JP2012052155A - Mask unit for vacuum film deposition and vacuum film deposition apparatus with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mask unit for vacuum vapor deposition that increases the accuracy of patterning, and to provide a vacuum film deposition apparatus including the same.SOLUTION: The vacuum film deposition apparatus 10 includes: the mask unit for vacuum film deposition; and a substrate pressing mechanism 6. The mask unit for vacuum film deposition includes: a metallic frame 2; and a metallic foil 4 fixed to the metallic frame 2, in which an opening pattern is formed. In the mask unit for vacuum film deposition, a substrate receiving part 3 that supports a substrate to be film-deposited (substrate 1) via the metallic foil and is formed in a tapered shape inclined concavely toward the central part of the substrate to be film-deposited, is provided on the inner edge side of the metallic frame. The substrate pressing mechanism 6 brings the substrate to be film-deposited into close-contact with the metallic foil to be mounted to the mask unit for vacuum film deposition.

Description

  The present invention relates to a vacuum film formation mask unit and a vacuum film formation apparatus including the same.

  When forming the organic compound layer or electrode constituting the organic EL element in a specific pattern by a vacuum film-forming method such as sputtering or vapor deposition, a shadow mask in which an opening corresponding to the film-forming site is formed as a specific method. A patterning technique using the is widely adopted.

  In recent years, in response to a demand for higher definition of elements, a vacuum film forming mask that can form a high-definition pattern with high accuracy is required.

  Patent Document 1 discloses a method of using a thin metal foil having a thickness of several tens of μm to one hundred μm as a mask foil. According to this method, formation of a thin film patterned into a fine stripe can be realized.

  However, since the mask foil alone cannot maintain rigidity and the opening pattern accuracy cannot be maintained, fix the four sides of this mask foil on the metal frame in a tensioned state, and then weld the edges of the mask foil. The foil is held on a metal frame.

JP 2004-323888 A

  By the way, in a vacuum film forming apparatus, a substrate on which a thin film is to be formed is placed on a mask on which a predetermined opening pattern is formed and aligned (alignment), and then fixed in a state facing an evaporation source or a sputtering target. After that, the film is formed. However, when the substrate is placed on the mask, the metal foil on which the substrate is placed bends together with the substrate due to the weight of the substrate itself. Even if the metal foil is attached to the metal frame under tension, this deflection is still not resolved.

  Here, since the metal foil is fixed at the frame portion, the deflection of the metal foil tends to be relaxed as it approaches the frame portion. However, since the substrate placed on the metal foil has a higher rigidity than the metal foil, the deflection of the substrate becomes larger than the deflection of the metal foil as it approaches the frame portion. Then, a phenomenon that the substrate is separated from the metal foil, so-called “floating” occurs.

  Here, if the above-mentioned “floating” does not occur when the substrate is in close contact with the metal foil up to the inner edge of the frame, there will be no problem during vapor deposition, but the above “floating” from a position inside the inner edge of the frame. Is generated, a gap is formed between the metal foil and the substrate. In this case, the material cannot be deposited according to the mask pattern at the time of deposition, which causes color blur and color mixing.

  In addition, even if the central part of the substrate and the part where the “floating” is generated are attracted to the magnet or pressed against the substrate in order to eliminate the above “floating”, a new “floating” is generated from the part that is not attracted or pressed by the magnet. Will occur. For this reason, it has been difficult to secure the adhesion between the substrate and the metal foil by the conventional method for fixing the substrate.

  On the other hand, in recent years, since the panel has been increased in definition and the substrate size has been increased, it is considered that the problem of ensuring the adhesion between the substrate and the metal foil becomes more obvious.

  The present invention is to solve the above-described problems, and an object of the present invention is to provide a vacuum vapor deposition mask unit for improving patterning accuracy and a vacuum film forming apparatus including the same.

The vacuum deposition mask unit of the present invention includes a metal frame,
A metal foil fixed to the metal frame and having an opening pattern formed thereon;
Provided on the inner edge side of the metal frame with a substrate receiving portion that supports the film formation substrate via the metal foil,
The substrate receiving portion has a taper shape inclined in a concave shape toward a central portion of the deposition target substrate.

  The vacuum deposition mask unit of the present invention and the deposition apparatus using the same are recessed toward the center of the substrate on the inner edge side of the metal frame so as to correspond to the deflection of the substrate (deposition substrate). A substrate receiving portion having a tapered shape inclined to the shape is provided. By doing so, the metal foil can be deformed so as to correspond to the deflection of the substrate. For this reason, adhesion of a board | substrate and metal foil is realizable in the whole surface of a board | substrate.

  Therefore, according to the present invention, it is possible to provide a vacuum deposition mask unit for improving the patterning accuracy and a vacuum film forming apparatus including the same.

It is a cross-sectional schematic diagram which shows the example of embodiment of the vacuum film-forming apparatus provided with the mask unit for vacuum film-forming of this invention. It is a schematic diagram which shows the vacuum film-forming apparatus provided with the mask unit for vacuum film-forming used by the comparative example.

