JP2006235378A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus and an image forming method for preventing misalignment between a mark position and an exposure position due to temperature changes during measuring the mark and during exposure. <P>SOLUTION: The image forming apparatus is equipped with a stage 16 to mount a work 22, a drawing means that detects a reference mark on the work mounted on the stage and draws an image based on the detected reference mark position, and a chassis housing the stage 16 and the drawing means. The apparatus is further equipped with a inner temperature control means 50 to control the inner temperature of the chassis so as to control the stage temperature to be substantially equal to an environmental temperature median as the median of the environmental temperature in the installation environment where the image forming apparatus is placed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus and an image forming method, and more particularly to an image forming apparatus and an image forming method that enable high-precision image formation with a simple system.

  In recent years, an exposure unit in which a plurality of exposure heads that selectively turn on and off a plurality of pixels to expose a workpiece are arranged along the x direction and a workpiece to be exposed are placed, and the exposure unit In contrast, a so-called patternless method is used in which an exposure apparatus including an exposure stage that is relatively movable along the y direction orthogonal to the x direction is used to expose a display glass substrate without using a pattern film on which a circuit pattern is baked. Exposure is widely performed (Patent Document 1).

  When exposure is performed by reciprocating the exposure stage in the exposure apparatus, the position of the reference mark attached to the workpiece is detected in the forward path, and in the backward path, image data is based on the position of the reference mark detected in the forward path. Exposure is performed while correcting.

  However, the temperature of the work depends on the environmental temperature outside the apparatus, and when the environmental temperature changes, the temperature of the work also changes.

  Therefore, even if the exposure apparatus is provided with temperature control means and the temperature inside the apparatus is controlled so that the temperature of the exposure stage is constant, there is a difference between the temperature of the workpiece supplied from outside the apparatus and the temperature of the exposure stage. For this reason, the temperature of the workpiece changes during mark measurement and exposure, and a deviation occurs between the mark position and the exposure position.

  As a countermeasure to the above problem, it is conceivable to directly control the workpiece temperature so that the workpiece temperature does not change during mark measurement and exposure.

  As an exposure apparatus that has taken such measures, for example,

  In an exposure apparatus that exposes an original film in close contact with a substrate, the temperature in the exposure unit is controlled based on the result of index reading provided on the substrate and the original film by the reading means (Patent Document 2),

  A substrate table unit for placing a substrate housed in the environmental chamber, a detection unit for detecting a temperature in the chamber, and an air conditioner for air-conditioning the environmental chamber based on the detected temperature of the detection unit. An exposure apparatus that adjusts the temperature of the base table based on the temperature detected by the detector (Patent Document 3), and

  A substrate supply unit placed in the atmosphere, a chamber having a substrate processing unit therein, a load lock unit for replacing the atmosphere to transfer the substrate between the substrate supply unit and the substrate processing unit, and a load A substrate processing apparatus having a substrate holding chuck for holding a substrate in a lock unit, the substrate holding unit holding the substrate by suction and controlling the temperature (Patent Document 4)

There is.
JP 2004-163798 A JP-A-7-013340 JP-A-11-176730 JP 2003-045947 A

  However, all of the temperature control systems proposed in Patent Documents 2 to 4 attempt to directly control the temperature of the substrate, and the exposure apparatus in the form of the exposure apparatus described in Patent Document 1 is used. The problem is that the system is too complex to apply.

  The present invention has been made in order to solve the above-described problem. With a simpler system, the temperature of the workpiece changes during mark measurement and exposure, and a deviation occurs between the mark position and the image forming position. An object of the present invention is to provide an image forming apparatus and an image forming method capable of preventing the above-described problem.

  The invention according to claim 1 is a stage on which a workpiece is placed, a drawing means for detecting a reference mark on the workpiece placed on the stage, and forming an image based on the detected reference mark position; An image forming apparatus including the stage and a housing that houses the drawing unit, wherein the temperature of the stage and the median environmental temperature that is the median environmental temperature in an installation environment in which the image forming apparatus is installed Further, the present invention relates to an image forming apparatus comprising an in-machine temperature adjusting means for controlling the temperature inside the casing so that the two are substantially equal to each other.

  The temperature of the workpiece just inserted in the image forming apparatus is approximately equal to the environmental temperature.

  In the image forming apparatus, the temperature inside the housing is controlled by an in-machine temperature control means so that the temperature of the stage is substantially equal to the median environmental temperature. There is almost no temperature difference between the workpiece and the stage.

  Therefore, there is no deviation between the mark position and the exposure position due to a change in the temperature of the workpiece during mark measurement and exposure.

  Here, there are various definitions of the median environmental temperature, but in general, it can be defined as an intermediate value between the maximum value and the maximum value of the environmental temperature in a certain time range.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the drawing unit includes a plurality of exposure heads along the x direction for exposing the work by selectively turning on and off a plurality of pixels. Relates to an array of exposure units.

  The image forming apparatus is an example in which the present invention is applied to an image forming apparatus having an exposure unit as a drawing unit.

