JP4235964B2 - Exposure equipment - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an exposure apparatus used for exposing a circuit pattern drawn on a mask onto a substrate, and more particularly to a light source system for irradiating the substrate with light.
[0002]
[Prior art]
Conventionally, an exposure apparatus uses an ultrahigh pressure mercury lamp as a light source. And the circuit pattern was exposed to the board | substrate fixed to the exposure stand with the light irradiated from this ultrahigh pressure mercury lamp.
[0003]
However, ultra high pressure mercury lamps generally have a short life. For this reason, the user has to frequently perform the replacement work and the light amount adjustment work accompanying the replacement, which is troublesome. In addition, since the ultra high pressure mercury lamp takes time until a stable amount of light is irradiated after the power is turned on, the exposure operation cannot be started immediately after the apparatus is started. Furthermore, since the ultra-high pressure mercury lamp needs to be lit at all times so that a stable amount of light continues to be radiated, there is also a problem that power consumption inevitably increases.
[0004]
[Problems to be solved by the invention]
In view of the above-described conventional problems, the present invention provides an exposure apparatus that can reduce the burden on the user, suppress power consumption, and can immediately expose a substrate using a stable amount of light. With the goal.
[0005]
[Means for Solving the Problems]
An exposure apparatus according to the present invention is an exposure apparatus that exposes a circuit pattern drawn on a mask onto an exposed surface of a substrate, and includes a light source unit having a light source unit in which a plurality of light emitting elements are discretely arranged in two dimensions. A light source unit and a scanning means for relatively linearly moving the mask and the exposed surface along the first direction during the exposure period, and a first direction of light emitted from the light source unit; The exposure width in the orthogonal second direction is configured to be longer than the maximum length of the exposed surface, and the light emitting element is moved by the relative movement of the light source unit, the mask, and the exposed surface by the scanning unit. The entire surface to be exposed is arranged so as to be exposed all over.
[0006]
By using a light-emitting element that has a longer lifetime than the ultra-high pressure mercury lamp as the light source, it is possible to reduce the work burden on the user regarding the replacement of the light source. Further, since the light emitting element also has a feature of high stability immediately after being turned on, it is possible to emit light (turn on) only during exposure. That is, power consumption in the light source unit can be suppressed. Although the area that can be irradiated (exposed) by a single light emitting element is narrow, a plurality of elements are arranged in a predetermined state, and the light source unit and the exposed surface (mask) are moved relative to each other by the scanning means, so that the entire exposed surface is It can be exposed all over. Specifically, the arrangement in the predetermined state is as follows.
[0007]
For example, a plurality of light emitting elements are arranged at predetermined intervals in the second direction, and a third inclined at a predetermined angle with respect to the first direction in a plane defined by the first and second directions. It is preferable that a plurality are arranged at predetermined intervals in the direction (Claim 2).
[0008]
Here, the diameter of the spot formed by the light emitted from each light emitting element and incident on the surface to be exposed is a, the arrangement pitch of the spot diameters in the second direction is b, and the number of the light emitting elements arranged in the third direction Is K,
(A × K) / b ≧ 1 (1)
If a plurality of light emitting elements are arranged so as to satisfy the condition, the light emitted from the light source unit can be exposed to the entire surface to be exposed by the scanning of the scanning unit.
[0009]
More specifically, it is desirable that each light source unit satisfies the following conditions (2) and (3) in order to make the amount of light incident on the exposed surface to be exposed of the circuit pattern substantially uniform.
(A × K) / b ≧ 2 (2)
K = (b / d) × n (3)
However, d is the amount of deviation of the light emitting elements arranged along the third direction from the other adjacent light emitting elements in the second direction, and n is a natural number.
[0010]
An exposure apparatus according to a seventh aspect of the invention is characterized in that the light source unit further includes an optical system that converts the light emitted from the plurality of light emitting elements into parallel light. When exposure is performed using parallel light, the parallel light enters the mask and the substrate substantially perpendicularly, so that more accurate exposure is possible. When a conventional ultra-high pressure mercury lamp is used for the light source section, a very large-scale optical system is required to form parallel light. For this reason, adjustment with extremely high accuracy is required. However, in the present invention, since a small light emitting element is used as a light source, there is an advantage that parallel light can be formed with an inexpensive and simple configuration. Specifically, as in the invention described in claim 8, it is possible to configure the optical system with a single flat plate having a plurality of collimator lenses arranged corresponding to the arrangement of the light emitting elements. Become.
