JP2786946B2 - Film exposure apparatus and film exposure method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film exposure apparatus suitable for producing a film circuit board, and more particularly to a film exposure apparatus capable of controlling a position and a magnification for each frame of a conveyed film.

[0002]

2. Description of the Related Art Photolithography is known as a technique for performing fine processing on the surface of an object. This technology has been applied not only to semiconductor integrated circuits but also recently to the production of film circuit boards used for mounting electronic components.

[0003] Such an exposure apparatus projects an irradiator having a light source, a reticle on which a circuit pattern to be exposed is formed by irradiating light emitted from the irradiator, and an image set on the reticle. It comprises a lens and a stage for setting a film at the projection position to form an exposure position. In the conventional apparatus, when performing the projection exposure, it is necessary to adjust the magnification of the projected image before starting the projection exposure. The operation of adjusting the magnification is performed by a method as described in, for example, Japanese Patent Application Laid-Open No. 1-191493. That is, the projection lens position adjustment mechanism and the reticle position adjustment mechanism are moved in the optical axis direction while monitoring images such as patterns and alignment marks projected on the exposure surface with a monitor system.

However, a projection lens position adjusting mechanism and a reticle position adjusting mechanism are operated for focusing.
When the projection lens and the reticle are displaced in the optical axis direction, the focal point of the projected image may be displaced.

In order to solve such a problem, magnification is adjusted while maintaining the positional relationship between a projection lens, a reticle, and a projection plane based on a focal point set as disclosed in Japanese Patent Application No. 2-81337. A method has been proposed.

[0006]

However, in the conventional apparatus, the magnification is set accurately only before actually starting the exposure. That is, once the exposure operation is started, the projected image is projected at the position of the reticle and the position of the projection lens set before the start. And
If the positions of the reticle and the projection lens go out of order for some reason, the values naturally deviate from these set values. As a result, the exposure is performed in a state where the magnification is shifted, and if the apparatus is continuously operated without noticing such a situation, a large amount of film is wasted.

On the other hand, even if the position of the reticle and the position of the projection lens are accurate, the same problem occurs if the conveyed film is not set at the correct position. On the other hand, the above problem can be solved temporarily by performing the adjustment work performed before the start even after the start of the exposure work, but it is very complicated for a human to perform such work regularly. is there.

An object of the present invention is to provide a film exposure apparatus and a film exposure method which can perform exposure in an optimum state even after the exposure operation is started.

[0009]

In order to achieve the above object, a film exposure apparatus according to the present invention is a film exposure apparatus for sequentially exposing a circuit pattern along the length of a belt-like film. A reticle having a reticle side mark separately from a circuit pattern to be projected, a reticle disposed at a position where light from the irradiator is irradiated, and a projection lens for projecting an image of the reticle; A reticle position adjustment mechanism that adjusts the position by displacing in the horizontal and horizontal directions; a projection lens position adjustment mechanism that adjusts the position by displacing the projection lens in the optical axis direction; A film feed mechanism for step-feeding a film having holes or light-transmitting portions corresponding to the marks, and recording for one frame of the film after the step-feed; A detecting means for detecting a positional relationship between the projected image of the mark on the side of the lens and the hole or the light transmitting portion; and a system controller for moving a reticle and a projection lens based on a signal from the detecting means. Is to move the reticle horizontally by the film feed mechanism and then move the reticle horizontally to detect the positional relationship between the reticle-side mark and the film-side hole or translucent section. By moving the reticle in the horizontal direction by the reticle position adjusting mechanism based on the value and controlling the positional relationship between the reticle side mark and the hole or the light transmitting portion, further based on the detected value, the reticle position adjusting mechanism Move the reticle in the horizontal direction to control the positional relationship between the reticle mark and the film-side hole or light-transmitting part. The Le position adjusting mechanism, the reticle in the optical axis direction, is moved in the optical axis direction of the projection lens by the projection lens position adjusting mechanism is to conduct a magnification adjustment control.

[0010]

According to the present invention, the reticle is moved in the horizontal direction for each frame of the conveyed film, and the positional relationship between the reticle-side mark and the hole or the light-transmitting portion on the film is detected. By this detection, the magnification can be controlled by displacing the reticle and the projection lens in the optical axis direction, and the position can be controlled by displacing the reticle in the horizontal direction (perpendicular to the optical axis).

