JP4477482B2 - Exposure pattern forming method and exposure apparatus - Google Patents

Description

  The present invention relates to an exposure pattern forming method and an exposure apparatus that directly exposes a predetermined exposure pattern on an object to be exposed, and more specifically, an imaging unit that conveys a reference substrate on which a pattern is previously formed and an object to be exposed side by side. An exposure pattern forming method and an exposure apparatus for forming an exposure pattern while continuously conveying an object to be exposed by controlling irradiation or stopping of irradiation of a light beam based on image data of a pattern imaged by It is concerned.

A conventional exposure apparatus of this type includes an exposure optical system having a laser light source, a polygon mirror, an fθ lens, and a cylindrical lens, and a transport unit including a feed roller and a feed roller, while transporting a recording paper sheet by the transport unit. The exposure optical system scans the laser beam in a direction orthogonal to the conveyance direction of the recording paper sheet, and controls the irradiation of the laser beam and the irradiation stop based on the image data stored in the storage means so that exposure is performed line by line. (For example, refer to Patent Document 1).
JP 2003-107586 A

  However, in such a conventional exposure apparatus, for example, the image data stored in the storage means is read and the image is exposed on the recording paper sheet based on the image data. It was necessary to convert the data into CAD data and store it in the storage means, which required time and effort for exposure.

  In particular, when the amount of information of CAD data is large, it is necessary to provide a large-capacity HDD, CD-ROM, or RAM as the storage means and store the CAD data in the storage means. It was difficult. Therefore, it has been difficult to realize an exposure apparatus that performs exposure by reading CAD data at high speed while continuously feeding recording paper sheets. For this reason, in general, the exposure is performed while intermittently feeding the recording paper sheet, and the exposure takes time.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an exposure pattern forming method and an exposure apparatus that address such problems and attempt to form an exposure pattern while continuously conveying an object to be exposed.

  In order to achieve the above object, an exposure pattern forming method according to the present invention includes an exposure optical system that scans a light beam relative to an object to be exposed and directly exposes a predetermined pattern on the object to be exposed. In the pattern forming method, the reference substrate on which the pattern is formed in advance and the object to be exposed are arranged side by side, and the reference substrate and the object to be exposed are transported by a transport unit in conjunction with each other. The pattern on the reference substrate is imaged by an imaging unit disposed opposite to the image sensor, and the light beam from the exposure optical system is irradiated by the control unit based on the image data of the pattern imaged by the imaging unit. The irradiation stop is controlled, and the pattern is exposed on the object to be exposed.

  By such a method, the reference substrate and the object to be exposed are arranged side by side by the conveying means and conveyed in conjunction with each other, the pattern previously formed on the reference substrate is imaged by the imaging means, and the image is taken by the imaging means by the control means. The irradiation of the light beam from the exposure optical system and the stop of the irradiation are controlled based on the image data of the pattern, and the pattern is exposed on the object to be exposed. Thus, an exposure pattern is formed while continuously conveying the object to be exposed.

  The reference substrate is formed in an endless belt shape by joining one end portion and the other end portion of a sheet-like member having a predetermined width, and is conveyed in an endless state by the conveying means. Accordingly, the reference substrate formed in an endless belt shape by joining one end portion and the other end portion of the sheet-like member having a predetermined width is conveyed in an endless state by the conveying means.

  And the said to-be-exposed body is a sheet-like board | substrate which has a predetermined width and predetermined length, and is continuously conveyed by the said conveyance means. Thereby, the sheet-like object to be exposed having a predetermined width and a predetermined length is continuously conveyed by the conveying means.

  An exposure apparatus according to the present invention is an exposure apparatus that scans a light beam relative to an object to be exposed by an exposure optical system and directly exposes a predetermined pattern on the object to be exposed. A transport unit that transports a reference substrate formed in advance and an object to be exposed arranged side by side with the reference substrate in conjunction with each other, and is disposed to face the reference substrate, and a pattern on the reference substrate is arranged. An image pickup means for picking up an image and a control means for controlling irradiation of the light beam from the exposure optical system and stop of irradiation based on the image data of the pattern picked up by the image pickup means.

  With such a configuration, the reference substrate and the object to be exposed are arranged side by side in the transport unit and transported in conjunction with each other, the pattern previously formed on the reference substrate is imaged by the imaging unit, and the image is captured by the imaging unit by the control unit. The irradiation of the light beam from the exposure optical system and the stop of the irradiation are controlled based on the image data of the pattern, and the pattern is exposed on the object to be exposed.

