JP2798488B2 - Film exposure equipment - Google Patents

Description

The present invention relates to an exposure apparatus for manufacturing a printed circuit board used for mounting and assembling electronic components, for example.

(Prior art)

As a technique for performing fine processing on the surface of an object, a photolithography technique is known. 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.

Such an exposure apparatus includes an irradiator having a light source, a reticle on which a circuit pattern to be exposed and radiated from the irradiator is formed, a lens for projecting an image set on the reticle, and a lens. It is composed of a stage or the like that sets a film at a projection position and forms an exposure position.

By such a configuration, the circuit pattern is projected and exposed on the film, but even the reticle and lens
The magnification of the projected image to be exposed can be determined by the ratio of the distance between the lens and the film in the optical axis direction. That is, by adjusting the magnification before the operation of the apparatus, the circuit pattern can be exposed at a desired magnification.

[Problems to be solved by the invention]

However, in the conventional apparatus, when the exposure operation is actually started, the apparatus itself vibrates for some reason or is affected by an external temperature, and the positions of the lens and the reticle set to obtain a desired magnification are changed. May deviate from the set value.

Normally, even though such a situation occurred, the apparatus was operated as it was, and the exposure process was terminated.
It often happens that you notice it for the first time in the next step.

Alternatively, exposure and development are performed on a trial basis, the magnification is checked using a magnifying projector or the like, and the exposure apparatus is readjusted. There is also a method of performing exposure, development, and confirmation of the magnification again, but such a method takes too much time for setup.

An object of the present invention is to provide a film exposure apparatus capable of easily detecting the magnification of a projected image even while the exposure apparatus is operating, in order to solve such a problem.

[Means for solving the problem]

In order to solve the above problems, the film exposure apparatus of the present invention is a film exposure apparatus that sequentially conveys a film to an exposure position, and projects and exposes a circuit pattern, on the exposure position, in the conveyance direction of the film, A projection image monitor that is movable in a direction perpendicular to the transport direction and a unit that detects a moving distance when the projection image monitor is moved are provided.

[Action]

According to the above configuration, the projected image can be observed on the projected image monitor for each of the sequentially transported films. Specifically, the projection image monitor is moved in the transport direction and the direction perpendicular to the transport direction with respect to the film arranged at the exposure position, and the projected images are observed at a plurality of locations, and the movement distance is measured. By detecting the distance between the observation points of the projected image, confirmation of the magnification,
And the distortion of the projected image can be detected.

〔Example〕

Hereinafter, the present invention will be described specifically. FIG. 1 is an overall schematic diagram showing one embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an irradiation unit including a light source 11, a reflection mirror, and an integrator lens. As the light source 11, a light source which efficiently emits light having sensitivity of a resist, such as an ultrahigh pressure mercury lamp, is applied.

Reference numeral 10 denotes a reticle, which is arranged at a position where light from the irradiation unit 1 is irradiated. On the reticle 10, a circuit pattern to be projected and transferred onto the film F is formed.

M10 is a position adjusting mechanism of the reticle 10, and is composed of, for example, a servomotor. Reference numeral 20 denotes a projection lens, which projects an image of the reticle 10 irradiated. This projection lens
Numeral 20 has a resolution of, for example, an exposure line width of 10 μm. Reference numeral 21 denotes a position adjusting mechanism of the projection lens 20. Numeral 30 denotes a stage, in which the film F to be exposed is stepwise fed to the exposure position for each frame. This method, for example,
A sensor (not shown) on the stage detects the performance provided on the film F, and the conveyance of the film F can be detected and stopped. Only at the time of exposure, for example, the film F is vacuum-adsorbed on the stage.

Reference numeral 60 denotes a film F feeding mechanism. One frame of the film F is stepped to the position where the image is projected by the projection lens 20. 61 is a feed roller, 66 and 67 are auxiliary rollers, 68 is a supply roller, and 69 is a take-up roller.

Reference numeral 40 denotes a projection image monitor of the film F which has been step-fed to the exposure position. Reference numeral 41 denotes a semi-transparent thin film (commonly called a pellicle) for reflecting a projected image on the film F.
The reflected light 41 can be observed with the optical microscope 42.

Then, the projected image monitor 40 is moved in the transport direction of the film F,
Then, the projected image is observed at a plurality of positions while being moved in a direction perpendicular to the transport direction. By measuring the distance between the observation points, it is possible to confirm the projection state, particularly the magnification and the distortion of the image. Hereinafter, observation by the projection image monitor 40 will be specifically described.

FIG. 2 shows the film F conveyed to the exposure position, the projection image monitor 40, and the optical microscope 42, which is the main part thereof.
The optical microscope 42 has a semi-permeable thin film 41 (hereinafter referred to as a pellicle) at the tip. The projection image can be observed from the eyepiece 43 by the pellicle 41 as described above. Although not shown, an objective lens and the like are incorporated in the optical microscope 42. The projection image can be magnified and observed.

