JP2008180896A - Exposure method, exposure device and method for manufacturing color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure method for forming a first columnar spacer and a second columnar spacer thinner than the first columnar spacer, the method for forming the second columnar spacer with excellent uniformity of film thickness and line width without changing an aperture ratio of a photomask or subjecting a photomask to a process of reducing the transmittance for light, and to provide an exposure device and a method for manufacturing a liquid crystal display device. <P>SOLUTION: The exposure method for exposing the surface of a photosensitive material layer formed on a substrate that is moved while scanning so as to form a first columnar spacer and a second columnar spacer thinner than the first columnar spacer, is characterized in that: the exposure is carried out by irradiating a region of the photosensitive material where the first columnar spacer is to be formed and a region where the second columnar spacer is to be formed with the light from a blinking light source through a photomask having an aperture for the first columnar spacer and an aperture for the second columnar spacer; and the number of exposure times in the region where the first columnar spacer is to be formed is larger than the number of exposure times in the region where the second columnar spacer is to be formed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an exposure method, an exposure apparatus, and a color filter manufacturing method.

  Since the liquid crystal display device has characteristics such as light weight, thinness, and low power consumption, it is widely used in various display devices such as notebook personal computers, portable information terminals, desktop monitors, and digital cameras. Among them, most of the displays used for mobile devices such as mobile phones and digital cameras are liquid crystal display devices.

  A liquid crystal panel used in such a mobile device needs to have pressure resistance because the display may be strongly pressed during use. In order to satisfy this pressure resistance, a columnar spacer is interposed between the substrates in which the liquid crystal is accommodated.

  In order to obtain high pressure resistance, it is only necessary to arrange a large number of columnar spacers, but when a large number of columnar spacers are arranged, the columnar spacers maintain their shape and the spacing between the substrates is maintained. When the liquid crystal contracts at a low temperature, there arises a problem that bubbles are generated in the liquid crystal.

  In order to solve such problems and satisfy both high pressure resistance and prevention of bubble generation at low temperatures, it is proposed to arrange a sub-column spacer with a low height in addition to the original main column spacer. (For example, refer to Patent Document 1). That is, even if the main columnar spacers contract due to the pressing, the distance between the substrates can be maintained by the sub columnar spacers. In addition, even if the liquid crystal shrinks at low temperatures, the main columnar spacer contracts following the contraction of the liquid crystal, preventing the generation of bubbles. You can return to

  Such main columnar spacers and sub columnar spacers having different heights are formed by using a photomask in which the aperture ratio is changed or the light transmittance is reduced in the exposure process. In other words, a method has been adopted in which columnar spacers having different heights are formed by changing the exposure ratio of a photomask or by reducing the light transmittance to form a columnar spacer having a different height (for example, patents). Reference 2).

  However, when the aperture ratio of the photomask is changed or the light transmittance reduction process is performed, the sub-columnar spacer formation portion is affected by the influence of the diffracted light due to the small openings and the light transmittance reduction process, Since it is more easily affected by the variation in the distance between the mask and the substrate than a normal columnar spacer, it is difficult to form a sub-columnar spacer having a uniform film thickness and line width. In addition, depending on the processing state of the light transmittance reduction processing unit, there is a problem in that sub-columnar spacers having inferior film thickness and line width uniformity are easily formed.

In addition, a photomask used for exposure is extremely expensive, but a photomask subjected to light transmittance reduction processing is more expensive. Furthermore, since the aperture ratio is changed to reduce the exposure energy and the light transmittance is reduced, a new photomask must be manufactured each time the spacer specifications are changed. Cost is extremely high.
JP 2002-84779 A JP 2006-39507 A

  The present invention has been made under the circumstances as described above, and is an exposure method for forming a first columnar spacer and a second columnar spacer having a thickness smaller than that of the first columnar spacer. An exposure method, an exposure apparatus, and an exposure apparatus capable of forming the second columnar spacers having excellent film thickness and line width uniformity without changing the aperture ratio of the mask or reducing the light transmittance. It is another object of the present invention to provide a method for manufacturing a liquid crystal display device.

