

The frame 12 is comprised by 12 A of case parts with a high back, and the stage part 12B provided so that it may protrude from the one side surface of this case part 12A. The stage part 12B is a structure whose upper surface is lower than the case part 12A, and becomes the position which became almost slack when an operator stood in front of the stage part 12B.

The opening / closing cover 14 is provided on the upper surface of the stage part 12B. A hinge (not shown) is attached to one side of the case portion 12A side of the opening / closing cover 14, and the opening and closing operation is possible around the one side. And the exposure stage 20 (refer FIG. 4) can be exposed on the upper surface of the stage part 12B of the state which the opening-closing cover 14 opened.

Moreover, the surface plate 18 which becomes a reference | standard of the movement trace of the exposure stage 20 is extended from the stage part 12B to the case part 12A. This surface plate 18 is supported by the mount 16 which is firmly fixed to the square pipe which comprises the case part 12A. On the other hand, one end of the longitudinal direction (moving direction) of the surface plate 18 reaches the stage portion 12B, and in the state where the exposure stage 20 is located at this position, the operator places the photosensitive material 60 on the exposure stage 20. ) Can be mounted or withdrawn.

In addition, the upper surface of the surface plate 18 is provided with a pair of sliding rails 22 parallel to each other in the longitudinal direction thereof, and when viewed in a cross section attached to the lower surface of the exposure stage 20, the shape is almost C-shaped. 20A of legs (refer FIG. 4) is supported by the sliding rail 22 so that sliding is possible. Therefore, since the exposure stage 20 is supported by the sliding rail 22, it can slide in a scanning direction with almost no frictional resistance (if it exists only through the bearing etc., only the rolling resistance of the bearing).

In addition, a linear motor section 24 is provided between the pair of sliding rails 22 on the upper surface of the surface plate 18. The linear motor part 24 is a linear drive source which applied the driving force of a stepping motor. The linear motor part 24 is provided in the rod-shaped stator part (magnet part) 24A (refer FIG. 2) provided along the longitudinal direction of the surface plate 18, and at the lower surface side of the exposure stage 20, and the stator part It consists of the coil part 24B arrange | positioned at 24 A with predetermined intervals.

The exposure stage 20 obtains a driving force by the magnetic force action of the magnetic field generated by the energization of the coil portion 24B and the magnetic field of the stator portion 24A, and the length of the exposure stage 20 along the sliding rail 22. Direction (scanning direction). In addition, since the principle is the same as that of a stepping motor, the exposure stage 20 enables high-precision drive control, such as constant speed, positioning accuracy, and torque fluctuation at the time of starting and stopping by electrical control. .

In addition, a linear encoder (not shown) is attached to the linear motor unit 24. This linear encoder pulses the pulse signal of the polarity corresponding to this reciprocating direction by the number of pulses proportional to the movement amount when the coil section 24B moves relative to the stator section 24A in the scanning direction together with the exposure stage 20. It is the configuration to output to the counter.

On the upper surface of the exposure stage 20, a rectangular flat plate-shaped photosensitive material 60, which is an exposure object, is mounted in a state where it is positioned at a predetermined position by positioning means (not shown). The exposure stage 20 has a plurality of slots (not shown) formed on the mounting surface thereof, and after the photosensitive material 60 has been positioned and mounted at a predetermined position, the photosensitive material is made into a negative pressure by a vacuum pump or the like. It is a structure which adsorbs and maintains 60.

The photosensitive material 60 is provided with the some alignment mark M which shows the reference | standard of an exposure position in the drawing area on the exposure surface. For example, as shown in FIG. 3, the alignment marks M are comprised by circular through-holes, and are arranged at predetermined intervals in the short direction including the corner part of the photosensitive material 60, and are mentioned later, Four rows are provided in the longitudinal direction at intervals equal to or less than the installation interval between the exposure head unit 28 and the alignment unit 30. Thereby, the exposure process while measuring the alignment mark M can be implement | achieved.

The exposure head unit 28 (refer FIG. 5) is provided in the substantially intermediate position of the movement trace on the surface plate 18 in the exposure stage 20. As shown in FIG. The exposure head unit 28 is formed so as to span a pair of struts 26 provided on the outer side of the width direction both ends of the surface plate 18, and the exposure head unit 28 and the surface plate 18 are exposed between the exposure stage ( 20) is a configuration that can pass.

The exposure head unit 28 is constituted by a plurality of head assemblies 28A arranged along the width direction of the surface plate 18, and each head assembly 28A at a predetermined timing while moving the exposure stage 20 at a constant speed. From the photosensitive material 60 on the exposure stage 20. Thereby, the exposure surface (drawing area) of the photosensitive material 60 is exposed.

The head assembly 28A constituting the exposure head unit 28 is arranged in a substantially matrix shape of m rows n columns (for example, 2 rows 5 columns), as shown in Fig. 6B, The plurality of head assemblies 28A are arranged in a direction (width direction) orthogonal to the moving direction (scanning direction) of the exposure stage 20. Here, a total of 10 head assemblies 28A are arranged in two rows and five rows in relation to the width of the photosensitive material 60.

