Vapor deposition mask, method for manufacturing same, and method for manufacturing display device

Abstract

The method for manufacturing a vapor deposition mask includes: a patterning step in which a mask substrate is patterned so that a plurality of pattern regions are formed on the mask substrate; a bonding step in which the mask substrate and a support substrate are bonded to form a laminate; and a processing step in which the mask substrate is processed such that the plurality of pattern regions in the laminate are separated from each other.

Description

Technical Field

[0001] The present invention relates to an evaporation mask, a method for manufacturing the same, and a method for manufacturing a display device. Background Art

[0002] In Patent Document 1, an evaporation mask is disclosed which includes: a frame body having a plurality of openings, and a plurality of mask bodies respectively disposed in the plurality of openings. Here, at each of the openings, one mask body is joined via a metal layer. In such a configuration, it is necessary to position the mask bodies for each of the plurality of openings, and a positioning error may occur between the plurality of mask bodies.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent No. 4369199 Summary of the Invention

[0006] The present invention provides an advantageous technique for improving the relative positional accuracy of a plurality of pattern regions in an evaporation mask.

[0007] A first aspect of the present invention relates to a method for manufacturing an evaporation mask, the method for manufacturing the evaporation mask including: a patterning step of patterning the mask substrate so as to form a plurality of pattern regions on the mask substrate; a bonding step of bonding the mask substrate to a support substrate to form a laminate; and a processing step of processing the mask substrate so that the plurality of pattern regions in the laminate are separated from each other.

[0008] A second aspect of the present invention relates to a method for manufacturing a display device, the method for manufacturing the display device including: an evaporation step of evaporating a substrate using the evaporation mask manufactured by the method for manufacturing the evaporation mask; and a processing step of processing the substrate that has undergone the evaporation step to obtain a display device.

[0009] A third aspect of the present invention relates to an evaporation mask, the evaporation mask including: a support substrate having a plurality of first openings and a plurality of second openings, a plurality of masks supported by the support substrate, and a plurality of members supported by the support substrate, each mask including a pattern region exposed through any one of the plurality of first openings, and each member including an alignment mark exposed through any one of the plurality of second openings. Brief Description of the Drawings

[0010] Figure 1A A diagram for illustratively explaining a method for manufacturing an evaporation mask according to an embodiment.

[0011] Figure 1BThis is a diagram for exemplarily illustrating a method for manufacturing an evaporation mask according to an embodiment.

[0012] Figure 1C This is a diagram for exemplarily illustrating a method for manufacturing an evaporation mask according to an embodiment.

[0013] Figure 1D This is a diagram for exemplarily illustrating a method for manufacturing an evaporation mask according to an embodiment.

[0014] Figure 1E This is a diagram for exemplarily illustrating a method for manufacturing an evaporation mask according to an embodiment.

[0015] Figure 1F This is a diagram for exemplarily illustrating a method for manufacturing an evaporation mask according to an embodiment.

[0016] Figure 1G This is a diagram for exemplarily illustrating a method for manufacturing an evaporation mask according to an embodiment.

[0017] Figure 1H This is a diagram for exemplarily illustrating a method for manufacturing an evaporation mask according to an embodiment.

[0018] Figure 2 This is a schematic plan view of the evaporation mask according to the embodiment as viewed from the side of the support substrate.

[0019] Figure 3 This is a schematic plan view of the evaporation mask according to the embodiment as viewed from the side of the pattern region.

[0020] Figure 4 This is a plan view schematically showing the evaporation mask according to the embodiment and the lattice defined by it. Detailed Embodiments

[0021] Hereinafter, the embodiments will be described in detail with reference to the drawings. In addition, the following embodiments do not limit the claims of the patent. Although multiple features are described in the embodiments, not all of these multiple technical features are essential for the invention. In addition, the multiple features can be combined arbitrarily. Further, in the drawings, the same or similar components are denoted by the same reference numerals, and repeated descriptions are omitted.

