TWI614354B - Deposition mask - Google Patents

Abstract

The present invention is a film-forming mask, which is a film-forming mask 1 having a structure in which a resin-made film 3 is closely adhered to one surface of a sheet-shaped magnetic metal member 2, and the sheet-shaped magnetic metal member 2 has A plurality of slit-shaped through-holes 5 arranged side by side, and a plurality of opening patterns 6 in a part of each of the through-holes 5 penetrating the film 3 are provided; the film 3 has a linear expansion coefficient which is different in orthogonal two axes The anisotropy is such that the axis with a small linear expansion coefficient of the film 3 coincides with the direction crossing the major axis of the through hole 5 of the magnetic metal member 2.

Description

Film forming mask

The present invention relates to a composite film-forming mask having a structure in which a magnetic metal member and a resin film are closely adhered, and more particularly, to a film-forming mask capable of realizing high-definition film patterns by suppressing thermal deformation.

Conventional film-forming masks use a resist mask to wet-etch a metal plate with a thickness of about 30 μm to 100 μm to form slit-shaped opening patterns (for example, refer to Japanese Patent Application Laid-Open No. 2009-129728). ).

However, in such a conventional film-forming mask, a metal plate is wet-etched to form a plurality of opening patterns through the metal plate, so the resolution of the opening pattern may be caused by the isotropic etching of the wet etching. Deterioration can only form an opening width that is several times the plate thickness.

In particular, when nickel steel (invar) having a linear expansion coefficient as small as about 1 × 10 ^-6 / ° C is used as a metal plate, nickel steel is difficult to perform wet etching, so the formed opening pattern cannot be used with electrodes of TFT substrates for organic EL. The shape is uniformly formed into a rectangular shape. Therefore, when nickel steel is used as the base material of the mask, the opening pattern is usually formed in the shape of an elongated slit as described in Patent Document 1 described above.

Moreover, as shown in FIG. 6 (a), the film-forming mask 1 of such a metal is The magnet 15 placed on the back surface of the substrate 17 as the substrate to be formed is attracted, and is used while being kept in close contact with the film-forming surface of the substrate 17. In this case, there are cases in which the magnetic flux acting on the elongated portion 22a between the adjacent opening patterns 6 of the nickel steel 22 is not the same across the entire surface of the film-forming mask 1. Therefore, in order to improve the adhesion, The strength of the magnetic field of the magnet 15 becomes stronger, so that the above-mentioned portion 22a of the nickel steel 22 moves in a direction (X-axis direction) that intersects its long axis, thereby deforming the opening pattern 6. Therefore, a magnetic field (for example, about 20 mT) that weakens the strength to such an extent that the aforementioned portion 22a of the nickel steel 22 does not move is usually applied.

On the other hand, as shown in FIG. 6 (b), the film-forming mask 1 is applied to one side so that the evaporation source 20 as a film-forming source is along the long axis (Y-axis) of the slit-shaped opening pattern 6. When the vapor deposition device is a film-forming device that is moved in the direction of intersection (X-axis direction) and vapor-deposited, only the portion of the film-forming mask 1 opposed to the vapor deposition source 20 is heated by the radiant heat of the vapor deposition source 20 . In particular, the nickel steel 22 in this portion is thin and slender, and thus has a smaller heat capacity than the substrate 17. Therefore, the elongated portion 22a between the adjacent opening patterns 6 of the nickel steel 22 is thermally expanded to extend in the long axis direction (Y-axis direction).

As described above, since a strong magnetic field cannot be applied to the film-forming mask 1, the binding force of the nickel steel 22 generated by the magnet 15 is weak. Therefore, as shown in FIG. 6 (b), the above portion 22a of the nickel steel 22 extended and heated by the evaporation source 20 is peeled off from the vapor deposition surface of the substrate 17 and hangs down. A gap 23 is formed between the vapor deposition surfaces of the substrate 17. Therefore, there is a problem that the edges of the thin film pattern 21 are blurred or the shape is enlarged due to the return of the vapor deposition material M evaporated from the vapor deposition source 20. In particular, the higher the fineness of the thin film pattern 21, the more this problem cannot be ignored, and it also becomes an important reason for limiting high definition.