  Further, the reference substrate is formed in an endless belt shape by joining one end portion and the other end portion of a sheet-like member having a predetermined width, and is conveyed in an endless state by the conveying means. Accordingly, the reference substrate formed in an endless belt shape by joining one end portion and the other end portion of the sheet-like member having a predetermined width is conveyed in an endless state by the conveying means.

  Furthermore, the object to be exposed is a sheet-like substrate having a predetermined width and a predetermined length, and is continuously transported by the transport means. Thereby, the sheet-like object to be exposed having a predetermined width and a predetermined length is continuously conveyed by the conveying means.

  The conveying means applies a rotational driving force to the feeding and feeding rollers, a pair of rotating rods that rotate in synchronization with the rotation of the feeding and feeding rollers, and a feeding and feeding rollers that convey the object to be exposed. And a transport means body, and the reference substrate is hung around the pair of rotating rods so as to be transported in an endless state. As a result, a rotational driving force is applied to the feeding and feeding rollers in the conveying means main body, the object to be exposed is conveyed by the feeding and feeding rollers, and a pair of rotating rods that rotate in synchronization with the rotation of the feeding and feeding rollers. The reference substrate hung around the pair of rotating rods is transported in an endless state.

  According to the first and fourth aspects of the present invention, while reading the pattern formed on the reference substrate with the imaging means, the irradiation of the light beam and the irradiation stop are controlled based on the image data of the pattern on the object to be exposed. By performing the exposure, the pattern reading operation and the exposure operation can be executed in real time. Therefore, it is possible to form an exposure pattern while continuously conveying the object to be exposed.

  According to the inventions according to claims 2 and 5, the reference substrate is formed in an endless belt shape by joining one end and the other end of the sheet-like member having a predetermined width, and is conveyed in an endless state by the conveying means. By doing so, the pattern formed on the reference substrate may be the minimum unit of the pattern in the transport direction exposed to the object to be exposed, and the length of the reference substrate can be shortened. Therefore, the cost of the reference substrate can be reduced.

  Furthermore, according to the invention which concerns on Claim 3 and 6, by exposing the to-be-exposed body to the sheet-like board | substrate which has a predetermined width and predetermined length, it exposes, conveying a sheet-like to-be-exposed body continuously. A pattern can be formed.

  According to the seventh aspect of the present invention, the feeding and feeding rollers that transport the object to be exposed by the conveying means, the pair of rotating rods that rotate in synchronization with the rotation of the feeding and feeding rollers, and the feeding and feeding rollers And a transfer means main body that applies a rotational driving force to the pair of rotating rods, the reference substrate is transferred in an endless manner in conjunction with the transfer of the object to be exposed when the reference substrate is hung around the pair of rotating rods. Can do.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a conceptual view showing an embodiment of an exposure apparatus according to the present invention. The exposure apparatus 1 directly exposes a pattern on an object to be exposed, and includes a laser light source 2, an exposure optical system 3, a transport unit 4, an imaging unit 5, and a control unit 6.

  The laser light source 2 emits a light beam. For example, the laser light source 2 is a high-power all-solid mode-locked laser light source having an output of 4 W or more for generating 355 nm ultraviolet rays.

  An exposure optical system 3 is provided in front of the laser light source 2 in the light beam emission direction. The exposure optical system 3 reciprocates a laser beam as a light beam on an object to be exposed. From the front side of the laser beam emission direction, an optical switch 7, a light deflecting unit 8, and a first mirror 9. A polygon mirror 10, an fθ lens 11, and a second mirror 12.

  The optical switch 7 switches between laser beam irradiation and irradiation stop state. For example, as shown in FIG. 2, the first and second polarizing elements 13A and 13B are switched to the polarizations of the polarizing elements 13A and 13B. The axes p are arranged so as to be orthogonal to each other (in the figure, the polarization axis p of the first polarization element 13A is set in the vertical direction, and the polarization axis p of the second polarization element 13B is set in the horizontal direction. The electro-optic modulator 14 is disposed between the first and second polarizing elements 13A and 13B. The electro-optic modulator 14 operates to rotate the polarization plane of polarized light (linearly polarized light) at a high speed of several nsec when a voltage is applied. For example, when the applied voltage is zero, linearly polarized light having, for example, a vertical polarization plane selectively transmitted by the first polarizing element 13A in FIG. The second polarizing element 13B is reached. Since the second polarizing element 13B is disposed so as to selectively transmit linearly polarized light having a horizontal polarization plane, the linearly polarized light having a vertical polarization plane cannot be transmitted. The laser beam is stopped from irradiation. On the other hand, when a voltage is applied to the electro-optic modulator 14 and the polarization plane of the linearly polarized light incident on the electro-optic modulator 14 is rotated by 90 degrees as shown in FIG. The linearly polarized light having a horizontal polarization plane when exiting the electro-optic modulator 14 passes through the second polarizing element 13B. As a result, the laser beam enters an irradiation state.

