TWI599855B - ITO pattern exposure device - Google Patents

Description

ITO pattern exposure device

The present invention relates to an ITO pattern exposure apparatus for producing an ITO pattern on a transparent film of a PET (Polyethylene terephthalate) film in the production of a film electrode for a touch panel.

The touch panel on the screen of the smart phone and the tablet terminal is formed by a transparent electrode formed on the transparent film. The transparent electrode is formed by a pattern of an ITO (Indium Tin Oxide) film formed on a transparent film. In recent years, with the popularization of smart phones and tablet terminals, the high-definition requirements for the wiring pattern of the ITO film have been increased, and a means for realizing this requirement is to use optical lithography.

The optical lithography overlaps the mask on which the circuit pattern is drawn on the transparent PET film placed on the platform, and then uses the camera to observe the position of the alignment film mark and the mask mark provided on the respective surfaces, and the image is utilized. After processing the position difference, the position of the platform is adjusted in the x, y, and θ directions, and the alignment of the two is performed, and then ultraviolet exposure is performed to transfer the pattern on the mask to the PET film. Coated photoresist on the coating.

The mask is provided with a glass mask, a film mask, etc., but from the viewpoint of cost effectiveness, a film mask is mainly used, and the film mask is closely attached to a mask made of a transparent body such as glass or resin for supporting it. Used on the holder.

A large problem with such an ITO pattern exposure apparatus is that the alignment of the above-mentioned film mask with the PET film is difficult.

One of the reasons is that the film mark on the PET film is formed using an ITO film (transparent electrode), and since the ITO film is transparent to visible light, position identification of the film mark is difficult.

Therefore, it is possible to perform irradiation with a shorter wavelength in the near ultraviolet region (before and after the wavelength of 400 nm) which lowers the transmittance of the ITO film, enhances the reflectance, and photographs with a camera; and by performing the glass surface of the mask holder Vertical irradiation increases the difference in reflectance between the film mark of the ITO film and the surface portion of the glass.

Further, there is also a proposal to separately form an alignment mark by using a metal film on the ITO film (Patent Document 1); and to design a structure for selecting an illumination wavelength by using a spectral reflectance of ITO, and to perform mark recognition (Patent Literature) 2) Other methods.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2011-100360

[Patent Document 2] Japanese Patent Special Publication No. 5-87763

The reason why the position identification of the film mark is difficult is that in addition to the transparency of the ITO film, interference fringes are also generated, which cause the alignment accuracy to be greatly reduced.

Fig. 8 shows a film mark 60' formed of an ITO film on a PET film 5', and a photoresist film 51' is provided thereon, and a mask made of glass is superposed thereon. The film mask 1' held by the holder 3' is placed in a state in which the mask mark 10' of the film mask 1' is aligned with the film mark 60', and the illumination incident light 95 of the illumination device of the camera is irradiated from above.

A micro-gap S is provided between the film mask 1' and the mask holder glass 30' of the mask holder 3' because the gap S causes illumination of the incident light 95 as shown in the mask holder glass. The reflected light reflected at the back surface 32' of 30' interferes with the reflected light reflected at the surface 12' of the film mask 1' to cause an interference fringe F to occur. The interference fringe F changes as the size of the gap S changes. Although the variation of the light intensity of the interference fringe F is only slight, since the contrast mark 60' of the ITO film is small in comparison with itself, it becomes a noise image, which causes a problem that hinders the recognition of the film mark by image processing. .

It is an object of the present invention to solve the above problems of the prior art.

In order to achieve the above object, the present invention comprises: a film mask which has been patterned with a circuit pattern to be exposed, and a mask holder which is formed by a transparent body supporting the film mask, and is provided with the above-described patterned ITO An ITO pattern exposure apparatus for performing exposure on a transparent film of a film, comprising: marking a aligning film having an ITO film on the transparent film, and disposing at a position corresponding to the film mark of the film mask; A mask hole larger than the film mark and a registration mask disposed around the mask hole are marked with a mask.

In the above structure, the use of the mask hole eliminates the reflected light from the surface of the film mask, and the interference fringes of the reflected light on the back surface of the mask holder are eliminated, and the film mark can be satisfactorily recognized.

Furthermore, it is preferable to further include the above-mentioned mask holder, and The masking hole of the film mask can be adsorbed around the adsorption groove on the mask holder. According to this configuration, it is possible to prevent the air from flowing into the mask hole, and to prevent the adhesion between the film mask and the mask holder from being reduced in a wide range centered on the hole, and to prevent deterioration of the exposure resolution.

According to the ITO pattern exposure apparatus of the present invention, interference fringes can be prevented from occurring, and the image recognition of the film mark can be favorably maintained, and the effect of performing high-precision alignment exposure while maintaining the exposure resolution can be achieved.