Moreover, the exposure area 28B by one head assembly 28A becomes a rectangle which makes a scanning direction a short side, and is inclined at the predetermined inclination angle with respect to the scanning direction, and the movement of the exposure stage 20 is carried out. As a result, a strip-shaped exposed area 28C is formed in each of the head assemblies 28A in the photosensitive material 60 (see Fig. 6A).

On the other hand, as shown in FIG. 1, the light source unit 48 is provided in the case part 12A in the place which does not prevent the movement of the exposure stage 20 on the surface plate 18. As shown in FIG. The light source unit 48 accommodates a plurality of lasers (semiconductor lasers), and guides the light emitted from the lasers to the respective head assemblies 28A through an optical fiber (not shown).

Each head assembly 28A is guided by an optical fiber, and the incident light beam is controlled in dots by a digital micromirror device (DMD), not shown, which is a spatial light modulation element, and the dot is applied to the photosensitive material 60. The pattern is exposed. Here, the density of one pixel is expressed using a plurality of dot patterns.

In addition, as shown in Fig. 7, the exposure area 28B (one head assembly 28A) is formed by 20 dots arranged in a two-dimensional array (for example, 4x5). Since the dot pattern of the two-dimensional array is inclined with respect to the scanning direction, each dot parallel to the scanning direction passes between the dots parallel to the direction crossing the scanning direction, so that the actual pitch between dots can be narrowed. It is. Thereby, it is the structure which can aim at high resolution.

As described above, the tilt of the head assembly 28A may overlap a plurality of dot patterns on the same scan line depending on the setting of the standard resolution of the exposure apparatus 10. In such a case, a dot pattern which does not use the DMD corresponding to one of the dot patterns (for example, the dot pattern shown by oblique lines in FIG. 7) is always turned off.

The exposure process with the photosensitive material 60 positioned and mounted on the exposure stage 20 mounts the photosensitive material 60 on the exposure stage 20 and moves inward along the sliding rail 22 on the surface plate 18. Instead of moving (backward), it is executed once when the inner end (case part 12A side) end of the surface plate 18 is reached and returns to the stage part 12B (return).

That is, the traveling path of the exposure stage 20 is a movement for obtaining the positional information of the photosensitive material 60 on the exposure stage 20, and as shown in FIG. 8 on the surface plate 18 as a unit for obtaining this positional information. The same alignment unit 30 is provided. In addition, although only the high magnification camera part 38 mentioned later is shown in FIG. 8, the low magnification camera part 36 is similarly provided in the back surface side.

As shown in Figs. 2 and 3, the alignment unit 30 is provided on the inner side in the path direction than the exposure head unit 28, and a pair of the two vertically placed on the outer sides of the width direction both ends of the surface plate 18, respectively. It is hypothesized in the prop 26. The alignment unit 30 is provided so as to be movable in the width direction of the surface plate 18 on both sides of the base portion 32 having both ends fixed to the pair of struts 26 and the scanning direction of the base portion 32. It is comprised by the camera part 36 and 38 of several (for example, four each).

The camera parts 36 and 38 have a high magnification (high resolution) camera part 38 on the inner side in the cross direction, and the camera part 36 of the low magnification (low resolution) on the front side in the backward direction (exposure head unit 28 side). have. In addition, as shown in FIG. 8, each of the camera parts 36 and 38 is slidably attached to the pair of rail parts 34 parallel to each other provided along the base part 32 through the camera base 40. Each of them is movable independently.

In addition, each of the camera parts 36 and 38 is provided with lens parts 36B and 38B on the lower surfaces of the camera bodies 36A and 38A, and a ring-shaped strobe light source (LED) is provided at the protruding ends of the lens parts 36B and 38B. Strobe light sources) 36C and 38C are mounted. Each lens portion 36B, 38B is disposed downward so that the lens optical axis is substantially perpendicular, and the light from the strobe light sources 36C, 38C is irradiated onto the photosensitive material 60 on the exposure stage 20 to reflect the reflected light. The alignment mark M on the photosensitive material 60 can be image | photographed by inputting into the camera main body 36A, 38A through the lens part 36B, 38B.

The strobe light source 36C of the low magnification camera section 36 emits light having a long wavelength (for example, red), and the strobe light source 38C of the high magnification camera section 38 has a short wavelength (for example, blue) light. Investigate. In general, in the case of photographing employing short wavelength light as a strobe light source, the resolution can be improved.

Although both the low magnification camera section 36 and the high magnification camera section 38 preferably perform stroboscopic imaging using short wavelength light, the high magnification camera section 38, which requires high precision because the strobe light source for irradiating short wavelength light is expensive. The strobe light source 38C which can irradiate light of a short wavelength is adopted. Thereby, the resolution at the time of image | photographing the alignment mark M can be aimed at.

Each camera base 40 is movable in the width direction of the surface plate 18 by the drive of the ball screw mechanism part 42, respectively, by the movement of the exposure stage 20, and the driving force of the ball screw mechanism part 42. The optical axis of the lens parts 36B and 38B can be arrange | positioned at the desired position of the photosensitive material 60 by the movement to the width direction of the surface plate 18.