  According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, the in-machine temperature adjusting means measures an environmental temperature measuring means for measuring the environmental temperature, and an environmental temperature measured by the environmental temperature measuring means. A median computing means for obtaining the median ambient temperature based on the image temperature, and the temperature inside the image forming apparatus is set to be higher than the median ambient temperature so that the stage temperature and the median ambient temperature are equal. And an air conditioner that controls the temperature to be lower by the offset value.

  In the image forming apparatus, the median environmental temperature is obtained based on the environmental temperature actually measured by the environmental temperature measuring means, and the internal temperature of the air conditioner is set to a temperature lower than the median environmental temperature by a predetermined offset value. It is controlled to become.

  Therefore, even if the environmental temperature changes, mark measurement and exposure can be performed with almost no temperature difference between the workpiece and the stage supplied from outside the apparatus.

  Here, the temperature inside the apparatus is controlled so as to be lower than the environmental temperature median by a predetermined offset value because the stage is irradiated with the light beam from the exposure head and becomes higher than the temperature inside the apparatus. This is for correction. Here, the offset value is a difference between the median environmental temperature and the stage temperature.

  A fourth aspect of the present invention relates to the image forming apparatus according to the third aspect, wherein the offset value is predetermined for each median environmental temperature.

  In the image forming apparatus, whether the environmental temperature is high or low, the stage temperature can be controlled to be equal to the environmental temperature median value by using an offset value corresponding to the environmental temperature.

  According to a fifth aspect of the present invention, in the image forming apparatus according to the third or fourth aspect of the present invention, the in-machine temperature adjusting means obtains a new environmental temperature median value by the median value computing means at predetermined time intervals. Further, the present invention relates to an apparatus for controlling an in-machine temperature of an image forming apparatus in the air conditioner based on a median environmental temperature value and an offset value corresponding thereto.

  In the image forming apparatus, when the environmental temperature changes, a new environmental temperature median value is obtained, and the in-machine temperature of the image forming apparatus is controlled based on the environmental temperature median value and the corresponding offset value. Even when the environmental temperature rapidly changes during operation of the image forming apparatus, mark measurement and exposure can be performed with almost no temperature difference between the workpiece and the stage supplied from outside the apparatus.

  According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the third to fifth aspects, the air conditioner is installed in the same environment as an installation environment of the image forming apparatus. In which the air is sucked and supplied to the image forming apparatus.

  In the image forming apparatus, since the temperature of the image forming apparatus is controlled by sucking air in the same environment as the installation environment of the image forming apparatus, the burden on the air conditioner is small.

  A seventh aspect of the present invention is the image forming apparatus according to any one of the first to sixth aspects, further comprising stage temperature measuring means for measuring the surface temperature of the stage, and the stage measured by the stage temperature measuring means. If the difference between the temperature and the environmental temperature median obtained by the median computing means based on the environmental temperature measured by the environmental temperature measuring means is greater than a predetermined value, the stage temperature and the environmental temperature The present invention relates to an apparatus for obtaining a waiting time until the temperature of a workpiece placed on a stage is stabilized based on a median value, and performing mark measurement and exposure after the waiting time has elapsed.

  Also in the image forming apparatus of the present invention, it is considered that some time may be required until the stage temperature becomes equal to the median environmental temperature after the operation is started, depending on the capability of the air conditioner.

  However, in the image forming apparatus, a waiting time is obtained based on the stage temperature and the median environmental temperature, and mark measurement and exposure are performed after the waiting time has elapsed and the temperature of the workpiece has stabilized. Therefore, even when the capacity of the air conditioner is small, mark measurement and exposure can be performed with almost no temperature difference between the workpiece and the stage supplied from outside the apparatus.

  The invention according to claim 8 is a stage on which a work is placed, a drawing unit that detects a reference mark on the work placed on the stage, and forms an image based on the detected reference mark position; An image forming method for forming an image on the workpiece using an image forming apparatus including a stage and a housing for housing a drawing unit, wherein the temperature of the stage and the image forming apparatus are installed The present invention relates to an image forming method characterized in that image formation is performed while controlling the temperature inside the housing so that the median environmental temperature, which is the median environmental temperature of the installation environment, becomes substantially equal.

  According to the image forming method, for the same reason as described in claim 1, mark measurement and exposure can be performed in a state where there is almost no temperature difference between the workpiece and the stage supplied from outside the apparatus.

  As described above, according to the present invention, with a simple system, an image forming apparatus that can prevent the temperature of a workpiece from changing during mark measurement and exposure and causing a deviation between the mark position and the exposure position, and An image forming method is provided.

  1. Embodiment 1

  An exposure apparatus that is an example of the image forming apparatus of the present invention will be described below.

  As shown in FIGS. 1 to 3, the exposure apparatus 10 according to the first embodiment is a flat bed type.

  The exposure apparatus 10 is configured such that each part is accommodated in a rectangular frame 12 formed by assembling rod-shaped square pipes into a frame shape. A panel (not shown) is attached to the frame body 12 to block the inside and outside.

