JP2004085778A - Contact exposure method and contact exposure apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contact exposure method and a contact exposure apparatus in which a mask plate is hardly damaged when a substrate such as a large-size flat display panel is exposed. <P>SOLUTION: The apparatus is equipped with a mask holder which has a mask plate and a frame to fix the mask plate and in which a sealed space is formed between the mask plate and the mask base and the warpage of the mask plate due to its weight is prevented by keeping specified negative pressure in the sealed space. The substrate to be exposed and the mask plate are arranged with a gap interposed corresponding to the warpage due to its weight while specified negative pressure is kept in the sealed space. The negative pressure in the sealed space is released to bring the substrate to be exposed into tightly contact with the mask plate by using the warpage by the self weight. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a contact exposure method and a contact exposure apparatus, and more particularly, to a contact exposure method and a contact exposure apparatus in which a mask plate is not easily damaged when exposing a substrate such as a large flat display panel.
[0002]
[Prior art]
In manufacturing a display panel such as an organic EL panel and a liquid crystal panel, a process of projecting and exposing an image of the original plate to a glass substrate coated with a photosensitive material and copying the pattern using a mask plate having a pattern drawn on a transparent plate as an original plate. There is. Examples of this type of exposure apparatus include JP-A-3-272127, JP-A-4-5659, and JP-A-7-134426.
FIG. 3 is a plan view of a main portion of a mask plate supporting device and a side view centering on a mask plate supporting portion in the latter exposure device disclosed in JP-A-7-134426. is there.
In FIG. 3A, a frame 7 having good flatness is formed by four sides 7a, 7b, 7c, 7d having the same dimensions as the outer diameter of the mask plate 1, and an air suction groove Gr is provided on each side. Make it an adsorption surface. The mask plate 1 adsorbed by the air is held with good parallelism.
[0003]
Next, at the center of one side 7a of the frame 7 and at two symmetrical positions near both ends of the opposite side 7c, an L-shaped fitting 81 shown in FIG. Each of the support members 8 including the adjusting screws 82 is attached. By rotating each adjusting screw 82, the position of each of the three steel balls S is adjusted to be the same distance with respect to the lower surface of the frame 7, and each of the three steel balls S is connected to the horizontal portion 3a of the support member 3. To support the frame 7 at three points.
Next, a connection composed of an L-shaped bracket 91, a mounting tool 92, and a connection pin 93 for connecting them, shown at (c), at two symmetrical points near both ends of one side 7a and at the center of the opposite side 7c. Tools 9 are provided respectively. When the L-shaped bracket 91 is fixed to the horizontal portion 3a of the support member 3 and the fixture 92 is fixed to the frame 7, the frame 7 is flexibly connected to the support member 3.
As described above, the small mask plate 1 is not curved, and the frame 7 is not distorted, the mask plate 1 is fixed to the support member 3 with good parallelism, the focus adjustment accuracy is improved, and accurate exposure is performed. It becomes possible.
[0004]
On the lower side of the mask plate 1, a mounting table (glass plate chuck stage) for a plate to be exposed is arranged. In the proximity type exposure, the mask plate 1 and the glass substrate mounted on the mounting table are used. Is adjusted to a proximity gap, that is, a parallel and minute gap Δg (for example, 50 to 100 μm). In this adjustment, the mounting table is lowered to place the glass substrate thereon, and then raised to approach the mask plate 1, and a plurality of gap measuring devices, usually three measuring devices, are used to adjust the mask plate 1 at three points. The gap between the substrate and the glass substrate is measured. Referring to the measured gaps at three points, the three positions of the mounting table are respectively raised or lowered by three tilt mechanisms (up and down moving mechanisms), so that the mask plate 1 and the glass substrate have a uniform gap Δg. Is adjusted as follows.