  In order to solve the above-mentioned problem, a first aspect of the present invention includes a first columnar spacer on a surface of a photosensitive material layer formed on a scanning moving substrate, and a thickness greater than that of the first columnar spacer. In the exposure method for performing exposure to form a thin second columnar spacer, the exposure includes light from a flashing light source having a first columnar spacer opening and a second columnar spacer opening. The exposure is performed by irradiating the first columnar spacer formation region and the second columnar spacer formation region of the photosensitive material layer through a photomask. There is provided an exposure method characterized in that the number of exposures to a columnar spacer formation region is increased.

  According to a second aspect of the present invention, there is provided a means for scanning a substrate having a photosensitive material layer on a surface thereof, a flashing light source, a photomask having a first columnar spacer opening, and a second columnar spacer opening, and Means for irradiating light from the flashing light source to the first columnar spacer formation region and the second columnar spacer formation region of the photosensitive material layer through the photomask, There is provided an exposure apparatus characterized in that the number of exposures is greater than the number of exposures to the second columnar spacer formation region.

  In the above exposure method and exposure apparatus, the number of first columnar spacer openings in the photomask is greater than the number of second columnar spacer openings, and the first columnar spacer openings are formed on the substrate. A plurality of them are provided at a predetermined pitch along the scanning direction, and the exposure can be performed each time the substrate is moved by the pitch of the first columnar spacer openings.

  In addition, the exposure includes first exposure for irradiating light to the first columnar spacer formation region and the second columnar spacer formation region through the first columnar spacer opening and the second columnar spacer opening, respectively. Only the first columnar spacer formation region irradiated with light by the first exposure passes through only the first columnar spacer opening different from the first columnar spacer opening used in the first exposure. 2nd exposure which irradiates.

  Furthermore, exposure to the first columnar spacer formation region and the second columnar spacer formation region is performed by adjusting the number of first columnar spacer openings and the number of second columnar spacer openings in the photomask. And adjusting the difference in exposure energy between the first columnar spacer formation region and the second columnar spacer formation region, thereby adjusting the thickness of the first columnar spacer and the second columnar spacer. Can be controlled.

  Note that laser light or flash lamp light can be used as the light.

  According to a third aspect of the present invention, the first columnar spacer and the first columnar spacer are formed by exposing and developing the photosensitive material layer formed on the scanning moving substrate by the exposure method described above. There is provided a method for producing a color filter, comprising the step of forming a second columnar spacer having a thinner thickness.

  According to the present invention, there is provided an exposure method for forming a first columnar spacer and a second columnar spacer having a thickness smaller than that of the first columnar spacer, wherein the first photosensitive material layer is exposed. By changing the number of exposures for the columnar spacer formation region and the second columnar spacer formation region, the film thickness and line width can be changed without changing the aperture ratio of the photomask or reducing the light transmittance. There are provided an exposure method, an exposure apparatus, and a manufacturing method of a liquid crystal display device that can form a second columnar spacer having excellent uniformity.

  Hereinafter, embodiments of the present invention will be described.

  An exposure method according to one embodiment of the present invention includes a first columnar spacer (hereinafter referred to as a main columnar spacer) on the surface of a photosensitive material layer formed on a substrate that moves by scanning, rather than the main columnar spacer. When performing exposure for forming a thin second columnar spacer (hereinafter referred to as a sub-columnar spacer), the number of exposures to the main columnar spacer-forming region of the photosensitive material layer is determined by sub-columnar spacer-forming region. This is characterized in that the exposure energy amount is varied by increasing the number of exposures to the above.

  FIG. 1 shows main columnar spacers and sub-columnar spacers formed by exposure and development by such a method. In FIG. 1, a color filter layer 2 is formed on a glass substrate 1, and a main columnar spacer 3 and a sub columnar spacer 4 are formed on the color filter layer 2.