  The frame body 12 includes a tall housing portion 12A and a stage portion 12B provided so as to protrude from one side surface of the housing portion 12A.

  The stage portion 12B has an upper surface lower than the housing portion 12A, and is disposed so as to have a substantially waist height when an operator stands in front of the stage portion 12B.

  An opening / closing lid 14 is provided on the upper surface of the stage portion 12B. A hinge (not shown) is attached to one side of the opening / closing lid 14 on the housing 12A side, and opens and closes around this one side.

  On the upper surface of the stage portion 12B with the opening / closing lid 14 opened, an exposure stage 16 corresponding to the stage of the main attack can be exposed.

  As shown in FIG. 4, a leg portion 16 </ b> A having a substantially U-shaped cross section is attached to the lower surface of the exposure stage 16. The leg portions 16A support the exposure stage 16 slidably with respect to the surface plate 18 extending from the stage portion 12B to the housing portion 12A, and are parallel to each other and in the longitudinal direction of the surface plate 18. Are supported via a pair of slide rails 20 disposed along the rails. Therefore, the exposure stage 16 moves along the y direction on the slide rail 20 with almost no frictional resistance.

  The photosensitive material 22 which is an example of the workpiece of the present invention is placed on the photosensitive material placement surface 17 in the exposure stage 16. The photosensitive material mounting surface 17 is provided with a plurality of grooves (not shown) so that the inside of the grooves can be made negative pressure by a vacuum pump or the like. By applying a negative pressure in the groove using a vacuum pump or the like, the photosensitive material 22 is brought into close contact with the photosensitive material placement surface 17 and is prevented from moving during mark measurement and exposure.

  As shown in FIG. 1 to FIG. 3, one end of the surface plate 18 in the longitudinal direction reaches the stage portion 12 </ b> B, and the operator places the photosensitive material 22 on the exposure stage 16 with the exposure stage 16 positioned at this position. Can be placed or removed.

  The stage unit 12B is provided with an infrared thermometer 19 that measures the temperature of the exposure stage 16.

  The surface plate 18 is supported by a gantry 24 that is firmly fixed to a square pipe that constitutes the casing 12A, and serves as a reference for the movement locus of the exposure stage 16.

  A linear motor portion 26 is disposed between the pair of slide rails 20 disposed along the longitudinal direction of the surface plate 18.

  The linear motor unit 26 is a linear drive source that applies the driving force of the stepping motor, and as shown in FIGS. 1 and 2, a rod-shaped coil unit 26A provided along the longitudinal direction of the surface plate 18 and The stator portion (magnet portion) 26B provided on the lower surface side of the exposure stage 16 and arranged with a predetermined distance from the coil portion 26A.

  The exposure stage 16 obtains a driving force by a magnetic field generated by energization of the coil portion 26A, and moves on the surface plate 18 along the slide rail 20 along the y direction.

  As described above, since the principle is the same as that of the stepping motor, the exposure stage 16 according to the first embodiment has high accuracy by electrical control such as constant speed, positioning accuracy, and torque fluctuation at start and stop. Drive control is possible.

  An exposure unit 28 is disposed at an approximately middle position of the movement locus on the surface plate 18 in the exposure stage 16.

  As shown in FIG. 1, the exposure unit 28 is disposed so as to be spanned between a pair of support columns 30 erected on the outer sides of both end portions in the width direction of the surface plate 18, thereby allowing the exposure stage 16 to pass. A gate is formed.

  As shown in FIG. 5, the exposure unit 28 includes a plurality of head assemblies 28A arranged in the width direction of the surface plate 18, that is, the x direction. The head assembly 28A corresponds to the exposure head in the present invention. In the exposure unit 28, a plurality of light beams (details will be described later) are irradiated from the respective head assemblies 28A to the photosensitive material 22 on the exposure stage 16 at a predetermined timing while moving the exposure stage 16 at a constant speed. The photosensitive material 22 is exposed.

  As shown in FIG. 6B, the head assembly 28A constituting the exposure unit 28 is arranged in a substantially matrix form of m rows and n columns (for example, 2 rows and 4 columns), and a plurality of head assemblies 28A are arranged as x. In other words, they are arranged in the direction perpendicular to the moving direction of the exposure stage 16, that is, the scanning direction b. In the exposure apparatus 10 according to the first embodiment, 4 × 2 rows = 8 head assemblies 28 </ b> A are provided in relation to the width of the photosensitive material 22. As shown in FIGS. 1 to 3 and 5, the eight head assemblies 28 </ b> A are arranged in a staggered manner.

  An exposure area 28B by one head assembly 28A has a rectangular shape with a short side in the scanning direction b, and is inclined at a predetermined inclination angle with respect to the scanning direction b. Accordingly, when the exposure stage 16 moves, a strip-shaped exposed region is formed in the photosensitive material 22 for each head assembly 28A, as shown in FIG.

  As shown in FIG. 1, a light source unit 29 is disposed at a location that does not hinder the movement of the exposure stage 16 in the housing 12A. The light source unit 29 accommodates a plurality of laser light sources. Laser light emitted from the laser light source is guided to each head assembly 28A via an optical fiber.

