Patterning apparatus and method for fabricating continuous pattern using the same

A flexible substrate, which has a photosensitive agent applied thereon, is continuously supplied from a supply unit to a guide unit where light is irradiated from a light source on a section of the substrate. A mask is positioned between the substrate and the light source so that the light from the light source selectively subjects the section of the substrate to exposure. Hence, it is possible to form a pattern having a continuous slanted structure for a large-area display panel.

The present application claims, under 35 U.S.C. § 119, the priority benefit of Korean Patent Application No. P03-091997 filed Dec. 16, 2003 in Republic of Korea, the entire contents of which are herein fully incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to a patterning apparatus and a patterning method using the same, and more particularly to an apparatus for fabricating a pattern of a continuous structure, which is used in a large-area display, and a method for fabricating a pattern of a continuous structure using the same.

As used herein, the pattern of a continuous structure refers to a pattern of, e.g., barrier ribs of a Plasma display panel (PDP), which are arranged in line in one direction with a uniform cross section.

2. Description of the Related Art

Conventional patterning methods include an electron beam lithography method, an optical lithography method, and an X-ray lithography method.

According to the electron beam lithography method, a photosensitive agent, which reacts to electrons, is applied on the upper surface of a substrate and a predetermined pattern is directly etched using electron beams, without any mask. This method can form a high-resolution pattern of 0.2 μm or less, since the electrons have a short wavelength.

However, it takes a long time to etch a predetermined pattern using the electron beam lithography method. This decreases productivity. In addition, since the depth of a formed pattern is small, the accuracy of overlay and etching is poor. Furthermore, the method uses expensive electron-emission equipment. Consequently, the electron beam lithography method is not suitable for fabricating a pattern for use in a large-area display panel.

According to the optical lithography method, a photosensitive agent is applied on the upper surface of a substrate, a mask is placed thereon, and UV rays are irradiated to fabricate a predetermined pattern. This method can form a vertical or slanted pattern according to the irradiation angle of the UV rays.

However, if the optical lithography method is used, it is difficult to fabricate a vertical pattern with a thickness of a few tens of μm or more, as well as to form a uniformly slanted pattern, due to the diffraction characteristics peculiar to the UV rays. In addition, since the UV rays have dispersion, they cannot be irradiated only on selected portions or form a micro-pattern with a line width of 0.2 μm or less. Accordingly, this method cannot form a highly-integrated pattern.

According to an X-ray lithography method, a photosensitive agent is applied on the upper surface of a substrate and X-rays are irradiated via a mask to fabricate a predetermined pattern. Since the X-rays have a short wavelength, this method can form a micro-structure with a line width of 0.1 μm or less.

However, when a substrate1and a mask2are kept parallel to each other and X-rays are irradiated with a slant to form a pattern1aof a slanted structure, as shown inFIG. 1, a problem occurs as follows:

If the mask2is positioned with a slant relative to the X-rays, there is a difference in the traveling distance L1, L2of the X-rays to the absorbent body2bof the mask2. This decreases the degree of precision in shape. In order to solve this problem, the mask2should have a trapezoid absorbent body, which is difficult to fabricate. Since the width d of the X-rays is not zero, it is also impossible to form a continuous pattern.

In addition, when the substrate1and the mask2are retained parallel to each other and X-rays are irradiated vertically to form a pattern1aof a slanted structure, as shown inFIG. 2, a problem occurs as follows:

If the X-rays are irradiated on the upper surface of the substrate1, a thickness T of a photosensitive agent, which has been applied on the upper surface of the substrate, is subject to exposure as far as they penetrate into the substrate. Accordingly, this method can form only a pattern1aof a thickness T of tens or hundreds of μm, which corresponds to the thickness of the substrate. In other words, such a conventional vertical irradiation method cannot continuously form a pattern of a three-dimensional slanted structure having a predetermined thickness or more.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made to solve one or more of the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a patterning apparatus capable of forming a pattern in a relatively large area of substrate and a patterning method using the same.

Another object of the present invention is to provide a patterning apparatus capable of fabricating a highly-integrated pattern and a patterning method using the same.

Another object of the present invention is to provide a patterning apparatus capable of fabricating a continuous pattern and a patterning method using the same.

Another object of the present invention is to provide a patterning apparatus capable of continuously fabricating a pattern of a slanted structure of a predetermined thickness or more and a patterning method using the same.

In order to accomplish one or more of the above objects, there is provided a patterning apparatus comprising: a guide unit for continuously guiding a flexible substrate, which has a photosensitive agent applied thereon, in a predetermined region including the top point of the guide unit; a light source for vertically irradiating beams on a vertical section of the photosensitive agent, which has been applied on the substrate; and a mask positioned between the substrate, which is guided by the guide unit, and the light source so that the beams are selectively transmitted to the photosensitive agent.