  The vacuum film-forming mask unit of the present invention includes a metal frame and a metal foil fixed to the metal frame and having an opening pattern. In addition, a substrate receiving portion that supports the film formation substrate via a metal foil is provided on the inner edge side of the metal frame, and this substrate reception portion is inclined in a concave shape toward the central portion of the film formation substrate. It has a tapered shape.

  Hereinafter, a vacuum film formation mask and a vacuum film formation apparatus of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing an example of an embodiment of a vacuum film forming apparatus provided with the vacuum film forming mask of the present invention. The vacuum film forming apparatus of the present invention is an apparatus for performing vacuum deposition in a vacuum chamber, but in FIG. 1, the vacuum chamber is omitted for convenience of explanation.

  The vacuum film forming apparatus 10 in FIG. 1 includes an evaporation source as the film forming means 7, a vacuum film forming mask 11, and a substrate pressing mechanism 6.

  First, the vacuum film forming mask of the present invention will be described.

  A vacuum film formation mask 11 which is a constituent member of the vacuum film formation apparatus 10 in FIG. 1 is a member composed of a metal frame 2, a substrate receiving part 3, and a metal foil 4. As shown in FIG. 1, a film formation substrate (substrate 1) on which a thin film is formed is placed on a metal foil 4 constituting a vacuum film formation mask 11, and a part of the substrate 1, specifically, Specifically, the sides and corners of the substrate 1 are supported by the substrate receiving part 3 directly below the metal film 4 via the metal foil 4.

The substrate receiving part 3 is formed by cutting the inner edge part of the metal frame 2. Here, the shape of the taper of the substrate receiving portion 3 is not particularly limited as long as it can reduce the floating that may occur between the substrate 1 and the metal foil 4. The shape of the taper is determined by the cutting of the inner edge portion of the metal frame 2, but specific shapes of the taper include a shape in which the cutting surface is flat (conical section) and a shape in which the cutting surface is curved. . The taper angle of the taper of the substrate receiving portion 3 (the angle formed by the straight line connecting the top surface of the metal frame 2 and the apex of the taper end) is preferably in the range of more than 0 degree and 0.5 degree or less. A range of more than 0 degree and 1.0 × 10 ⁻³ degrees or less is more preferable.

  By providing the taper-shaped substrate receiving portion 3, a space corresponding to play is formed between the metal frame 2 and the metal foil 4 at the inner edge portion of the metal frame 2. Here, when the substrate 1 is placed at a position where the substrate receiving portion 3 is provided, the substrate 1 and the metal foil 4 enter the “space corresponding to play”. Then, since the relative distance between the metal frame 2 and the substrate 1 in the substrate receiving portion 3 becomes small, there is little or no floating in the substrate receiving portion 3 even if it occurs.

  As shown in FIG. 1, the metal foil 4 constituting the vacuum film forming mask 11 is welded at the outer edge portion of the metal frame 2, specifically, the welded portion 5 shown in FIG. 2 It is being fixed to the upper surface. The metal foil 4 has an opening pattern in a predetermined region so that a thin film can be formed in a desired pattern.

  Next, the substrate pressing mechanism will be described. The substrate pressing mechanism is provided for closely attaching the deposition target substrate (substrate 1) onto the metal foil (on the metal foil 4) provided in the vacuum film formation mask unit.

  A substrate pressing mechanism 6 which is a constituent member of the vacuum film forming apparatus of FIG. 1 includes a plurality of pins 6a for pressing the substrate 1 on a smooth plate (not shown) such as a surface plate. The pins 6a are provided at regular intervals at positions corresponding to at least the center, sides and corners of the substrate 1. However, in consideration of the adhesion between the substrate 1 and the metal foil 4, the pin at the position corresponding to the central portion of the substrate may be omitted. As shown in FIG. 1B, the substrate pressing mechanism 6 applies pressure in the metal frame region by pins 6a during film formation. At this time, the substrate receiving portion 3 has a tapered shape that is inclined concavely toward the central portion of the deposition target substrate. For this reason, when the substrate 1 is pressed by the substrate pressing mechanism 6, the deflection of the substrate 1 is absorbed into the tapered shape of the substrate receiving portion 3, and the entire surface of the substrate 1 can be brought into close contact with the metal foil 4.

  The pin 6a provided in the substrate pressing mechanism 6 may be fixed to a smooth plate, but can be swung in the vertical direction using an elastic member such as a spring for the purpose of accurately responding to the deflection of the substrate 1. It may be in the form.

  The substrate pressing mechanism 6 is not limited to the pin 6a described above. A method of attracting the magnetic frame using a magnet can also be adopted.

  By the way, when the substrate pressing mechanism 6 presses the substrate in a state where “floating” occurs between the substrate 1 and the metal foil 4, if the “floating” is small, the deflection of the substrate 1 may be reduced. It is correct | amended and the adhesiveness of the board | substrate 1 and the metal foil 4 can be ensured. However, when this “floating” is a size of several tens of μm, the deflection of the substrate 1 is corrected at the pressed position, but it is newly added at the position where the pressure is not applied due to the repulsive force against the pressure generated when pressed. Deflection occurs. For this reason, in order not to generate this force (repulsive force), it is necessary to provide a taper-shaped substrate receiving portion 3 to reduce the “floating” between the substrate and the metal foil that can occur at the inner edge of the metal frame 2.