[0011]
In addition, it is preferable to use an ultraviolet LED that emits ultraviolet light having the highest sensitivity of the photosensitive material applied to the substrate as the light emitting element.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of an exposure apparatus according to the present invention will be described. FIG. 1 is an enlarged perspective view of the vicinity of the light source unit 1 and the exposure table 2 of the exposure apparatus 100 of the embodiment. FIG. 2 is a top view of the vicinity of the exposure table 2 and FIG. 3 is a side view of the vicinity of the exposure table 2. The exposure apparatus 100 of the embodiment is an apparatus for exposing a circuit pattern drawn on a mask M onto a substrate S. In this exposure apparatus 100, exposure is performed by separating the mask M and the substrate S slightly (10 μm to 20 μm). Proximity method is used. In each drawing, the X direction (and the opposite direction to the X direction) is a direction (first direction) in which the light source unit 1 and the exposure table 2 move relatively, that is, a scanning direction in the exposure apparatus 100. The Y direction is a direction (second direction) orthogonal to the X direction on the exposed surface (exposed surface) of the substrate. The Z direction is a direction orthogonal to the surface to be exposed, that is, a straight traveling direction of light emitted from the light source unit 1.
[0013]
As shown in FIGS. 1 to 3, the exposure apparatus 100 includes a light source unit 1 (indicated by a two-dot chain line in FIG. 1), an exposure table 2, a first motor 3, a first rail 4, a first driver 5, and a pair of A rail (second rail) 6, a first ball screw 7 a, a table drive motor 7 b, a base 8, and a mask holder portion 9 are provided.
[0014]
The light source unit 1 moves in the X direction along the first rail 4 by driving the first motor 3. The first motor 3 is controlled by the control unit 10 via the first driver 5. Here, the maximum width in the Y direction exposed by the light emitted from the light source unit 1 is sufficiently longer than the maximum length in the Y direction of the substrate S that can be exposed by the exposure apparatus 100. That is, the entire surface of the exposed surface of the substrate S of any size is exposed by the parallel movement of the light source unit 1 in the X direction.
[0015]
The exposure table 2 on which the substrate S is placed is provided on the base 8. The exposure table 2 is in a state that can be driven in the X direction by rotating the first ball screw 7a by the table drive motor 7b with the lower surface guided along the second rail 6 extending in the X direction. [0016]
A mask M indicated by a hatched portion in each drawing is held by a mask holder portion 9. Specifically, the mask holder portion 9 has a concave cross-sectional shape as shown in FIG. 3, and the mask M is placed in the concave portion. The mask M placed in the recess is fixed at a predetermined position by an X adjustment mechanism 9a that performs positioning in the X direction and a pair of Y adjustment mechanisms 9b that perform positioning in the Y direction. Specifically, each adjustment mechanism 9a, 9b is provided with an L-shaped mask support member (filled in the figure), and when each mask support member is driven in the X or Y direction, Positioning is performed. Note that the mask M can be rotated in the XY plane if the driving amounts of the pair of Y adjustment mechanisms 9b are different at the time of positioning. Since the mask holder unit 9 is attached to the exposure table 2 by the Z-axis base 9c, the mask holder unit 9 moves in the X direction together with the exposure table 2 during scanning (during exposure operation). The mask holder portion 9 is in a state that it can be raised and lowered in the Z direction by the lifting mechanism 9d.
[0017]
In the pre-process, the substrate S coated with the photosensitive material on the surface is transported to the exposure apparatus 100 and placed and fixed on the exposure table 2. At that time, relative positioning of the mask M with respect to the substrate S is performed by the above-described X and Y adjusting mechanisms. At this time, the mask holder portion 9 is raised in the reverse direction of the Z direction (that is, in the direction of the light source portion 1) by the lifting mechanism 9d to a height that does not hinder the movement of the substrate S. When the substrate S is positioned and fixed to the exposure table 2, the mask holder unit 9 is moved in the Z direction (that is, the exposure table 2) by the elevating mechanism 9 d until the distance between the mask M and the substrate S becomes about 10 μm to 20 μm. Direction).