  In each head assembly 28A, an incident light beam guided by the optical fiber is controlled in units of pixels by a digital micromirror device (DMD, not shown) which is a spatial light modulation element, and the photosensitive material 22 is controlled. Is exposed to a pixel pattern. In the exposure apparatus 10 according to the first embodiment, a plurality of pixels are overlapped to express the density of one pixel.

  As shown in FIG. 7, in one head assembly 28 </ b> A, the exposed region 28 </ b> B is formed by 20 pixels that are two-dimensionally arranged (for example, 4 × 5).

  Since the 20 pixels are inclined with respect to the scanning direction, the pixels in one column pass between two adjacent pixels in the column located further downstream in the scanning direction. Therefore, the substantial pitch between pixels can be reduced, and high resolution can be achieved.

  The exposure process to the photosensitive material 22 positioned on the exposure stage 16 is not performed when the exposure stage 16 moves on the slide rail 20 toward the back of the housing portion 12A (outward path a), but as described above. As described above, the process is executed when the vehicle once reaches the back of the housing 12A and returns to the stage 12B (return path b).

  That is, the forward path a is a movement for obtaining position information of the photosensitive material 22 on the exposure stage 16, and as a unit for obtaining this position information, as shown in FIG. 1 to FIG. 3 and FIG. A camera unit 32 is disposed on the top 18.

  The camera unit 32 is disposed downstream of the exposure unit 28 in the direction of the forward path a as shown in FIGS. 1 to 3, and constitutes a part of the housing portion 12A as shown in FIG. Are fixed to a pair of beam portions.

  As shown in FIG. 8, the camera unit 32 includes a base portion 36 fixed to the pair of beam portions 34 and a plurality of camera units 32 (in the first embodiment, movable in the width direction of the surface plate 18). 4) camera units 38.

  The camera section 38 is attached to a pair of parallel rail sections 40 disposed along the base section 36 independently of each other so as to be slidable in the x direction via the camera base 42.

  The camera unit 38 is provided with a lens unit 38B on the lower surface of the camera body 38A, and a ring-shaped strobe light source 38C is attached to the protruding tip of the lens unit 38B.

  The light from the strobe light source 38C is applied to the photosensitive material 22 on the exposure stage 16, and the reflected light is input to the camera body 38A via the lens portion 38B. (See FIG. 8).

  The camera base 42 can be moved along the width direction of the surface plate 18, that is, the x direction, by driving the ball screw mechanism 44, and the movement of the exposure stage 16 and the driving of the ball screw mechanism 44. The optical axis of the lens portion 38A can be arranged at a desired position of the photosensitive material 22 by the movement of the surface plate 18 in the width direction by force.

  The relative positions of the exposure stage 16 and the photosensitive material 22 are determined by the operator placing the photosensitive material 22 on the photosensitive material placement surface 17. However, the photosensitive material 22 is placed on the photosensitive material placement surface 17. There may be a slight deviation between the position to be formed and the actual position of the photosensitive material 22. Therefore, as shown in FIG. 9, the mark M provided on the photosensitive material 22 is photographed by the camera body 38A. The deviation is recognized by this photographing, and the exposure timing by the exposure unit 28 is corrected.

  A procedure for measuring the marks with the camera unit 32 will be described below.

  As shown in FIG. 10, when a stage operation control signal is input and a predetermined waiting time elapses, the camera operation control unit 56 of the controller unit 54 inputs an activation signal to the camera unit 38. In response to the activation signal, the camera unit 38 starts photographing. That is, the operation timing of the exposure stage 16 and the shooting timing by the camera unit 38 are synchronized.

  In addition, the size information is input to the width direction position setting unit 58 together with the stage operation control signal, and the operation of the ball screw mechanism unit 44 is controlled by the width direction position setting unit 58, and the size of the surface plate 18 of the camera unit 38 is controlled. The position in the width direction is adjusted.

  During the photographing operation of the camera unit 38, the exposure stage 16 moves at a constant speed along the forward path on the surface plate 18. For this reason, the mark M given to the photosensitive material 22 placed on the exposure stage 16 is photographed by the camera unit 38.

  The captured data is sent to the captured data analysis unit 60, where the captured data is analyzed. Basically, the captured image data is analog data (the amount of light is converted into voltage immediately after photoelectric conversion). Therefore, the analog data is converted into digital image data, and the digital image data is combined with the position data. Numerical value (density value) is managed.

  The digital image data analyzed by the photographic data analysis unit 60 is sent to the mark extraction unit 62, where marks are extracted and sent to the mark collation unit 64. On the other hand, the position data associated with the digital image data is sent to the exposure position correction coefficient calculation unit 66.

  The mark collating unit 64 collates the extracted mark image data with the mark data stored in the mark data memory 68 in advance, and sends a signal indicating coincidence / mismatch to the exposure position correction coefficient computing unit 66.