  The light deflecting means 8 is adjusted so as to scan the correct position by shifting the scanning position of the laser beam in a direction orthogonal to the scanning direction (coinciding with the direction of arrow A shown in FIG. 1 in the moving direction of the object to be exposed). For example, an acousto-optic element (AO element) is used.

  The first mirror 9 is a plane mirror for bending the traveling direction of the laser beam that has passed through the light deflecting means 8 in the installation direction of the polygon mirror 10 described later. Further, the polygon mirror 10 performs reciprocal scanning with a laser beam, and for example, eight mirrors are formed on the side surface of a regular octagonal columnar rotating body. In this case, the laser beam reflected by one of the mirrors is scanned in a one-dimensional forward direction as the polygon mirror 10 rotates, and returns in the moment when the irradiation position of the laser beam moves to the next mirror surface. Returning to step S1, the one-dimensional forward scanning is started again with the rotation of the polygon mirror 10.

  The fθ lens 11 is arranged so that the scanning speed of the laser beam is constant on the object to be exposed, and the focal position is substantially matched with the position of the mirror surface of the polygon mirror 10. The second mirror 12 reflects the laser beam that has passed through the fθ lens 11 and makes it incident in a direction substantially perpendicular to the surface of the object to be exposed, and is a flat mirror. Further, a line sensor 15 is provided at a scanning start side portion of the laser beam that performs reciprocal scanning in the vicinity of the exit side surface of the fθ lens 11 so as to be orthogonal to the scanning direction. The amount of deviation between the position and the actual scanning position is detected, and the start of scanning of the laser beam is detected. The line sensor 15 may be provided anywhere on the fθ lens 11 side as long as the laser beam scanning start point can be detected. For example, the line sensor 15 may be provided on the conveyance unit 4 side described later.

  A conveying means 4 is provided below the second mirror 12. For example, the conveying means 4 has a sheet-like flexible printed circuit board 16 having a predetermined width and a predetermined length as an object to be exposed in a direction perpendicular to the scanning direction of the laser beam (in the direction of arrow A in FIG. 1). Conveying continuously at a speed, the feeding roller 17A and the feeding roller 17B for conveying the flexible printed circuit board 16 are provided in the conveying means main body 4a for applying a rotational driving force to the feeding roller 17A and the feeding roller 17B. Yes. Further, a pair of rotating rods 18A and 18B that rotate in synchronization with the rotation of the feeding roller 17A and the feeding roller 17B are provided so as to protrude from the side surface of the conveying means main body 4a and are formed on the flexible printed circuit board 16. A reference substrate 19 formed in an endless band shape by joining one end and the other end of a sheet-like member having a predetermined width on which an original image of an exposure pattern is recorded is wound around the pair of rotating rods 18A and 18B to be in an endless state. It can be transported. The reference substrates 19 are arranged next to the flexible printed circuit board 16 and can be transported in the same direction (arrow A direction in FIG. 1) in conjunction with each other. The feed roller 17A and the feed roller 17B are driven by a motor (not shown), for example. Further, the conveyance means 4 is provided with a speed sensor (not shown), and is controlled by a control means 6 described later to convey the flexible printed circuit board 16 at a constant speed.

  An imaging means 5 is provided above the reference substrate 19 spanned between the two rotating rods 18A and 18B of the conveying means 4. The image pickup means 5 picks up an original image pattern recorded on the reference substrate 19 and is, for example, a line CCD in which light receiving elements are arranged in a line. Then, the imaging unit 5 causes the imaging position of the imaging unit 5 to be a position closer to the front side than the exposure position of the exposure optical system 3 in the conveyance direction of the flexible printed board 16 (the direction of arrow A shown in FIG. 1). The exposure optical system 3 is arranged side by side. Illumination means (not shown) is provided in the vicinity of the imaging means 5, and an image of the original image recorded on the reference substrate 19 is illuminated to enable imaging by the imaging means 5. FIG. 1 shows an example in which one imaging unit 5 is installed. However, when the imaging area of the imaging unit 5 is narrow with respect to the pattern of the reference substrate 5, a plurality of imaging units 5 may be installed. . Further, when the scanning width of the laser beam is narrower than the exposure width of the flexible printed board 16, a plurality of exposure optical systems 3 may be installed.

