JP2000155430A - Automatic alignment method for double-sided aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily, rapidly and accurately perform processing for loading both of front side and back side masks on both front and back surface sides of a member to be aligned by driving at least two of an image pickup means, the front side mask and the back side mask by a driving means. SOLUTION: A controller calculates relative deviation between alignment marks FAM1 and BAM1 based on a superposed image obtained by superposing the alignment mark FAM1 on the front side mask and the alignment mark BAM1 on the back side mask picked up by a camera 50a, and drives and controls a camera driving mechanism 52a or a surface printing frame driving mechanism 55 so as to correct the relative deviation. It similarly calculates the relative deviation between the alignment marks FAM2 and BAM2 based on the superposed image obtained by superposing the alignment mark FAM2 on the front side mask and the alignment mark BAM2 on the back side mask picked up by a camera 50b, and drives and controls a camera driving mechanism 52b or the mechanism 55 so as to correct the relative deviation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided exposure apparatus for arranging front and back masks on both front and back surfaces of a member to be exposed and simultaneously exposing the front and back surfaces of the member to be exposed, and more particularly to a front side photomask (hereinafter referred to as a front mask). The present invention relates to an automatic alignment apparatus for automatically aligning a backside photomask (hereinafter, referred to as a backside mask) with a backside photomask.

[0002]

2. Description of the Related Art Conventionally, in this type of double-sided exposure apparatus, two predetermined alignment marks are formed on both a front mask and a mask, and these two sets of alignment marks are individually imaged by two cameras. Thus, the alignment between the front mask and the back mask is automatically performed.

That is, an image of each set of alignment marks of a front mask and a back mask taken by two cameras is taken into a microcomputer, and a deviation error between the alignment marks of the front mask and the back mask is calculated based on the images. On the basis of the obtained deviation error, one of the masks is finely moved by a motor to correct the deviation between the alignment marks of the two masks.

In this case, with the two cameras fixed at predetermined positions, one of the two masks is set on a grill which can be moved in the XYθ directions, and the other mask is set on a fixed grill. The front mask and the back mask are relatively moved by controlling the movement of one of the burning frames, and the misalignment correction is performed by matching the corresponding alignment marks of both masks.

[0005]

However, in the conventional double-side exposure apparatus, the camera position is fixed and only one of the front and back masks is movable. In order to put each alignment mark on each mask into the field of view of the corresponding camera, first, the grid on the XYθ table is moved by a motor, and two masks of one mask set on the grid are set. Put the alignment marks in the field of view of the corresponding camera. Then, if the two alignment marks of the mask set in the fixed frame are not in the field of view of the corresponding camera, place the mask on the frame with your fingertips. I was moving.

As described above, it is necessary to manually perform the positioning when setting the mask, and it takes a long time to perform the positioning.

Further, since the camera is constituted by a CCD camera or the like, and its field of view is very narrow, a mask with a precision of several hundred μm is required to simultaneously put two alignment marks in the field of view of the corresponding camera. It is necessary to perform positioning, and it has been difficult to manually perform this highly accurate positioning. In particular, when performing double-sided exposure of a thin plate-shaped etching product such as a shadow mask or a lead frame, skill is required to manually and accurately position a mask having a weight of about 10 kg.

The present invention has been made under such a background, and an object thereof is to provide a front mask and a back mask in such a manner that the alignment mark enters the center of the field of view of the image pickup means. An object of the present invention is to enable simple, quick, and high-accuracy loading processing.

[0009]

In order to solve the above-mentioned problems, the present invention is to load a front mask and a back mask each having a predetermined alignment mark formed on both front and back surfaces of a member to be exposed, and image the alignment mark. Means for automatically aligning the front mask and the back mask based on image information obtained by imaging by the means, in a double-sided exposure apparatus, wherein the imaging means, the front mask, at least one of the back mask By driving the two by the driving unit, the alignment marks formed on the front mask and the back mask are respectively positioned in the center of the visual field of the imaging unit, and the alignment of the front mask and the back mask is performed. I have to.

[0010]

According to the present invention, at least two of the image pickup means, the front mask, and the back mask are driven by driving means, so that the alignment marks formed on the front mask and the back mask are image-captured. It is controlled to enter the center of the field of view of the means.

Therefore, it is possible to automate the processing of loading the front mask and the back mask on both the front and back sides of the member to be exposed, such that the alignment mark enters the center of the field of view of the imaging means. It can be done easily, quickly and with high precision.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram showing a schematic configuration of an entire double-side exposure apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes stainless steel serving as a base member of a member to be exposed;
This is a rewinding machine equipped with a coil 3 of a strip-shaped metal thin plate such as a steel plate, brass, aluminum or the like, and a predetermined back tension is given by a motor 1a. The base member 2 unwound from the unwinding machine 1 is supplied to a tension leveler 4, and is subjected to repeated bending stress by the tension leveler 4, thereby correcting the curl.