Therefore, an object of the present invention is to provide a film-forming mask capable of realizing high-definition film patterns while suppressing thermal deformation while coping with such problems.

In order to achieve the above object, the film-forming mask of the present invention has a structure in which a resin-made film is closely adhered to one surface of a sheet-shaped magnetic metal member, and the sheet-shaped magnetic metal member has a plurality of slit-shaped through holes arranged side by side Holes, and a plurality of opening patterns are provided in the through-holes through the film, and the film has an anisotropy in which the linear expansion coefficient is different from the orthogonal two axes, so that the linear expansion coefficient of the film is small. It coincides with the direction which intersects with the long axis of the said through-hole of the said magnetic metal member.

According to the present invention, the slender portion between the adjacent through holes of the magnetic metal member is connected to the dielectric diaphragm in a direction intersecting with its long axis, and the movement in that direction is restricted. Therefore, even if the shield is tightly attached to the magnetic metal member for adsorption The substrate makes the magnetic field strength of the magnet disposed on the back of the substrate stronger than conventional, and there is no risk that the above-mentioned part of the magnetic metal member moves. Therefore, by making the magnetic field strength of the magnet stronger and increasing the adsorption force on the magnetic metal member, even if the magnetic metal member is partially heated and extended by the radiant heat of the film-forming source, the above-mentioned part of the magnetic metal member can be prevented from self-propagating. The substrate surface peels off and hangs down. Therefore, generation of a gap between the mask and the substrate can be suppressed, and the film-forming material arriving from the film-forming source can flow back to the back side of the mask, thereby suppressing blurring of the edges of the film pattern or expansion of the shape. Therefore, it is easy to cope with even the progress of high-definition thin film patterns.

In addition, since the film has anisotropy in the coefficient of linear expansion, and the axis where the coefficient of linear expansion of the film is small coincides with the direction intersecting with the major axis of the through hole of the magnetic metal member, it is possible to suppress the film from extending in that direction ( Thermal deformation), thereby suppressing the opening pattern in that direction Offset and shape enlargement. Therefore, it is possible to cope with the high definition of the thin film pattern.

1‧‧‧ film forming mask

2‧‧‧ magnetic metal components

2a, 22a ‧‧‧ slender parts

3‧‧‧ film

3a, 3b‧‧‧face

4‧‧‧frame

5‧‧‧through hole

6‧‧‧ opening pattern

6a‧‧‧Open end edge

7‧‧‧ opening

8‧‧‧ seed layer

9‧‧‧ resist layer

10‧‧‧ Island pattern

11‧‧‧ opening

12‧‧‧Mask members

13‧‧‧XY platform

14‧‧‧ glass plate

15‧‧‧magnet

16‧‧‧ Liquid

17‧‧‧ substrate

18‧‧‧ sidewall

19‧‧‧ substrate holder

20‧‧‧Evaporation source

21‧‧‧ film pattern

22‧‧‧ Nickel steel

23‧‧‧ Clearance

L‧‧‧ laser light

M‧‧‧Evaporation material

FIG. 1 is a view showing an embodiment of a film-forming mask of the present invention, (a) is a plan view, and (b) is an enlarged sectional view of a main part.

FIG. 2 is a cross-sectional view showing the production of a film-forming mask according to the present invention, and explaining the manufacturing steps of the mask member.

FIG. 3 is a cross-sectional view showing the production of a film-forming mask according to the present invention and explaining a frame joining process.

FIG. 4 is a cross-sectional view showing the production of a film-forming mask according to the present invention, and illustrating a step of forming an opening pattern.

FIG. 5 is a cross-sectional view illustrating film formation using the film formation mask of the present invention.

FIG. 6 is a cross-sectional view illustrating film formation using a conventional metal mask.

Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings. FIG. 1 is a view showing an embodiment of a film-forming mask of the present invention, (a) is a plan view, and (b) is an enlarged sectional view of a main part. This film-forming mask 1 has a structure in which a magnetic metal member and a resin film are in close contact with each other, and includes a magnetic metal member 2, a resin film 3, and a frame 4.

