JP2005146338A - Vapor deposition mask - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor deposition mask which realizes elimination of the influence of radiation heat on the positional accuracy of opening patterns formed at a mask body, and consequently realizes formation of vapor deposition patterns with satisfactory positional accuracy. <P>SOLUTION: A mask body 6 in a vapor deposition mask 1 is composed of thin film-shaped first mask layers 3 provided with opening patterns 3a and second mask layers 5 having opening windows 5a including the opening patterns 3a and provided so as to be superimposed on the first mask layers 3, thus the film thickness of the mask body 6 is made large while holding the shape accuracy of the opening patterns 3a. In this way, the release of heat in the mask body 6 is facilitated, and degradation in the positional accuracy of the opening patterns 3a caused by the loosening of thin film parts due to radiation heat can be prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vapor deposition mask used for depositing a predetermined pattern on a deposition object.

In general, in a manufacturing process of a display using an organic electroluminescence element (organic electroluminescence element; hereinafter referred to as “organic EL element”), an organic material corresponding to each color component of R, G, and B is formed by vacuum deposition using a deposition mask. A film pattern is deposited on the substrate by vapor deposition.
It is carried out.

  This vapor deposition mask includes a mask main body having an opening pattern having a shape corresponding to a pattern formed by vapor deposition (so-called vapor deposition pattern), and a frame that is fixed to a region near the outer peripheral edge of the mask main body and supports the mask main body. What is provided is known. The mask main body is made of a thin plate member such as a copper plate, a nickel plate, a rolled stainless steel plate or the like, and an opening pattern is provided in the pattern region by etching or laser processing. On the other hand, the frame has a sufficient thickness and is formed with high rigidity by a material having a thermal expansion coefficient equivalent to that of the substrate that is the deposition target. And the vapor deposition mask which consists of these mask main bodies and a frame has the mask main body fixed to a frame in the state which gave tension to a mask main body so that a slack may not arise in a mask main body (above, the following patent) Reference 1).

Registered Utility Model No. 3082805

  By the way, when performing vacuum vapor deposition using a vapor deposition mask, the vapor deposition mask receives radiant heat from the vapor deposition source because the vapor deposition source is heated to evaporate the organic material from the vapor deposition source. Therefore, in the conventional vapor deposition mask, as described above, the frame body has the same thermal expansion coefficient as that of the substrate in order to avoid the occurrence of deviation in the alignment position between the vapor deposition mask substrates at room temperature and high temperature. It is made of a material (for example, Invar material). However, since it is necessary to form an opening pattern with high accuracy for the mask body, it is necessary to use a thin film. Usually, the thermal expansion is higher than the material constituting the frame body, such as a copper plate, a nickel plate, and a rolled stainless steel plate. A thin film of a material having a large coefficient is used.

  For this reason, when the mask main body is expanded by receiving radiant heat, it may bend, loosen, wrinkle, etc. in the mask main body at a high temperature even if it does not occur at normal temperature. When these occur, the position accuracy of the open pattern in the pattern area of the mask body cannot be maintained. Even when there is no bending, slack, wrinkles, etc., the internal stress generated when trying to expand the heat causes uneven distortion in the mask body, which maintains the positional accuracy of the opening pattern. It may be impossible.

  The problem regarding the position accuracy of the opening pattern caused by thermal expansion or contraction due to such radiant heat results in a decrease in the formation accuracy of the vapor deposition pattern formed using the vapor deposition mask. If it is a manufacturing process, there is a risk of hindering improvement in display image quality.

  Therefore, the present invention provides a vapor deposition mask that can eliminate the influence of copying heat on the positional accuracy of an opening pattern formed in a mask body and can perform vapor deposition pattern formation with good positional accuracy. With the goal.

  In order to achieve such an object, the vapor deposition mask of the present invention includes a mask body in which a plurality of recesses are formed on one main surface side, and an opening pattern is arranged in a thin film portion formed by the bottom of the recesses. It is characterized by that.

  In the vapor deposition mask having such a configuration, by arranging the opening pattern in the thin film portion formed by the bottom of the concave portion formed in the mask main body, the portion other than the thin film portion where the opening pattern is formed is a thick film. It has become. For this reason, the thickness of the mask body is ensured and the heat capacity is increased in a state where the formation accuracy of the opening pattern in the mask body is secured. Therefore, even when this mask body receives radiant heat during vapor deposition, the heat of the thin film portion that is most likely to expand due to the influence of radiant heat is easily radiated to the thickened portion, thus forming an opening pattern. Expansion of the formed thin film portion and loosening due to expansion are prevented.

