JP6168944B2 - Deposition mask - Google Patents

Description

The present invention relates to a film formation mask for forming a thin film pattern on a substrate, and in particular, suppresses deformation of the mask due to a difference in linear expansion coefficient between the mask material and the thin film material, thereby improving the position accuracy of the thin film pattern. those of the deposition mask capable.

  The conventional film-forming mask uses a film-forming mask that uses a flexible adhesive film made of a flexible film made of a flexible film that covers a portion that should be a non-deposition area and adheres closely to the substrate surface. A film forming process in which the adhesive film is adhered to the entire surface of the base material on the film forming side, and then the flexible adhesive film covering a region where a desired deposited layer is to be formed is selectively removed and then the deposited layer is formed. Finally, the flexible adhesive film left on the substrate surface was removed (see, for example, Patent Document 1).

JP 2012-111985 A

  However, in such a conventional film formation mask, since the mask material is a flexible resin film such as polyimide, a line between the film and a thin film material deposited on the film, for example, a transparent conductive film is used. There was a problem that deformation of the film such as wrinkles and warpage occurred due to the difference in the expansion coefficient, and the position accuracy of the thin film pattern to be formed deteriorated.

Therefore, the present invention addresses such problems and suppresses mask deformation caused by the difference in linear expansion coefficient between the mask material and the thin film material, thereby improving the position accuracy of the thin film pattern. The purpose is to provide

In order to achieve the above object, a film-forming mask according to a first invention comprises a resin mask in which an opening pattern is formed corresponding to a thin film pattern formed on a substrate, and a through-hole having a size including the opening pattern. And a metal mask of a magnetic metal member that is provided on one side of the resin mask by forming a hole, and is provided on the back surface of the substrate between the resin mask and the metal mask. When the magnetic force of the magnet acts on the metal mask, the metal mask is attracted and adhered to the resin mask, and when the magnetic force of the magnet is removed, the metal mask can be separated from the resin mask by its elastic restoring force. A gap of a size is provided .

  According to the present invention, since the predetermined gap is provided between the resin mask and the metal mask, at the time of film formation, the metal mask is attracted by the magnet disposed on the back surface of the substrate and the resin mask is brought into close contact with the substrate surface. In addition, after the film formation is completed, when the attracting action of the metal mask by the magnet is released, the metal mask can be separated from the resin mask by its elastic restoring force. Therefore, the thin film deposited on the resin mask is divided, and internal stress caused by the difference in linear expansion coefficient between the resin mask material and the thin film material is also divided, so that deformation of the resin mask can be suppressed. Therefore, the positional accuracy of the thin film pattern formed on the substrate can be improved.

It is a center line sectional view showing an embodiment of a film formation mask by the present invention. It is an exploded view of the said film-forming mask, (a) shows a 1st mask, (b) shows a 2nd mask. It is explanatory drawing shown about formation of the through-hole of the said 2nd mask, (a) is sectional drawing when wet-etching from one surface side, (b) is sectional drawing when wet-etching from both surfaces, (c) is It is sectional drawing which shows the usage example which made the surface with a large opening area the resin mask side of the said 1st mask. It is the schematic which shows one structural example of the film-forming apparatus which uses the film-forming mask of this invention. It is explanatory drawing shown about installation to the film-forming substrate of the film-forming mask of this invention, (a) shows the case where the attraction | suction effect | action of the magnetic force of the magnet arrange | positioned at the back surface of a board | substrate does not reach, (b) Indicates a state in which the metal mask is attracted by the magnetic force of the magnet and is in close contact with the resin mask. It is explanatory drawing which expands and shows a part of FIG. 5, (a) is an enlarged view of FIG. 5 (a), (b) is an enlarged view of FIG.5 (b). It is explanatory drawing shown about the film-forming using the film-forming mask by this invention. It is explanatory drawing which shows the state after completion | finish of the said film-forming, (a) shows immediately after completion | finish of film-forming, (b) shows the state by which the attraction | suction action of the magnet to a metal mask was cancelled | released. It is explanatory drawing which expands and shows a part of FIG. 8, (a) is an enlarged view of FIG. 8 (a), (b) is an enlarged view of FIG.8 (b). It is a top view which shows the example of 1 structure of the touchscreen board | substrate manufactured using the film-forming mask by this invention.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a center line sectional view showing an embodiment of a film forming mask according to the present invention. The film formation mask 1 is used to form a thin film pattern on a substrate, and includes a first mask 2 and a second mask 3.

  The first mask 2 is formed on the substrate through the opening pattern 4 to form a thin film pattern, and serves as a main mask. As shown in FIG. It is configured to include a manufactured film (hereinafter referred to as “resin mask 5”), a metal thin film 6, and a first frame 7.