The magnetic metal member 2 is used to hold the film 3 described below, and is attracted by a magnet (for example, an electromagnet) disposed on the back surface of a substrate to be formed (hereinafter referred to simply as a "substrate") and sandwiched between the substrate and the substrate. The above-mentioned film 3 is adhered to the film-forming surface of the substrate, and has a coefficient of linear expansion similar to that of a glass substrate such as a glass substrate (for example, 5 × 10 ^-6 / ° C). Sheet-like members such as Ni-based alloys and Fe-Ni-Co-based alloys. Furthermore, the plurality of through holes 5 having an elongated slit shape are arranged side by side at predetermined predetermined intervals.

A resin film 3 is provided on one surface of the magnetic metal member 2 to allow visible light to pass therethrough. The film 3 is the body of the mask, and has an anisotropy in which the coefficient of linear expansion is different from the orthogonal two axes (X-axis, Y-axis), and the axis (X-axis) that makes the coefficient of linear expansion small and the above magnetic properties. The directions in which the major axes of the through holes 5 of the metal member 2 intersect are the same. In this case, a resin film is selected, that is, the linear expansion coefficient in the axis (X-axis) direction of the small linear expansion coefficient of the resin film is consistent with the linear expansion coefficient of the magnetic metal member 2, for example, at 50 ° C. The temperature range of ~ 200 ℃ is 4 × 10 ^-6 / ℃ ~ 5 × 10 ^-6 / ℃. As such a resin film, for example, a polyimide film Kapton (registered trademark of American DuPont) 150EN-A manufactured by Toray DuPont Co., Ltd. is specifically mentioned.

In each of the through holes 5 of the magnetic metal member 2, a plurality of opening patterns 6 of the through film 3 are provided side by side with the long axis direction of the through holes 5. The opening pattern 6 is used to selectively pass a film-forming material which is a film-forming source, such as an evaporation source, to form a fixed-shape thin-film pattern on a substrate. Therefore, for example, the opening pattern 6 is formed with a TFT substrate for an organic EL. The anode electrodes have the same shape and size. Alternatively, it may be formed in a size across a plurality of anode electrodes corresponding to the same color.

A frame 4 is provided on the peripheral edge portion of the magnetic metal member 2. The frame 4 supports the composite sheet of the magnetic metal member 2 and the film 3 in a spread state, and therefore is a frame-shaped member having the openings 7 having the size of the plurality of through holes 5 described above, and is made of the magnetic metal member 2 The same metal material or a metal material having an approximate linear expansion coefficient is formed. In addition, the bonding of the magnetic metal member 2 and the frame 4 can also be performed using an adhesive, but there is heat due to film formation. The generated outgas may contaminate the thin film pattern, so it is preferable to be soldered.

Next, the manufacture of the film-forming mask 1 comprised in this way is demonstrated. The film-forming mask 1 of the present invention is generally manufactured through a mask forming step, a frame bonding step, and an opening pattern forming step. First, a step of forming a mask member will be described with reference to FIG. 2.

First, as shown in FIG. 2 (a), the linear expansion coefficient of cutting is different from the orthogonal two-axis and has an anisotropic thickness of about 10 μm to 30 μm and is a long film such as a polyimide film, and a film having a fixed area is produced. 3.

The polyimide film is, for example, Kapton (registered trademark) 150EN-A manufactured by Toray DuPont Co., Ltd. The linear expansion coefficient of the polyimide film in the longitudinal direction (mechanical conveying direction, corresponding to the Y-axis direction in FIG. 1) is 12 × 10 ^-6 / ° C, and the line in the width direction (corresponding to the X-axis direction in FIG. 1). The expansion coefficient is 5 × 10 ^-6 / ° C, and it is manufactured by extending in the width direction while applying a predetermined specific temperature in advance.

Next, as shown in FIG. 2 (b), a seed crystal composed of a highly conductive metal film is formed on one surface of the film 3 with a thickness of about 50 nm by a well-known film-forming technology such as evaporation, sputtering, or electroless plating. Layer 8. In this case, when the film 3 is polyimide as described above, it is preferable to use nickel or the like as the seed layer 8. Since copper diffuses in polyimide, it is not good as a seed layer 8 for polyimide.

Next, as shown in FIG. 2 (c), a photoresist is spray-coated on the seed layer 8 of the film 3 at a thickness of 30 μm to 50 μm, for example, and then dried to form a resist layer 9.