The optical microscope 42 is moved together with the projected image monitor 40 by a rail 70 installed in parallel with the transport direction of the film F.
The film F can be moved in the transport direction X. FIG. 3 is a longitudinal sectional view of the projection image monitor 40. FIG. 4,
FIG. 5 is a sectional view taken along the line AA in FIG. 3, and FIG.
FIG. 3B shows a cross-sectional view of FIG. These figures show the projection image monitor
The state of movement in the X direction of 40 will be explained.
When the rotation is loosened by 52, the fixed contact with the rail 70 is released and the rail 70 can be moved. Thus, the base 86 moves on the rail 70. On the other hand, when the minute movement adjuster 53 (comprising a micrometer) is rotated, the base 73 is slightly moved while repelling the force of the spring. In other words, the coarse movement adjuster 52 is used to make a large movement, and the minute movement adjuster.
Fine-adjust with 53. With the movement in the X direction, the base 86
The movement distance can be detected by the movement distance detector 88 at a portion 87 of FIG. These moving distance detectors 88 and 87
For example, it is composed of a photosensor and a light shielding plate.

Numeral 54 is a micro-adjuster for the optical axis direction, which can be used for focusing an image to be observed. This is a micro-adjuster
Rotating 54 acts on point 82 about axis 81. Thus, the position can be adjusted by moving the point 83 in the Z direction while repelling the spring 84.

On the other hand, in the direction perpendicular to the transport direction X of the film F (in the width direction of the film F), the adjuster 51 for coarse movement and the adjuster 50 for fine movement (composed of micrometer) are also used.
The entire base 71 can be similarly moved. The direction orthogonal to the transport direction X of the film F is shown as Y. This is because the fixed contact with the base 72 is released by rotating the coarse movement adjuster 51, and the base 71 can be moved along the rail 71 '. On the other hand, by adjusting the adjuster 50 for minute movement, the point 85 is acted. Although this structure is not shown, the principle of the adjustment is the same as that of the fine adjustment by the fine adjuster 54, and the fine movement is made around a point axis, not shown. And it has a sensor for detecting the movement distance as well as the movement in the X direction.

The optical microscope is moved by such movement in the X and Y directions.
By moving 42, the position of pellicle 41 can also be moved. This makes it possible to observe the projected image at any point on the exposure position,
The moving distance can be measured.

Now, when one frame of the film F is transported, the circuit pattern formed on the reticle 10 is projected and exposed as described above. Then, the film feed mechanism is temporarily stopped. At this time, in order to perform the projection exposure on the film F, it is necessary to move the optical microscope 42 to a position outside the optical path, which does not hinder the exposure. When the transport of the film F is temporarily stopped, the optical microscope 42 is moved in the X direction and the X direction as described above, and the projected images at the corner points F12 and F13 of the circuit pattern F11 are observed in the X direction, for example. I do. This observation point is stored in a computer (not shown).
Then, along with the movement from F12 to F13, it is input from the above-mentioned moving distance detector to a computer connected to the optical microscope 42, and the distance can be calculated and displayed. Similarly, in F13 and F14, the distance can be displayed. At this point, it is necessary to surely set the position with the fine adjuster while observing with the eyepiece 43 as described above. By detecting the size of the projection image in this way, it is possible to confirm whether or not the magnification is correct, based on the relationship with the size formed on the reticle 10. At this time, it is also possible to detect a distortion or the like of the projected image.

Even if such an abnormal state is found, the positions of the reticle 10 and the lens 20 can be readjusted, and the exposure operation can be started again.

Note that the optical microscope 42 can be substituted by, for example, a CCD or the like.

〔effect〕

As described above, according to the film exposure apparatus of the present invention, the projected image can be observed on the projected image monitor for each of the sequentially transported films. Specifically, for the film disposed at the exposure position, the transport direction of the film, by moving the projection image monitor in a direction perpendicular to the transport direction,
By measuring the distance, the magnification can be confirmed and the distortion of the projected image can be observed.

[Brief description of the drawings]

FIG. 1 is a schematic view of the entire film exposure apparatus of the present invention, and FIGS. 2, 3, 4, and 5 are diagrams for explaining a projection image monitor and its operation. In the figure, F: film, 10: reticle, 20: projection lens, 42: optical microscope, 41: semi-transparent thin film, 43: eyepiece,

Claims (1)

(57) [Claims] 1. A film exposure apparatus for projecting and exposing a circuit pattern by sequentially transporting a film to an exposure position, wherein the projection is movable on the exposure position in a transport direction of the film and in a direction perpendicular to the transport direction. A film exposure apparatus comprising: an image monitor; and means for detecting a moving distance when the projection image monitor is moved.