JP2930144B2 - Light source device for printing exposure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing exposure light source device used for manufacturing an IC lead frame, a color TV shadow mask, and the like, and more particularly, to illuminating light from a light source by uniformly distributing the light. The present invention relates to a light source device for printing exposure.

[0002]

2. Description of the Related Art For example, in the case of a light source device for exposing and printing a pattern of an original on a surface of a base material coated with a photosensitive material used for manufacturing a shadow mask, an irradiation area is generally large (for example, 24 ″). × 32 ″) In addition, since a good light quantity distribution is desired, the shape of the reflector that reflects the light from the light source may be a parabola in cross section or a shape in which this is deformed to have a diffusive property. Many.

[0003]

However, when the pattern of the original shadow mask is printed as described above, if the light amount distribution from the light source device is poor, the size of the printed pattern changes depending on the position. Quality cannot be obtained. For example, when the parabolic reflecting mirror 1 is used as shown in FIG. 10, the outer periphery of the irradiation surface 3 becomes dark.
Good distribution cannot be obtained. In order to improve the distribution with the reflector 1, it is necessary to increase the distance 4 between the lamp 2 and the irradiation surface 3. This is because, as shown in FIG. 10, the parabola originally has such a property that light is largely reflected to the center of the irradiation surface 3 (bright) and light is not reflected to the outer periphery (dark). This is because the angle of incidence with respect to the reflecting mirror 1 becomes larger as the tip 5 becomes larger, and light having a larger angle of incidence is diffused and the reflectivity becomes worse.

As described above, when the distance 4 to the irradiation surface 3 is increased, the illuminance decreases, and accordingly, the exposure time must be increased.

In the case of the reflector 1 using a parabola, the size 6 of the reflector 1 needs to be substantially the same as the size 7 of the irradiation surface 3, but the size 6 of the light source device is small. The better the resolution (parallelism) is, the larger the size 6 is, the more the printed image is blurred.
That is, when a parabola is used, there is a problem that an image is blurred because the size 6 of the light source device is large.

Another problem with the light source device is that, among the light emitted from the light source device during exposure, light (eg, visible light, infrared light) other than light (eg, ultraviolet light) required for exposure is reflected. There was also a problem that the irradiated surface was heated, and the dimensions of the original plate and the baked substrate were likely to shift.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to reduce the size of a reflection plate and to achieve a uniform light amount distribution without increasing the irradiation distance. An object of the present invention is to provide a printing exposure light source device using a plate.

[0008]

In order to solve the above-mentioned problems, various studies have been made on a reflector having a reflecting surface which makes the size of the reflector smaller and makes the light quantity distribution uniform without increasing the irradiation distance. As a result, the present invention has been completed.

That is, the light source device for printing exposure according to the present invention is a light source device for exposing and printing an original having a pattern drawn on the surface of a base material coated with a photosensitive material. A reflector that reflects the emitted light toward the irradiation surface, among the light incident on the reflection plate and reflected on the irradiation surface, the light with a small incident angle on the reflection plate to the outer peripheral portion of one irradiation surface, It is characterized in that light having a large angle of incidence on the reflection plate is reflected to the outer peripheral portion on the opposite side.

In this case, in a cross section perpendicular to the axis of the rod-shaped lamp and perpendicular to the irradiation surface or a cross section including the point lamp and perpendicular to the irradiation surface, the reflection surface of the reflection plate passes through the lamp and is perpendicular to the irradiation surface. The line, which is symmetrical with respect to the axis and represents the reflecting surface, has a point A on one side of the optical axis which is opposite to the illuminated surface with respect to the lamp. Starting from the first straight line reflecting at the outer periphery of the irradiation surface at an angle φ ₁ , the angle θ with respect to the straight line connecting the lamp and point A
The light incident on the first straight line at the intersection B with the first straight line
Oite, the light from the lamp for the light given angle angle plus a predetermined angle c phi to ₁ φ ₁ + c (however, theta
≠ c. c may be negative. ), The second straight line reflected on the irradiation surface follows the first straight line, and light incident on the second straight line at an angle 2θ with respect to the straight line connecting the lamp and the point A intersects the intersection C with the second straight line. There, the third straight line that reflects the irradiated surface without the angle c to twice the angle by adding angles phi ₁ + 2c to the angle phi ₁ light to the light from the lamp is continued in the second straight line, Hereinafter, light incident on the N-th straight line at an angle Nθ (N is a positive integer) with respect to the straight line connecting the lamp and the point A is located at the intersection X with the N-th straight line, and the light from the lamp is converted to the light. On the other hand, it is desirable that the (N + 1) -th straight line reflected at the irradiation surface at an angle φ ₁ + Nc be a line following the N-th straight line. Further, a line representing the reflecting surface is represented by a point A B C.
It is more desirable to connect X by a smooth curve.