Next, as shown in FIG. 2 (d), the resist layer 9 is exposed and developed using a photomask, and the through-holes are formed corresponding to the formation positions of the plurality of elongated slit-shaped through-holes 5 corresponding to the through-holes. The plurality of island patterns 10 having the same shape and size of the holes 5. In this case, the slit-shaped through hole 5 has a long axis in a direction (Y-axis direction) that intersects with the axis (X-axis) direction of the small thermal expansion coefficient of the film 3, so the island pattern 10 is formed along the Y-axis direction It is slender. At the same time, an island pattern for alignment marks (not shown) is also formed at a predetermined position in a portion outside the film-forming effective region containing a plurality of island patterns 10 therein.

Next, the membrane was immersed in the plating bath 3, FIG. 2 (e), the island on the outside of the pattern 10 above the seed layer 8, a thickness of 30μm ~ 50μm is formed of, for example, linear expansion coefficient of 5 × 10 ^{- At} about ⁶ / ° C, for example, a Fe-Ni-based alloy, a Fe-Ni-Co-based alloy, or the like is used as the magnetic metal member 2. In this case, the plating bath to be used is appropriately selected from well-known plating baths in accordance with the magnetic metal member 2 to be formed. Thereafter, as shown in FIG. 5 (f), the island pattern 10 is peeled off using an organic solvent or a release agent for the above-mentioned resist, and an opening portion 11 is formed at a position corresponding to the island pattern 10.

Then, as shown in FIG. 2 (g), the film 3 is passed through the etching solution of the seed layer 8, and the seed layer 8 in the opening 11 is etched and removed to form a through hole 5. Further, the film 3 is washed to obtain a mask member 12.

Next, the frame joining process will be described with reference to FIG. 3.

First, as shown in FIG. 3 (a), the masking member 12 is spread on the frame-like frame 4 in a state where a fixed tension is applied in the X-axis and Y-axis directions. As shown in FIG. 3 (b), The peripheral portion of the mask member 12 is irradiated with laser light L to weld the magnetic metal member 2 and the frame 4.

Next, the opening pattern forming step will be described with reference to FIG. 4.

First, as shown in FIG. 4 (a), the film 3 is placed on the lower side, and the mask member 12 is placed on the XY stage 13 of the laser processing apparatus. The XY stage 13 has a glass plate 14 The front surface serves as a mounting surface, and a magnet 15 (for example, an electromagnet) is arranged on the back side of the glass plate 14, and is configured to be movable in the X-axis and Y-axis directions. Therefore, the mask member 12 is adhered and fixed to the glass plate 14 by attracting the magnetic metal member 2 with the magnet 15. At this time, it is preferable to apply a liquid 16 such as ethanol to the glass plate 14 as shown in the figure, and make the film 3 adhere to the glass plate 14 by the surface tension of the liquid 16.

Next, as shown in FIG. 4 (b), an opening pattern 6 is formed. In detail, the opening pattern 6 moves the XY stage 13 along the XY direction at a predetermined predetermined pitch while focusing the laser light L having a wavelength of 355 nm on a laser irradiation device (not shown), for example. The film 3 is formed on the film 3 in the through hole 5 of the magnetic metal member 2 by laser ablation. At this time, the cross-sectional shape at the focal point of the focused laser light L is adjusted so that the shape becomes the same shape and size as the opening pattern 6. Therefore, if the focal height position is appropriately controlled so that the focal position of the laser light L coincides with the position of the lower surface of the film 3, the opening of the opening pattern 6 on the side opposite to the magnetic metal member 2 can be consistent with the design. The end shape is finished. Therefore, as shown in FIG. 5, if the surface 3 a of the film 3 on the opposite side to the magnetic metal member 2 is set as a close contact surface with the substrate 17, a thin film pattern 21 having a size consistent with the design can be formed by vapor deposition. In addition, the wavelength of the laser light L is not limited to 355 nm, and may be 266 nm, 254 nm or less as long as the resin film 3 can be subjected to an ablation process.