  As described above, according to the vapor deposition mask of the present invention, it is possible to maintain the positional accuracy of the opening pattern during vapor deposition because the thin film portion on which the opening pattern is formed is prevented from slackening due to thermal expansion. . And it becomes possible to form a vapor deposition pattern with sufficient positional accuracy with respect to a to-be-deposited object by vapor deposition film formation using a vapor deposition mask. As a result, for example, the organic film pattern of the organic EL element can be deposited with good positional accuracy, and the display image quality of the display formed by arranging the organic EL elements on the substrate can be improved. Become.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each embodiment, an embodiment in which the present invention is applied to a vapor deposition mask used for forming an organic film pattern in the manufacture of a display (organic EL display) in which organic EL elements are arranged on a substrate is used. As will be described, the vapor deposition mask of the present invention is not limited to the one used for manufacturing an organic EL display.

<First Embodiment>
FIG. 1A is a plan view showing the configuration of the vapor deposition mask of the first embodiment, and FIG. 1B is a cross-sectional view taken along line AA ′ in the plan view.

  The vapor deposition mask 1 shown in these figures includes a thin film-like first mask layer 3, a second mask layer 5 disposed so as to overlap therewith, and a mask body 6 composed of these mask layers 3 and 5 at the periphery thereof. And a frame body 7 that is supported by.

  The first mask layer 3 is formed by arranging a plurality of opening patterns 3 a on a thin film of about several tens of μm, and is provided in a state of being stretched in the frame body 7 so as to cover the opening of the frame body 7. It has been. The opening pattern 3a has a fine shape corresponding to the organic film pattern formed using the vapor deposition mask 1, and is arrayed with a dimensional accuracy of about several μm. And in order to implement | achieve the highly accurate formation of such a fine opening pattern 3a, the 1st mask layer 3 is usually a metal foil formed by plating such as nickel or copper, or a rolled stainless steel plate Etc., and is fixed to the frame 7 by adhesion or welding.

  The second mask layer 5 provided so as to overlap the first mask layer 3 is formed by forming a plurality of opening windows 5a in a thick film having a sufficient thickness as compared with the first mask layer 3. Is. Similar to the first mask layer 3, the second mask layer 5 is provided in a state of being stretched in the frame body 7 so as to cover the opening of the frame body 7. The mask body 6 composed of the first mask layer 3 and the second mask layer 5 is provided with a recess whose one side of the opening window 5a is covered with the first mask layer 3, and the bottom of the recess, that is, the opening. The opening pattern 3a is arranged in a portion of the first mask layer 3 in the window 5a. The position accuracy of the opening window 5a may be 100 level accuracy.

  In particular, the side wall of the opening window 5a (that is, the side wall of the recess) has an opening width narrowed toward the first mask layer 3 side, and may be formed in a tapered shape as shown in the drawing, or a staircase. It may be formed into a shape. In addition, each opening part 5a may be a shape corresponding to the display surface of each display produced using this vapor deposition mask 1, for example. In the case of the vapor deposition mask 1 shown in the figure, it corresponds to nine openings 5a and is used to form organic film patterns of nine displays.

  The second mask layer 5 as described above is preferably configured using a material having high thermal conductivity such as aluminum, and is fixed to the frame body 7 by fitting or welding. On the other hand, the first mask layer 3 and the second mask layer 5 may be provided in a state of being fixed to each other, or may be provided in a separated state, but a flat plate shape on the second mask layer 5 side. It is important that when a deposition object (substrate) is placed, it is in close contact with each other over a wide area.

  The frame body 7 that supports the first mask layer 3 and the second mask layer 5 uses, for example, a low expansion material such as an invar material in order to prevent thermal expansion during the evaporation of the entire evaporation mask 1. It is supposed to be configured.

  In the case of producing the vapor deposition mask 1 having the above-described configuration, for example, as shown in FIG. 2, first, the first mask layer 3 is stretched on one main surface side of the frame body 7. Thereafter, the second mask layer 5 is fitted into the frame body 7 with the surface of the second mask layer 5 having the narrower opening width of the opening window 5a facing the first mask layer 3 side. Layer 3 and second mask layer 5 are overlaid. At this time, it is important that the first mask layer 3 and the second mask layer 5 are in contact with each other. In this state, the second mask layer 5 is fixed to the frame body 7.