  The exposure position correction coefficient calculation unit 66 recognizes an error between the position data corresponding to the mark data determined to match as a result of the collation and the original (designed) mark position data, and the exposure position. Correction coefficients for (the exposure start position in the moving direction of the exposure stage 16 and the pixel shift position in the width direction of the exposure stage 16) are calculated and sent to the exposure control system.

  Here, the feature of mark detection in the first embodiment is that the mark is detected while moving the exposure stage 16 at a constant speed. As shown in FIG. 9A, when the mark M originally imparted to the photosensitive material 22 is circular, if the photograph is taken while moving the exposure stage 16, the photographed image is set to the shutter speed at the time of photography. However, as shown in FIG. 9B, an oval mark ML is formed.

  Therefore, the mark data stored in the mark data memory 68 is, as shown in FIG. 9C, an image ML ′ that takes into account the shooting environment of the camera unit 38 (shutter speed, movement speed of the exposure stage 16, etc.). In other words, not the original mark shape but the mark data corresponding to the actually photographed image in the photographing environment is stored in the mark data memory 68 so as to optimize the collation.

  As shown in FIG. 1, a chamber 46 is further provided inside the housing 12 </ b> A of the exposure apparatus 10, and the exposure unit 28 and the camera unit 32 are disposed in the chamber 46.

  An air conditioner 50 is also provided in the room where the exposure apparatus 10 is installed, and the air conditioner 50 and the chamber 46 communicate with each other through a duct 48. When air adjusted to a predetermined temperature is sent from the air conditioner 50 to the chamber 46, the pressure in the chamber 46 becomes positive, and the stage in the housing 12 passes through the only escape area, that is, the movement space of the exposure stage 16. Flow to part 12B. Due to this flow, dust around the exposure unit 28 can be discharged, and even when the opening / closing lid 14 is opened, new dust can be prevented from entering due to the pressure difference.

  As shown in FIGS. 1 and 2, an in-machine thermometer 47 for measuring the in-machine temperature of the exposure apparatus 10 is provided inside the chamber 46, and the installation environment temperature of the exposure apparatus 10 is provided outside the chamber 46. An out-of-machine thermometer 49 is provided. The measurement results in the in-machine thermometer 47 and the out-of-machine thermometer 49 are fed back to the air conditioner 50 via the control board 51 provided in the air conditioner 50, and the inside of the chamber 46 is the median value of the installation environment temperature of the exposure apparatus 10. The air conditioner 50 is controlled so as to be held at a temperature lower than the predetermined offset value.

  Hereinafter, a procedure for controlling the air conditioner 50 based on the measurement results of the in-machine thermometer 47 and the out-of-machine thermometer 49 will be described.

  As shown in FIG. 11, in step S202, the control board 51 calls the environmental temperature from the external temperature system 49 for a predetermined time. In step S204, a median environmental temperature that is an intermediate value between the minimum and maximum values is obtained from the minimum and maximum values of the environmental temperature at the predetermined time.

  When the median ambient temperature is obtained, an offset value corresponding to the median ambient temperature is read from the memory in the control board 51 in step S206.

  The offset value is the number of degrees Celsius lower in the chamber 46 than the median ambient temperature in order for the temperature of the photoconductor mounting surface 17 of the exposure stage 16 to be equal to the median ambient temperature. It is a value.

  An example of a relationship obtained experimentally in advance with respect to the relationship between the offset value and the environmental temperature is shown in FIG. The memory in the control board 51 stores the relationship between the offset value and the environmental temperature as shown in FIG.

  The control board 51 calls the graph of FIG. 12 from the memory, and obtains an offset value corresponding to the environmental temperature median value obtained in step S204.

  Next, in step S208, the control board 51 calls the internal temperature from the internal thermometer 47 in real time, and in step S210, the internal temperature is equal to the temperature obtained by subtracting the offset value from the environmental temperature median value, that is, the temperature adjustment set temperature. Judge whether or not.

  If the difference between the in-machine temperature and the temperature control set temperature is within a preset error δt, it is determined Yes, and in step S212, the output of the air conditioner 50 is held as it is, and the process returns to step S202.

  On the other hand, if the difference between the in-machine temperature and the temperature control set temperature exceeds the error δt, it is determined No in step S210, and it is determined in step S214 whether the in-machine temperature is lower than the temperature control set temperature.

  If the determination in S214 is Yes, the output of the air conditioner 50 is decreased in step S216 and the process returns to step S210.

  On the other hand, when the determination in S214 is No, the output of the air conditioner 50 is increased in step 218, and the process returns to step S210.

  On the side of the exposure unit 28 close to the stage portion 12B, a static eliminator (ionizer) 52 is disposed across the width direction of the surface plate 18.

  The static eliminator 52 is composed of a hollow pipe-shaped blowing part 52A and an ion generating part 52B that supplies ionized air to the blowing part 52A, and has a structure that blows ionized air toward the surface plate 18. It has become.

  More specifically, in the ion generating part 52B, ions are generated by generating corona discharge between the ground electrode and the discharge electrode, and the ions are guided to the blowing part 52A by a blower source, and are made resistant to electricity by static electricity. Neutralize with ions of different polarity from the dust and neutralize.