Here, the resin mask 5 is formed by forming a plurality of opening patterns 4 penetrating in the same shape and dimensions as the thin film pattern corresponding to the plurality of thin film patterns formed on the substrate. It is a resin film that transmits visible light, such as polyimide of about 30 μm or polyethylene terephthalate (PET). In the following description, a case of polyimide having a linear expansion coefficient of approximately 3 × 10 ^{−6 to} 5 × 10 ⁻⁶ / ° C. that approximates the linear expansion coefficient of glass as a film formation substrate will be described.

  Specifically, the opening pattern 4 is obtained by applying a laser beam shaped into the shape of the opening pattern 4 to be formed in a state where a polyimide film is stretched and fixed on a first frame 7 described later. It is formed by irradiating a polyimide film from one side. In this case, the reference is observed through transparent polyimide by placing the film on a transparent glass substrate on which a plurality of reference marks are formed corresponding to the formation positions of the plurality of opening patterns 4 to be formed. A plurality of opening patterns 4 may be formed on the film by irradiating the mark with the laser beam. Alternatively, a plurality of opening patterns 4 may be formed in the plane of the film while stepping the laser beam at a predetermined pitch.

  Further, on one surface 5 a of the resin mask 5, a metal thin film 6 composed of a plurality of isolated patterns is formed along the peripheral portion of the resin mask 5 in an outer region of the effective region where the plurality of opening patterns 4 are formed. Is provided. This metal thin film 6 is spot-welded to one end face 7a of a first frame 7 described later, and fixes the resin mask 5 to the first frame 7. For example, a metal film such as nickel is about 30 μm. The thickness is plated. Alternatively, it may be formed by sputtering or vapor deposition using a dedicated metal mask. After a metal thin film is formed on the entire surface 5a of the resin mask 5, a pattern of a plurality of metal thin films 6 isolated by etching is formed. It may be formed.

  Further, a first frame 7 is provided on the one surface 5 a side of the resin mask 5. The first frame 7 supports the resin mask 5 by spot welding a portion of the metal thin film 6 of the resin mask 5 to one end surface 7a in a state where the resin mask 5 is stretched. For example, an invar or an invar having a thickness of about 30 mm to 50 mm, for example, having a frame shape with an outer shape substantially equal to the outer shape of the resin mask 5. A magnetic metal member such as an alloy. In FIG. 2B, reference numeral 10 denotes a screw hole for fixing the first mask 2 to the second mask 3.

  The second mask 3 is provided on the surface 5 a side of the resin mask 5 of the first mask 2 with a predetermined gap 9 defined in advance with respect to the resin mask 5. The second mask 3 is for preventing the resin mask 5 from being deformed due to the difference in the linear expansion coefficient between the resin mask 5 and the thin film material due to the thin film material deposited on the resin mask 5. Yes, it is a sub mask, and comprises a metal mask 11 and a second frame 12 as shown in FIG.

  Here, the metal mask 11 is a magnetic metal member having, for example, a thickness of about 30 μm to 50 μm in which a through-hole 13 having a size including at least one opening pattern 4 is formed, and has an outer shape of the first frame 7. The resin mask 5 is provided with the gap 9 provided in the opening 8. When the magnetic force of the magnet installed on the back surface of the substrate acts on the metal mask 11, the gap 9 attracts the metal mask 11 to adhere to the resin mask 5, and when the magnetic force of the magnet is removed, the metal mask 11 is removed. It is desirable to set the size so that it can be separated from the resin mask 5 by an elastic restoring force, for example, about 300 μm. The through-hole 13 may have a size including a plurality of opening patterns 4, but the deposition area of the thin film material on the resin mask 5 is reduced to reduce the mask material and the thin film material. In order to suppress the deformation of the resin mask 5 caused by the difference in linear expansion coefficient, it is more desirable that the through hole 13 has a size including one opening pattern 4.

  Specifically, the through hole 13 may be formed by wet etching a sheet of magnetic metal member using a resist mask 14 as shown in FIG. In this case, since the magnetic metal member is isotropically etched in the wet etching, if the etching is performed only from one surface side as shown in FIG. 14 is formed so as to become narrower from the formation surface side toward the other surface side. Further, as shown in FIG. 4B, when the magnetic metal member is etched from both sides, the through hole 13 is formed so that the opening area on both sides is wider than the inside. Therefore, in order to prevent the thin film material from adhering to the side wall of the through hole 13 during film formation and to easily separate the metal mask 11 from the resin mask 5 after film formation, the metal mask 11 is shown in FIG. ), The surface side of the through hole 13 having a large opening area may be opposed to the resin mask 5. In the present embodiment, a case will be described in which the side of the through hole 13 having a small opening area is the resin mask 5 side in order to prevent the edge of the through hole 13 from being a shadow of film formation. However, in the case of sputtering film formation, since sputtered particles wrap around more than vapor deposition, as shown in FIG. 3 (c), even if the surface side with a large opening area of the through hole 13 is the resin mask 5 side, the through hole The influence of 13 edges on film formation is small.