1‧‧‧film mask

1'‧‧‧ film mask

2‧‧‧Mask hole

3‧‧‧Mask holder

3'‧‧‧Mask holder

4‧‧‧Adsorption ditch

4'‧‧‧Adsorption ditch

5‧‧‧PET film

5'‧‧‧PET film

6‧‧‧ITO film

8‧‧‧Control device

10‧‧‧ mask marks

10'‧‧‧ mask mark

12‧‧‧ Film mask surface

12'‧‧‧ surface

15‧‧‧ circuit graphics

30‧‧‧Mask holder glass

30'‧‧‧Mask holder glass

31‧‧‧sucking ditch

32‧‧‧Mask holder glass back

32'‧‧‧ Back

40‧‧‧Suction device

45‧‧‧Connecting trench

51‧‧‧Photoresist film

51'‧‧‧Photoresist film

60‧‧‧film mark

60'‧‧‧ film mark

95‧‧‧ illumination incident light

96‧‧‧Camera lighting

97‧‧‧ camera

98‧‧‧XY θ platform

99‧‧‧Exposure source

A‧‧‧reflected light

B‧‧‧reflected light

F‧‧‧ interference fringes

S‧‧‧ gap

Fig. 1 is a schematic perspective view showing an embodiment of the present invention.

Fig. 2 is a partial side sectional view showing an embodiment of the present invention.

Fig. 3 is an operation explanatory view showing an embodiment of the present invention.

Fig. 4 is a partially enlarged plan view showing the configuration of the adsorption groove 4 according to the embodiment of the present invention.

Fig. 5 is a plan view showing the configuration of the adsorption groove 4 according to the embodiment of the present invention.

Fig. 6 is an explanatory view showing the effect of the adsorption groove 4 according to the embodiment of the present invention.

Fig. 7 is a plan view showing another configuration of the adsorption groove 4 according to the embodiment of the present invention.

Fig. 8 is an explanatory view showing the generation of interference fringes of a conventional exposure apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a schematic perspective view showing the ITO pattern exposure apparatus of the present invention.

In Fig. 1, a PET film 5 on which an ITO film 6 has been formed is placed on an XYθ stage 98 which is movable in the XYθ direction, and is constituted by an exposure light source 99. The exposure light is exposed to the circuit pattern 15 depicted on the film mask 1 located above and held by the mask holder 3.

A film mark 60 is formed on the PET film 5 at four places on the four corners, and four mask marks 10 are drawn on the film mask 1 at the position corresponding to the film mark 60, and are photographed by the camera 97 including the camera illumination device 96. The film mark 60 and the mask mark 10 are used to obtain the difference in position between the two, and the PET film 5 is moved in the XY θ direction by the XY θ stage 98, so that the film mark 60 is consistent with the mask mark 10. Thereby, the alignment of the PET film 5 and the film mask 1 is performed. Irradiation light in a near-ultraviolet region (before and after a wavelength of 400 nm) or a shorter wavelength that lowers the transmittance of the ITO film 6 and increases the reflectance is irradiated from the camera illumination device 96.

The control of the exposure apparatus is performed by the control device 8, and the image processing and alignment of the film mark 60 and the mask mark 10 are also configured by the use control device 8. Further, a suction device 40 to be described later is included.

In FIG. 1, the mask mark 10, the film mark 60, the camera illumination device 96, and the camera 97 are omitted, and only two are depicted, but in reality, four are included.

Figure 2 is a partial enlarged view. The ITO film 6 is formed on the PET film 5 as described above, and the film mark 60 is also formed using ITO. A photoresist film 51 is further formed on the ITO film 6 and the film mark 60 made of ITO. In addition, the photoresist film 51 is not shown in FIG.

The film mask 1 is adhered to the mask holder glass 30 of the mask holder 3, and is attracted to the mask holder 3 by the suction grooves 31 provided in the mask holder glass 30. The mask holder glass 30 is sucked by the suction device 40 The negative pressure constitutes a state in which the film mask 1 is adsorbed.

A mask hole 2 is formed at a position where the film mask 1 corresponds to the film mark 60, and a hole is formed by the film mask 1 notch. The mask hole 2 is larger than the size of the film mark 60 and has a diameter of about 2 times. In the embodiment, the film mark 60 is 2mm size, the opposite mask hole 2 is 5mm size.

With the mask hole 2, at the upper portion of the film mark 60, the film mask 1 and the mask holder glass 30 are not in close contact with each other, and no interference fringes are generated on the mark.

An annular mask mark 10 is drawn around the mask hole 2. The size (outer diameter) of the mask mark 10 is larger than the diameter of the mask hole 2, and even if the shape change and the positional change of the mask hole 2 occur, the alignment accuracy does not cause a problem. In the present embodiment, the mask mark 10 is the outer diameter. 6mm, pre-made 6mm black dots, opened at the center The annular mask mark 10 is formed by the 5 mm mask hole 2.

2(B) shows an image of the film mark 60 and the mask mark 10 taken by the camera 97.

The camera 97 and the camera illumination device 96 are disposed above the mask holder 3, and the illumination light is slightly vertically emitted from the camera illumination device 96, and the mask mark 10 and the film mark 60 are photographed, thereby obtaining the image of FIG. 2(B) described above. Perform a counterpoint.

As shown in Figs. 3(A) and (B), the film mask 1 having the above structure is superposed on the PET film 5, and the film mark 60 is aligned with the mask mark 10.