On the other hand, at the time of contact exposure, the mask plate and the glass substrate were positioned in the same manner as described above, and the mask plate and the glass plate were placed close to each other by a distance of several tens of μm in the same manner as in the method performed on a wafer or the like. Thereafter, exposure is performed after the mask plate and the glass plate are brought into close contact with each other by applying a vacuum, or the glass plate side is pressed and pushed up to make close contact.
[0005]
[Problems to be solved by the invention]
However, the contact exposure method as described above is possible for a small liquid crystal panel or a wafer, but for a large flat display panel exceeding 30 inches, the contact pressure can be partially uneven at the time of contact, There is a disadvantage that it is difficult to make uniform close contact as a whole, the contact pressure between the substrate to be exposed and the mask plate is high, and the mask plate is easily damaged.
An object of the present invention is to solve such a problem of the prior art, and to provide a contact exposure method and a contact exposure apparatus in which a mask plate is hardly damaged when a substrate such as a large flat display panel is exposed. Is to do.
[0006]
[Means for Solving the Problems]
The features of the contact exposure method and the contact exposure apparatus of the present invention for achieving such an object include a mask plate and a frame for fixing the mask plate, a closed space is formed between the mask plate and the frame, The closed space is provided with a mask holder for preventing deflection of the weight of the mask plate by being set to a predetermined negative pressure,
The substrate to be exposed and the mask plate are arranged via a gap corresponding to the amount of deflection of the weight of the mask plate in a state where the closed space is under a predetermined negative pressure, and the negative pressure in the closed space is released to release the substrate and the mask. The plate is brought into close contact with the substrate using the deflection of its own weight, and is exposed.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
As in the above configuration, in the present invention, the substrate to be exposed and the mask plate are brought into close contact with each other by the deflection of the mask plate by its own weight, so that only the deflection of the mask plate by its own weight or a pressure close to this is achieved. It does not add to the substrate to be exposed. Therefore, no unnecessary force is generated between the mask plate and the mask plate.
Further, even when the mask substrate is separated from the substrate to be exposed which is in close contact with the mask plate, the substrate can be easily separated simply by applying a negative pressure to the negative pressure chamber.
As a result, when exposing a substrate such as a large flat display panel, it is possible to realize a contact exposure method and a contact exposure apparatus in which a mask plate is hardly damaged.
[0008]
【Example】
FIG. 1 is a schematic sectional view of a contact exposure apparatus to which the contact exposure method of the present invention is applied, and FIG. 2 is a flowchart of the contact exposure processing.
In FIG. 1, reference numeral 10 denotes a contact exposure apparatus, and 1 denotes a mask plate thereof. The mask plate 1 has four sides adsorbed and supported by a mask base (rectangular frame) 2, and the mask base 2 is supported by a support member 3 provided on the optical unit 4. In the optical unit 4, gap measuring devices G1, G2, and G3 are provided at three places on the mask plate 1 which are appropriately dispersed on a plane. Correspondingly, three tilt mechanisms T1, T2, T3 are provided below the mounting table 5a on which the substrate to be exposed (usually a glass substrate) 5 is mounted to support the mounting table 5a. Has been.
Reference numeral 6 denotes a tilt device. The tilt device 6 includes these tilt mechanisms T1, T2, and T3 that support the mounting table 5a, a base board 6a that mounts these, and three tilt mechanisms T1, T2, and T3. And a tilt drive circuit 6b for driving the same. Here, each of the tilt mechanisms T1, T2, and T3 is a vertical movement mechanism, and the tilt of the substrate 5 to be exposed is adjusted by vertically moving at three positions independently. The tilt device 6 is a specific example of the position adjusting mechanism of the present invention.
Reference numeral 11 denotes a gap measuring device, which includes three gap measuring devices G1, G2, G3 and a gap calculating circuit 11a, and the gap calculating circuit 11a measures each of the measurements obtained from the gap measuring devices G1, G2, G3. The values are calculated in the form of respective measurement results, converted into digital values, and sent to the control device 12.
