JP2005179739A - Mask for vapor deposition, and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mask for vapor deposition in which, even when it is influenced by heat, and its intra-plane temperature distribution is made uneven, the adverse influence by the unevenness of the temperature distribution can be eliminated as possible, and which can correspond to patterning with high precision. <P>SOLUTION: In the mask for vapor deposition provided with a thin sheet-shaped mask body 2 having an opening with a shape corresponding to a formation pattern to the object to be treated and a frame body supporting the region in the vicinity of the outer circumferential edge thereof, and in which the mask body 2 is stuck to the frame body, the stuck part of the mask body 2 and the frame body is formed of a line-shaped portion 6 having a curved part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an evaporation mask used for forming a predetermined pattern on an object to be processed and a method for manufacturing the same.

  In general, in the manufacturing process of an organic electroluminescent element (organic electroluminescent element; hereinafter referred to as “organic EL element”), the water resistance of the organic material forming the organic layer is low and a wet process cannot be used. An organic layer (thin film) is formed thereon. Further, in the manufacturing process of the organic EL element, in order to perform patterning film formation (for example, film formation corresponding to each color component of R, G, B) on the glass substrate, the shape corresponding to the formation pattern is usually used. An evaporation mask having an opening (passage for organic material) is used.

  Conventionally, as a mask for vapor deposition, a mask main body in which an opening having a shape corresponding to a formation pattern is formed in a pattern region, and a frame body that supports an outer peripheral edge region other than the pattern region of the mask main body are provided. Is known. The mask 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 is provided in the pattern region by etching or laser processing. On the other hand, the frame has a sufficient thickness and high rigidity made of a material having a thermal linear expansion coefficient equivalent to that of the glass substrate that is the object to be processed. And the mask for vapor deposition which consists of these mask main bodies and a frame is fixed to the frame in the state where tension was given to the mask main body so that slack may not arise in the mask main body (for example, patent) Reference 1).

Registered Utility Model No. 3082805

  However, in the conventional vapor deposition mask, the mask body and the frame are fixed to each other by, for example, spot welding or laser welding. As shown in FIG. Therefore, it is not necessarily preferable to maintain high uniformity of the deposited film (organic layer), formation position accuracy, and the like.

  In general, when vacuum deposition is performed using a deposition mask, the deposition source of the organic material is heated to a high temperature, and therefore the deposition mask receives radiant heat from the deposition source. At this time, in the mask surface of the vapor deposition mask, for example, as shown in FIG. 6, it is conceivable that the temperature distribution becomes uneven as the temperature increases near the center. Such non-uniformity of the temperature distribution in the mask surface causes a difference in the deformation movement state depending on each position on the mask surface. That is, since the material forming the mask body expands larger in the high temperature portion than in the low temperature portion, the mask main body has a barrel shape, for example, as shown in FIGS. 7A and 7B. It will lead to deformation. Therefore, if the fixed part of the mask body and the frame is arranged in a straight line, there is a possibility that the position deviation of the vapor deposition pattern may become non-uniform due to the difference in the deformation movement state at each position on the mask surface. However, it is not always possible to maintain high uniformity and formation position accuracy of the deposited film. This problem with respect to pattern position accuracy results in a decrease in the formation accuracy of the organic layer by the vapor deposition mask, and there is a possibility that the display image quality improvement may be hindered in the manufacturing process of the organic EL element.

  Therefore, the present invention can eliminate as much as possible the adverse effects due to the non-uniformity of the temperature distribution even when the deposition mask can be affected by heat and the in-plane temperature distribution can be non-uniform. It is an object of the present invention to provide an evaporation mask and a method for manufacturing the same that can cope with high-precision patterning.

  The present invention is a vapor deposition mask devised to achieve the above object. That is, it comprises a thin plate-shaped mask main body having an opening having a shape corresponding to a formation pattern on the object to be processed, and a frame body that supports a region near the outer peripheral edge of the mask main body, and the mask main body is the frame body. The vapor deposition mask is configured to be fixed to the mask body, wherein the mask main body and the frame are fixed so that the fixing portion has a line-shaped portion, and the line-shaped portion has a curved portion. To do.