If the irradiation surface does not want to be heated to a high temperature, it is desirable to apply a single-layer or multilayer coating having infrared absorption and ultraviolet reflection characteristics to the surface of the reflection plate to form a cold mirror. When the reflection plate has a high temperature and is not durable, it is desirable to provide one or both of an air cooling and a water cooling mechanism.

[0012]

According to the present invention, a reflector for reflecting light emitted from a rod-like or point-like lamp toward an irradiation surface is provided. Since the light having a small incident angle is reflected to one outer peripheral portion of the irradiation surface, and the light having a large incident angle to the reflector is reflected to the outer peripheral portion on the opposite side, the reflector can be downsized. The light amount distribution on the irradiation surface can be made uniform without increasing the irradiation distance. In addition, there is no problem such as blurring of an image.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. First, the shape of the reflector 16 used in the light source device for printing exposure according to the present invention will be described with reference to FIG. FIG. 1 shows the upper half of the cross section of the reflecting plate 16, and the lower half of the cross section is symmetrical with respect to the dashed line of the center line passing through the lamp 17 represented as a point light source. Arrows in the figure indicate light rays emitted from the lamp 17, reflected by the reflection plate 16, and reaching the irradiation surface 18. Lines representing the reflecting surface of the reflecting plate 16 are points A, B, C, D, E
The points A, B, C, D, E,... Are determined as follows.

As shown in FIG. 1 and FIG.
Is specified. Although the designation of point A is optional, ramp 1
A point relatively close to the lamp 17 on the opposite side of the irradiation surface 18 with respect to 7 is selected. Next, from the ramp 17, point A
The angle φ ₁ formed by the light beam 10 reflected from the point A with respect to the light beam incident on the light source A is appropriately designated. Then, the intersection of the straight line passing through the ramp 17 at an angle θ with respect to the straight line connecting the ramp 17 and the point A and the straight line passing through the point A with the bisector of the angle φ ₁ as the normal is defined as B. Next, the angle formed by the light beam 11 reflected from the point B with respect to the light beam incident on the point B from the lamp 17 is φ ₁ + c (where θ た だ し c, where c may be negative). A straight line passing through the lamp 17 at an angle θ with respect to a straight line connecting the lamp 17 and the point B, and an angle φ
The intersection of the bisector of ₁ + c and the straight line passing through the point B is defined as C. Next, the angle formed by the light beam 12 reflected from the point C with respect to the light beam incident on the point C from the lamp 17 is φ ₁
+ 2c. A straight line passing through the ramp 17 at an angle θ with respect to a straight line connecting the ramp 17 and the point C, and an angle φ
The intersection of the bisector of ₁ + 2c and the straight line passing through the point C is defined as D. Hereinafter, points E, F,... Are similarly determined.

When the reflector 16 represented by a curve connecting the points A, B, C, D, E... Obtained by the method described in FIG. 2 with a straight line or a smooth line is used, as shown in FIG. In addition, the light uniformly emitted from the lamp 17 is 10,
Are reflected as 11, 12, 13, 14,..., And the intervals at the respective irradiation surfaces 18 are gradually shorter, that is, a>b>
c> d, the position 11 is brighter than the position 10 and 1
Although the position 12 is brighter than the position 1, the angles of incidence of the light 11 on the reflector 16 and the light 12 on the reflector 16 are larger than those of the light 10 (δ ₃ > δ).
₂ > δ ₁ ), and consequently, both are cancelled, and a good light quantity distribution can be obtained.

The point A of the reflecting plate 16 as described above,
The light reflected from B, C, D, E.
Φ ₁ , φ ₁ + (c−
θ), φ ₁ +2 (c−θ), φ ₁ +3 (c−θ), φ ₁
+4 (c−θ)... And increases by a certain angle in order ((c−
It is evident by simple proof that reflections occur when θ) is positive) or decrease (when (c−θ) is negative).

According to such a method, the reflection plate 1
Since the size of 6 is arbitrarily determined, miniaturization is possible, and there is no dimensional restriction with the auxiliary device, and the parallelism is improved, so that the resolution is also improved. As the surface shape of the reflection plate 16, basically, a mirror surface having no irregularities is used.
When the light emission diameter is extremely small, the shape accuracy of the reflection plate 16 affects the severeness. Such unevenness is preferably embossed or satin-finished by shot peening.