[0018]
FIG. 4 is a diagram showing an outline of the light source unit 1. The light source unit 1 includes a plurality of light source units in which a plurality of light emitting elements are discretely two-dimensionally arranged (U1 to Un). Each light source unit U1-Un is provided side by side in the X direction. FIG. 5 is a cross-sectional view of the light source unit U1 cut along the YZ plane. Since each of the light source units U1 to Un has the same structure, unless otherwise specified in the following text, only the light source unit U1 will be described, and description of the other light source units will be omitted. As shown in FIG. 5, the light source unit U <b> 1 is a lens panel in which a plurality of light emitting elements 16 attached to a printed circuit board 15 and a plurality of collimator lenses 17 a positioned on the front surface corresponding to the light emitting elements 16 are formed. 17. In the present embodiment, an ultraviolet LED that emits light in the ultraviolet region, which has the highest sensitivity for the photosensitive material applied to the substrate S, is used as the light emitting element. Moreover, by making the light emitted from each ultraviolet LED 16 into parallel light using the collimator lens 17a, the circuit pattern can be printed onto the exposed surface more accurately.
[0019]
FIG. 6 is a diagram showing the arrangement of the ultraviolet LEDs 16 of the light source unit U1 and the collimator lenses 17a formed on the lens panel 17 corresponding to the ultraviolet LEDs 16. As shown in FIG. Here, the exposure apparatus 100 needs to expose the entire exposed surface of the substrate S in order to accurately print the circuit pattern on the substrate during the exposure period. Therefore, when attention is paid to the X direction, a plurality of ultraviolet LEDs 16 and collimator lenses 17a are arranged along a line segment extending in a third direction inclined by a predetermined angle with respect to the X direction in the XY plane. Here, the ultraviolet LED 16 arranged along the line segment extending in the third direction has the same amount of deviation in the Y direction from the other adjacent ultraviolet LED 16. Further, when attention is paid to the Y direction, a plurality of ultraviolet LEDs 16 and collimator lenses 17a are arranged at equal intervals on a line segment parallel to the Y direction. That is, the ultraviolet LED 16 and the collimator lens 17a are two-dimensionally arranged on a surface (substantially parallelogram shape) defined by the Y direction and the third direction.
[0020]
Further, in order to avoid the occurrence of an unexposed region due to the displacement of the ultraviolet LEDs 16, the light source unit U1 is formed on the exposed surface by the light emitted from each ultraviolet LED 16 disposed in the third direction. The X-direction trajectories of the spots are drawn so as to touch each other or partially overlap in the Y-direction.
[0021]
That is, the light source unit U1 of the exposure apparatus 100 sets the spot diameter emitted from the ultraviolet LED 16 and formed on the exposed surface via the lens panel 17 (collimator lens 17a) between the centers of adjacent spots in the a and Y directions. When the distance (arrangement pitch) is b and the number of arrangement of the ultraviolet LEDs 16 in the third direction is K, the following condition (1) is satisfied.
(A × K) / b ≧ 1 (1)
[0022]
By adopting a configuration that satisfies the condition (1), the trajectories of the spot diameters of the ultraviolet LEDs 16 arranged in the third direction on the exposed surface partially overlap each other in the Y direction. Specifically, the case where the left side of the condition (1) is 1 means a state where the locus of each spot on the exposed surface is in contact in the Y direction. Further, the case where the left side of the condition (1) is larger than 1 means a state in which the locus of each spot on the exposed surface partially overlaps in the Y direction. As described above, the ultraviolet LEDs 16 (and the collimator lens 17a) in the third direction and the Y direction are arranged at equal intervals. Therefore, when the condition (1) is satisfied, the entire exposed surface of the substrate S is exposed all over by the relative movement of the light source unit 1 and the exposure table 2 in the X direction.
[0023]
Here, in order to enable exposure with higher accuracy, the incident light amount (exposure amount) at any point on the exposed surface is required to be uniform. Therefore, in the exposure apparatus 100 of the present embodiment, the light source unit is configured to satisfy the following condition (2) and condition (3) that further limit the condition (1).
(A × K) / b ≧ 2 (2)
K = (b / d) × n (3)
However, d is the deviation | shift amount in the Y direction of the ultraviolet LED 16 arrange | positioned along a 3rd direction with the adjacent other ultraviolet LED 16, and n is a natural number.