  Moreover, this invention is the manufacturing method of the mask for vapor deposition devised in order to achieve the said objective. That is, it comprises a thin plate-shaped mask main body having an opening having a shape corresponding to a formation pattern on the object to be processed, and a frame body that supports a region near the outer peripheral edge of the mask main body, and the mask main body is the frame body. In the method of manufacturing a vapor deposition mask that is fixed to a mask, the fixing portion between the mask body and the frame has a line-shaped portion, and the line-shaped portion has a curved portion. It is characterized by.

  In the manufacturing method of the vapor deposition mask having the above-described configuration and the vapor deposition mask having the above-described procedure, the fixing portion between the mask main body and the frame is arranged so as to have a line-shaped portion. Here, the line-shaped portion means a portion where the fixing portions are arranged in a line (line shape) if the fixing is performed by welding or a fastener (screw, etc.), for example, the fixing is by adhesion. If it is a thing, it means the part where the edge of the adhering region is lined up. And such a line-shaped part is distribute | arranged so that it may have a curved part. Here, the curved portion refers to a non-linear portion, and it is either a case where the entire linear portion is a curved portion or a case where a portion of the linear portion is a curved portion. It doesn't matter.

  As described above, if the fixing portion between the mask main body and the frame is a line-shaped portion having a curved portion, even if the in-mask temperature distribution is non-uniform, the non-uniform aspect is obtained. Accordingly, it is possible to arrange the curved portion. Specifically, for example, it is possible to arrange a curved part such that the part where the temperature is high on the mask body is close to the fixing part, and the part where the temperature is lower is far from the fixing part. It becomes. Therefore, even if there is a difference in the thermal expansion state at each position on the mask body due to the influence of the non-uniform temperature distribution, the position of the fixing portion with respect to each position also varies accordingly. The deformation movement state at each position on the main body can be made uniform.

  In the present invention, even if the in-plane temperature distribution of the evaporation mask can be non-uniform, the mask main body and the frame are secured to the mask main body by using a linear portion having a curved portion. Since the deformation movement state above can be made uniform, adverse effects due to the non-uniform temperature distribution can be eliminated as much as possible. Accordingly, it is possible to easily realize the high accuracy of the vapor deposition pattern by suppressing the pattern deformation due to the nonuniform temperature distribution, and to cope with the high-precision patterning.

  Hereinafter, the vapor deposition mask and the manufacturing method thereof according to the present invention will be described with reference to the drawings. 1 and 2 are schematic views showing an example of a schematic configuration of a vapor deposition mask according to the present invention.

  As shown in FIG. 1, the vapor deposition mask 1 described here includes a mask body 2 and a frame 3.

  The mask body 2 is made of a thin plate member such as a copper plate, a nickel plate, a rolled stainless steel plate or the like, and the region on the plane is roughly divided into a pattern formation region 4 and other portions. And in the pattern formation area 4, the opening 5 of the shape corresponding to a vapor deposition pattern is formed as an organic material passage hole by etching, laser processing, or the like. The pattern formation region 4 is not limited to a rectangular shape, and may have various arbitrary shapes. Further, the mask body 2 may be formed of a thin metal film such as nickel in which a large number of fine holes 5 are provided in the pattern formation region 4 by the “electroforming (plating) manufacturing method”. .

  On the other hand, the frame body 3 is formed in a shape corresponding to the outer peripheral edge of the mask main body 2 and is for supporting a portion other than the pattern formation region 4 of the mask main body 2. Here, the frame 3 has a linear thermal expansion coefficient, a heat capacity, a surface radiation emission rate, a heat transfer amount flowing in and out by the surrounding support and heat conduction, etc., and a temperature change at the time of vapor deposition. In order to synchronize and match the dimensional change in expansion and contraction due to the above, it is assumed that the optimal adjustment is set.