[0009]
The control device 12 has an MPU 12a, a memory 12b, an interface 12c, and the like, and these are connected by a bus 12d. The memory 12b stores a gap measurement / position adjustment program, a negative pressure control program, and the like. The measurement position coordinates of the gap measuring devices G1, G2, G3 and the position coordinates where the tilt mechanisms T1, T2, T3 are installed are stored.
The MPU 12a executes the gap measurement / position adjustment program by the MPU 12a, and executes a program for each tilt with respect to the target gap (here, the contact start gap Δgc (described later)) based on the measurement results of the gap measurement devices G1, G2, and G3. The movement amounts of the mechanisms T1, T2, and T3 are obtained, a drive signal is generated in the tilt drive circuit 6b, and the tilt mechanisms T1, T2, and T3 are driven to start uniform contact at the interval between the mask plate 1 and the substrate 5 to be exposed. The gap is set to Δgc.
The control device 12 controls the vacuum pump 13 and the adjustment valves 14a and 14b by executing a negative pressure control program in addition to the measurement and position adjustment of the gap between the mask plate 1 and the substrate 5 to be exposed. Then, a negative pressure chamber 42 (described later) is set to a predetermined negative pressure, or a control for releasing the negative pressure is performed. Further, control is performed to attract the mask plate 1 to the mask base 2.
[0010]
The mask base 2 is a frame-shaped frame having a rectangular opening 40 corresponding to the maximum exposure area of the mask plate. A window plate 41 made of the same material as the mask plate 1 is adhered to the upper surface of the opening 40 that receives the exposure light. It is fixed by the agent. The mask plate 1 is fixed to the lower surface of the opening 40 of the mask base 2 by vacuum suction.
Therefore, the space of the opening 40 together with the mounted mask plate 1 is made a closed space, and is kept airtight. Thereby, the space of the opening 40 becomes the negative pressure chamber 42.
Four grooves are formed as suction holes along the sides of the rectangle on the contact surface of the mask base 2 with the mask plate 1. Two grooves on the left and right of the four grooves are suction holes 43 and 44. The suction holes 43 and 44 communicate with the ports 45 and 46, respectively, and the air is sucked by the vacuum pump 13 through the ports 45 and 46 and the adjustment valve 14a, so that the mask plate 1 is negatively attached to the lower surface of the mask base 2. Pressure suction is applied. The other two suction holes (not shown) are also suctioned with negative pressure through the same ports, so that the mask plate 1 is suction-held on the mask base 2.
[0011]
The port 47 is a port that communicates with the negative pressure chamber 42 to make the negative pressure chamber 42 have a negative pressure. The air in the negative pressure chamber 42 is sucked by the vacuum pump 13 Is set to a negative pressure. The pressure is maintained at a predetermined negative pressure specified in advance by adjusting the adjustment valve 14b. This cancels out the own weight of the mask plate 1 and prevents it from sagging under its own weight. The adjustment of the adjustment valves 14a and 14b is performed by the control device 12. Further, the predetermined negative pressure is given as an average of a large number of negative pressure values obtained in advance by experiments or the like to cancel the self-weight according to the material and size of the mask plate 1 and stored in the memory 12c of the control device 12. ing. The adjusting valve 14b is adjusted by the MPU 12a according to the stored value, and the negative pressure chamber 42 is set to a predetermined negative pressure.
[0012]
At the time of exposure, first, the mask plate 1 is sucked and held on the mask base 2, and the air in the negative pressure chamber 42 is sucked and held at a predetermined negative pressure. Thereby, the mask plate 1 is held substantially uniformly without sagging by its own weight.
In this state, next, the interval between the mask plate 1 and the substrate 5 to be exposed is set to a contact start gap Δgc (for example, several tens μm). Note that the contact start gap Δgc is given as an average value of the slack amount of the mask plate 1 due to its own weight at atmospheric pressure. For example, for a mask plate of about 1000 mm to 1500 mm × 1200 mm to 1900 mm, it is about 20 μm to 30 μm.