The base material of the reflection plate 16 is made of an aluminum material in order to improve the surface smoothness. The irradiation surface 18
In order to reduce the dimensional deviation between the original plate and the photosensitive substrate due to the temperature rise, it is desirable to perform a single-layer or multilayer coating process for absorbing infrared rays on the surface and reflecting ultraviolet rays. At this time, when the ultra-high pressure mercury lamp 5 kW, for example, is used due to the absorbed infrared rays, the temperature of the aluminum material of the reflector base material reaches about 300 ° C. In order to avoid the shape deformation due to the temperature rise, for example, FIG. As shown in the sectional view,
It is desirable that the air-cooling fins 20 be provided on the back surface of the reflector 16 relatively far from the lamp 17 and that some water-cooling tubes 21 be provided inside the reflector 16 base near the lamp 17. Water cooling is performed by circulating water through a water cooling pipe 21 through a radiator (not shown).

As described above, since the size of the reflecting plate 16 is reduced (1/8 of the conventional case), it is possible to perform processing by molding, and the shape accuracy is about ± 0.1 mm, which is smaller than that of the conventional sheet metal working. Is also good.

When a rod-like light source is used as the lamp 17, the reflecting plate 16 has the same shape as shown in FIG. 1 regardless of the axial direction of the lamp 31 at any position in the axial direction. Since the light source distribution is too large to control the light amount distribution, as shown in the horizontal sectional view of FIG.
3. Some degree of control can be achieved by changing the amount of opening 32 of the reflector 30 provided on the side of the reflector 16 in accordance with the distance 35 between the light source device and the irradiation surface 18.

When a point light source is used as the lamp 17, the reflection plate 16 has a rotationally symmetric shape with respect to the central axis (dashed line in FIGS. 1 and 3).

Next, FIGS. 5 to 7 show an example of the shape of the reflector 16 obtained according to the present invention and the distribution of the amount of illumination light by a light source device using the same. FIG. 5 shows the upper half of the reflecting plate 16 and the reflected light beam and reflected light amount distribution at every 10 °. FIG. 6 shows a direct ray from the lamp 17 every 5 °,
4 shows a direct light quantity distribution. FIG. 7 shows each light amount distribution and the total light amount distribution as the sum of the distributions. In this example,
As shown in FIG. 8, when the direction opposite to the irradiation direction through the lamp 17 is the x coordinate, and the direction parallel to the irradiation surface is the y coordinate, the start point (point A in FIG. 1) is x = 20 mm, y =
5 mm, irradiation angle 21 ° to horizontal line (center line)-
30 °, θ = 0.1 °, c = 0.0645 °, lamp 1
The distance from 7 to the irradiation surface 18 was 1100 mm (FIG. 5). As is clear from FIG. 7, according to the light source device of this example, an extremely uniform light amount distribution can be obtained from the center to the outer periphery.

FIG. 9 is an exploded perspective view of one embodiment of a light source device using a rod-shaped lamp and a reflector configured as described above.
In order to facilitate replacement of the lamp 48, the reflector is made into two parts, a front part 50 and a rear part 50 ', and is integrated when it is mounted on the mounting base 56 as shown.
The attachment / detachment method is performed by screwing (not shown),
A commercially available one-touch mounting jig or the like may be used. Further, as shown in FIG.
In order to make the mounting position with respect to 0 'accurate, the commercially available fine adjustment tables 51 and 52 are used, and the lamp 48 can be adjusted vertically and longitudinally with respect to the mounting base 56. In addition, the height of the entire light source device with respect to the irradiation surface 18 can be adjusted. For this purpose, for example, the mounting base 56 is attached to the support column 55 by a slide part 53 so as to be adjustable in height, the fixing screw 54 is loosened to adjust the slide part 53 up and down, and after the position is determined, the screw 54 is What is necessary is just to tighten and fix. Adjustment of the entire light source device with respect to the irradiation surface 18 in the front, rear, left and right directions is performed by equipping the light source device with a free caster (not shown). In addition,
The lamp 48 is inserted into a water cooling jacket tube 49 to be cooled.

With the light source device of the present invention as described above,
Since the light can be efficiently reflected to the irradiation surface, the illuminance on the irradiation surface has increased about twice and the light source has been reduced, so that the parallelism of the illumination light has increased to twice the performance. Due to the cold mirror, etc., the temperature rise on the irradiation surface was reduced by 10 ° C., which was favorable.

The light source device for printing exposure according to the present invention has been described based on the embodiments. However, the present invention is not limited to these embodiments, and various modifications are possible.