  Then, on one plane of the frame 3 (hereinafter, this surface is referred to as a “support surface”), a portion other than the pattern formation region 4 in the mask body 2 extends over the entire circumference in a state where tension is applied to the mask body 2. It is fixed. Thereby, the mask main body 2 fixed with tension is expanded and contracted according to the fixed frame 3. Therefore, as a result, the mask main body 2 can expand and contract in synchronization with the glass substrate that is the object to be processed in synchronism with the dimensional change of expansion and contraction. The tension and the direction of the tension applied to the mask body 2 are preferably set so that the stress distribution generated in the pattern formation region 4 of the mask body 2 is uniform. Further, the mask body 2 is fixed to the frame 3 with an adhesive having stable properties against temperature changes such as welding such as spot welding or laser welding, or a heat-resistant ceramic adhesive or a heat-resistant epoxy resin adhesive. Although it can be considered to be performed by using the adhesive used, it may be performed by using fasteners (screws) such as screws.

  By the way, as shown in FIG. 2, the fixing portion between the mask main body 2 and the frame body 3 is arranged so as to have a line-shaped portion 6. Here, the line-shaped portion 6 means a portion where the fixing portions are arranged in a line (line shape) if the fixing is performed by welding or a fastener, for example, if the fixing is by adhesion. For example, it means a portion where the edge of the fixed region is lined up. In the illustrated example, a case where four line-shaped portions 6 are arranged along the outer peripheral edge of the mask body 2 is shown.

  Furthermore, these line-shaped parts 6 are arranged so that each has a curved part. Here, the curved portion refers to a non-linear portion, and it is either a case where the entire linear portion is a curved portion or a case where a portion of the linear portion is a curved portion. It doesn't matter. In the example shown in the figure, all of the four line-shaped portions 6 are curved portions. In addition, when there are a plurality of line-shaped portions 6 as in the illustrated example, it is sufficient that at least one of them has a curved portion.

  Next, the manufacturing procedure of the evaporation mask 1 as described above, and more specifically, the fixing procedure of the mask body 2 and the frame body 3 constituting the evaporation mask 1 will be described.

  When the mask body 2 and the frame 3 are fixed, first, based on the use conditions of the vapor deposition mask 1, the temperature change during vapor deposition that the vapor deposition mask 1 receives, that is, the temperature due to the influence of radiant heat during vapor deposition. By grasping the distribution, the amount of distortion generated in the mask main body 2 due to the thermal stress when the temperature change occurs is recognized. More specifically, the magnitude and direction of expansion / contraction that can occur at each location of the mask body 2 when a temperature change occurs is calculated by performing operational analysis based on the thermal linear expansion coefficient of the mask body 2.

  At this time, in the pattern formation region 4 of the mask main body 2, for example, a portion where the openings 5 are dense and a portion where the openings 5 are not dense, or an opening 5 having a particularly large size compared to many other openings 5 is provided. If there is a portion, the magnitude and direction of expansion / contraction will not be uniform, and a distribution according to their arrangement will occur. Therefore, in such a case, for example, the distribution is analyzed using a calculation process by a finite element method, and the magnitude and direction of expansion / contraction are calculated including the state of the distribution.

  Then, after recognizing the amount of distortion due to thermal stress, the fixing location between the mask body 2 and the frame 3 is specified. Specifically, as will be described in detail later, the size and direction of the curved portion of the line-shaped portion 6 are specified so that the strain amount due to thermal stress is offset. This specification may also be performed using, for example, a calculation process based on the finite element method based on the above-described recognition results. Note that the calculation process by the finite element method and the analysis (simulation) technique using the calculation process can be realized by using a known technique, and thus the description thereof is omitted here.