Since the relative positional relationship of the exposure stage 20 and the photosensitive material 60 is determined by the operator mounting the photosensitive material 60 to the exposure stage 20, some difference may arise. Therefore, first, the predetermined area | region containing the alignment mark M formed in the photosensitive material 60 is image | photographed with the low magnification camera part 36, and the position of the high magnification camera part 38 in the width direction based on this imaging result. Is adjusted, and the high magnification camera section 38 is then configured to photograph the alignment mark M. FIG.

The alignment mark M can be reliably photographed even if a positional difference occurs in the photosensitive material 60 mounted on the exposure stage 20 by this two-step imaging method. Then, the exposure timing by the exposure head unit 28 which has a relative relationship with the movement of the exposure stage 20 is corrected, and the relative position of the photosensitive material 60 and image data (exposure start position) is thereby corrected. ).

1 to 3, a reference scale S for camera correction is provided at an end portion in the backward direction front side of the upper surface of the exposure stage 20. The reference scale S is made of, for example, a material that does not cause a disturbance in the accuracy of glass or the like (dimension does not change over time), and a plurality of marks are arranged on the upper surface at regular intervals. .

By photographing the marks of the scale S with the respective camera units 36 and 38, the position of the camera stages 36 and 38 with respect to the upper surface of the exposure stage 20 can be accurately determined, and the photosensitive material 60 is removed to expose the stage. Even when mounted on (20), it is the structure which image | photographing (measurement) of the alignment mark M in each camera part 36 and 38 is possible.

Moreover, the linear motor part 24, the head assembly 28A, the camera parts 36, 38, etc. which move the exposure stage 20 are connected to the controller part 50 which is a control means which controls these (FIG. 1). The exposure stage 20 is controlled to move at a predetermined speed by the controller unit 50, the camera units 36 and 38 are controlled to photograph the alignment mark M of the photosensitive material 60 at a predetermined timing, and the head Assembly 28A is controlled to expose photosensitive material 60 at a predetermined timing.

The method of detecting the alignment mark M applied to the photosensitive material 60 and grasping the relative positional relationship of the photosensitive material 60 and the exposure head unit 28 is demonstrated. When the exposure stage operation control signal is input, the camera operation control unit in the controller unit 50 sends a start signal to the camera units 36 and 38. By this starting signal, the cameras 36 and 38 are started up and are ready for shooting.

In addition, in the trigger signal generation unit in the controller unit 50, when the pulse counter for counting the output pulse of the linear encoder takes a predetermined count value (for example, the photosensitive conveyed to the exposure stage 20 moving to the king) When the alignment mark M of the material 60 counts the number of pulses corresponding to the position entered into the photographing angle of view of the camera unit 36] A trigger signal is generated and sent to the camera operation control unit and the strobe light emission control unit.

At the input timing of this trigger signal, the camera operation control unit sends a timing signal to the camera unit 36, and the camera unit 36 takes a picture. In addition, the strobe light emission control part transmits a timing signal to the strobe light source 36C, and the strobe light source 36C emits light in association with the photographing operation of the camera unit 36. In this manner, the operation timing (movement operation) of the exposure stage 20, the imaging timing by the camera unit 36, and the emission timing of the strobe light source 36C are synchronized.

Moreover, the size data of the photosensitive material 60 is input to the width direction positioning part with the exposure stage operation control signal, and the operation | movement of the ball screw mechanism part 42 is controlled by this width direction positioning part, and the low magnification camera The width direction position with respect to the surface plate 18 of the part 36 is adjusted. Thereby, the alignment mark M does not deviate from the field of view of the low magnification camera part 36, and the predetermined area | region containing the alignment mark M is moved to the low magnification camera part 36 during the movement of the exposure stage 20 to the west. Is taken by.

In this way, the data photographed by the low magnification camera section 36 is sent to the photographing data analysis section, and the photographing data is analyzed. Based on the results, the operation of the ball screw mechanism 42 in the high magnification camera portion 38 is controlled to adjust the widthwise position relative to the surface plate 18 of the high magnification camera portion 38.

When the widthwise position of the high magnification camera portion 38 is adjusted, the alignment mark M is photographed by the high magnification camera portion 38 while moving to the ear of the exposure stage 20, and the position of the drawing region is thus measured. In addition, the movement speed of the exposure stage 20 is faster than when moving to the ear where precision is required when moving to the back and forth where precision is not necessary. Thereby, processing efficiency (productivity) can be improved.

The data photographed by the high magnification camera section 38 is sent to the photographing data analysis section to analyze the photographing data. Basically, since the photographed image data is analog data (the amount of light is converted to voltage immediately after photoelectric conversion), the analog data is converted into digital image data, and the digital image data is numerically managed (concentration value) together with the position data. .

The digital image data analyzed by the photographing data analyzing unit is sent to the mark extracting unit, the alignment mark M is extracted, and sent to the mark combining unit. The mark combining unit combines the extracted image data of the alignment mark M and the mark data stored in the mark data memory in advance, and sends out a signal indicating coincidence / unmatching to the exposure position correction coefficient calculating unit. The position data corresponding to the digital image data is also sent to the exposure position correction coefficient calculating unit.