The base member 2 whose curl has been corrected is supplied to a resist coating device 5, which coats, for example, a negative type resist on both the front and back surfaces of the base member 2, and exposes the exposed member 6. Is formed.

The exposed member 6 is step-transported to a baking furnace 7a for resist drying and a double-sided exposure section 8 by a roller-like transport mechanism 7 having a resin coating on the outer surface, for example. Then, the predetermined pattern P and the alignment mark M (see FIG. 2) are exposed by the double-sided exposure unit 8, and the resist layer is exposed.

The exposed member 6 is exposed to a double-sided exposure unit 8.
Is transported to a mark reader 9 disposed immediately after this, the alignment mark M exposed on the resist layer is read by the mark reader 9, and based on the read information, an optical system is And the relative position between the exposure target member 6 is performed.

A developing section 10 for developing the exposed member 6 is disposed downstream of the mark reader 9, and the developed member 6 is disposed downstream of the developing section 10.
An etching unit 11 for etching the resist layer is provided, and a winder 12 is provided at a stage subsequent to the etching unit 11. The winder 12 is rotationally driven clockwise by controlling the drive of a drive motor 12b via a motor driver 12a by a control signal synchronized with a control signal of the transport mechanism 7 from the alignment control device 30. .

As shown in FIGS. 2 and 3, the double-sided exposure section 8 has a front mask 13 and a back mask 14 supported by a burning frame, which will be described later, at positions opposed to each other with the exposed member 6 interposed therebetween. Is done. Light sources 18a and 18b are disposed on the opposite side of the front mask 13 and the back mask 14 from the exposed member 6 via optical systems 17a and 17b such as condenser lenses.

As shown in FIG. 3, a predetermined pattern P such as a circuit pattern is formed on the front mask 13 and a light transmitting portion is provided at a central portion of the front and rear positions when viewed from a plane not facing the member 6 to be exposed. Relatively wide L-shaped alignment marks FAM1 and FAM2 having a property are formed, and at least a peripheral portion thereof is an opaque portion.

As shown in FIG. 3, a predetermined pattern such as a circuit pattern is formed on the back mask 14 similarly to the front mask 13, and the back mask 14 corresponds to the alignment marks FAM1 and FAM2 of the front mask 13. L-shaped alignment mark BAM that does not transmit light to the position and is narrower than alignment marks FAM1 and FAM2
1, BAM2 is formed, and at least the peripheral portion thereof is a translucent portion.

On the other hand, on the lower surface side of the back mask 14 of the double-sided exposure section 8, as shown in FIG.
1, at the position facing FAM2 and BAM1, BAM2,
Light emitting elements 20a and 20b such as light-emitting diodes are arranged via the convex lenses 19a and 19b, respectively. Also, on the upper surface side of the front mask 13 facing these light emitting elements 20a and 20b, one-dimensional image sensors 23ax and 23ay as graphic reading elements are provided via convex lenses 21a and 21b and half mirrors 22a and 22b. 23
bx and 23by are provided.

The image sensors 23ax, 23bx
Is the alignment mark FAM of each of the masks 13 and 14.
1, FAM1, and BAM1 and BAM2 are arranged in parallel to the moving direction of the exposed member 6 so as to read a portion orthogonal to the moving direction of the exposed member 6, and the image sensors 23ay,
23by is arranged orthogonal to the moving direction of the exposed member 6 so as to read the portions of the alignment marks FAM1 and FAM2 of the masks 13 and 14, and BAM1 and BAM2 parallel to the moving direction of the exposed member 6. ing. Then, each of the image sensors 23ax, 23ay and 23bx, 23
Read information, which is a pulse output output from by, is input to the controller 30, and the front mask 13 and the back mask 14 are aligned based on the read information.

[First Embodiment] FIG. 4 shows a first embodiment of the present invention.
FIG. 3 is a configuration diagram illustrating a schematic configuration of a double-sided exposure unit 8 according to the embodiment. 4, reference numerals 50a and 50b denote mask alignment cameras. The camera 50a includes the convex lens 21a, the half mirror 22a, and the one-dimensional image sensors 23ax and 23ay shown in FIG. The above-mentioned convex lens 21b, half mirror 22b, and one-dimensional image sensor 23bx, 2
It is composed of 3 by. Also, 51a, 51b
Is an illuminator, the illuminator 51a is composed of the convex lens 19a shown in FIG. 2 and the light emitting element 20a such as a light emitting diode, and the illuminator 51b is a convex lens 19a shown in FIG.
b and a light emitting element 20b such as a light emitting diode. The movement of these two cameras 50a and 50b can be independently controlled in the XYθ directions by the camera driving mechanisms 52a and 52b.