  As another example of producing the vapor deposition mask 1, for example, as shown in FIG. 3, the second mask layer 5 is fitted and fixed in a frame 7. At this time, it is important to arrange the one main surface of the frame 7 and the surface of the second mask 5 with the narrower opening width of the opening window 5 on the same surface. In this state, the first mask layer 3 is stretched on one main surface side of the frame body 7.

  In FIG. 4, the block diagram in the case of performing vapor deposition using the vapor deposition mask 1 of the structure mentioned above was shown. As shown in this figure, the vapor deposition mask 1 is disposed above the vapor deposition source 9 during vapor deposition using the vapor deposition mask 1. The vapor deposition mask 1 is disposed with the first mask layer 3 facing upward, and the substrate W, which is a deposition target, is placed on the first mask layer 3. In this state, the vapor deposition material g is evaporated from the vapor deposition source 9, passes through the opening window 5a of the second mask layer 5 in the vapor deposition mask 1, and further passes through the opening pattern 3a of the first mask layer 3 to the substrate. A deposition pattern is formed on the substrate W by depositing on the substrate W. At this time, since the side wall of the opening window 5a has a shape in which the opening width is narrowed toward the first mask layer 5, the thick second mask layer 5 is prevented from being hindered by vapor deposition. .

  As described above, in the vapor deposition mask 1 having the configuration described with reference to FIGS. 1 to 4, the mask body 6 supported by the frame body 7 includes the first mask layer 3 in the form of a thin film in which the opening pattern 3 a is formed, and the opening window. The second mask layer 5 having 5a is overlaid. Thereby, in the part in which the opening pattern 3a is formed, the thin film state of the mask main body 6 can be maintained to such an extent that the shape accuracy of the opening pattern 3a can be secured. Moreover, the mask main body 6 can be made thicker at the portion where the first mask layer 3 and the second mask layer 5 overlap.

  For this reason, even if this mask main body 6 receives the radiant heat at the time of vapor deposition, the thin film part which expand | swells most easily by the influence of a radiant heat, ie, the 1st mask exposed in the opening window 5a of the 2nd mask layer 5. The heat of the layer 3 portion where the opening pattern 3a is formed is easily radiated to the thickened portion. Therefore, the thin film portion where the opening pattern 3a is formed is prevented from expanding and loosening due to the expansion, and the positional accuracy of the opening pattern 3a can be maintained without being affected by radiant heat. And it becomes possible by vapor deposition film formation using the vapor deposition mask 1 to form a vapor deposition pattern with sufficient positional accuracy with respect to the board | substrate W which is a to-be-deposited object.

  As a result, for example, the organic film pattern of the organic EL element can be deposited with good positional accuracy, and the display image quality of the display formed by arranging the organic EL elements on the substrate can be improved. Become.

  In the vapor deposition mask 1 having such a configuration, the second mask layer 5 is made of a material having high thermal conductivity such as aluminum, so that the heat radiation from the second mask layer 5 as described above is further increased. It will be done promptly.

Second Embodiment
In FIG. 5, sectional drawing of the vapor deposition mask 1a of 2nd Embodiment is shown. The difference between the vapor deposition mask 1a shown in this figure and the vapor deposition mask 1a of the first embodiment described with reference to FIG. 1 is the arrangement state of the opening pattern 3a in the first mask layer 3, and the other configurations are the same. Suppose that there is.

  That is, in the vapor deposition mask 1a of the second embodiment, the opening patterns 3a are arranged and arranged almost uniformly at the center of the first mask layer 3. Here, the central portion of the first mask layer 3 is a portion on the inner peripheral side with respect to a portion where the first mask layer 3 is disposed so as to overlap the frame body 7. For this reason, in this vapor deposition mask 1 a, a part of the opening pattern 3 a provided in the first mask layer 3 is blocked by overlapping with the second mask layer 5. Only the opening pattern 3a arranged in the opening window 5a of the second mask layer 5 is used for vapor deposition.

  Also in this vapor deposition mask 1a, the first mask layer 3 may be in a state of being fixed to at least the frame body 7 and in close contact with the second mask layer 5 over a wide area. For this reason, the 1st mask layer 3 and the 2nd mask layer 5 may be provided in the state mutually fixed, and may be provided in the state isolate | separated.

  The vapor deposition mask 1a having such a configuration is manufactured and the vapor deposition method using the vapor deposition mask 1a is the same as that in the first embodiment.