The guide unit can be a roller of a cylindrical shape and an auxiliary guide unit, which corresponds to the guide unit, is additionally provided so that the substrate is guided while being forced against the guide unit.

The guide unit is directly driven by a driving motor to move and guide the substrate.

The patterning apparatus further comprises a supply unit for supplying the substrate to the guide unit and a winding unit for collecting the substrate, which has been subject to exposure in the guide unit, both of the supply and winding units providing driving power to move the substrate.

The guide unit and the mask are installed on a frame and the mask is positioned by an alignment controller unit, which is provided on the frame.

The guide unit and the mask are installed on a frame and the guide unit is positioned by a guide unit adjustment unit, which is provided on the frame.

According to another aspect of the present invention, there is provided a patterning apparatus comprising: a supply unit for continuously supplying a flexible substrate, which has a photosensitive agent applied thereon; a guide unit fixedly installed and adapted to continuously guide the substrate, which is supplied from the supply unit, in a predetermined region including the top point of the guide unit; a light source for vertically irradiating beams on a vertical section of the substrate, which is positioned on the top point of the guide unit; a mask positioned between the substrate, which is guided by the guide unit, and the light source so that the beams are selectively transmitted to the photosensitive agent; and a winding unit for collecting and winding the substrate, which has been subject to exposure in the guide unit.

The guide unit has a curved surface formed at least from its supply unit side to its top point, which contacts the substrate and guides it.

The guide unit has a flat surface formed in a predetermined region from its top point to its winding unit side, which contacts the substrate and guides it.

The guide unit and the mask are installed on a frame and the mask is positioned by an alignment controller unit, which is provided on the frame.

The guide unit and the mask are installed on a frame and the guide unit is positioned by a guide unit adjustment unit, which is provided on the frame.

According to still another aspect of the present invention, there is provided a patterning method wherein a flexible substrate, which has a photosensitive agent applied on its surface, is supplied from a supply unit; is collected by a winding unit; is contacted by a predetermined region of a guide unit, including at least its top point, between the supply and winding units; and is guided, the method comprising: a first step of continuously guiding the substrate from the supply unit to the predetermined region of the guide unit, including its top point; a second step of irradiating beams from a light source in a direction perpendicular to a vertical section of the photosensitive agent, which is positioned on the top point of the guide unit, via a mask; and a third step of collecting the substrate, which has been subject to exposure in the guide unit, from the guide unit to the supply unit.

The mask is positioned parallel to the vertical section and the beams are vertically irradiated on the mask.

The period of time during which the beams are irradiated on the photosensitive agent and the amount of irradiation are determined by a speed control, which guides and moves the substrate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 3shows the outline of a first embodiment of a patterning apparatus according to the present invention andFIGS. 4aand4bshow the principal parts ofFIG. 3for explaining the concept of the present invention.

As shown, a predetermined region of a flexible substrate10, which has a photosensitive agent applied on its surface, is wound around a guide unit20, which has a shape of a cylindrical roller, and is guided. The guide unit20is rotated by a driving motor30. The driving motor30has a rotation shaft32, which is concentrically connected to the rotation center of the guide unit20to rotate it. For reference, the rotation direction of the guide unit20is not necessarily identical to the movement direction of the substrate10and, for example, may be opposite to the movement direction of the substrate10.

A mask40is positioned adjacently to the guide unit20and is parallel to the normal direction Z of the guide unit20. The mask40is composed of an opening42, through which beams52from a light source50(described below) pass, and an absorption unit44, which absorbs the beams52. The opening42is formed in such a manner that its shape corresponds to the sectional shape of a pattern to be formed and the absorption unit44forms a vertical wall around the opening42. The mask40may also be provided with a cover (not shown) to selectively shield the opening42.

A light source50is positioned in a location spaced a predetermined distance from the mask40. The light source50provides beams52, which are irradiated on the photosensitive agent to form a pattern. In other words, the beams52from the light source52pass through the opening42of the mask40and are irradiated on the photosensitive agent of the substrate, which is wound around the guide unit20. In the present embodiment, the light source50emits X-rays, which travel in an exactly straight line, have very little dispersion, and have energy tens of thousands of times larger than other rays.

It will now be explained how the photosensitive agent on the substrate10is subject to exposure, with reference toFIGS. 4aand4b. If the substrate is cut parallel to the Z axis through the center of the guide unit20, a yz section is obtained in a location corresponding to the top point of the guide unit20. Hereinafter, this section will be referred to as a “vertical section H”.