[0011]

Embodiments of the present invention will be described below. This apparatus exposes the circuit pattern of the reticle 10 sequentially along the length of the belt-like film F.

FIGS. 1, 2 and 3 are explanatory views of a film exposure apparatus according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a light source 11 and an irradiating unit which includes a light source 11 and a radiated light from the light source 11 and includes a reflecting mirror and an integrator lens. Light source 11
For example, a resist that efficiently emits light having sensitivity to the resist, such as an ultra-high pressure mercury lamp, is applied.

Reference numeral 10 denotes a reticle, which is disposed at a position where light from the irradiation unit 1 is irradiated. The reticle 10 has a reticle-side mark in addition to a circuit pattern to be projected and transferred onto the film F. The reticle-side mark is formed by, for example, providing a cross-shaped light-transmitting portion in a rectangular opaque portion. The film-side mark is formed of, for example, a round hole for each frame on the film F.

Reference numeral 12 denotes a reticle position adjusting mechanism, which comprises, for example, a servomotor. Reference numeral 20 denotes a projection lens, which projects an image of the reticle 10 irradiated. The projection lens 20 has a resolution of, for example, an exposure line width of 10 μm. Reference numeral 21 denotes a projection lens position adjusting mechanism of the projection lens 20. Then, the reticle position adjusting mechanism 12 and the projection lens position adjusting mechanism 21 are driven by the system controller 50. Reference numeral 30 denotes a stage, and as shown in FIG. 2, a suction hole 31 for vacuum-sucking the film F only at the time of exposure is provided. Reference numeral 40 denotes a detection unit, which includes an objective lens 41, a condenser lens 42, and a light receiver 43 including a photodiode or the like. Reference numeral 60 denotes a film feed mechanism, which steps one frame of the film F to a position where an image is projected by the projection lens 20. 61 is a feed roller, 63 is a press roller, 64 is a sprocket roller, 65 is a press roller, 66 and 67 are auxiliary rollers, 6
8 is a supply roller, 69 is a winding roller.

Next, the operation of the apparatus will be described. First,
One frame of the film to be exposed by the film feed mechanism 60 is transported stepwise to an exposure position in the apparatus. At this time, the irradiating unit 1 is set at a wavelength (alignment wavelength) at which the film F is not exposed while being conveyed.
Through the reticle-side mark and projected onto the film F. Then, when the film-side mark reaches the projection position of the reticle-side mark as the film F is transported, light having a wavelength for alignment passing through the film-side mark, which is a hole, is received by the detection unit 40. Thus, it is detected that one frame of the film F has been transported to the exposure position, and a signal is sent from the system controller 50 to the film transport mechanism 60 to stop the transport. In this state, although one frame of the film is roughly conveyed, more accurate positioning is performed.

This operation will be described with reference to FIGS. 3, 4, and 5. FIG. 3 shows a reticle 10 in addition to a circuit pattern 12 projected on a film and a reticle side mark 1 described above.
3 are formed. FIG. 4 shows a film in which, in addition to the exposure position F10 of the circuit pattern 12, two holes F13 serving as film-side marks are formed with the circuit pattern 12 interposed therebetween.

The reticle 10 is scanned (moved) in the X direction along the feeding direction of the film F. At this time, the electric signal generated in the detection unit 40 is as shown in FIG. When the projected image of the reticle-side mark 13 starts to overlap the hole 13 on the film side, a rising portion T1, a flat portion T2 where the overlapping area of both is almost constant, and a rising position where the projection position of the reticle-side mark 13 starts to deviate from the hole 13. A pulse-like waveform composed of a falling portion T3 is obtained.

In the X direction, a position at time T3 corresponding to, for example, the center of the flat portion T2 having the largest overlapping area of the marks is detected, and stored in the system controller 50 as information on the position of the reticle 10.