Reference numeral 53 denotes a front-side burning frame (hereinafter, referred to as a front-side burning frame), and reference numeral 54 denotes a rear-side burning frame (hereinafter, referred to as a back-side burning frame). The mask 13 and the back mask 14 are configured to be held by vacuum suction. Further, the case-burning frame 53 is configured to be able to control the minute movement in the XYθ directions by the case-burning frame driving mechanism 55, and the case-burning frame 54 is fixed at a position facing the light source 18b. Two alignment marks FAM1 and FAM2 are formed on the front mask 13 as described above.
In FIG. 4, two alignment marks BAM1 and BAM2 are formed.

The cameras 50a and 50b, the camera drive mechanisms 52a and 52b, and the cover frame drive mechanism 55 are shown in FIG.
Is connected to the controller 30 shown in FIG. The controller 30 is constituted by a computer system having a keyboard, a display device, and the like, and has camera driving mechanisms 52a and 52b and a burning frame driving mechanism 55 by key operation or the like.
Can also be controlled.

The controller 30 determines a relative position between the alignment mark FAM1 and the alignment mark BAM1 based on a superimposed image of the alignment mark FAM1 on the front mask 13 and the alignment mark BAM1 on the back mask 14 captured by the camera 50a. This relative shift is corrected by calculating the shift and controlling the drive of the camera driving mechanism 52a or the cover making frame driving mechanism 55. Similarly, the controller 30 determines a relative position between the alignment mark FAM2 and the alignment mark BAM2 based on a superimposed image of the alignment mark FAM2 on the front mask 13 and the alignment mark BAM2 on the back mask 14 captured by the camera 50b. The shift is calculated and the camera driving mechanism 5
The relative displacement is corrected by controlling the driving of the burning frame driving mechanism 55 or 2b.

Next, the mask load processing unique to the present invention will be described. When loading a mask on the double-sided exposure unit 8,
First, the back mask 14 is placed on the back firing frame 54. And
Looking at the image displayed on the display screen of the controller 30,
Alignment marks BAM1, BAM2 on back mask 14
Is in the field of view of the cameras 50a and 50b, respectively. As a result, the alignment mark BA
When M1 and BAM2 are not in the fields of view of the cameras 50a and 50b, respectively, a key operation is performed while looking at the display screen of the controller 30 so that the camera driving mechanism 52 is operated.
a, 52b to control the alignment mark B
AM1 and BAM2 are set to be within the visual fields of the cameras 50a and 50b, respectively. In this case, the alignment mark B
It is preferable to display AM1 and BAM2 simultaneously.

After the alignment marks BAM1 and BAM2 enter the field of view of the cameras 50a and 50b, respectively, by the key operation, the alignment marks BAM1 and BAM2 are automatically changed to the cameras 50a and 50b under the control of the controller 30. Camera 50
Positioning control of a and 50b is performed. As described above, the alignment mark B is set at the center of the visual field of the cameras 50a and 50b.
The reason why the images of AM1 and BAM2 are taken is that the alignment mark BAM is formed due to the aberration of the optical system at the periphery of the visual field.
This is to prevent the image of BAM2 from being distorted and mask alignment not to be performed accurately.

Next, the front mask 13 is placed on the front frame 53. Then, looking at the image displayed on the display screen of the controller 30, the alignment mark FA on the front mask 13 is displayed.
It is checked whether M1 and FAM2 are in the field of view of the cameras 50a and 50b, respectively. As a result, the alignment marks FAM1 and FAM2 are set to the camera 50a and the camera 50a, respectively.
If not in the field of view 50b, the controller 30
By operating the keys while viewing the display screen, the printing frame drive mechanism 55 is controlled so that the alignment marks FAM1 and FAM2 fall within the fields of view of the cameras 50a and 50b, respectively. Also in this case, it is preferable to display the alignment marks BAM1 and BAM2 simultaneously.

After the alignment marks FAM1 and FAM2 enter the visual fields of the cameras 50a and 50b, respectively, by the key operation, under the control of the controller 30, the alignment marks FAM1 and BAM1 and the alignment marks FAM2 and BAM2 are aligned. Is done automatically.