[0013]
Under the control of the control device 12, the contact start gap Δgc is set by lowering the mounting table 5a, mounting the substrate to be exposed 5, for example, the glass substrate 5, and then moving up to approach the mask plate 1. Then, the gaps Δg1, Δg2, Δg3 between the mask plate 1 and the glass substrate 5 at three points are measured by the respective gap measuring devices G1, G2, G3. The control device 12 refers to the measured gaps Δg1, Δg2, and Δg3, sends a control signal to the tilt drive circuit 6a, and drives the three tilt mechanisms T1, T2, and T3. By the driving, the three positions of the mounting table 5a are respectively raised or lowered, and the mask plate 1 and the glass substrate 5 are adjusted so as to have a uniform gap Δgc. Here, the three points where the gap measuring devices G1, G2 and G3 are disposed and the three positions where the tilt mechanisms T1, T2 and T3 are disposed may be different. The controller 12 calculates the amount of elevation of each tilt mechanism based on the coordinates of the measurement position and the coordinates of the tilt position, and the mounting table 5a is raised or lowered by the respective tilt mechanisms so that the gap Δg becomes uniform. Then, when a uniform gap Δgc is obtained, the negative pressure is released and the close contact is started.
[0014]
FIG. 2 is a flowchart of a contact exposure process by an exposure device (not shown) having the control device 12.
The mask plate 1 is sucked and held (step 101), and the air in the negative pressure chamber 42 is sucked by the vacuum pump 13 so that the negative pressure chamber 42 is kept at a predetermined negative pressure (without slack by its own weight, and the mask plate 1 is substantially uniform). (Negative pressure held at step 102) (step 102). Next, the gap is measured by the gap measuring device 11, and the gap between the mask plate 1 and the substrate 5 to be exposed is set to the contact start gap Δgc under the control of the control device 12 (step 103). Then, the air suction of the vacuum pump 13 is stopped, the negative pressure in the negative pressure chamber 42 is released (set to the atmospheric pressure) (step 104), and the exposure process is started (step 105). Enter (step 106). As a result of this determination, when the NO condition is satisfied, the exposure is repeated. When the exposure is completed, the determination becomes YES, and the air in the negative pressure chamber 42 is sucked by the vacuum pump 13 to a predetermined level of negative pressure. It is set (step 107).
[0015]
Next, the tilt mechanisms T1, T2, and T3 are lowered to separate the glass substrate 5 (substrate to be exposed) from the mask plate 1 and separate them (step 108), thereby ending the exposure processing.
When a larger substrate is to be handled, a pressurizing step by static pressure is provided between step 104 of releasing the negative pressure and step 105 of the exposing step, so that the mask plate 1 and the substrate to be exposed (glass substrate) 5 It is advisable to eliminate uneven contact.
Further, the negative pressure at the predetermined level in step 107 is a negative pressure at which the mask plate 1 is maintained substantially uniformly without sagging under its own weight or a negative pressure higher than this.
[0016]
As described above, in the embodiment, the configuration of the negative pressure chamber 42 formed between the mask plate 1 and the mask base 2 is an example. The configuration of the negative pressure chamber, the shape of the mask plate 1, and the attachment of the mask plate 1 to the mask base 2 can take various forms.
[0017]
【The invention's effect】
As described above, in the present invention, the substrate to be exposed and the mask plate are brought into close contact with each other by the deflection of the mask plate by its own weight, so that only the deflection of the mask plate by its own weight or a pressure close thereto is applied. It does not add to the exposed substrate. Therefore, no unnecessary force is generated between the mask plate and the mask plate.
Further, even when the mask substrate is separated from the substrate to be exposed which is in close contact with the mask plate, the substrate can be easily separated simply by applying a negative pressure to the negative pressure chamber.
As a result, when exposing a substrate such as a large flat display panel, it is possible to realize a contact exposure method and a contact exposure apparatus in which a mask plate is hardly damaged.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of an exposure apparatus to which a contact exposure method of the present invention is applied.