  Thereby, when the exposure stage 16 on which the photosensitive material 22 is placed moves on the surface plate 18, the surface of the photosensitive material 22 is neutralized to remove dust adhering thereto due to static electricity, and the exposure stage 16 is blown with air. It is possible to remove dust floating in the upper space of the.

  Hereinafter, the operation of the exposure apparatus 10 will be described.

  The exposure stage 16 having the photosensitive material 22 adsorbed on the surface thereof is driven by the driving force of the linear motor unit 26 along the slide rail 20 of the surface plate 18 from the stage unit 12B to the back side of the housing unit 12A at a constant speed a. (Outward path a). Here, when the exposure stage 16 passes through the camera unit 32, the mark M previously given to the photosensitive material 22 is detected by the camera unit 38. The mark M is collated with a mark stored in advance, and the exposure start time by the exposure unit 28 is corrected based on the positional relationship.

  The exposure start timing correction routine is shown in the flowchart of FIG.

  In step S100, it is determined whether or not an exposure start instruction has been issued. If an affirmative determination is made, the process proceeds to step S300 to determine whether or not the stage temperature is higher than the median ambient temperature.

  On the other hand, if the determination in step S100 is negative, this routine ends.

  When a determination of Yes is made in step S300, a waiting time is obtained in the following procedure in step S302.

  As shown in FIG. 14, first, in step S304, the temperature of the photosensitive material stacking surface 17 of the exposure stage 16, that is, the stage temperature is called from the infrared thermometer 19, and the temperature difference ΔT between the stage temperature and the median ambient temperature is obtained. .

  Then, in step S306, the thickness t of the photosensitive material 22 is called, and in step S308, a temperature response speed table showing the relationship between the thickness t of the photosensitive material 22 and the temperature response speed is called, and the temperature response corresponding to the thickness t. The speed v is obtained.

In step S310, the waiting time tw is obtained from the size S of the photosensitive material 22, the temperature difference ΔT, and the temperature response speed v.

  When the waiting time tw is obtained, it is determined in step S312 whether or not the waiting time has elapsed from the time when the exposure start instruction is given.

  If YES is determined in step S312, the camera unit 38 is instructed to be activated in step S102.

  When it is determined No in step S312, the process returns to step S312 and continues to determine whether the waiting time has elapsed.

  On the other hand, if No is determined in step S300, the process immediately proceeds to step S102.

  When the activation of the camera unit 38 is instructed in step S102, the process proceeds to step S104, where it is determined whether or not the size information of the photosensitive material 22 has been input. If an affirmative determination is made in step S104, the ball screw mechanism 44 is driven based on the size information input in step S106 and the position of the camera unit 38 in the width direction with respect to the surface plate 18 is adjusted.

  In step S108, it is determined whether or not the adjustment is completed. If an affirmative determination is made, the process proceeds to step S110, and the outward movement of the exposure stage 16 is started. The movement of the exposure stage 16 is constant speed conveyance.

  While the exposure stage 16 is moving forward, in step S112, the position of the exposure stage 16 is confirmed (can be determined by the drive pulse of the linear motor unit 26), and in step S114, it is determined whether or not it is an imaging timing. That is, it is determined whether or not the front end of the exposure stage 16 in the moving direction is a position immediately before passing under the camera unit 38. If an affirmative determination is made, the process proceeds to step S116 to start imaging.

  In the next step S118, the position of the exposure stage 16 is confirmed, and in step S120, it is determined whether or not it is the photographing end timing. That is, it is determined whether or not the rear end of the movement direction of the exposure stage 16 has passed right under the camera unit 38. If an affirmative determination is made, the process proceeds to step S122 to end the shooting.

  In the next step S124, the photographed data is analyzed, and then the process proceeds to step S126 to extract image data corresponding to the mark M.

  Next, in step S128, the reference data is read from the mark data memory 68, and in step S130, the photographed and extracted mark image data is compared with the reference data.

  In the next step S132, an exposure position correction coefficient is calculated based on the collation result, the process proceeds to step S134, and the calculated correction coefficient data is sent to the exposure control system, and this routine ends.

  When the exposure stage 16 reaches the forward path end, it turns back and returns at a constant speed in the direction of the stage portion 12B indicated by the arrow b (return path b). When passing through the exposure unit 28 on the return path b, the exposure unit 28 irradiates the DMD with laser light based on the corrected exposure start time, and the laser light reflected when the DMD micromirror is in the ON state. Is guided to the photosensitive material 22 through the optical system, and an image is formed on the photosensitive material 22 to form an image.

  In the exposure apparatus 10 according to this embodiment, the air conditioner 50 controls the temperature in the chamber 46 so as to be lower than the median environmental temperature by an offset value. As a result, the photosensitive material placement surface 17 of the exposure stage 16 can be maintained at the median environmental temperature, so that it is possible to prevent the photosensitive material 22 from being stretched between the mark measurement and the exposure.