The exposure position correction coefficient calculating unit recognizes an error between the position data corresponding to the mark data determined to match and the position data of the original (design) alignment mark M as a result of the combination, and the exposure position (exposure stage). The correction coefficients of the exposure start position in the movement direction of (20) and the shift position of the dot in the width direction of the exposure stage 20] are calculated and sent to the exposure control system. Based on this correction coefficient, the timing of image recording (exposure) start by the respective head assemblies 28A of the exposure head unit 28 is corrected so that the position of the image to be recorded on the photosensitive material 60 becomes an appropriate position. do.

That is, the position of the alignment mark M in the image determined from the image data (reference position data) of each input alignment mark M, the pitch between the alignment marks M, etc., and the alignment mark M are image | photographed Difference between the position of the photosensitive material 60 on the exposure stage 20, the inclination with respect to the moving direction, and the dimensional accuracy error from the position of the exposure stage 20 and the position of the camera portion 38 at the time of performing the calculation. Etc., the appropriate exposure position with respect to the exposure surface (drawing area) of the photosensitive material 60 is calculated.

In addition, image data for generating an exposure pattern is once stored in a memory in the controller unit 50. Therefore, at the time of image exposure by each head assembly 28A, correction control (alignment) is performed such that the control signal generated based on the image data stored in the memory is exposed to the image at the appropriate exposure position. The image data (exposure pattern) is data representing the density of each pixel constituting the image in binary (with or without dot recording).

In addition, as shown in FIG. 2, in the surface plate 18, a chamber 54 is further provided to isolate the inside of the exposure head unit 28 from the space in the case portion 12A. The surface plate 18 extends in the chamber 54 to the stage portion 12B, and only the exposure stage 20 moves in and out of the chamber 54.

One end of the blower duct 44 is attached to the ceiling of the chamber 54, and the other end of the blower duct 44 is attached to the air outlet of the blower 46 (see FIG. 1). Thus, when blower 46 is actuated, air is drawn into chamber 54 through blower duct 44.

When air enters into the chamber 54, the chamber 54 becomes a static pressure, and flows to the stage part 12B through the moving space of the exposure stage 20. FIG. By this flow, dust around the exposure head unit 28 and alignment unit 30 which should be avoided most can be discharged, and when the opening / closing cover 14 is opened (the exposure stage of the photosensitive material 60). Even when detached onto (20)], intrusion of new dust can be prevented by the pressure difference.

In addition, an antistatic device (ionizer) 52 is provided on the front side of the exposure stage 20 in the exposure head unit 28 in front of the exposure direction 20, that is, the side closer to the stage portion 12B over the width direction of the surface plate 18. It is installed (see Figs. 1 and 3). The antistatic device 52 is comprised from the blowout part 52A of a hollow pipe shape, and the ion generating part 52B which supplies the ionized air to this blowout part 52A, and air ionized toward the surface plate 18 Take out.

The photosensitive material 60 is electrostatically charged by the base material, and has a property of attracting dust by charging an electric charge. The dust attracted and attached by static electricity cannot be wiped out by the static electricity elimination device 52 because it cannot be wiped out by the flow of air alone. Specifically, in the ion generating unit 52B, the corona discharge is generated between the earth electrode and the discharge electrode to generate ions, and the ions are guided to the extraction unit 52A by a blowing source to take out the electrostatic charges. It neutralizes with the dust charged by the ion and the pole of another pole, and discharges static electricity.

That is, when the exposure stage 20 on which the photosensitive material 60 is mounted moves on the surface plate 18, the surface of the photosensitive material 60 is statically removed, and dust attached by static electricity can be removed, and air blow This makes it possible to remove dust floating in the upper space of the exposure stage 20.

[Operation of Exposure Device]

Next, the effect | action of the above exposure apparatus 10 is demonstrated. Moreover, as the photosensitive material 60 which performs image exposure by the exposure apparatus 10, a photosensitive epoxy is formed on the surface of a printed wiring board, a board | substrate as a material which forms (image exposure), such as a liquid crystal display element, and the surface of glass plates, etc. In the case of apply | coating photoresist, such as resin, or a dry film, the thing etc. which were laminated are mentioned.

9 is a flowchart showing an exposure start timing correction routine. First, the photosensitive material 60 is mounted on the exposure stage 20 (mounting surface). And the inside of a slot is made into negative pressure by a vacuum pump etc., and the photosensitive material 60 is adsorbed-held on the mounting surface. Subsequently, it is determined whether or not an exposure start instruction has been made in step 100, and if it is determined as affirmative, the process proceeds to step 102 and instructs the low magnification camera section 36 and the high magnification camera section 38 to be activated. . In addition, in the case of a negative determination in step 100, this routine is terminated.