  In the vapor deposition mask 1a having such a configuration, the residual stress in the first mask layer 3 can be made in-plane uniform by providing the opening pattern 3a on the entire surface of the first mask layer 3. In particular, when the first mask layer 3 is stretched with respect to the frame body 7 in the manufacturing process, the tensile stress applied to the first mask layer 3 is also made in-plane uniform. For this reason, in the state of being stretched on the frame body 7, the influence of the residual stress and tensile stress can be eliminated, and the positional accuracy of the opening pattern 3a in the vapor deposition mask 1 can be improved.

  Further, if the first mask layer 3 and the second mask layer 5 are provided in a state of being separated from each other, the Young's modulus and Poisson's ratio in the first mask layer 3 can be obtained by providing the opening pattern 3a on the entire surface. Since it is made uniform in the plane, thermal deformation due to radiant heat during vapor deposition can be made uniform over the entire surface of the first mask layer 3. Therefore, it is possible to form an evaporation pattern without distortion on the substrate W that is an object to be deposited by vapor deposition using the vapor deposition mask 1.

  Furthermore, if the first mask layer 3 and the second mask layer 5 are provided in a state of being separated from each other, the second mask layer 5 can be exchanged. For this reason, for example, by fitting the second mask layer 5 having a different size, shape, number, etc. of the opening window 5a into the frame body 7 and fixing it, it is possible to cope with production of a display having a different display area. Therefore, the manufacturing cost of the display can be reduced.

<Third Embodiment>
In FIG. 6, sectional drawing of the vapor deposition mask 1b of 3rd Embodiment is shown. The difference between the vapor deposition mask 1b shown in this figure and the vapor deposition mask 1 of the first embodiment described with reference to FIG. 1 is that the second mask layer 5 and the frame 7 are integrally formed. The other configurations are the same.

  In this case, the integrated object 8 with the second mask layer 5 and the frame body 7 is configured using, for example, a low expansion material such as an invar material in order to prevent thermal expansion during the evaporation of the entire evaporation mask 1. I will do it.

  Also in this vapor deposition mask 1b, the first mask layer 3 may be in a state where it is fixed to at least the frame 7 and is in close contact with the second mask layer 5 over a wide area. For this reason, the part of the 1st mask layer 3 and the 2nd mask layer 5 may be provided in the fixed state, and may be isolate | separated.

  The vapor deposition mask 1b having such a configuration is manufactured according to the procedure described with reference to FIG. 3 in the first embodiment. The vapor deposition method using the vapor deposition mask 1b is the same as in the first embodiment.

  Even with the vapor deposition mask 1b having such a configuration, it is possible to obtain the same effect as the vapor deposition mask of the first embodiment.

  Even the vapor deposition mask 1b having such a configuration can be combined with the second embodiment, and the first mask layer 3 is formed by arranging the opening patterns 3a almost uniformly in the center thereof. be able to. Thereby, the effect of 2nd Embodiment can also be acquired collectively.

<Fourth embodiment>
In FIG. 7, sectional drawing of the vapor deposition mask 1c of 4th Embodiment is shown. The vapor deposition mask 1c shown in this figure is a modification of the vapor deposition mask 1b of the third embodiment described with reference to FIG. 6, and is an integrated body 8 of the second mask layer 5 and the frame 7 and the first mask layer 3. The heat radiation layer 13 made of a material having high thermal conductivity such as aluminum is sandwiched between the two.

  In the vapor deposition mask 1c having such a configuration, the heat of the first mask layer 3 in which the opening pattern 3a is formed is an integrated body of the second mask layer 5 having a large volume and the frame body 7 through the heat dissipation layer 13. 8 is easily dissipated. Therefore, as compared with the third embodiment, the effect of maintaining the positional accuracy of the opening pattern 3a without being affected by radiant heat is enhanced.

  As shown in the figure, the heat radiation layer 13 does not need to be provided on the entire surface between the second mask layer 5 and the integrated body 8 of the frame body 7 and the first mask layer 3. However, it is preferable to provide the entire surface between the portion of the second mask layer 5 and the first mask layer 3, thereby ensuring the effect of radiating the heat of the first mask layer 3.