  Control means 6 is provided connected to the laser light source 2, optical switch 7, light deflection means 8, polygon mirror 10, line sensor 15, transport means 4 and imaging means 5. The control unit 6 controls the irradiation of the laser beam of the laser light source 2 or the stop of the irradiation based on the image data of the pattern of the original image recorded on the reference substrate 19 imaged by the imaging unit 5 and the line sensor 15. Based on the output, the voltage applied to the light deflecting means 8 is controlled to deflect the laser beam emission direction, the rotational speed of the polygon mirror 10 is controlled to maintain the scanning speed of the laser beam at a predetermined speed, and the conveying means 4 The conveyance speed of the flexible printed circuit board 16 and the reference board 19 is controlled to a constant speed. A light source driving unit 20 that turns on the laser light source 2, a light deflecting unit driving unit 21 that controls the deflection amount of the laser beam in the light deflecting unit 8, a polygon driving unit 22 that controls driving of the polygon mirror 10, and conveyance A transport controller 23 for controlling the transport speed of the means 4, an image processing section 24 for outputting image data obtained by binarizing the image captured by the image capturing means 5, and image data obtained by the image processing section 24. And an optical switch controller 25 for controlling the irradiation and stoppage of the laser beam based on the above, and a control unit 26 for appropriately controlling the entire apparatus to perform a predetermined target operation.

Next, the operation of the exposure apparatus configured as described above will be described.
First, when the exposure apparatus 1 is turned on, each part of the apparatus is activated to enter an exposure standby state. Next, the reference substrate 19 on which the original image of the exposure pattern is recorded is wound around a pair of rotating rods 18A and 18B provided so as to protrude from the side surface of the transport unit body 4a of the transport unit 4. Further, the long flexible printed circuit board 16 is stretched between the feeding roller 17A and the feeding roller 17B of the conveying means 4. When a switch (not shown) is operated, an exposure operation starts while the reference substrate 19 and the flexible printed circuit board 16 are continuously conveyed at a constant speed.

The exposure pattern forming method will be described below with reference to FIG.
First, in step S1, the polygon mirror 10 is rotated to start scanning with a laser beam. In this case, as soon as the scanning of the laser beam is started, the optical switch 7 is turned on by the optical switch controller 25, the irradiation of the laser beam is turned on as shown in FIG. 5, and the laser beam crosses the line sensor 15. As a result, the scanning start of the laser beam is detected by the line sensor 15, and this detection signal is received by the control means 6 and output to the imaging means 5. Then, the process proceeds to step S2. Since the flexible printed circuit board 16 is continuously conveyed at a constant speed, a deviation occurs in the conveying direction indicated by the arrow A in FIG. 1 between the scanning start position and the scanning end position of the laser beam. In this case, the control means 6 calculates the amount of deviation from the scanning range of the laser beam and the conveyance speed of the flexible printed circuit board 16, and controls the deflection direction of the laser beam by the light deflection means 8 via the light deflection means drive unit 21. Thus, the deviation is corrected.

In step S2, upon receiving a laser beam scanning start signal from the line sensor 15, the clock (CLK) of the imaging means 5 starts counting as shown in FIG. Then, the original image of the exposure pattern recorded on the reference substrate 19 by the imaging unit 5 is read for each line. The image read by the imaging unit 5 is subjected to image processing by the image processing unit 24 and binarized, and the binarized image data is sent to the optical switch controller 25. For example, when the original picture is as shown in FIG. 4, the image data of the line L ₁ is “... 01111100000011111. Note that the clock count is stopped only during the period until the next laser beam scanning start signal is generated when the forward scanning of the laser beam is completed, and at the same time, the imaging of the imaging unit 5 is also stopped. However, since this period is extremely short with respect to the conveyance speed of the flexible printed circuit board 16, it can be ignored in the image reading operation of the reference board 19 by the imaging unit 5.

In step S3, the optical switch controller 25 drives the optical switch 7 on and off based on the image data to perform exposure. That is, in response to “1” of the image data, the optical switch controller 25 activates the optical switch 7 to irradiate the laser beam. In response to “0” of the image data, the optical switch controller 25 drives the optical switch 7 OFF to stop the laser beam irradiation. In this way, a predetermined exposure pattern is exposed on the flexible printed circuit board 16. For example, when performing exposure by reading by the image pickup means 5 the original image shown in FIG. 4, at the timing shown in FIG. 5 may be ON and OFF control of the laser beam for each line L ₁ ~L _n.