FIG. 2 is a flowchart of the contact exposure process.
FIG. 3 is a plan view of a main part of a mask plate supporting device in an exposure apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 7-134626 and a side view centering on a mask plate supporting portion.
[Explanation of symbols]
1 ... mask plate,
2 ... Mask base,
3. Support member,
4 optical unit, 40 aperture
41: window plate, 42: negative pressure chamber,
43, 44 ... suction holes,
45, 46, 47 ... ports,
5: glass substrate, 5a: mounting table,
6 tilt device, 6a base board, 6b tilt drive circuit,
7… Frame,
7a, 7b, 7c, 7d ... four sides of the frame,
8: Supporting tool, 81: L-shaped bracket, 82: Adjusting screw,
9: coupling tool, 91: L-shaped bracket, 92: mounting tool, 93: coupling pin,
10: contact exposure apparatus, 11: gap measuring apparatus,
12: control device, 13: vacuum pump, 14a, 14b: regulating valve,
G1, G2, G3 ... gap measuring device,
_Gr : air suction groove, S: steel balls T1, T2, T3: tilt mechanism.

Claims (7)

A closed space is formed between the mask plate and the frame having a mask plate and a frame for fixing the mask plate, and the closed space is set to a predetermined negative pressure to reduce the deflection of the weight of the mask plate. Equipped with a mask holder to prevent
The substrate to be exposed and the mask plate are arranged via a gap corresponding to the amount of deflection of the weight of the mask plate in a state where the closed space is under the predetermined negative pressure, and the negative pressure of the closed space is released. A contact exposure method in which the substrate to be exposed and the mask plate are brought into close contact with each other by utilizing the deflection of their own weight and exposed. 2. The contact exposure method according to claim 1, further comprising, after exposing the substrate in close contact with each other, applying a predetermined negative pressure to the closed space or a negative pressure higher than the predetermined negative pressure, thereby separating the substrate to be exposed and the mask plate. The substrate to be exposed is a glass substrate or a resin substrate of a flat display panel, is placed on a table, a gap between the mask plate and the glass substrate or the resin substrate is measured, and the gap of the table is measured in accordance with a measurement result. 3. The contact exposure method according to claim 2, wherein the position of the mask plate is adjusted to position the mask plate in a gap corresponding to the deflection amount. A method for manufacturing a display panel using the contact exposure method according to any one of claims 1 to 3. A closed space is formed between the mask plate and the frame having a mask plate and a frame for fixing the mask plate, and the closed space is subjected to a negative pressure to prevent deflection of the mask plate by its own weight. A mask holder,
A table on which the substrate to be exposed is placed;
A position adjustment mechanism that adjusts a distance between the exposure target substrate and the mask plate by moving at least one of the mask holder and the table toward and from the other,
By setting the closed space to a negative pressure and controlling the position adjustment mechanism to set the distance between the substrate to be exposed and the mask plate to a distance corresponding to the amount of deflection of the mask plate by its own weight, the negative pressure of the closed space is set. And a control device for releasing the substrate and bringing the substrate to be exposed and the mask plate into close contact with each other by using the deflection of its own weight. Further, after the exposure is completed, the control device controls the closed space to be at or below the predetermined negative pressure to separate the substrate to be exposed and the mask plate. The contact exposure apparatus according to the above. Further, the apparatus has a measuring device for measuring a gap between the mask plate and the substrate to be exposed at a plurality of positions, and the position adjusting mechanism includes a plurality of advancing and retreating mechanisms for moving the table relative to the mask plate. The apparatus controls the plurality of advancing and retreating mechanisms in accordance with the measurement results of the plurality of locations of the measuring apparatus to set the interval between the exposure target substrate and the mask plate to an interval corresponding to a deflection amount of the weight of the mask plate. 7. The contact exposure apparatus according to claim 6, wherein the substrate to be exposed is a glass substrate or a resin substrate of a flat display panel.

Images