In addition, if the height position of the focal point of the laser light L is gradually lowered from the side of the magnetic metal member 2 side of the film 3 toward the side 3a on the opposite side, and the opening pattern 6 is formed by multiple irradiations on one side, as shown in FIG. 1 As shown in (b), the opening pattern 6 is formed by providing a wedge shape to the side wall 18 so that the opening area temporarily narrows from the surface 3b on the magnetic metal member 2 side of the film 3 toward the surface 3a on the opposite side. At this time, if the wedge angle of the side wall 18 of the opening pattern 6 and the molecule of the film forming material are made When the maximum incident angle (the angle that becomes the normal to the mask surface) with respect to the mask surface is uniformly formed at, for example, 20 ° to 50 °, the opening pattern 6 on the magnetic metal member 2 side of the film 3 can be more effectively prevented The opening end edge portion 6a becomes a dead angle of film formation.

Furthermore, in the opening pattern forming step, a predetermined coordinate position for the coordinate position of any one of the opening patterns 6 in the plurality of opening patterns 6 is also defined, that is, the film 3 in the through hole for the alignment mark of the magnetic metal member 2. An alignment mark (not shown) for forming a penetration with the substrate 17 is formed.

Next, the formation of the thin film pattern 21 using the film-forming mask 1 of the present invention will be described. Here, as an example, the case where a film-forming apparatus is a vapor deposition apparatus is demonstrated.

First, as shown in FIG. 5 (a), the substrate 17 is held on the substrate holder 19 in a state where a magnet 15 (for example, an electromagnet) is disposed on the back surface.

Next, the film mask 1 is arranged with the surface 3 a of the film 3 and the vapor deposition surface of the substrate 17 facing each other, and the two are aligned using an alignment mark provided in advance on the substrate 17 and the film formation mask 1. Then, in a state where the two are aligned, the magnetic metal member 2 of the film-forming mask 1 is adsorbed by the magnetic force of the magnet 15, and the film-forming mask 1 is tightly fixed to the vapor deposition surface of the substrate 17. At this time, as shown in FIG. 1 (a), the elongated portions 2a of the magnetic metal member 2 located between the adjacent through holes 5 are connected to each other in the X-axis direction of the dielectric diaphragm 3, and movement in that direction is restricted. Therefore, even if the magnetic field strength of the magnet 15 is made stronger than conventional, the above-mentioned portion 2a of the magnetic metal member 2 will not move. Therefore, in this embodiment, the magnetic field strength of the magnet 15 is set to 200 mT which is 10 times stronger than the conventional one.

As shown in FIG. 5 (b), the substrate holder 19 that integrally holds the substrate 17 and the film-forming mask 1 is a substrate mounting portion in which a vapor deposition surface side of the substrate 17 is mounted downward in a vacuum tank of a vapor deposition apparatus.

The vapor deposition device used here is a slit-shaped through hole 5 with the film-forming mask 1 Correspondingly, a vapor deposition source 20 having a long crucible is provided in a long axis (Y axis) direction, and the vapor deposition source 20 is configured to be capable of intersecting the long axis (Y axis) of the through hole 5 (X axis). Direction).

Therefore, as shown in FIG. 5 (b), the deposition system on the substrate 17 moves the evaporation source 20 at a fixed speed along the X-axis direction, and is located directly above the evaporation source 20 at each time point during the movement. The opening pattern 6 of the mask 1 is formed. Therefore, as in the conventional technique, a part of the film-forming mask 1 located directly above the evaporation source 20 at each time point during the movement is heated by the radiant heat of the evaporation source 20.

However, unlike the conventional technique, in this embodiment, the magnetic field strength of the magnet 15 is set to 200mT which is 10 times stronger than the conventional one. Therefore, the film-forming mask 1 is adsorbed on the substrate 17 by the strong magnetic force of the magnet 15 without The elongated portion 2 a of the magnetic metal member 2 located between the adjacent through-holes 5 extends to peel off from the substrate 17 and hang down. Therefore, a gap is not generated between the film-forming mask 1 and the substrate 17, and the evaporation material M evaporated from the evaporation source 20 is prevented from flowing back to the mask back side, so that the edge of the thin film pattern 21 is not blurred or the shape The risk of expansion.