  In step S4, it is determined whether one scanning of the laser beam is completed. Here, if it becomes "YES" determination, it will progress to Step 5.

  In step S5, it is determined by the control unit 26 whether or not the exposure for the predetermined exposure area set in advance has been completed. Here, if “NO” determination is made, the process returns to step S1 to execute the exposure operation for the next line. If “YES” is determined in step S 6, the exposure is completed, and an exposure pattern corresponding to the original image as shown in FIG. 6 is formed on the flexible printed board 16.

  As described above, according to the exposure apparatus 1 of the present invention, while the original image pattern formed on the reference substrate 19 is read by the imaging unit 5, the irradiation of the light beam and the irradiation stop are controlled based on the image data of the original image pattern. Since the flexible printed circuit board 16 is exposed, the pattern reading operation and the exposure operation can be executed in real time. Therefore, it is possible to form an exposure pattern while continuously conveying the flexible printed board 16.

  1 illustrates the case where the imaging unit 5 is arranged such that the imaging position of the imaging unit 5 is in front of the laser beam scanning position in the direction of arrow A. However, the imaging position of the imaging unit 5 is illustrated. May be either before or after the laser beam scanning position in the direction of arrow A or at the same position.

  Moreover, in the said embodiment, although the case where the flexible printed circuit board 16 was used as a to-be-exposed body was demonstrated, it is not restricted to this, A to-be-exposed body may be any board | substrates, such as a glass substrate.

It is a conceptual diagram which shows embodiment of the exposure apparatus by this invention. It is a perspective view explaining the structure and operation | movement of an optical switch. It is a flowchart explaining the procedure of the pattern formation method by this invention. It is explanatory drawing which shows the reading operation | movement of the original picture by an imaging means. It is a timing chart which shows control of laser beam irradiation and irradiation stop. It is a figure which shows the example of the exposure pattern exposed based on the original picture.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Exposure apparatus 3 ... Exposure optical system 4 ... Conveyance means 4a ... Conveyance means main-body part 5 ... Imaging means 6 ... Control means 16 ... Flexible printed circuit board (to-be-exposed body)
17A ... Feeding roller 17B ... Feeding roller 18A, 18B ... Rotating rod 19 ... Reference board

Claims (7)

An exposure pattern forming method in which a light beam is scanned relative to an object to be exposed by an exposure optical system, and a predetermined pattern is directly exposed on the object to be exposed,
The reference substrate on which the pattern is formed in advance and the object to be exposed are arranged side by side, and the reference substrate and the object to be exposed are conveyed by a conveying unit in conjunction with each other,
The pattern on the reference substrate is imaged by the imaging means arranged facing the reference substrate,
Based on the image data of the pattern imaged by the imaging means, the control means controls irradiation of the light beam from the exposure optical system and irradiation stop,
An exposure pattern forming method, wherein the pattern is exposed on the object to be exposed.   2. The reference board is formed in an endless belt shape by joining one end and the other end of a sheet-like member having a predetermined width, and is transported in an endless state by the transport means. Exposure pattern forming method.   3. The exposure pattern forming method according to claim 1, wherein the object to be exposed is a sheet-like substrate having a predetermined width and a predetermined length, and is continuously transported by the transport unit. An exposure apparatus that scans a light beam relative to an object to be exposed by an exposure optical system and directly exposes a predetermined pattern on the object to be exposed,
A transport means for transporting the reference substrate on which the pattern is formed in advance and the exposed objects arranged side by side with the reference substrate in conjunction with each other;
An imaging unit disposed opposite to the reference substrate and imaging a pattern on the reference substrate;
Control means for controlling irradiation of the light beam from the exposure optical system and irradiation stop based on the image data of the pattern imaged by the imaging means;
An exposure apparatus comprising:   5. The reference substrate according to claim 4, wherein the reference substrate is formed in an endless belt shape by joining one end portion and the other end portion of a sheet-like member having a predetermined width, and is conveyed in an endless state by the conveying means. Exposure device.   6. The exposure apparatus according to claim 4, wherein the object to be exposed is a sheet-like substrate having a predetermined width and a predetermined length, and is continuously transported by the transport unit.   The transport means includes a feed and feed roller for transporting the object to be exposed, a pair of rotating rods that rotate in synchronization with the rotation of the feed and the feed roller, and a transport means that applies a rotational driving force to the feed and feed rollers. 6. An exposure apparatus according to claim 5, further comprising a main body, wherein the reference substrate is wound around the pair of rotating rods so as to be transported in an endless state.

Images