  Thus, after specifying the size and direction of the curved portion of the line-shaped portion 6 based on the temperature distribution in the mask body 2 during vapor deposition and the position of the opening 5 in the mask body 2, the mask body In a state where a predetermined tension is applied to 2 and a region near the outer peripheral edge is pulled outward, a portion other than the pattern formation region 4 in the mask body 2 is placed in close contact with the frame 3, The mask body 2 is fixed to the frame 3. The fixing at this time is performed by welding, bonding, fastener fastening, or the like, and the fixing portion has a line-shaped portion 6 and the line-shaped portion 6 has a curved portion having a specified size and direction. Do. It should be noted that the formation of the bending portion, that is, the bending of the line-shaped portion 6 may be realized using a publicly known technique, and thus the description thereof is omitted here.

  By the procedure as described above, the above-described vapor deposition mask 1, that is, the vapor deposition mask in which the line-shaped portion 6 is arranged so as to have a curved portion is obtained.

  When vacuum deposition is performed using the vapor deposition mask 1 having such a configuration, as already described, the mask main body 2 has a higher temperature, for example, near the center due to the influence of radiant heat from the vapor deposition source. Becomes a non-uniform temperature distribution (see FIG. 6). However, even in such a case, in the vapor deposition mask 1, in more detail, the line-shaped portion 6, which is a fixing portion between the mask main body 2 and the frame body 3, has a curved portion. The central part is arranged so as to curve toward the central part. Therefore, near the center of the mask body 2, that is, the portion where the temperature is high on the mask body 2, the distance to the line-shaped portion 6 is short, and the portion where the temperature is lower is far from the fixing portion. become.

  Therefore, since the vicinity of the center of the mask body 2 becomes high temperature due to the influence of radiant heat, the amount of thermal expansion increases, but since the distance to the line-shaped portion 6 is short, the amount of deformation due to the thermal expansion is limited, As a result, the deformation movement state at each position on the mask main body 2 can be made uniform. In general, the degree of thermal expansion (thermal strain) is specified by the linear thermal expansion coefficient of the forming material of the mask body 2 and the radiant heat received by the mask body 2. The deformation amount of the mask body 2 is specified by multiplying the thermal strain by the size of the mask body 2 (the length in the line direction in the virtual cross section). That is, even if the thermal strain near the center portion of the mask body 2 is large, if the distance to the line-shaped portion 6 is short, the deformation movement amount near the center portion can be suppressed. The deformation movement state with the part can be made uniform.

  FIG. 3 is a schematic diagram showing an example of the simulation result of the deformation movement state at each position on the mask surface of the vapor deposition mask according to the present invention. According to the simulation results shown in FIGS. 3 (a) and 3 (b), as described above, the distance to the line-shaped portion 6 is close in the vicinity of the central portion of the mask main body 2, and the fixing portion is in other portions. If the line-shaped portion 6 that is a fixing portion between the mask body 2 and the frame body 3 is disposed so as to be far away, the mask body can be obtained even if the temperature distribution becomes higher near the center of the mask body 2. It can be seen that 2 does not deform into a barrel shape and deforms uniformly in each of the X and Y directions on the mask body 2. That is, it can be said that the deformation movement state of each position on the mask main body 2 is made uniform.

  As described above, if the fixing portion between the mask body 2 and the frame 3 is a line-shaped portion 6 having a curved portion, even if the mask in-plane temperature distribution is non-uniform, the non-uniformity is not achieved. It becomes feasible to arrange the curved portion according to the aspect. Therefore, even if there is a difference in the thermal expansion state at each position on the mask main body 2 due to the influence of the non-uniformity of the temperature distribution, the position of the fixing portion with respect to each position also differs accordingly. The deformation movement state at each position on the mask body 2 can be made uniform. This uniformity makes it possible to maintain high uniformity of the deposited film and formation position accuracy, etc., so that it is possible to cope with high-precision patterning, and display image quality can be improved in the manufacturing process of organic EL elements. It is expected to lead to

  In general, with respect to the opening 5 on the mask body 2, in order to eliminate the deviation at the time of forming the vapor deposition pattern, the formation position of the opening 5 is often corrected at the design stage or the formation stage. On the other hand, if the deformation movement state of each position on the mask main body 2 can be made uniform, it is very easy to perform the correction. Therefore, this point also makes it possible to cope with high-accuracy patterning, which is suitable for improving the display image quality of the organic EL element.