  In the exposure process, since the number of exposures to the main columnar spacer formation region is greater than the number of exposures to the sub columnar spacer formation region, the amount of exposure energy to the main columnar spacer formation region is large. The degree of cross-linking of the functional material layer increases and it becomes difficult to be dissolved by the developer. On the other hand, the amount of exposure energy to the sub-columnar spacer formation region is small, and therefore the degree of crosslinking of the photosensitive material layer in the sub-columnar spacer formation region is small and is easily dissolved by the developer.

  As a result, as shown in FIG. 1, a thick main columnar spacer 3 and a thin sub columnar spacer 4 are formed.

  In order to perform the exposure described above, the number of main columnar spacer openings is larger than the number of sub-columnar spacer openings as a photomask used for exposure, and the main columnar spacer openings are scanned on the substrate. A plurality of the electrodes provided at a predetermined pitch along the direction may be used, and the exposure may be performed every time the substrate moves by the pitch of the main columnar spacer openings.

  For example, first, the main columnar spacer forming region and the sub columnar spacer forming region are exposed to the main columnar spacer forming region and the sub columnar spacer forming region, respectively, and then only the main columnar spacer opening different from the main columnar spacer opening is used. Then, the main columnar spacer formation region can be exposed more times than the sub columnar spacer formation region by irradiating only the main columnar spacer formation region that has been previously exposed. Thereby, a difference in exposure energy can be provided between the main columnar spacer formation region and the sub columnar spacer formation region, and the thickness of the sub columnar spacer can be made thinner and uniform than the main columnar spacer. .

  The number of exposures to the main columnar spacer formation region and the sub columnar spacer formation region is controlled by appropriately adjusting the number of main columnar spacer openings and the number of sub columnar spacer openings. It is possible to control the thickness of the main columnar spacer and the sub columnar spacer by adjusting the difference in exposure energy to the sub columnar spacer formation region.

  The light used for exposure is light from a blinking light source, and laser light or flash lamp light is used.

  FIG. 2 is a perspective view showing a laser scanning exposure apparatus capable of pulse exposure used in the exposure method according to an embodiment of the present invention. In FIG. 2, a plurality of (four in the figure) exposure heads 12 are arranged in a fixed direction (in the case of FIG. 2) above the exposed area of the substrate 11 having a photosensitive material layer (not shown) formed on the surface. , X direction). Under these exposure heads 12, the substrate 11 scans in the direction intersecting the parallel direction of the heads (in the case of FIG. 2, the Y direction orthogonal to the X direction) and sent from the laser oscillator 13. The laser beam 14 is branched to each exposure head 12 and irradiated from the individual exposure head 12 through the photomask 15 to the exposure area on the substrate 11 to perform exposure. The exposure light is not limited to laser light, and light that can be flashed instantaneously, such as flash lamp light, can also be used.

  A photomask 15 used in the exposure apparatus shown in FIG. 2 is shown in FIG. As shown in FIG. 3A, the photomask 15 has one sub-columnar spacer opening 21 and six main columnar spacer openings 22a to 22f provided at predetermined pitches in the Y direction on both sides thereof. Have. Hereinafter, an example will be described in which the photosensitive material layer formed on the substrate 11 is exposed using the photomask 15 to form a main columnar spacer and a sub columnar spacer.

  In FIG. 2, when a stage (not shown) to which the substrate 11 is fixed moves in the Y direction and the exposed area on the substrate 11 reaches below the photomask 15, the laser oscillator 13 branches to the exposure head 12. The pulsed laser beam 14 is irradiated to the exposed region on the substrate 11 through the photomask 15. 3B, 3 </ b> C, and 3 </ b> D, the position where one exposed region 31 on the substrate 11 is moved by one pitch of the openings 22 a to 22 f of the photomask 15 is the position of the photomask 15. Shown in correspondence. Actually, the exposed region 31 shown in FIGS. 3B, 3C, and 3D is under the photomask 15, but in order to correspond to the position of the opening of the photomask 15, the photomask 15 is shown for convenience. It is shown on the right side.