  On the opposite side of the metal mask 11 from the resin mask 5 side, a second frame 12 is provided. As shown in FIG. 2B, the second frame 12 supports the metal mask 11 by spot-welding the peripheral edge of the metal mask 11 to the one end surface 12a as shown in FIG. It has an opening 15 having a size that encloses the plurality of through-holes 13 of the metal mask 11, and has a frame shape whose size can be accommodated in the opening 8 of the first frame 7. Is a magnetic metal member such as Invar or Invar alloy having a thickness of about 30 mm to 50 mm. Further, a flange 16 is provided on the other end surface 12 b side of the second frame 12 so as to protrude to the opposite side to the opening 15 side. The other end surface 7 b of the first frame 7 is screwed to the collar 16. (Refer to FIG. 1). In this case, each thickness of the first frame 7, the second frame 12, and the collar 16 is such that the gap 9 is generated in a state where the first frame 7 is fixed to the collar 16 of the second frame 12. Is determined. In FIG. 2B, reference numeral 18 denotes a hole through which the screw 17 is passed.

Next, film formation using the film formation mask 1 configured as described above will be described. In the following description, the case where the film forming apparatus is a sputtering apparatus as shown in FIG. 4 will be described.
First, the film formation mask 1 is prepared by fixing and assembling the first frame 7 of the first mask 2 and the second frame 12 of the second mask 3 with the screws 17.

Next, the deposition mask 1 is attached to the mask holder 20 provided in the vacuum chamber 19 of the sputtering apparatus so that the first mask 2 is on the deposition target substrate (hereinafter simply referred to as “substrate 22”) side. . Further, for example, a cylindrical indium tin oxide (hereinafter referred to as “ITO”) as a film forming material is provided on the target holder 23 configured to be reciprocally movable in the directions of arrows A and B parallel to the surface of the substrate 22 installed in the substrate holder 21. (Indium Tin Oxide) ”) 24) is attached with its cylinder axis intersecting the moving direction .

  When the deposition mask 1 is attached, the exhaust valve 26 is opened with the gas introduction valve 25 closed, and the air in the vacuum chamber 19 is exhausted and evacuated until a predetermined degree of vacuum is reached. .

When the degree of vacuum in the vacuum chamber 19 reaches a predetermined value, the front chamber (not shown) is partitioned by the gate valve 27 and maintained at substantially the same degree of vacuum (in FIG. 4, adjacent to the vacuum chamber 19 on the back side). substrate 22 made provided.) by the substrate loading mechanism (not shown) from the transparency of glass is conveyed, it is placed on the substrate holder 21. Thereafter, the substrate loading mechanism is retracted to the front chamber, and the gate valve 27 is closed.

  Next, the mask holder 20 moves in the direction of arrow C in FIG. 4 to place the deposition mask 1 on the substrate 22. Specifically, as shown in FIG. 5A, the resin mask 5 of the first mask 2 is placed on the film formation surface of the substrate 22. At this time, as shown in FIG. 6A, a predetermined gap 9 is maintained between the resin mask 5 and the metal mask 11. After that, as shown in FIG. 5B, the magnetic force of the magnet 28 built in the substrate holder 21 is applied to attract the metal mask 11 of the second mask 3, and the metal mask 11 is elastically bent. The resin mask 5 is pressed, and the resin mask 5 is brought into close contact with the film forming surface of the substrate 22 and fixed. At the same time, as shown in FIG. 6B, the metal mask 11 adheres to the surface of the resin mask 5.

  Subsequently, the gas introduction valve 25 is opened and the exhaust valve 26 is adjusted so that an inert gas such as argon (Ar) gas is introduced into the vacuum chamber 19 until a predetermined value is reached.

  When the gas pressure in the vacuum chamber 19 reaches the predetermined value, a high voltage is applied to the target holder 23 and plasma 29 is generated between the target 24 and the substrate 22 as shown in FIG. And sputtering is performed by reciprocating in the directions of arrows A and B shown in FIG. In detail, a shutter (not shown) is inserted between the target 24 and the substrate 22 for a certain time (pre-sputtering time) before the main sputtering is started, and the sputtered particles adhere to the substrate 22. Is blocking.