In addition, the used film 3 has an anisotropy in which the linear expansion coefficient is different from the orthogonal two axes, and the direction in which the axis with the small linear expansion coefficient of the film 3 intersects with the long axis of the through hole 5 of the magnetic metal member 2 (X The axial direction) is consistent, so that the extension of the film 3 in the X-axis direction is suppressed, so that the positional deviation of the opening pattern 6 in this direction and the expansion of the shape are suppressed. Therefore, even if, for example, the pixel pitch in the organic EL TFT substrate is narrowed and high-definition is improved, it is possible to avoid attaching organic EL materials of other colors to adjacent pixels.

Furthermore, since the linear expansion coefficient of the magnetic metal member 2 and the linear expansion coefficient of the X-axis direction of the film 3 are made to coincide with the linear expansion coefficient of the substrate 17, the substrate 17, the magnetic metal structure The deformation amount of the element 2 and the film 3 in the X-axis direction is substantially the same, so that the positional deviation of the thin-film pattern 21 formed on the substrate 17 in the X-axis direction can be suppressed. In addition, the positional shift in the Y-axis direction is, for example, a positional shift between the same colors in the case of a TFT substrate for an organic EL, and therefore it is not a problem.

In addition, although the case where the film-forming mask 1 is equipped with the frame 4 was demonstrated in the said embodiment, this invention is not limited to this, The frame 4 may not be provided. In this case, it is preferable to set the sheet-shaped film-forming mask 1 on the substrate 17 in a state of stretching its four sides by a fixed tension, and after the substrate 17 and the film-forming mask 1 are aligned, The magnetic metal member 2 is attracted by the magnet 15 and the film-forming mask 1 is brought into close contact with the substrate 17.

Also, in the above embodiment, the case where the film 3 is polyimide has been described, but the present invention is not limited to this. As long as the film 3 has anisotropy in the coefficient of linear expansion, the coefficient of linear expansion is small. The coefficient which is similar to the linear expansion coefficient of the magnetic metal member 2 may be another resin film or a multilayer laminated film.

1‧‧‧ film forming mask

2‧‧‧ magnetic metal components

2a‧‧‧ slim

3‧‧‧ film

3a, 3b‧‧‧face

4‧‧‧frame

5‧‧‧through hole

6‧‧‧ opening pattern

6a‧‧‧Open end edge

7‧‧‧ opening

18‧‧‧ sidewall

Claims (9)

A film-forming mask having a structure in which a resin-made film is closely adhered to one surface of a sheet-shaped magnetic metal member, the sheet-shaped magnetic metal member has a plurality of slit-shaped through holes arranged side by side, and is provided with The plurality of opening patterns in the through-holes that penetrate the film are characterized in that the film has an anisotropy in which the coefficient of linear expansion is different from the orthogonal two axes, so that the axis of the film with a small coefficient of linear expansion and The direction crossing the long axis of the through hole of the magnetic metal member is the same. For example, the film-forming mask of the first patent application range, wherein the linear expansion coefficient of the magnetic metal member is consistent with the linear expansion coefficient of a small coefficient of the film. For example, the film-forming mask in the second scope of the application for a patent, wherein the linear expansion coefficients of the respective films are consistent with the linear expansion coefficients of the substrates to be formed. For example, the film-forming mask according to any one of claims 1 to 3, wherein the film is polyimide. For example, the film-forming mask according to any one of claims 1 to 3 is applicable to a film-forming device that is used in close contact with the vapor-deposited surface of a substrate to be film-formed, and one side is in contact with the through-hole. The direction in which the major axes intersect causes the film formation substrate to move relatively to the film formation source, and film formation is performed on one side. For example, the film-forming mask in item 4 of the scope of patent application is suitable for a film-forming device, which is used in close contact with the vapor-deposited surface of a substrate to be film-formed, with one side in a direction crossing the long axis of the through hole. The film formation substrate is moved relatively to the film formation source, and film formation is performed. For example, the film-forming mask according to any one of claims 1 to 3 includes a frame-shaped frame, the frame-shaped frame is connected to a peripheral portion of the magnetic metal member, and has a plurality of internal elements. The opening of the size of the through hole. For example, the film-forming mask of item 4 of the patent application includes a frame-like frame which is joined to a peripheral edge portion of the magnetic metal member and has an opening having a size including the plurality of through holes. For example, the film-forming mask in the scope of the patent application No. 5 is provided with a frame-like frame which is joined to the peripheral edge portion of the magnetic metal member and has an opening having a size containing the plurality of through holes.