  In addition, the configuration in which such a heat dissipation layer 13 is provided is not limited to the configuration in which the second mask layer 5 and the frame body 7 are integrated, and the first embodiment described with reference to FIG. It is applicable also to the structure of. When applied to the first embodiment, in particular, the second mask layer 5 is applied to a configuration in which the second mask layer 5 is configured using a low expansion material such as an invar material in the same manner as the frame body 7, so that a heat dissipation effect is obtained. Even when the second mask layer 5 which is not so high is used, it is effective because heat can be radiated through the heat radiating layer 13. Even if the second mask layer 5 is made of a material having a high thermal conductivity such as aluminum, the heat radiation layer 13 is made of a material having a higher thermal conductivity, thereby dissipating heat. It is possible to increase the effect.

  FIG. 8 shows the temperature distribution of the first mask layer of each vapor deposition mask during vapor deposition. Here, “(1) Conventional example” is the temperature of the vapor deposition mask in which the mask body is composed only of the first mask layer in the form of a thin film. “(2) With a second mask layer” is the temperature of the vapor deposition mask 1b made of an invar material in which the second mask layer 5 and the frame body 7 are integrated as shown in FIG. Further, “(3) second mask layer + heat dissipation layer” is a deposition in which the second mask layer 5 and the frame body 7 are made of an invar material as shown in FIG. 7, and a heat dissipation layer 13 made of aluminum is provided. This is the temperature of the mask 1c.

  As shown in these graphs, the temperature distribution of the vapor deposition masks (2) and (3) provided with the second mask layer is uniform as compared with the conventional example (1), and the mask body is partially The effect of thickening was confirmed. Furthermore, from the comparison result between (2) and (3), it was confirmed that the temperature distribution of the vapor deposition mask was further uniformed by providing a heat dissipation layer between the first mask layer and the second mask layer. .

  In the first embodiment described above, a configuration in which the first mask layer 3, the second mask layer 5, and the frame 7 are separate members will be described. In the third embodiment and the fourth embodiment, The configuration in which the two mask layers 5 and the frame 7 are integrated has been described. However, the vapor deposition mask of the present invention is not limited to such a configuration, for example, a configuration in which the first mask layer 3 and the second mask layer 5 are integrated, or the first mask layer 3 and the first mask layer 3. The two mask layers 5 and the frame 7 may be integrated, and the same effect can be obtained.

It is the top view and sectional drawing which show the structure of the vapor deposition mask of 1st Embodiment. It is the top view and sectional drawing which show an example of the preparation procedures of the vapor deposition mask of 1st Embodiment. It is the top view and sectional drawing which show the other example of the preparation procedures of the vapor deposition mask of 1st Embodiment. It is a figure which shows an example of the vapor deposition method using the vapor deposition mask of 1st Embodiment. It is sectional drawing which shows the structure of the vapor deposition mask of 2nd Embodiment. It is sectional drawing which shows the structure of the vapor deposition mask of 3rd Embodiment. It is sectional drawing which shows the structure of the vapor deposition mask of 4th Embodiment. It is a graph which shows the temperature distribution of each vapor deposition mask at the time of vapor deposition.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 1a, 1b, 1c ... Deposition mask, 3 ... 1st mask layer, 3a ... Opening pattern, 5 ... 2nd mask layer, 5a ... Opening window (recessed part), 6 ... Mask main body, 7 ... Frame, 13 ... Heat dissipation layer

Claims (8)

A vapor deposition mask, comprising: a mask body in which a plurality of concave portions are formed on one main surface side, and an opening pattern is arranged in a thin film portion formed by a bottom portion of the concave portions. The vapor deposition mask according to claim 1.
The side wall of the recess has an opening width narrowed toward the bottom side. The vapor deposition mask according to claim 1.
The mask main body is stretched in a frame body. The vapor deposition mask according to claim 1.
The mask main body is composed of a thin film-like first mask layer provided with the opening pattern and a second mask layer provided with an opening window including the opening pattern so as to overlap the first mask layer. And
The thin film portion of the mask body includes the first mask layer portion disposed in the opening window of the second mask layer. The vapor deposition mask according to claim 4.
The opening pattern is provided on the entire inner peripheral portion of the frame body in the first mask layer,
A vapor deposition mask, wherein a part of the opening pattern is covered with the second mask layer. The vapor deposition mask according to claim 5, wherein
The vapor deposition mask, wherein the first mask layer and the second mask layer are separated at an inner peripheral portion of the frame.
On the entire surface The vapor deposition mask according to claim 4.
The vapor deposition mask, wherein the second mask layer and the frame are integrally formed. The vapor deposition mask according to claim 4.
A vapor deposition mask, wherein a heat dissipation layer made of a material having higher thermal conductivity than the second mask layer is sandwiched between the second mask layer and the first mask layer.

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