When the low magnification camera section 36 and the high magnification camera section 38 are instructed in step 102, the flow advances to step 104 where it is determined whether or not the size data of the photosensitive material 60 has been input. If it is determined as affirmative in this step 104, it transfers to step 106 and drives the ball screw mechanism part 42 with the width direction position with respect to the surface plate 18 of the low magnification camera part 36 based on the input size data. Adjust by adjusting.

In step 108, it is determined whether or not the adjustment is completed. If affirmative determination is made, the flow advances to step 110 to start the movement of the exposure stage 20 in which the photosensitive material 60 is adsorbed and held on the mounting surface. That is, the exposure stage 20 is moved at a constant speed toward the inside of the case portion 12A from the stage portion 12B along the sliding rail 22 of the surface plate 18 by the driving force of the linear motor portion 24.

In step 112 during the movement of the exposure stage 20, the pulse counter counts the output pulses of the linear encoder installed in the linear motor unit 24 to recognize the position of the exposure stage 20 (the Can be discriminated even with drive pulses] In step 114, it is determined whether or not it is an imaging timing.

That is, it is determined whether the front end of the moving direction of the exposure stage 20 is a position immediately before passing through the low magnification camera portion 36 on the front side in the backward direction, and if affirmative, proceeds to step 116. Start shooting. Thereby, the predetermined area | region containing the alignment mark M previously provided to the photosensitive material 60 is image | photographed by the low magnification (wide view) camera part 36 (refer FIG. 10 (A)).

That is, the strobe light source 36C (long wavelength light) of the low magnification camera section 36 is made to emit light when the alignment mark M reaches a predetermined shooting position. Then, by inputting the reflected light from the upper surface of the photosensitive material 60 of the strobe light irradiated to the photosensitive material 60 into the camera main body 36A through the lens portion 36B (a predetermined region including the alignment mark M) (Fig. Denoted by E1 in 10 (A)].

Here, even if the photosensitive material 60 mounted on the exposure stage 20 is the same size, when the position of the alignment mark M differs for every lot or every kind, or when it mounts on the mounting surface of the exposure stage 20, it is desired. Since it may deviate from the position to make, first, the job which grasps the position of the alignment mark M to some extent by the low magnification (wide view) camera part 36 is performed first. In addition, the position of the low magnification camera part 36 at this time is recognized by the reference scale S. FIG.

In the next step 118, the position of the exposure stage 20 is confirmed, and in step 120 it is determined whether or not it is the shooting end timing. That is, it is determined whether or not the rear end of the exposure direction 20 passes through just below the alignment unit 30, and if it is determined to be affirmative, the process proceeds to step 122 and the shooting is finished.

In this way, when the low magnification camera section 36 captures a predetermined area including the alignment mark M, the imaging data is analyzed in step 124. Accordingly, if the position of the alignment mark M can be specified to some extent, the position in the width direction with respect to the surface plate 18 of the high magnification camera section 38 is viewed in accordance with the position of the alignment mark M in step 126. The screw mechanism 42 is controlled by drive control (see FIG. 10 (B)).

At this time, the relative position through the exposure stage 20 of the low magnification camera section 36 and the high magnification camera section 38 can be confirmed by the reference scale S, and the position of the high magnification camera section 38 is adjusted based on this. Can be. After that, it is judged whether or not the adjustment is completed at step 128, and if it is determined as affirmative, the process proceeds to step 130 and moves to the ear of the exposure stage 20 where the photosensitive material 60 is adsorbed and held on the mounting surface. To start.

That is, the exposure stage 20 is moved at a constant speed from the case portion 12A toward the stage portion 12B side along the sliding rail 22 of the surface plate 18 by the driving force of the linear motor portion 24. In step 132, the pulse counter counts the output pulses of the linear encoder installed in the linear motor unit 24 while moving to the exposure stage 20, thereby recognizing the position of the exposure stage 20 (the linear motor unit ( Can be discriminated even with the driving pulse of 24) In step 134, it is judged whether or not it is an imaging timing.

That is, it is determined whether or not the front end of the moving direction of the exposure stage 20 is a position just before passing under the high magnification camera portion 38 in the backward direction, and if it is determined as affirmative, the process proceeds to step 136 and is photographed. Initiate. Thereby, the alignment mark M previously given to the photosensitive material 60 is image | photographed by the high magnification (narrow field view) camera part 38 (refer FIG. 10 (C)).

That is, the strobe light source 38C (short wavelength light) of the high magnification camera section 38 is made to emit light when the alignment mark M reaches a predetermined shooting position. And the alignment mark M (FIG. 10 (C)) by inputting the reflected light from the upper surface of the photosensitive material 60 of the strobe light irradiated to the photosensitive material 60 to the camera main body 38A via the lens part 38B. Indicated by E2].

In addition, since the position of the high magnification camera part 38 is arrange | positioned at an appropriate position based on the imaging (detection) result by the low magnification camera part 36, the alignment mark M can be imaged reliably here. Therefore, an error due to the inability to detect the alignment mark M does not occur. In addition, since the strobe light at the time of imaging with the high magnification camera part 38 is a light of short wavelength (for example, blue), the resolution at the time of imaging the alignment mark M which requires precision can be improved.