  When sputtering for a predetermined time is executed and a certain thickness of ITO conductive film is deposited on the substrate 22, the shutter is closed and the sputtering is completed. Then, the application of the high voltage to the target holder 23 is released, and the generation of the plasma 29 is stopped as shown in FIG. At this time, as shown in FIG. 9A, the ITO conductive film 30 includes the surface of the substrate 22 in the opening pattern 4, the sidewall of the opening pattern 4, the peripheral edge of the opening pattern 4 of the resin mask 5, and the sidewall of the through hole 13. And deposited on the surface of the metal mask 11 on the target 24 side.

Next, as shown in FIG. 8B, when the attracting action on the metal mask 11 by the magnetic force of the magnet 28 built in the substrate holder 21 is removed, as shown in FIG. The original state is restored by the elastic restoring force. Thereby, the ITO conductive film 30 deposited on the resin mask 5 is separated from the metal mask 11. At the same time, since the pressing force of the metal mask 11 on the film formation surface of the substrate 22 is released, the resin mask 5 is peeled off from the film formation surface of the substrate 22. Thus, the substrate 22 of the transparency of glass, a touch panel substrate 32 in which a plurality of electrodes 31 of ITO conductive film 30 (thin film pattern) is formed is formed as shown in FIG. 10.

  Next, the mask holder 20 is moved in the direction of arrow D shown in FIG. 4 to separate the deposition mask 1 from the substrate 22 and the inert gas in the vacuum chamber 19 is exhausted. Then, the gate valve 27 for partitioning the vacuum chamber 19 and the front chamber is opened, and the touch panel substrate 32 is carried out from the vacuum chamber 19 to the front chamber by the substrate loading mechanism. The substrate 22 is carried in and installed in the substrate holder 21.

  Thereafter, film formation is performed on a new substrate 22 in the same manner as described above, and a new touch panel substrate 32 is formed. Each time the film formation on the substrate 22 is completed, the metal mask 11 is separated from the resin mask 5, so that the ITO conductive film 30 deposited on the resin mask 5 is separated from the metal mask 11 each time. Therefore, the ITO conductive film 30 deposited on the resin mask 5 is only the peripheral portion of the opening pattern 4 and is divided between the adjacent opening patterns 4. Therefore, the shrinkage stress of the ITO conductive film 30 is divided and the resin mask 5 is divided. Is prevented from being deformed. Therefore, the positional accuracy of the electrode 31 made of the ITO conductive film 30 can be improved. At the same time, since the deformation of the resin mask 5 is suppressed, there is an advantage that the life of the resin mask 5 is extended.

  In the above embodiment, the case where the first mask 2 and the second mask 3 are each provided with a frame has been described. However, the present invention is not limited to this, and the first mask 2 includes only the resin mask 5. The second mask 3 may be only the metal mask 11. In this case, a metal spacer may be provided between the resin mask 5 and the metal mask 11 so that a gap 9 is formed between them.

  Moreover, although the case where the film-forming apparatus was a sputtering apparatus was demonstrated in the said embodiment, this invention is not limited to this, The film-forming apparatus may be a vapor deposition apparatus.

  Furthermore, although the case where the thin film is the ITO conductive film 30 has been described in the above embodiment, the present invention is not limited to this, and the thin film may be any of an organic material thin film, an inorganic material thin film, or a metal thin film. Good.

DESCRIPTION OF SYMBOLS 1 ... Film-forming mask 2 ... 1st mask 3 ... 2nd mask 4 ... Opening pattern 5 ... Resin mask 7 ... 1st frame 9 ... Gap 11 ... Metal mask 12 ... 2nd frame 13 ... Through-hole 22 ... Substrate 28 ... Magnet 30 ... Transparent conductive film 31 ... Electrode 32 ... Touch panel substrate

Claims (4)

A resin mask having an opening pattern corresponding to the thin film pattern formed on the substrate;
A metal mask of a magnetic metal member formed on one surface side of the resin mask by forming a through-hole having a size including the opening pattern;
Configured with
Between the resin mask and the metal mask, when the magnetic force of the magnet installed on the back surface of the substrate acts on the metal mask, the metal mask is attracted and brought into close contact with the resin mask. A film-forming mask having a gap of a size capable of separating the metal mask from the resin mask by its elastic restoring force when the action is removed.   The film-forming mask according to claim 1, wherein at least the opening area on the resin mask side of the through hole of the metal mask is wider than the opening area inside the through hole. The resin mask has a peripheral edge fixed to the first frame, and the metal mask has a peripheral edge fixed to the second frame,
3. The composition according to claim 1, wherein the first frame and the second frame are detachably fixed so that the gap is formed between the resin mask and the metal mask. Membrane mask.   The film-forming mask according to claim 1, wherein the thin film pattern is a transparent conductive film formed by sputtering.