  Next, the film forming means will be described.

  The film forming means 7 which is a constituent member of the vacuum film forming apparatus in FIG. 1 is an apparatus provided with a vapor deposition source, a sputtering target, etc., and well-known members and apparatuses are used for the film forming means 7. Can do.

  Examples of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the present embodiment.

  When forming a vapor deposition film with the vacuum film-forming apparatus 10 of FIG. 1, first, a substrate 1 (a glass substrate having a depth of 360 mm, a width of 460 mm, and a thickness of 0.5 mm) subjected to alignment processing is shown in FIG. As shown, it is placed on the metal foil 4. At this time, the substrate 1 has a shape in which a gentle arc is drawn on the metal foil 4 due to deflection due to its own weight. For this reason, a gap (floating) is generated between the substrate 1 and the metal foil 4 on the substrate receiving portion 3 that supports the substrate 1. This “float” is the largest at the corner of the substrate 1.

On the other hand, the substrate receiving portion 3 provided at the inner edge of the metal frame 2 has an inner edge of the metal frame 2 such that the taper angle is a conical section with a tilt of 4.4 × 10 ⁻⁵ degrees toward the center of the substrate 1. It is provided by cutting.

  Next, as shown in FIG. 1B, the substrate 1 is pressed by the substrate pressing mechanism 6 to fix the substrate 1 on the metal foil 4. When the substrate 1 is pressed here, the substrate 1 and the metal foil 4 are pushed into the substrate receiving portion 3 and deformed. Then, the deflection of the substrate 1 is absorbed by the substrate receiving portion 3 while making use of the deflection that draws a gentle arc due to the weight of the substrate 1. For this reason, the entire surface of the substrate can be brought into close contact with the metal foil 4.

  When vacuum deposition was performed after the substrate was fixed in this manner, no defect in pattern shape or deterioration in patterning accuracy was observed in the deposited film pattern formed on the substrate.

[Comparative example]
The vacuum film formation was performed in the same manner as in the example using a vacuum film formation mask in which the substrate receiving portion was not provided on the metal frame 2. The vacuum film forming apparatus 20 used in this comparative example has the same configuration as the vacuum film forming apparatus 10 in FIG. 1, but a part of it may be omitted for convenience of explanation.

  In this comparative example, when the substrate 1 is placed on the metal foil 4 as shown in FIG. 2A, the substrate 1 has a shape in which a gentle arc is drawn on the metal foil 4 due to deflection due to its own weight. Become. At this time, the substrate 1 is in close contact with the metal foil 4 up to the inner edge of the metal frame 2 although it is bent by its own weight at the side of the substrate (AA cross section in FIG. 2A) (FIG. 2). (B)). On the other hand, at the corner portion of the substrate (cross section BB in FIG. 2A), the substrate 1 is the metal foil at the inner side of the inner edge of the metal frame 2, specifically, at the portion C in FIG. “Floating” has occurred away from 4. In this comparative example, the “floating” is 40 μm to 50 μm.

  Here, when the vacuum film formation is performed without pressing the substrate 1 (in the state of FIGS. 2B and 2C), the film formation pattern shape and accuracy are particularly poor in the portion where the “floating” occurs. It was observed that there was.

  Here, in order to eliminate the “floating”, the corner portion of the substrate 1 was pressed against the metal frame 2 by the substrate pressing mechanism 6. Then, although the substrate 1 is in close contact with the metal frame 2 at the pressed portion, the substrate 1 is newly pressed due to the rigidity of the substrate 1 at a position where the substrate 1 is not pressed, specifically, at a portion D in FIG. Lift (50 μm to 60 μm) occurred. When vacuum film formation was performed in this state, it was observed that the film formation pattern shape and accuracy were particularly poor in the portion D in FIG. As a result, it has been found that it is difficult to improve the adhesion between the metal foil and the substrate only by pressing the substrate.

  1: Substrate, 2: Metal frame, 3: Substrate receiving part, 4: Metal foil, 5: Welded part, 6: Substrate holding mechanism, 7: Deposition source, 10 (20): Vacuum film forming apparatus, 11: Vacuum formation Membrane mask

Claims (2)

A metal frame,
A metal foil fixed to the metal frame and having an opening pattern formed thereon;
Provided on the inner edge side of the metal frame with a substrate receiving portion that supports the film formation substrate via the metal foil,
The vacuum film-forming mask unit, wherein the substrate receiving portion has a tapered shape inclined in a concave shape toward a central portion of the deposition target substrate. A vacuum deposition mask unit according to claim 1;
A vacuum film forming apparatus comprising: a substrate pressing mechanism for bringing a film formation substrate into close contact with a metal foil provided in the vacuum film forming mask unit.

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