In this way, when the alignment mark M is image | photographed with the high magnification camera part 38, in the next step 138, the data image | photographed in step 140 is analyzed, confirming the position of the exposure stage 20, and then, The flow advances to step 142 to extract image data corresponding to the alignment mark M. FIG. In the next step 144, reference data is read from the mark data memory, the image is taken in step 146, and the extracted mark image data is combined with the previously stored reference data.

Subsequently, in the next step 148, the exposure position correction coefficient is calculated on the basis of the combination result, the process proceeds to step 150, and the correction coefficient data calculated by the exposure control system is sent out, and this routine is completed. That is, the exposure start time etc. by each head assembly 28A in the exposure head unit 28 are correct | amended. Therefore, the image position recorded on the photosensitive material 60 becomes an appropriate position.

On the other hand, the alignment mark M applied to the photosensitive material 60 is detected as the exposure stage 20 moves at a predetermined speed. Therefore, even when the original alignment mark M is circular, if the photographing is performed while moving the exposure stage 20, the photographed image is almost elliptical, depending on the shutter speed and the like at the time of photographing.

Therefore, the mark data stored in the mark data memory is an image (elliptical image) reflecting the shooting environment (shutter speed, moving speed of the exposure stage 20, etc.) of the high magnification camera unit 38. That is, the combination is optimized by storing the mark data corresponding to the image photographed while actually moving the exposure stage 20 in the photographing environment instead of the original circular shape.

In this way, when the image recording position correction (exposure start timing correction) is finished, the exposure stage 20 passes through the exposure head unit 28. At this time, the exposure head unit 28 irradiates the laser light to the DMD based on the corrected exposure start time, and the laser light reflected when the micro mirror of the DMD is turned on is guided to the photosensitive material 60 through the optical system. It forms on the photosensitive material 60 (exposure surface).

That is, the image data stored in the memory of the controller unit 50 is sequentially read in a plurality of lines, and a control signal is generated for each head assembly 28A based on the read image data. The control signal is subjected to correction of the exposure position difference with respect to the photosensitive material 60 that has been aligned and measured by correction control (alignment), so that the photosensitive material 60 is exposed in units of pixels approximately equal to the number of pixels used in the DMD.

Since three alignment marks M are provided at predetermined intervals in the short side direction, they are provided in four rows in the longitudinal direction (scanning direction) or less than an interval between the high magnification camera portion 38 and the head assembly 28A. [The interval between the high magnification camera portion 38 and the head assembly 28A is equal to or greater than the interval of the alignment mark M in the scanning direction.] The alignment mark M is taken by the high magnification camera portion 38 (measured). The exposure process in the head assembly 28A can be performed.

That is, the alignment mark M of the 1st column of a longitudinal direction is measured with the high magnification camera part 38 with the return of the exposure stage 20, Then, at the time when the alignment mark M of the 2nd column is measured, The exposure position correction coefficient with respect to the drawing area | region between the alignment mark M of the 1st column and the alignment mark M of the 2nd column can be calculated (can also be calculated similarly after 2nd column). That is, the tip of the drawing region of the photosensitive material 60 with respect to the scanning direction passes through the position of the high magnification camera portion 38 and then to the position of the head assembly 28A to photograph the alignment marks M in the first row. Since the exposure position correction coefficient with respect to a drawing area can be calculated based on this, even if the space | interval of the high magnification camera part 38 and the head assembly 28A is narrow, exposure processing can be performed.

In this way, the photosensitive material 60 is moved with the exposure stage 20 at a constant speed so that a strip-shaped exposed area 28C is formed for each head assembly 28A in a direction opposite to the moving direction of the exposure stage 20. (See FIG. 6 (A)). And when the exposure process with respect to the photosensitive material 60 is completed and the exposure stage 20 is moved back to an initial position, the photosensitive material 60 will be canceled by the exposure stage 20, and the outside which is not shown in figure is shown. It is conveyed by the conveyance conveyor of and is conveyed to the next process.

[Modification of Exposure Device]

Next, the modification of the exposure apparatus 10 is demonstrated. In addition, about the site | part which has a function equivalent to the above, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted. As shown in FIGS. 11-13, this exposure apparatus 11 is provided with the surface plate 18 extended in the longitudinal direction (scanning direction), and the photographing (measurement) and the exposure process of the alignment mark M are performed by exposure. The stage 20 is configured to be completed by only moving in one direction (the direction of the arrow YB shown in FIG. 12).

That is, the position where the photosensitive material 60 is mounted on the exposure stage 20 with respect to the surface plate 18 and the position where the photosensitive material 60 is drawn out on the exposure stage 20 have different configurations, and the low magnification camera section 36 and the high magnification camera are used. The part 38 is provided in order at predetermined intervals along the one direction (arrow YB direction).

That is, the low magnification camera portion 36 is hypothesized on a pair of struts 56 provided on the surface plate 18, and the high magnification camera portion 38 is hypothesized on a pair of struts 58 provided on the surface plate 18. Each base part 32 is provided independently. In addition, two surface plates 18 and two exposure stages 20 are provided, a low magnification camera portion 36 is provided on one surface plate 18, and a high magnification camera portion 38 on the other surface plate 18. The exposure head unit 28 may be provided.