According to the present invention, the beams52are irradiated vertically on the vertical section H to subject the photosensitive agent to exposure. In particular, by irradiating the beams52on the vertical section H without interruption, while the substrate20is continuously moved, a region is subject to exposure at points to which the beams52are transmitted, as shown inFIG. 4b.

More theoretically, as a vertical section H, which has been subject to exposure, is moved along the circumstance of the guide unit20, the next vertical section H is positioned on the top point t of the guide unit20for exposure. As such, the photosensitive agent is divided into innumerable vertical sections H, which are subject to exposure successively.

In practice, part “a” of the photosensitive agent is initially subject to exposure. If the substrate10is moved and passes through the top point t of the guide unit, the entire vertical section H is subject to exposure. Of course, if the beams52can pass through the photosensitive agent even at the location where the substrate has passed the top point t, point “b” will be the last portion to be subject to exposure.

The period of time during which the photosensitive agent of the substrate10is subject to exposure can be calculated by multiplying the radius r of the guide unit20by the rotation angle ∂ of the guide unit20.

The mask40is preferably positioned parallel to the vertical section H. When passing through the opening42of the mask40, the beams52should be vertically incident on the vertical section H.

FIG. 5shows a second embodiment of the present invention. For clarity, the same components as in the first embodiment are given the same reference numerals and repeated explanation thereof will be omitted.

As shown in the drawing, a guide unit20is positioned on a frame20′ together with a mask40to guide a substrate10, in the present embodiment. The guide unit20is a cylindrical roller and contacts a predetermined region of the substrate10to guide it. An auxiliary guide unit22, which corresponds to the guide unit20, is provided. The auxiliary guide unit22cooperates with the guide unit20to guide the movement of the substrate10.

The auxiliary guide unit22is rotated together with the guide unit20and securely forces the moving substrate10against the upper surface of the guide unit20. In other words, the auxiliary guide unit22prevents the substrate10from being spaced from the upper surface of the guide unit20so that the beams52are accurately irradiated on the vertical section H.

The auxiliary guide unit22is not necessarily positioned adjacently to the guide unit20, as shown in the drawing. For example, one auxiliary guide unit22is positioned on a side of the guide unit20where the substrate10is supplied and another is positioned on a side where the substrate10is collected. The region of the substrate10, which contacts the guide unit20and is guided thereby, depends on the difference in location between the auxiliary guide unit22and the guide unit20, as well as the height of the auxiliary guide unit22.

The guide unit20may be driven by a driving motor, as in the previous embodiment. To this end, the driving motor may be positioned on a side of a frame20′. If a driving motor is used, driving control may be necessary to control the rotation speed of the driving motor, so that the traveling speed of the substrate10can be controlled.

Meanwhile, it is not mandatory to provide the frame20′ with a driving motor, which supplies driving power to move the substrate10. In other words, a separate driving source may provide the driving power to move the substrate10, while the guide unit20is simply rotated together with the substrate10and guides it. Such a configuration will be described later in relation to a supplying unit60and a winding unit70.

The guide unit20may be positioned along the longitudinal direction of the frame20′, that is, along a direction perpendicular to the moving direction of the substrate10. To this end, a guide unit controller unit25is positioned on the frame20′ and the guide unit20is supported thereby.

The mask40is supported on the frame20′ by an alignment controller unit40′. The alignment controller unit40′ is adapted to adjust the mask40precisely. The alignment controller unit40′ plays the role of aligning the mask40parallel to the vertical section H of the photosensitive agent, which has been applied on the substrate10.

A feature is preferably provided to align the light source50relative to the mask40. In particular, the light source50is preferably positioned so that the light, which is irradiated from the light source50, is accurately incident on the vertical section H via the mask40.

Meanwhile, a feature is provided to continuously supply the substrate10to the guide unit20and continuously collect the substrate10, which has been subject to exposure. In particular, the substrate10is wound into a roll form and placed in a supply unit60. The substrate10is then continuously unwound and supplied to the guide unit. A winding unit70is also provided to wind the substrate, which has been subject to exposure, into a roll form and collect it from the guide unit20. Alternatively, the substrate, which has been subject to exposure, may be continuously supplied to the next process and wound on the winding portion70, after the pattern formation is over.

To this end, the winding unit70should exert a drawing force to wind the substrate10. In that case, the winding unit70acts as a driving source. Of course, another driving source may be positioned on the moving path of the substrate10to move the substrate10.

FIG. 6shows a third embodiment of the present invention. For clarity, the same components as in the previous embodiment are given the same reference numerals and repeated explanation thereof will be omitted.