[0024]
If the configuration satisfying the condition (2) is satisfied, the number of spots passing through any point in the region (center portion) where the circuit pattern on the exposed surface is exposed becomes equal. That is, the exposure amount at the arbitrary point becomes equal. When the left side (a × K) / b is 2, the overlap of the locus of each spot in the Y direction is substantially the radius.
[0025]
Further, the condition (3) is a condition relating to the arrangement number K of the ultraviolet LEDs 16 in the third direction for making the exposure amount at any point on the exposed surface uniform when exposed only by the light source unit U1. In the light source unit that does not satisfy the condition (3), the number of ultraviolet LEDs 16 whose scanning trajectories substantially coincide on the surface to be exposed differs depending on the location, and the exposure amount cannot be made uniform. The ultraviolet LEDs 16 can be arranged so as to extend over a plurality of arrangement pitches b in the third direction by setting the coefficient n large. Here, since the coefficient n is limited to a natural number, the arrangement number K is set in units of arrangement pitch b, and the number of ultraviolet LEDs 16 whose scanning trajectories substantially coincide on the exposed surface is the same everywhere. It becomes. That is, even if a large number of ultraviolet LEDs 16 are arranged in a third direction so as to extend over a plurality of arrangement pitches b, the exposure amount is substantially the same at every place.
[0026]
The above is the description of the configuration of the light source unit U1. As shown in FIG. 4, the light source unit 1 of the present embodiment includes a plurality of light source units. Therefore, there is a possibility that uniform exposure may not be performed on a desired area on the surface to be exposed due to individual differences or attachment errors between the light source unit 1 and the light source units U1 to Un. Therefore, the light source units U1 to Un can be driven in the Y direction by a predetermined amount by rotating the second ball screw 12 by the third motor 13 while being guided along the third rail 11 extending in the Y direction. It is in a state.
[0027]
The third motor 13 is connected to the control unit 10 via the third driver 14. The control unit 10 is connected to each of the light source units U1 to Un so that uniform exposure is performed on a desired region based on data on the light amount from a light amount detection unit (not shown) provided on the exposure table 2 at the time of setting. The third motor 13 to be driven is controlled.
[0028]
At the time of exposure, first, the substrate S coated with a photosensitive material is conveyed from the previous process to the exposure apparatus 100. The transported substrate S is placed and fixed on the exposure table 2 while being positioned relative to the mask M. In this state, the light source unit 1 and the exposure table 2 (that is, the substrate S and the mask M) are relatively moved in the X direction so that the entire exposure surface of the substrate S is exposed with a uniform light amount without any gap. Can do.
[0029]
The above is the embodiment of the present invention. The present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention.
[0030]
In the above embodiment, in view of the ease of manufacturing the light source unit and the prevention of interference between adjacent ultraviolet LEDs 16, the ultraviolet LED 16 has a predetermined angle with respect to the X direction within the XY plane when attention is paid to the X direction. A plurality are arranged along a line segment extending in the inclined third direction. However, this is merely an example, and if the above-described conditions are satisfied, the arrangement of the ultraviolet LED 16 focusing on the X direction should be other than the arrangement along the line segment extending in the third direction. Is also possible.
[0031]
Moreover, in the said embodiment, in order to increase the exposure amount obtained by one scan, and to shorten the time concerning one scan, the light source part 1 is comprised from several light source units U1-Un. Yes. Here, if importance is attached to the miniaturization and cost reduction of the apparatus, the light source unit 1 can also be constituted by only the light source unit alone.
[0032]
The light source units U1 to Un include a lens panel 17 in which a collimator lens 17a is disposed at a position corresponding to the position where the ultraviolet LEDs 16 are arranged, and the light emitted from each ultraviolet LED 16 is converted into parallel light for exposure. It is carried out. However, the lens panel 17 is not necessarily provided. For example, when the photosensitive material applied to the substrate S is a negative type or used in a solder resist exposure process which is a process after circuit pattern exposure, the lens panel is used. It is also possible to use the light emitted from the ultraviolet LED 16 as it is as divergent light without using 17.
[0033]
Further, in the above embodiment, the ultraviolet LED 16 that emits ultraviolet light having the highest sensitivity of the photosensitive material is used as the light source, but other light emitting elements can also be used.