  In addition, since the temperature of the exposure stage 16 is not directly controlled, there are few components to be newly added to the exposure apparatus 10 until then.

  Further, since the installation environment temperature of the exposure apparatus 10 is measured momentarily with an external thermometer and the environmental temperature median value and the offset value are rewritten, even if the environmental temperature changes for some reason, the temperature of the exposure stage 16 Can be controlled to follow the change.

  Further, as shown in FIG. 15A, since the exposure unit 28 is arranged on the upstream side and the camera unit 32 is arranged on the downstream side with respect to the moving direction of the forward path a of the exposure stage 16, the exposure stage The movement distance L1 of 16 is the exposure stage when the camera unit 32 is arranged upstream and the exposure unit 28 is arranged downstream of the movement direction in the forward path a of the exposure stage 16 as shown in FIG. Compared to the moving distance L2 of 16, the processing efficiency can be improved.

  In addition, the area where the exposure unit 28 and the camera unit 32 are disposed is completely separated from the space in the housing 12 </ b> A by the chamber 46, and air is sent into the chamber 46 by the air conditioner 50. Therefore, since the inside of the chamber 46 is maintained at a positive pressure, the air flows to the stage portion 12B which is the only escape place.

  By this flow, dust around the exposure unit 28 and the camera unit 32 that should most avoid dust can be discharged from the stage portion 12B. Further, when the photosensitive material 22 is attached to or detached from the exposure stage 16, even if the opening / closing lid 14 of the stage portion 12B is opened, dust is prevented from entering from the opened stage portion 12B.

  The photosensitive material 22 is charged with static electricity depending on the material of the base, and the electric charge is charged, which may attract dust. In some cases, dust attracted by and adhering to static electricity cannot be wiped off only by the air flow.

  However, in the exposure apparatus 10, a static eliminator (ionizer) 52 is disposed across the width direction of the surface plate 18 on the front side in the forward movement direction of the exposure stage 16 in the exposure unit 28. The ionized air is blown from the blowing part 52A of the static eliminating device 52 to the photosensitive material 22 positioned on the exposure stage 16 that slides on the photosensitive member 22.

  Accordingly, since the charge of the charged dust is neutralized by the ionized air, when the exposure stage 16 on which the photosensitive material 22 is placed moves on the surface plate 18, the surface of the photosensitive material 22 is neutralized, Dust adhered by static electricity is removed, and dust floating in the space above the exposure stage 16 is also removed.

  In the exposure apparatus 10, a DMD is used as a spatial modulation element, and a pixel pattern is generated by turning on / off at a constant lighting time. However, pulse width modulation is performed by on-time ratio (duty) control. May be. Alternatively, the pixel pattern may be generated according to the number of times of lighting, with one lighting time being extremely short.

  Furthermore, in the first embodiment, the recording element unit 166 having the DMD as the spatial light modulation element has been described. However, in addition to such a reflective spatial light modulation element, a transmissive spatial light modulation element (LCD) is used. You can also. For example, a liquid crystal shutter such as a MEMS (Micro Electro Mechanical Systems) type spatial light modulator (SLM), an optical element (PLZT element) that modulates transmitted light by an electro-optic effect, or a liquid crystal light shutter (FLC). It is also possible to use a spatial light modulation element other than the MEMS type, such as an array. Note that MEMS is a general term for a micro system that integrates micro-sized sensors, actuators, and control circuits based on a micro-machining technology based on an IC manufacturing process. A MEMS-type spatial light modulator is an electrostatic force. It means a spatial light modulator driven by electromechanical operation using Further, a plurality of grating light valves (GLVs) arranged in two dimensions can be used. In the configuration using these reflective spatial light modulator (GLV) and transmissive spatial light modulator (LCD), a lamp or the like can be used as a light source in addition to the laser described above.

  The light source in the above embodiment includes a fiber array light source including a plurality of combined laser light sources, and a single optical fiber that emits laser light incident from a single semiconductor laser having one light emitting point. A fiber array light source obtained by arraying fiber light sources provided with a light source (for example, an LD array, an organic EL array, etc.) in which a plurality of light emitting points are arranged in a two-dimensional manner can be applied.

  Further, the exposure apparatus 10 can use either a photon mode photosensitive material in which information is directly recorded by exposure or a heat mode photosensitive material in which information is recorded by heat generated by exposure. When using a photon mode photosensitive material, a GaN-based semiconductor laser, a wavelength conversion solid-state laser, or the like is used for the laser device. When using a heat mode photosensitive material, an AlGaAs-based semiconductor laser (infrared laser), A solid state laser is used.

  The image forming apparatus of the present invention is suitably used for exposure of a display filter, a display substrate, and a flexible substrate as a workpiece, in addition to a sheet-like substrate.