In the present embodiment, a guide unit120, which guides a substrate10, is not rotated but fixed. The guide unit120does not need to have a curved surface anywhere but in a region adjacent to the top point t thereof, which contacts the substrate10and guides it. Except for this detail, the guide unit120may be arbitrarily configured.

For reference, as shown inFIG. 6a, the region from point “a” to the top point t is preferably composed of a curved surface, while the region from the top point “t” to point “b” may be composed of a flat surface. In that case, it is possible to modify the period of time during which the photosensitive agent is subject to exposure, by adjusting the length of the flat surface region.

Although not shown in the drawing, the guide unit120may be provided with an auxiliary guide unit, which forces the moving substrate10against the guide unit120.

As such, in the present embodiment, the guide unit120is fixed and just guides the movement of the substrate10. Accordingly, a supply unit60and a winding unit70provide the power necessary for the movement of the substrate10.

The supply unit60continuously supplies the substrate10, while the winding unit70pulls and winds the substrate10. Therefore, the winding unit70acts as a driving source. Of course, a separate driving source may be positioned in the movement path of the substrate10to provide the driving power to move the substrate10.

A mask40is positioned parallel to the vertical section H of the substrate10so that beams52are selectively irradiated on the vertical section H. The configuration of the mask40is the same as in the previous embodiment. The beams52, which are irradiated on the substrate10, are provided from a light source50. A feature may also be provided to align the mask40.

A patterning method using a patterning apparatus, configured as above, according to the present invention will now be described in detail with reference to the flow chart shown inFIG. 7.

A substrate10, which has a photosensitive agent applied on its surface, is continuously supplied between a guide unit20and an auxiliary guide unit22(step1). The substrate10is moved while contacting a surface of the guide unit20. The auxiliary guide unit22plays the role of forcing the substrate10against the surface of the guide unit20.

An alignment controller unit40′ is used to accurately position a mask40so that beams52, which are irradiated from a light source50, are correctly transmitted to a vertical section H (step2). Of course, the light source50should be correctly positioned relative to the mask40or the guide unit20.

The light source50irradiates beams52, while the substrate10is moved and guided by the guide unit20. The beams52pass through an opening42of the mask40and subject the photosensitive agent of the substrate10to exposure with a shape corresponding to that of the opening42(step3).

As such, while the substrate10is continuously supplied to the guide unit20, the beams52, which are provided from the light source50, continuously pass through the mask40and are irradiated on the vertical section H of the substrate10. Accordingly, the photosensitive agent is continuously subject to exposure and a continuous pattern is formed.

The period of time during which the photosensitive agent is subject to exposure or a necessary amount of exposure may be obtained by calculation. Of course, the exposure period or the exposure amount should be modified according to the type of the photosensitive agent or the beams52. The exposure period or the exposure amount may be controlled based on the speed of the substrate10, which is moved and guided by the guide unit20.

After the photosensitive agent is subject to exposure in the guide unit20, the substrate10is again wound into a roll form (step S4). Of course, the steps for supply, collection, and exposure of the substrate10, among other steps, are performed simultaneously and continuously, once they are begun.

Several steps should be performed additionally, including removing the photosensitive agent from parts, which have been subject to exposure, or from parts, which have not, to complete a pattern on the photosensitive agent, which has been subject to exposure through the above processes.

FIGS. 8ato8cpresent examples of patterns15, which have been formed on a substrate10according to a method of the present invention. Needless to say, the inventive method can form patterns having various sectional shapes, besides the patterns15shown inFIGS. 8ato8c.

In summary, the basic technological idea of the present invention is as follows: beams52are vertically irradiated on a vertical section H of a substrate10, which is continuously supplied along the outer peripheral surface of a guide unit20and through the top point t thereof, so that patterns of various sectional shapes can be fabricated in a continuous manner.

As mentioned above, the patterning apparatus and the patterning method according to the present invention are advantageous in that a pattern of a predetermined sectional shape can be formed in a relatively large area and thus a pattern for a large-area display can be fabricated easily.

Based on a completed pattern, beams are irradiated from a lateral surface, not from a top surface, of the pattern. This minimizes the spacing between patterns and enables the fabrication of a micro-pattern. Accordingly, it is possible to fabricate a highly-integrated pattern.

The lateral irradiation also makes it possible to continuously fabricate patterns having the same sectional shape. This reduces the process time for forming patterns and improves production efficiency.

Furthermore, the lateral irradiation makes it relatively easy to adjust the height of the patterns. Accordingly, patterns of various heights can be fabricated. Since the beams are irradiated on the upper and lower portions of a pattern at the same time, the upper and lower portions are subject to the same amount of exposure. This makes the width of the pattern uniform.