[0034]
In the above embodiment, for the sake of convenience, the description has been made assuming an exposure apparatus that exposes only one side of the substrate S, but the present invention can also be applied to a double-sided exposure apparatus. The present invention can also be applied to an apparatus that performs exposure by a technique other than the proximity method, such as the above-described embodiment, for example, a contact method.
[0035]
【The invention's effect】
As described above, in the exposure apparatus of the present invention, the life of the light source can be extended by using a plurality of light emitting elements arranged in a predetermined arrangement as a light source instead of the ultra high pressure mercury lamp. That is, it is possible to greatly reduce the burden on the user regarding the light source replacement work and the like.
[0036]
The light emitting element used in the light source unit has a feature that a stable amount of light is emitted immediately after the power is turned on, so that an exposure operation can be started immediately after the apparatus is started. it can. In addition, from the above characteristics, when a light emitting element is used, it is sufficient to emit light only during an exposure operation, so that excessive power consumption can be suppressed.
[0037]
Furthermore, the conventional exposure apparatus using an ultra-high pressure mercury lamp requires a cooling means for sufficiently cooling the mercury lamp, or a complicated and large-sized optical device for making the light irradiated from the mercury lamp parallel light. A system must be provided, and the light source section and thus the entire exposure apparatus must be enlarged. However, since the light source unit is composed of a plurality of light emitting elements, it is not necessary to always turn on the light, and the cooling means can be downsized. Further, by using an optical system that can be formed inexpensively and easily, for example, a lens panel, the entire exposure apparatus can be reduced in size and cost.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram of an exposure apparatus according to an embodiment of the present invention.
FIG. 2 is a top view showing the vicinity of an exposure table of an exposure apparatus according to an embodiment of the present invention.
FIG. 3 is a side view showing the vicinity of an exposure table of the exposure apparatus according to the embodiment of the present invention.
FIG. 4 is an enlarged view of a light source unit of the exposure apparatus of the embodiment.
FIG. 5 is a cross-sectional view of a light source unit constituting a light source unit.
FIG. 6 is a diagram illustrating an arrangement of ultraviolet LEDs constituting a light source unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Light source part 2 Exposure stand 10 Control part 16 Ultraviolet LED
17 Lens panel 17a Collimator lens U1-Un Light source unit 100 Exposure apparatus

Claims (6)

An exposure apparatus that exposes an exposed surface of a substrate with a circuit pattern drawn on a mask,
A plurality of light emitting elements are discretely arranged at a predetermined interval in the first direction, and the plane is defined by the first direction and the second direction orthogonal to the first direction. A light source unit having a plurality of light source units arranged at predetermined intervals in a third direction inclined at a predetermined angle with respect to the first direction ;
A scanning means for relatively linearly moving the light source unit, the mask and the exposed surface along a first direction during an exposure period;
Wherein the light emitted from the light source unit, pre-Symbol exposure width in the second direction is configured substantially the same as the length in the second direction of maximum exposure surface of the substrate can be exposed by the exposure device,
The light emitting element emits light from each light emitting element so that the entire surface to be exposed is exposed as a result of the scanning unit relatively moving the light source unit, the mask and the surface to be exposed. The diameter of the spot formed by the light incident on the exposed surface is a, the arrangement pitch of the spot diameters in the second direction is b, the number of arrangement of the light emitting elements in the third direction is K, When d is the amount of deviation in the second direction of the light emitting element adjacent to the light emitting element arranged along the third direction and n is a natural number, the following conditions (1) and (2) are satisfied: An exposure apparatus characterized by being arranged in the light source unit so as to satisfy both .
(A × K) / b ≧ 2 (1)
K = (b / d) × n (2) The exposure apparatus according to claim 1 , wherein the light source unit includes:
An exposure apparatus comprising a plurality of light source units arranged along the first direction. An exposure apparatus according to claim 2 ,
An exposure apparatus, further comprising drive means for moving the plurality of light source units by a predetermined amount in the second direction. The exposure apparatus according to any one of claims 1 to 3 ,
The light source unit further includes an optical system that converts light emitted from the plurality of light emitting elements into parallel light. The exposure apparatus according to claim 4 , wherein
The exposure apparatus according to claim 1, wherein the optical system is a single flat plate having a plurality of collimator lenses arranged corresponding to the arrangement of the light emitting elements. The exposure apparatus according to any one of claims 1 to 5, wherein the light-exposure apparatus, characterized in that the ultraviolet LED.

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