Then, the reticle 10 further moves in the X direction, and another hole 13 is similarly detected. When the position detection of the two holes 13 in the X direction is thus completed, the reticle 10 is similarly moved in the Y direction to detect the positions of the two holes 13. That is, the position of the film fed stepwise can be detected by detecting the positions of the holes or the light transmitting portions on the two film sides. Then, based on the detected value, that is, the position information sent to the system controller 50, the reticle 1
0 can be moved on the horizontal plane in the X and Y rotational directions to correspond to one frame of the conveyed film F. FIG. 4 shows this state. However, if the reticle 10 or the projection lens 20 is displaced in the optical axis direction,
The magnification changes and cannot be adjusted only by the aforementioned control. This state is shown in FIG.

In order to correct the projection magnification accuracy from the state shown in FIG.
When the detector signal is sent, a signal is sent to the reticle position adjusting mechanism 12 and the projection lens position adjusting mechanism 21, and each is moved in the optical axis direction to correct the magnification of the projected image. This magnification correction may be performed in parallel with the above-described positioning control for horizontally moving the reticle 10, or may be performed before or after that.

After the completion of the correction of the projection magnification and the projection position, the light of the exposure wavelength exposes the circuit pattern to one frame of the film set at the film-like exposure position. In this way, it is possible to detect and correct the magnification and the position of the projected image for the step feed of one frame of the film.

In the above embodiment, the image projected on the film side mark 10 can be focused by using an image sensor such as a CCD instead of or together with the light receiver 40.

[0023]

As described above, according to the film exposure apparatus of the present invention, an image projected for each frame of a film to be exposed is detected, and when the magnification is deviated, a reticle is used. And moving the projection lens in the direction of the optical axis, and when the position is out of alignment, moving the reticle in the horizontal direction following the deviation so that it can be adjusted for each frame of the film. is there.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention.

FIG. 2 is a side sectional view showing a configuration of a main part of FIG.

FIG. 3 is a plan view showing details of the reticle of FIG. 1;

FIG. 4 is an explanatory diagram illustrating the accuracy of projection magnification on a film in the present embodiment.

FIG. 5 is an explanatory diagram for explaining projection magnification accuracy on a film in the present embodiment.

FIG. 6 is a waveform diagram illustrating the states of FIGS. 4 and 5 using electric signals.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Irradiation part 10 Reticle 12 Reticle position adjustment mechanism 20 Projection lens 21 Projection lens position adjustment mechanism 40 Detector 50 System controller F Film

Claims (2)

(57) [Claims] 1. A film exposure apparatus for sequentially exposing a circuit pattern along a length direction of a belt-shaped film, comprising: an irradiation unit; and a projection unit arranged at a position where light from the irradiation unit is irradiated. A reticle having a reticle side mark separately from a circuit pattern to be formed, a projection lens for projecting an image of the reticle, a reticle position adjustment mechanism for adjusting the position by displacing the reticle in the optical axis direction and the horizontal direction, and a projection lens. A projection lens position adjusting mechanism for adjusting the position by displacing in the optical axis direction, and a film for stepwise feeding a film having a hole or a light transmitting portion corresponding to the reticle-side mark at an image projection position by the projection lens. A feeding mechanism, and a detecting means for detecting a positional relationship between a projected image of the reticle-side mark and a hole or a light transmitting portion for one frame of the film after the step feeding. , Based on the signal from the detection means,
A film exposure apparatus, comprising: a system controller for moving a reticle and a projection lens. 2. A film exposure method using the film exposure apparatus according to claim 1, wherein the reticle is moved in the horizontal direction after stepping one frame of the film by a film feed mechanism. The positional relationship between the side mark and the hole or light-transmitting part on the film side is detected, and the reticle is moved in the horizontal direction by the reticle position adjusting mechanism based on the detected value, and the reticle-side mark and the hole or light-transmitting part are detected. Control the positional relationship between the reticle and the reticle, and further control the positional relationship between the reticle-side mark and the hole or the light-transmitting portion on the film side by moving the reticle in the horizontal direction by the reticle position adjusting mechanism based on the detected value. ,
The reticle is adjusted in the optical axis direction by the reticle position adjustment mechanism.
A film exposure method, wherein a magnification adjustment control is performed by moving a projection lens in an optical axis direction by a projection lens position adjusting mechanism.