When the photosensitive material 60 is mounted on the exposure stage 20, and the exposure stage 20 starts to move in the direction of the arrow YB, first, the low magnification camera unit 36 includes the alignment mark M. A predetermined area is photographed. And the position in the width direction of the high magnification camera part 38 is adjusted based on this imaging result.

Then, the exposure stage 20 moves in the direction of the arrow YB, and the alignment mark M is imaged by the position-adjusted high magnification camera portion 38 this time. At this time, the low magnification camera unit 36 photographs a predetermined area including the alignment mark M so that even if the position of the photosensitive material 60 is out of position, the arrangement of the high magnification camera unit 38 is completed accordingly. M) can be taken reliably. In other words, it is possible to prevent the occurrence of an error due to a poor detection of the alignment mark M.

In this way, when the alignment mark M is image | photographed by the high magnification camera part 38, and the position of the photosensitive material 60 (drawing area) on the exposure stage 20 is measured by the controller part 50, an exposure stage ( 20 further moves in the direction of the arrow YB so that the photosensitive material 60 passes through the exposure head unit 28. And the exposure surface (drawing area) of the photosensitive material 60 is exposed by the head assembly 28A by this.

Further, when the exposure stage 20 moves in the direction of the arrow YB and the exposure process to the photosensitive material 60 is completed (see FIG. 12), the photosensitive material 60 is adsorbed by the exposure stage 20. The state is released and conveyed to an outside conveying conveyor not shown, and conveyed to the next step. Thereafter, the exposure stage 20 moves back in the state in which nothing is mounted on the mounting surface in the direction of the arrow YA shown in FIG. 12 in order to expose the next photosensitive material 60.

In addition, in the case of such an exposure apparatus 11, since the exposure process is performed after imaging (measurement) all the alignment marks M formed on the photosensitive material 60, the alignment mark M is photosensitive. It is sufficient if all four are provided in the vicinity of the corner part of the material 60, respectively.

As described above, when photographing the alignment mark M, first, the low magnification (wide field of view) camera unit 36 is used, and then the high magnification (narrow field of view) camera unit 38 is configured. Therefore, the alignment mark M can be photographed (detected) reliably, and the occurrence of an error due to the detection failure of the alignment mark M can be prevented reliably.

That is, in the case of the configuration in which only the high magnification (narrow field of view) camera portion 38 is provided, when the position of the photosensitive material 60 is mounted on the exposure stage 20 outside, or for each lot of the photosensitive material 60, the alignment is performed for each kind. When the mark M is out of position, the alignment mark M may not be photographed by the high magnification (narrow field of view) camera unit 38 (see Fig. 10 (B)). However, in this invention, in order to prevent this, the low magnification camera part 36 is provided, and the alignment mark M can be reliably photographed.

That is, since the image is initially captured by the low magnification (wide field of view) camera unit 36 (see FIG. 10 (A)), even if the position of the alignment mark M deviates from the predetermined position, the predetermined mark including the alignment mark M is included. By photographing an area, the alignment mark M can be detected reliably. Thereby, the position of the alignment mark M can be grasped (specific), and the correction distance (correction amount) of the width direction of the high magnification camera part 38 with respect to the photosensitive material 60 can be calculated based on this photographing result. Can be.

And since the position of the high magnification camera part 38 in the width direction is automatically adjusted with the correction amount, alignment mark M can be reliably photographed (measured) by the high magnification camera part 38 (FIG. 10 (C). ) Reference]. Therefore, even when the alignment mark M cannot be photographed by the high magnification (narrow field of view) camera portion 38, there is no need to properly adjust the photosensitive material 60 as in the prior art, and a decrease in manufacturing efficiency does not occur, The exposure process to the photosensitive material 60 can be performed efficiently.

In addition, in this embodiment, since the reading of the alignment mark M for correcting the image position recorded on the photosensitive material 60 is performed while moving the exposure stage 20 (photosensitive material 60), processing efficiency (productivity) ) Can be improved. In addition, in the said embodiment (except a modification), since it is the structure which reciprocates the exposure stage 20, the exposure head unit 28 and the alignment unit 30 can be arrange | positioned close, and the exposure apparatus 10 The compactness of the device can be achieved (to save space in the installation space).

In addition, when the alignment mark M cannot be image | photographed by the low magnification camera part 36, the photosensitive material 60 itself may be regarded as defective goods, and the photosensitive material 60 may be forcibly discharged on the exposure stage 20. FIG. . At this time, the number of measurement retry of the alignment mark M in the low magnification camera unit 36 is set in advance, and if the measurement cannot be performed by correcting the number of times, it is forcibly discharged. You may also

In addition, in this embodiment, although it is set as the structure which image | photographs the alignment mark M of the photosensitive material 60 mounted there, moving the exposure stage 20, it is not limited to this, When imaging the alignment mark M, it is taken. Needless to say, the configuration may be configured to stop the exposure stage 20 once.