As described above, by making the camera and one of the burning frames movable, it is not necessary to manually move one of the masks, and the alignment marks on both the front mask and the back mask can be easily and quickly formed. It is possible to place the camera in the center of the field of view with high accuracy.

It should be noted that the processing when the alignment mark is not in the field of view of the camera is performed based on the image taken by the camera without performing the key operation as described above.
It is also possible to perform this automatically by the controller 30.

[Second Embodiment] FIG. 5 shows a second embodiment of the present invention.
FIG. 3 is a configuration diagram illustrating a schematic configuration of a double-sided exposure unit 8 according to the embodiment. In the present embodiment, the cameras 50a and 50b are fixed, and both the front and back burning frames 53 and 54 are movable. That is, as shown in FIG. 5, the front grill 53 is configured to be capable of minute movement control in the XYθ direction by the grill driving mechanism 55, and the back grill 54 is also minutely moved in the XYθ direction by the back grill driving mechanism 57. It is configured to be able to control movement.

In the mask loading process according to the present embodiment, one of the front and back burning frames 53 and 54 is
First, the alignment marks FAM1 and FAM2 on the front mask 13 or the alignment marks BAM1 and BAM2 on the back mask 14 are respectively moved by the front and rear burning frame driving mechanism 55 or 57 to the first position. By the same processing as in the embodiment, the camera 50a, 50b is placed at the center of the visual field.

Next, the other back-burning frame 54 or the front-burning frame 5
3 is moved by the back-burning frame drive mechanism 57 or the front-burning frame drive mechanism 55, and the alignment mark B on the back mask 14 is moved.
AM1, BAM2, or alignment marks FAM1, FAM2 on the front mask 13 are respectively placed in the center of the field of view of the cameras 50a, 50b by the same processing as in the first embodiment. It goes without saying that the same effect as in the first embodiment can be obtained by such processing.

The present invention is not limited to the above embodiment, but can be variously applied and modified. For example, the first
In the embodiment, the two cameras are configured to be independently movable in order to be able to cope with a plurality of types of masks on which different circuit patterns and the like are formed.
It is also possible to attach two cameras to one frame so that the two cameras can be moved integrally by one driving mechanism. In addition, the present invention is applicable not only to a double-sided exposure apparatus that performs double-sided exposure on a long member to be exposed to be conveyed by an unwinding operation, but also to a double-sided exposure apparatus that performs double-sided exposure on a sheet-shaped member to be exposed. It is also possible.

[0037]

As described above, according to the present invention,
A front mask and a back mask each having a predetermined alignment mark formed on both the front and back surfaces of the member to be exposed are loaded, and the front mask and the back mask are automatically set based on image information obtained by imaging the alignment mark by an imaging unit. In an automatic alignment method in a double-sided exposure apparatus that performs alignment with a mask, at least two of the imaging unit, the front mask, and the back mask are driven by a driving unit to form the front mask and the back mask, respectively. The alignment of the front mask and the back mask is performed such that the alignment mark is located in the center of the field of view of the imaging unit, so that the alignment mark is located in the center of the field of view of the imaging unit. Automating the process of loading front and back masks on both front and back surfaces of the exposed member Can be, this process simple, quick,
And it can be performed with high accuracy.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an overall schematic configuration of a double-side exposure apparatus to which an automatic alignment method in a double-side exposure apparatus of the present invention is applied.

FIG. 2 is a configuration diagram illustrating a configuration of a camera of a double-sided exposure unit.

FIG. 3 is a plan view showing a front mask and a back mask.

FIG. 4 is a diagram showing a first embodiment of the present invention.

FIG. 5 is a diagram showing a second embodiment of the present invention.

[Explanation of symbols]

13: Front mask, 14: Back mask, 30: Controller, 50a, 50b: Camera, 53: Front printing frame, 54: Back printing frame, 52a, 52b: Camera driving mechanism, 55: Front printing frame driving mechanism, 57: Back-burning frame drive mechanism, FAM1, FAM2:
Alignment marks on table mask, BAM1, BAM2:
Alignment mark on the back mask.

Claims (1)

[Claims] 1. A front mask and a back mask each having a predetermined alignment mark formed on both the front and back surfaces of a member to be exposed are loaded, and the alignment mark is automatically obtained based on image information obtained by imaging the alignment mark with an imaging unit. An automatic alignment method in a double-sided exposure apparatus that performs alignment between the front mask and the back mask, wherein at least two of the imaging unit, the front mask, and the back mask are driven by a driving unit, and An automatic alignment method in a double-side exposure apparatus, wherein the alignment of the front mask and the back mask is performed such that the alignment marks formed on the back mask enter the center of the field of view of the imaging unit.