As described above, a portion of the film 5 is cut out due to the mask hole 2, so that the camera illumination device 96 from the film mask surface 12 is as illustrated in FIG. The reflected light of the illumination incident light 95 disappears, and the interference fringes between the reflected light a and the back surface 32 of the glass 30 disappear. Further, since the reflected light b of the resist film 51 and the reflected light a of the back surface 32 of the glass 30 become larger as shown in the optical path difference, interference fringes do not occur. Since the incident angle of the illumination incident light 95 is nearly vertical, the thickness of the optical path difference becomes the thickness of the thin film mask 1 (about 100 μm to 200 μm) × 2. On the other hand, the illumination light from the camera illumination device 96 is a near ultraviolet region having a wavelength of about 400 nm, and since the optical path difference is sufficiently larger than the interference distance of the illumination light, interference does not occur, and interference fringes are not generated.

In the mask holder glass 30, the adsorption groove 4 is formed at a position corresponding to the above-mentioned mask hole 2. The suction groove 4 is sucked by the suction device 40, so that the periphery of the mask hole 2 is in close contact with the mask holder glass 30.

As shown in FIGS. 4 and 5, the adsorption grooves 4 are formed at positions surrounding the respective mask holes 2, and each of the adsorption grooves 4 is in a state of being communicated with the suction grooves 31.

As shown in the figure, the suction grooves 31 and 31 are formed in a double-layered frame shape around the mask holder glass 30, and are configured such that the periphery of the film mask 1 is in close contact with the mask holder glass 30. The adsorption groove 4 forms a meandering groove that communicates with the inner suction groove 31, and a part of the suction groove 4 and the suction groove 31 form a groove that surrounds the mask hole 2.

The suction device 40 systematically sucks the adsorption grooves 4 and the suction grooves 31 and 31 to form a state in which the film mask 1 is in close contact with the mask holder glass 30.

Fig. 6 shows the effect of the adsorption groove 4.

When the adsorption groove 4 is not provided, as shown in (A), air is introduced from the mask hole 2, resulting in the film mask 1 and the mask holder glass 30 in a wide range centering on the mask hole 2. The degree of closeness between the contacts is lowered, resulting in deterioration of the exposure resolution at a position away from the mask hole 2. However, as in this embodiment, by enclosing the mask In the manner of the hole 2, the adsorption groove 4 is formed on the mask holder glass 30, and the air flowing in from the mask hole 2 formed in the film mask 1 is sucked, and the air is prevented from flowing into the outside of the adsorption groove 4 to have the circuit pattern 15 present. The center of the film mask 1 prevents the adhesion between the film mask 1 and the mask holder glass 30 from being lowered.

Fig. 7 shows another embodiment of the suction groove 4. In the present embodiment, the adsorption grooves 4' and 4' have the same length as the suction grooves 31 and 31, and are formed in two longitudinal directions so as to form parallel lines. The adsorption groove 4' is provided with a communication groove 45 at a plurality of places, and communicates with the inner suction groove 31 by the communication groove 45. In this configuration, the plurality of frame-shaped grooves are formed by the adsorption groove 4', the communication groove 45, and the inner suction groove 31, and each of the plurality of mask holes 2 is surrounded.

With this configuration, suction in a wide area can be performed. Further, it is also possible to accommodate the mask holes 2 in various places in the longitudinal direction and the short side direction of the film mask 1, and to differently cover the different film masks 1 in which the different mask holes 2 are provided.

In the embodiment described above, the illumination light reflection from the film mask surface 12 is eliminated by the mask hole 2, and interference fringes can be prevented from occurring, and the recognition of the film mark 60 can be performed satisfactorily, and the alignment accuracy can be improved.

1‧‧‧film mask

3‧‧‧Mask holder

4‧‧‧Adsorption ditch

5‧‧‧PET film

6‧‧‧ITO film

10‧‧‧ mask marks

10‧‧‧ mask marks

15‧‧‧ circuit graphics

30‧‧‧Mask holder glass

31‧‧‧sucking ditch

60‧‧‧film mark

Claims (3)

An ITO pattern exposure apparatus comprising: a film mask on which a circuit pattern to be exposed is drawn, and a mask holder supporting the film mask, the ITO film disposed on the transparent film is irradiated with light of the circuit pattern to be exposed The ITO pattern exposure apparatus of the above ITO film, comprising: on the film mask, a mask larger than the film mark is provided at a position corresponding to a mark of an ITO film provided on the transparent film a hole; and a mask mark for alignment is provided around the mask hole of the film mask. The ITO pattern exposure apparatus of claim 1, wherein the mask holder is formed with an adsorption groove for adsorbing the film mask; and the adsorption groove is formed around the mask hole to adsorb the film mask. s position. The ITO pattern exposure apparatus of claim 1, wherein the mask holder is formed with an adsorption groove for adsorbing the film mask; the plurality of mask holes are provided; and the plurality of adsorption grooves are provided The film mask is adsorbed in a state in which each of the above-mentioned mask holes is surrounded.