In this embodiment, the DMD is used as the spatial light modulation element, and the dot pattern is generated by turning on / off the constant lighting time, but pulse width modulation by the on-duty control may be performed. Further, the dot pattern may be generated by the number of lighting cycles with one lighting time being extremely short.

In addition, although the exposure head unit 28 provided with DMD was demonstrated as a spatial light modulation element in this Example, a transmissive spatial light modulation element (LCD) can also be used other than this reflective spatial light modulation element. For example, a MEMS type micro light mechanical modulator (SLM: Special Light Modulator), an optical element (PLZT element) that modulates transmitted light by an electro-optic effect, a liquid crystal light shutter (FLC), and the like. Spatial light modulation elements other than MEMS type, such as a liquid crystal shutter array, can also be used.

In addition, MEMS is a generic term for microsystems integrating micro-sized sensors, actuators, and control circuits using micromachining technology based on IC manufacturing processes. MEMS type spatial light modulation devices are used for electromechanical operation using electrostatic force. It means a spatial light modulation device driven by. Moreover, the thing which comprised two or more Grating Light Valve (GLV) two-dimensionally can also be used. In the configuration using these reflective spatial light modulation elements (GLV) and transmissive spatial light modulation elements (LCDs), lamps and the like can be used as a light source in addition to the laser.

As the light source, a fiber array light source including a plurality of haptic laser light sources, a fiber array light source in which a fiber light source including one optical fiber which emits laser light incident from a single semiconductor laser having one light emitting point, and a plurality of Light sources (e.g., LD arrays, organic EL arrays) in which light emitting points are arranged in two dimensions are applicable.

In addition, as the exposure apparatus, both a photon mode photosensitive material in which information is directly recorded by exposure and a heat mode photosensitive material in which information is recorded by heat generated by exposure can be used. When a photon mode photosensitive material is used, a GaN-based semiconductor laser, a wavelength conversion solid state laser, or the like is used for the laser device, and when a heat mode photosensitive material is used, an AlGaAs semiconductor laser (infrared laser), a solid state laser is used for the laser device. .

Claims (12)

A stage in which the photosensitive material is mountable and configured to be movable along a predetermined conveyance path; A first camera for photographing a predetermined area including an alignment mark of the photosensitive material mounted on the stage; A second camera having a higher magnification than the first camera and capable of adjusting the position of the photosensitive material on the basis of the photographing result by the first camera to photograph the alignment mark of the photosensitive material mounted on the stage; And exposure means for exposing the image data corrected based on the photographing result by the second camera to the photosensitive material. The method of claim 1, The movement along the predetermined conveying path of the stage is a reciprocating movement, The photographing by the first camera is performed while moving to the king of the stage, The exposure apparatus according to claim 2, wherein the photographing by the second camera and the exposure by the exposure means are performed while moving to the ear of the stage. The method of claim 1, At least the illumination light of the said 2nd camera is short wavelength, The exposure apparatus characterized by the above-mentioned. The method of claim 2, At least the illumination light of the said 2nd camera is short wavelength, The exposure apparatus characterized by the above-mentioned. The method of claim 2, An exposure apparatus according to claim 1, wherein the speed at the time of moving the stage to the back and forth is faster than the speed at the time of moving to the ear of the stage. The method of claim 2, An interval between the second camera and the exposure means in the movement direction of the stage is equal to or greater than an interval in the movement direction of the stage of the plurality of alignment marks of the photosensitive material mounted on the stage. Device. Photographing a predetermined area including an alignment mark of the photosensitive material with the first camera while moving the stage on which the photosensitive material is mounted along a predetermined conveying path; Adjust the position of the second camera having a higher magnification than the first camera based on the photographing result by the first camera; Photographing the alignment mark of the photosensitive material with the second camera while moving the stage along a predetermined conveying path; The exposure method characterized by exposing the image data corrected on the basis of the photographing result to the photosensitive material by exposure means. The method of claim 7, wherein The movement along the predetermined conveying path of the stage is a reciprocating movement, The first camera takes a picture while moving to the stage of the stage, And the second camera photographs while the exposure means exposes while moving to the ear of the stage. The method of claim 7, wherein The illumination method is characterized in that the illumination light is shortened when at least taken by the second camera. The method of claim 8, The illumination method is characterized in that the illumination light is shortened when at least taken by the second camera. Mounting the photosensitive material on the exposure apparatus stage; Moving the stage on which the photosensitive material is mounted along a predetermined conveying path; Photographing a predetermined area including an alignment mark of the photosensitive material with a first camera while the stage is moving; Adjust the position of the second camera having a higher magnification than that of the first camera based on the photographing result by the first camera with respect to the photosensitive material; Photographing the alignment mark of the photosensitive material with the second camera while moving the stage along a predetermined conveying path; The exposure method characterized by exposing the image data corrected on the basis of the photographing result to the photosensitive material by exposure means. The method of claim 11, The movement along the predetermined conveying path of the stage is a reciprocating movement, The first camera takes a picture while moving to the stage of the stage, And the second camera photographs while the exposure means exposes while moving to the ear of the stage.

Images