This application claims priority from and the benefit of Korean Patent Application No. 10-2008-0080483, filed on Aug. 18, 2008, which is hereby incorporated by reference for all purposes as if fully set forth herein.
1. Field of the Invention
The present invention relates to an exposure apparatus and exposure method that are used to expose a substrate in the manufacture of a display substrate of a liquid crystal display or the like.
2. Discussion of the Background
The manufacture of a thin film transistor (TFT) substrate or color filter substrate of a liquid crystal display used as a display panel, a substrate for a plasma display panel, and a substrate for an organic EL (electroluminescence) display panel may be carried out by forming a pattern on a substrate by a photolithography technique using an exposure apparatus. An exposure apparatus irradiates exposure light onto a substrate coated with a photosensitive resin material (photoresist) and transfers a pattern of a mask onto the substrate.
Light sources that generate exposure light of the exposure apparatus may include lamps with a high pressure gas filled by a valve, such as mercury lamps, halogen lamps, and xenon lamps. These lamps should be cooled during use because of they generate heat and there is a risk that the valve will rupture when an excessively high temperature is reached. Further, if the liquid crystal display panel is large, a plurality of lamps may be used, and thus uniformity may deteriorate due to a difference in the luminance of light between intervals of the lamps.
The present invention provides an exposure apparatus and exposure method that may provide for a uniform surface temperature of lamps and stabilized luminance of exposure light.
Additional features of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention.
The present invention discloses an exposure apparatus including a plurality of exposure lamps and a luminance changing mechanism disposed between the exposure lamps and an exposure target. The luminance changing mechanism changes a location at which exposure light generated from the exposure lamps reaches the exposure target by changing the direction in which the exposure light generated travels.
The present invention also discloses an exposure method including generating an exposure light using a plurality of lamps, passing the exposure light through a luminance changing mechanism, and allowing the exposure light that passed through the luminance changing mechanism to reach an exposure target. The location at which exposure light generated from a specific position of the exposure lamps reaches the exposure target varies with time.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of the invention.
The invention is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure is thorough, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. Like reference numerals in the drawings denote like elements.
It will be understood that when an element or layer is referred to as being “on” or “connected to” another element or layer, it can be directly on or directly connected to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on” or “directly connected to” another element or layer, there are no intervening elements or layers present.
Generally, the luminance of exposure light changes depending on the surface temperature of a lamp. A specified surface temperature for the lamp may be set, and when an exposure treatment is carried out, the surface temperature of the lamp should be kept at the specified surface temperature in order to stabilize the luminance of the exposure light.
The amount of exposure light is proportional to the luminance and exposure time of exposure light. Recently, as substrates increase in size due to the trend toward large-screen display panels, there has been a demand for a light source of an exposure apparatus that has higher luminance. The higher the luminance of the light source, the higher the luminance of the exposure light and the shorter the exposure time, which may reduce tack time and improve throughput.
Further, because the amount of exposure light required for exposure is different according to the size of a substrate or the type of photoresist, conventionally, lamps have had to be replaced to change the luminance of the light source. Since time and labor are needed to replace the lamps, there has been a demand for a way to change the luminance of the light source without replacing the lamps.
To satisfy this demand, the luminance of a light source may be increased by utilizing a plurality of lamps as the light source to generate exposure light, and the luminance of the light source may be changed by switching between the lamps. However, it may be difficult to make the surface temperature of the lamps uniform and therefore, the luminance of the exposure light may not be stabilized. This is because part of the exposure light generated from each lamp is irradiated onto an adjacent lamp directly or by transmitting through a condensing mirror formed around each lamp, and a temperature gap is generated at a portion on which exposure light of the adjacent lamp is irradiated and at a portion on which no exposure light of the adjacent lamp is irradiated. In addition, it may be difficult to make the surface temperature of the lamps uniform also because heat generated from each lamp is transferred to an adjacent lamp, and a temperature gap is generated at a location close to the adjacent lamp and at a location far from the adjacent lamp.
Here, there may be a plurality of lamps 20 to produce a desired luminance of light depending on the overall size of the panel.
The panel 10 may be a liquid crystal display that has a thin film transistor (TFT) formed on a first substrate and is filled with a liquid crystal containing monomers between the first substrate and a second substrate.
A water layer 30 is formed at an appropriate point between the plurality of lamps 20 and the liquid crystal panel 10, and the water layer 30 is formed wide enough to have a width and length similar to the plane area of the liquid crystal panel 10. However, the water layer 30 may be formed to have a width and length that are different from the plane area of the liquid crystal panel 10.
In addition, referring to the luminance profile of non-filtered light from the plurality of lamps as shown in
The movement direction 50 of the oscillator may be an up-and-down direction, however, the oscillator 40 may oscillate in various directions that are capable of generating waves of a similar waveform.
As shown in
However, in
Therefore, in
On the other hand, in
Furthermore, the aforementioned
In the exemplary embodiment of
Referring to
When describing the slit mask 200 of the exposure apparatus according to this exemplary embodiment in detail, the overall size of the slit mask 200 is almost the same as the size of the panel 10. This is because the slits of the slit mask 200 should have a sufficient size to affect the entire panel 10 in order to make the luminance of a light source uniformly reach every part of the liquid crystal panel 10 through the plurality of lamps 20.
The slits of the slit mask 200 of
In
In addition, the average distance between adjacent lamps may about 10 cm, and the proper height d of the slits may be about several mm, e.g., 1 mm. But the height and interval of the slits may be adjusted within an ideal range according to the type and intensity of UV rays.
Although the above described exemplary embodiment uses slits to adjust the amount of exposure, a grating quartz or the like may be used instead of the slits.
By using the exposure apparatus or exposure method according to exemplary embodiments of the present invention, the luminance of exposure light may be stabilized because the uniformity of luminance may be increased and the demand for luminance change may be met, which may enable the manufacture of a high-quality substrate within a short tack time.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
Number | Date | Country | Kind |
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10-2008-0080483 | Aug 2008 | KR | national |