FIG. 1 is a perspective view schematically showing an exposure apparatus according to the first embodiment. FIG. 2 is a side view showing a schematic outline of the exposure apparatus of the first embodiment. FIG. 3 is a plan view schematically showing the exposure apparatus according to the first embodiment. FIG. 4 is a perspective view showing a configuration of an exposure stage provided in the exposure apparatus. FIG. 5 is a perspective view showing a configuration of an exposure unit provided in the exposure apparatus. FIG. 6 is a plan view showing an exposure area by an exposure unit provided in the exposure apparatus and a plan view showing an array pattern of the head assembly. FIG. 7 is a plan view showing a dot pattern arrangement state of the head assembly provided in the exposure unit provided in the exposure apparatus. FIG. 8 is a perspective view showing a configuration of a camera unit provided in the exposure apparatus. FIG. 9 is an explanatory view showing a procedure for collating the mark on the photosensitive material exposed by the exposure apparatus and the mark on the reference memory. FIG. 10 is a functional block diagram showing a procedure for performing mark detection in the control system in the camera unit. FIG. 11 is a flowchart showing a procedure for controlling the temperature in the chamber based on the environmental temperature measured by the external thermometer. FIG. 12 is a graph showing an example of the relationship between the environmental temperature median value and the offset value. FIG. 13 is a flowchart showing an exposure start timing correction routine. FIG. 14 is a flowchart showing a procedure for obtaining the waiting time in the exposure start timing correction routine. FIG. 15 is a schematic side view showing the relative positional relationship between the exposure head unit and the camera unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Exposure apparatus 12 Frame 12A Housing | casing part 12B Stage part 14 Opening-closing lid | cover 16 Exposure stage (recording stage)
16A Leg part 18 Surface plate 19 Infrared thermometer 20 Slide rail 22 Photosensitive material 24 Mounting base 26 Linear motor part 26A Coil part 26B Stator part 28 Exposure unit 30 Post 28A Head assembly 28B Exposure area 30 Light source unit 32 Camera unit 34 Beam part 36 Base part 38 Camera part 40 Rail part 42 Camera base 38A Camera body 38B Lens part 38C Strobe light source 42 Camera base 44 Ball screw mechanism part 46 Chamber 47 In-machine thermometer 48 Air duct 49 Out-of-machine thermometer 50 Air conditioner 51 Control board 52 Static elimination Equipment (Ionizer)
52A Blowout unit 52B Ion generation unit 54 Controller unit 56 Camera operation control unit 58 Width direction position setting unit 60 Imaging data analysis unit 62 Mark extraction unit 64 Mark collation unit 66 Exposure position correction coefficient calculation unit 68 Mark data memory M mark

Claims (8)

A stage on which a workpiece is placed, a reference mark on the workpiece placed on the stage, a drawing unit that forms an image based on the detected reference mark position, and the stage and the drawing unit are housed. An image forming apparatus comprising a housing,
An in-machine temperature that controls the temperature inside the casing so that the temperature of the stage is substantially equal to the median environmental temperature that is the median environmental temperature in the installation environment where the image forming apparatus is installed. An image forming apparatus comprising a adjusting means.   2. The image forming apparatus according to claim 1, wherein the drawing unit is an exposure unit in which a plurality of exposure heads that selectively turn on and off a plurality of pixels to expose a workpiece are arranged in the x direction. The in-machine temperature control means is
Environmental temperature measuring means for measuring the environmental temperature;
A median computing means for obtaining the median environmental temperature based on the environmental temperature measured by the environmental temperature measuring means;
An air conditioner that controls the temperature inside the image forming apparatus to a temperature that is lower than the environmental temperature median value by a predetermined offset value so that the stage temperature and the environmental temperature median value are equal;
The image forming apparatus according to claim 1, further comprising:   The image forming apparatus according to claim 3, wherein the offset value is predetermined for each median environmental temperature.   In the in-machine temperature adjusting means, the median temperature calculating means obtains the median temperature of the environment by the median value computing means every predetermined time, and the image forming apparatus in the air conditioner is based on the newly obtained median temperature of the ambient temperature and the offset value corresponding thereto. The image forming apparatus according to claim 3, wherein the in-machine temperature is controlled.   The image forming apparatus according to claim 3, wherein the air conditioner is installed in an environment that is the same as an installation environment of the image forming apparatus, sucks air in the environment, and supplies the air to the image forming apparatus. apparatus. A stage temperature measuring means for measuring the surface temperature of the stage is provided,
When the difference between the stage temperature measured by the stage temperature measuring means and the environmental temperature median obtained by the median computing means based on the environmental temperature measured by the environmental temperature measuring means is greater than a predetermined value Is
Based on the stage temperature and the median environmental temperature, obtain a waiting time until the temperature of the workpiece placed on the stage is stabilized,
The image forming apparatus according to claim 1, wherein mark measurement and exposure are performed after the waiting time has elapsed. A stage on which a workpiece is placed, a reference mark on the workpiece placed on the stage, a drawing unit that forms an image based on the detected reference mark position, and the stage and the drawing unit are housed. An image forming method for forming an image on the workpiece using an image forming apparatus comprising a housing,
While controlling the temperature inside the casing so that the temperature of the stage is substantially equal to the median environmental temperature that is the median environmental temperature of the installation environment in which the image forming apparatus is installed, An image forming method comprising performing image formation.

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