  When the exposed region 31 comes to the position shown in FIG. 3B, the laser light 14 passes through the sub columnar spacer opening 21 and the main column spacer openings 22a and 22b of the photomask 15, and the laser beam 14 is sub columnar spacer forming region 32a and main. The columnar spacer formation regions 32b and 32c are irradiated.

  Next, when the stage (not shown) moves one pitch in the Y direction and the exposed region 31 comes to the position shown in FIG. 3C, the sub columnar spacer forming region 32a of the exposed region 31 and the main columnar spacer are formed. The regions 32b and 32c are at positions corresponding to the main columnar spacer openings 22c and 22d, and the main columnar spacer formation regions 32b and 32c are irradiated with the laser beam 14 through the main columnar spacer openings 22c and 22d of the photomask 15. The As a result, the irradiation units 32b and 32c are exposed twice. At this time, the sub-columnar spacer formation region 32a is not exposed and remains exposed once at the position shown in FIG. At this time, the laser beam 14 is irradiated to the new sub columnar spacer formation region 33a and the main columnar spacer formation regions 33b and 33c through the sub column spacer opening 21 and the main column spacer openings 22a and 22b of the photomask 15. The

  Thereafter, when the stage (not shown) further moves one pitch in the Y direction and the exposed region 31 comes to the position shown in FIG. 3D, the sub columnar spacer forming region 32a of the exposed region 31 and the main columnar spacer The formation regions 32b and 32c are at positions corresponding to the main columnar spacer openings 22e and 22f, and the laser beam 14 is irradiated to the main columnar spacer formation regions 32b and 32c through the main columnar spacer openings 22e and 22f of the photomask 15. The As a result, the main columnar spacer formation regions 32b and 32c are exposed three times. At this time, the sub-columnar spacer formation region 32a is not exposed and remains exposed once at the position shown in FIG.

  At this time, the laser beam 14 is applied to the main columnar spacer formation regions 33b and 33c through the main columnar spacer openings 22c and 22d of the photomask 15. As a result, the main columnar spacer formation regions 33b and 33c are exposed twice. At this time, the sub-columnar spacer formation region 33a is not exposed and remains exposed once at the position shown in FIG. Further, the laser beam 14 is irradiated to the new sub columnar spacer formation region 34a and the main columnar spacer formation regions 34b and 34c through the sub columnar spacer opening 21 and the main columnar spacer openings 22a and 22b of the photomask 15.

  The above process is repeated. As a result, all the main columnar spacer formation regions are exposed three times, whereas all the sub columnar spacer formation regions are exposed only once. Thereby, the exposure energy applied to the main columnar spacer formation region is three times the exposure energy applied to the sub columnar spacer formation region, and by development, the main columnar spacer and the sub columnar spacer having a smaller film thickness are Obtained with a uniform film thickness.

  As described above, according to the exposure method according to the present embodiment, since the aperture ratio of the photomask is not changed or the light transmittance is not reduced, it is not affected by the diffracted light. A liquid crystal display device having sub-columnar spacers with uniform line width and film thickness and having pressure resistance and low temperature foaming resistance can be manufactured.

  In addition, since a small photomask can be used, the cost of the photomask can be reduced, and the main columnar spacer opening and the sub columnar spacer opening can have the same size. There is an advantage that the photomask does not need to be remanufactured even if the specifications are changed.

It is sectional drawing which shows the spacer obtained by the exposure method which concerns on one Embodiment of this invention. It is a perspective view which shows the exposure apparatus used for the exposure method which concerns on one Embodiment of this invention. It is a figure which shows the position of the to-be-exposed area | region which moves corresponding to the photomask used for the exposure apparatus shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2 ... Color filter layer, 3 ... Main columnar spacer, 4 ... Sub columnar spacer, 11 ... Substrate, 12 ... Exposure head, 13 ... Laser oscillator, 14 ... Laser beam, 15 ... Photomask, 21 ... Sub columnar spacer openings, 22a to 22f ... main columnar spacer openings, 31 ... exposed regions, 32a, 33a, 34a ... sub columnar spacer forming regions, 32b, 32c, 33b, 33c, 34b, 34c ... main columnar spacer forming region.