[0026]

As described above, according to the light source device for printing exposure of the present invention, the reflecting plate for reflecting the light emitted from the rod-shaped or point-shaped lamp toward the irradiation surface is incident on the reflecting plate. Among the light reflected on the irradiation surface, light with a small incident angle to the reflector is reflected to one outer peripheral portion of the irradiation surface, and light with a large incident angle to the reflector is reflected to the outer peripheral portion on the opposite side. Therefore, the size of the reflector can be reduced, and the light quantity distribution on the irradiation surface can be made uniform without increasing the irradiation distance. In addition, there is no problem such as blurring of an image.

[Brief description of the drawings]

FIG. 1 is a view for explaining the shape of a reflector used in a light source device for printing exposure according to the present invention.

FIG. 2 is a diagram for explaining a method for drawing a line representing the reflector of FIG. 1;

FIG. 3 is a cross-sectional view for explaining a cooling structure of a reflector.

FIG. 4 is a horizontal sectional view of an exposure light source device according to the present invention when a rod-shaped light source is used as a lamp.

FIG. 5 is a diagram showing an upper half shape, a reflected light beam, and a reflected light amount distribution of an example of a reflector obtained by the present invention.

FIG. 6 is a diagram showing a direct ray and a direct light quantity distribution from a lamp.

FIG. 7 is a diagram showing each light amount distribution and a total light amount distribution as a sum thereof.

FIG. 8 is a diagram for explaining parameters of the reflector in the examples of FIGS. 5 to 7;

FIG. 9 is an exploded perspective view of one embodiment of a light source device using a rod-shaped lamp.

FIG. 10 is a view for explaining the operation of a conventional parabolic reflector.

[Explanation of symbols]

16: Reflector, 17: Lamp, 18: Irradiation surface, 20: Air-cooled fin, 21: Water-cooled tube, 30: Reflector provided on side surface,
48 ... lamp, 49 ... lamp water cooling jacket tube, 50
... Reflector front part, 50 '... Reflector rear part, 51,5
2 ... fine adjustment table, 53 ... slide part, 54 ... fixing screw, 55 ... support column, 56 ... mounting base.

Claims (5)

(57) [Claims] 1. A light source device for exposing and printing an original having a pattern painted on the surface of a substrate coated with a photosensitive material, wherein light emitted from a rod-like or point-like lamp is directed to an irradiation surface. The reflector to be reflected reflects light with a small incident angle on the reflector out of the light that is incident on the reflector and reflected on the illuminated surface. A light source device for printing exposure, wherein the light source is configured to reflect light to an outer peripheral portion on an opposite side. 2. In a cross section perpendicular to the axis of the rod-shaped lamp and perpendicular to the irradiation surface or a cross section including the point lamp and perpendicular to the irradiation surface, the reflecting surface of the reflector is an optical axis passing through the lamp and perpendicular to the irradiation surface. The line representing the reflecting surface is symmetrical with respect to the optical axis, and at a starting point A on one side of the optical axis and on the opposite side of the irradiation surface with respect to the lamp, the light from the lamp is set at a predetermined angle with respect to the light. Starting from the first straight line that is reflected to the outer peripheral portion of the irradiation surface at φ ₁ , the light incident on the first straight line at an angle θ with respect to the straight line connecting the lamp and point A intersects B with the first straight line. In this case, the light from the lamp is separated from the light by the predetermined angle φ _1.
Φ ₁ + c (where θ ≠
c. c may be negative. ), The second straight line reflected on the irradiation surface follows the first straight line, and the light incident on the second straight line at an angle 2θ with respect to the straight line connecting the lamp and the point A is the second straight line.
Intersection C Oite of the straight line, the third straight line which reflects the light irradiated surface without the angle c to twice the angle added angles phi ₁ + 2c to the angle phi ₁ with respect to the light from the lamp Second
Following the straight line, the light incident on the N-th straight line at an angle Nθ (N is a positive integer) with respect to the straight line connecting the lamp and the point A is the light from the lamp at the intersection X with the N-th straight line. Is reflected to the irradiation surface at an angle φ ₁ + Nc with respect to the light.
2. The light source device for printing exposure according to claim 1, wherein the +1 straight line is a line following the Nth straight line. 3. A line representing the reflection surface is a point A B C.
The light source device for printing exposure according to claim 2, wherein X is connected by a smooth curve. 4. A baking exposure apparatus according to claim 1, wherein a single-layer or multi-layer coating having infrared absorption and ultraviolet reflection properties is applied to the surface of the reflection plate to form a cold mirror. Light source device. 5. The light source device for printing exposure according to claim 1, wherein the reflection plate includes one or both of an air cooling and a water cooling mechanism.