  By the way, in embodiment mentioned above, although the line-shaped part 6 of four sides was distribute | arranged along the outer periphery edge of the mask main body 2, the case where all the line-shaped parts 6 were curved parts was mentioned as an example, Of course, the shape of the line-shaped portion 6 is not limited to this.

FIG. 4 is a schematic diagram showing another example of the schematic configuration of the evaporation mask according to the present invention. The figure shows a vapor deposition mask corresponding to a multi-cavity vapor deposition process. Thus, when a plurality of pattern formation regions 4 are arranged on the mask main body 2 so as to cope with multiple chamfering, the line-shaped portion has a curved portion corresponding to each pattern formation region 4 individually. By arranging 6, it may be possible to make uniform the deformation movement state of each position on the mask main body 2. That is, the line-shaped portion 6 may be determined from the result of arithmetic processing, simulation, or the like performed based on the temperature distribution of the mask main body 2 or the arrangement position of the apertures 5. It may be a combination, or may be a combination of a plurality of curved portions having different curvatures.

  In addition, although the preferable specific example of implementation of this invention was mentioned and demonstrated here, this invention is not limited to this, A various deformation | transformation is possible. That is, the material, shape, and the like of a series of constituent elements constituting the vapor deposition mask 1 described in the present embodiment are not necessarily limited to those described in the present embodiment, and the functions of the respective constituent elements are similarly secured. You can change it as much as you can.

  Moreover, in this embodiment, what was used by the manufacturing process of an organic EL element was mentioned as an example of the mask 1 for vapor deposition, but this invention is not limited to this, Other film-forming processes (For example, Needless to say, the mask used in the sputtering process can be applied in exactly the same manner.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram (the 1) which shows an example of schematic structure of the vapor deposition mask which concerns on this invention, and is a figure which shows the whole. It is a schematic diagram which shows an example of schematic structure of the vapor deposition mask which concerns on this invention (the 2), and is a figure which shows the principal part. It is a schematic diagram which shows an example of the simulation result of the deformation | transformation movement state in each position on the mask surface of the vapor deposition mask which concerns on this invention. It is a schematic diagram which shows the other example of schematic structure of the vapor deposition mask which concerns on this invention, and is a figure which shows the principal part. It is a schematic diagram which shows the principal part structural example of the conventional mask for vapor deposition. It is explanatory drawing which shows a specific example of the temperature distribution on a mask surface in the case of receiving the radiant heat from a vapor deposition source. It is a schematic diagram which shows an example of the simulation result of the deformation | transformation movement state in each position on the mask surface of the conventional vapor deposition mask.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Evaporation mask, 2 ... Mask main body, 3 ... Frame body, 4 ... Pattern formation area, 5 ... Opening, 6 ... Line-shaped part

Claims (2)

A thin plate-shaped mask main body having an opening having a shape corresponding to a pattern to be formed on the object to be processed; and a frame body that supports a region in the vicinity of the outer peripheral edge of the mask main body, and the mask main body is fixed to the frame body In the evaporation mask configured as described above,
The mask for vapor deposition characterized by being arranged so that the adhering part of the said mask main body and the said frame may have a line-shaped part, and the said line-shaped part may have a curved part. A thin plate-shaped mask main body having an opening having a shape corresponding to a pattern to be formed on the object to be processed; and a frame body that supports a region in the vicinity of the outer peripheral edge of the mask main body, and the mask main body is fixed to the frame body In the manufacturing method of the mask for vapor deposition constituted,
The method for producing a vapor deposition mask, wherein the mask main body and the frame body are arranged so that a fixed portion has a line-shaped portion and the line-shaped portion has a curved portion.

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