Claims (11)

  Exposure for performing exposure to form a first columnar spacer and a second columnar spacer having a thickness smaller than that of the first columnar spacer on the surface of the photosensitive material layer formed on the scanning moving substrate. In the method, the exposure is performed by passing light from a flashing light source through a photomask having a first columnar spacer opening and a second columnar spacer opening, in a first columnar spacer formation region of the photosensitive material layer. And the second columnar spacer formation region is irradiated, and the number of exposures to the first columnar spacer formation region is made larger than the number of exposures to the second columnar spacer formation region. Exposure method.   The number of the first columnar spacer openings in the photomask is larger than the number of the second columnar spacer openings, and a plurality of the first columnar spacer openings are predetermined along the scanning direction of the substrate. 2. The exposure method according to claim 1, wherein the exposure is performed every time the substrate moves by a pitch of the first columnar spacer openings.   The exposure includes first exposure for irradiating light to the first columnar spacer formation region and the second columnar spacer formation region through the first columnar spacer opening and the second columnar spacer opening, respectively. Light is irradiated only on the first columnar spacer formation region irradiated with light by the first exposure only through the first columnar spacer opening different from the first columnar spacer opening used in the first exposure. The exposure method according to claim 2, further comprising: a second exposure.   The number of exposures to the first columnar spacer formation region and the second columnar spacer formation region by adjusting the number of first columnar spacer openings and the number of second columnar spacer openings of the photomask. And adjusting the difference in exposure energy between the first columnar spacer formation region and the second columnar spacer formation region, thereby controlling the thickness of the first columnar spacer and the second columnar spacer. The exposure method according to claim 3.   The exposure method according to claim 1, wherein the light is laser light or flash lamp light.   Means for scanning and moving a substrate having a photosensitive material layer on its surface, a flashing light source, a photomask having a first columnar spacer opening and a second columnar spacer opening, and light from the flashing light source to the photo Means for irradiating the first columnar spacer formation region and the second columnar spacer formation region of the photosensitive material layer through a mask, and the number of exposures to the first columnar spacer formation region is determined by the second columnar spacer; An exposure apparatus characterized in that the number of exposures to the formation area is increased.   The number of the first columnar spacer openings in the photomask is larger than the number of the second columnar spacer openings, and a plurality of the first columnar spacer openings are predetermined along the scanning direction of the substrate. The exposure apparatus according to claim 6, wherein the exposure is performed every time the substrate moves by a pitch of the first columnar spacer openings.   The exposure includes first exposure for irradiating light to the first columnar spacer formation region and the second columnar spacer formation region through the first columnar spacer opening and the second columnar spacer opening, respectively. Light is irradiated only on the first columnar spacer formation region irradiated with light by the first exposure only through the first columnar spacer opening different from the first columnar spacer opening used in the first exposure. The exposure apparatus according to claim 7, further comprising: a second exposure.   The number of exposures to the first columnar spacer formation region and the second columnar spacer formation region by adjusting the number of first columnar spacer openings and the number of second columnar spacer openings of the photomask. And adjusting the difference in exposure energy between the first columnar spacer formation region and the second columnar spacer formation region, thereby controlling the thickness of the first columnar spacer and the second columnar spacer. The exposure apparatus according to claim 8, wherein:   The exposure apparatus according to claim 6, wherein the light is laser light or flash lamp light.   The first columnar spacer and the first columnar spacer by exposing and developing the photosensitive material layer formed on the scanning moving substrate by the exposure method according to claim 1. A method for producing a color filter, comprising the step of forming a second columnar spacer having a smaller thickness than the first columnar spacer.

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