[0022] Hereinafter, while referring to Figures 1A to 1H while exemplarily illustrating a method for manufacturing an evaporation mask according to the embodiment. In addition, Figures 1A to 1H This is a schematic cross-sectional view of the structure for explanation. First, while referring to Figures 1A to 1D while explaining the patterning process. In the patterning process, the mask substrate 110 is patterned so as to define or form a plurality of pattern regions in the mask substrate 110. In Figure 1AThe coating process is schematically shown. In the coating process, a photoresist is coated on the mask substrate 110, whereby a photoresist film RF can be formed. Regarding the mask substrate 110, for example, it can be a silicon substrate or a glass substrate.

[0023] In Figure 1B , the transfer process and the development process that can be performed after the coating process are schematically shown. In the transfer process, an exposure device such as a stepper or a scanner can be used to sequentially transfer the pattern of the original plate (referred to as "original plate" in Japanese) to a plurality of pattern formation regions PFR of the photoresist film RF. In addition, in the transfer process, in this exposure device, alignment marks can also be transferred to a plurality of alignment mark regions AA of the photoresist film RF. The alignment marks can also be transferred simultaneously with the pattern of the original plate. In the transfer process, while driving the substrate stage on which the mask substrate 110 having the photoresist film RF formed thereon in the coordinate system of the exposure device, the pattern of the original plate can be sequentially transferred to a plurality of pattern formation regions PFR. In addition, in the transfer process, while driving the substrate stage in the coordinate system of the exposure device, a plurality of alignment marks can be transferred to a plurality of alignment mark regions AA. Therefore, for each of the plurality of pattern formation regions PFR, the pattern of the original plate can be transferred according to the positioning accuracy of the substrate stage of the exposure device, and for each of the plurality of alignment mark regions AA, the alignment marks can be transferred according to the positioning accuracy of the substrate stage of the exposure device. Therefore, regarding the relative positional accuracy between the plurality of patterns transferred to each of the plurality of pattern formation regions PFR and the alignment marks transferred to each of the plurality of alignment mark regions AA, it becomes the one with high accuracy according to the positioning accuracy of the substrate stage. In the development process, by developing the photoresist film RF that has undergone the transfer process, a resist pattern RP can be formed.

[0024] In Figure 1C , the etching process that can be performed after the development process is schematically shown. In the etching process, the mask substrate 110 is etched through the openings of the resist pattern RP, whereby a plurality of pattern regions PR each including a plurality of grooves 13 and a plurality of alignment marks 12 can be formed. Regarding the plurality of pattern regions PR and the plurality of alignment marks 12, since the resist pattern RP is transferred, regarding the relative positional accuracy between the plurality of pattern regions PR and the plurality of alignment marks 12, it becomes the one with high accuracy according to the positioning accuracy of the substrate stage of the exposure device. In the etching process, a plurality of grooves 13 can be formed in the mask substrate 110 in such a manner that no through holes are formed in the mask substrate 110. In this case, the thinning process described later is performed. However, in the etching process, a plurality of grooves 13 can also be formed in the mask substrate 110 in such a manner that through holes are formed in the mask substrate 110.

[0025] In Figure 1D , the resist stripping process that can be performed after the etching process is schematically shown. In the resist stripping process, the resist film RF can be stripped.

[0026] In Figure 1E 、 Figure 1F ,a bonding process is schematically shown. The bonding process may be performed after the patterning process. For the patterning for forming the plurality of pattern regions PR described above, the first surface S1 of the mask substrate 110 is subjected to the patterning. In the bonding process, the support substrate 120 may be bonded to the first surface S1 side of the mask substrate 110. In the bonding process, the mask substrate 110 that has undergone the patterning process and the separately prepared support substrate 120 may be bonded to form a laminate ST. Here, in order to improve the bonding strength between the mask substrate 110 and the support substrate 120, before the bonding process, metal films 131 and 132 may be formed on the mask substrate 110 and the support substrate 120 respectively, and in the bonding process, the metal film 131 and the metal film 132 are bonded. In the bonding process, the mask substrate 110 and the support substrate 120 may be bonded by, for example, atomic diffusion bonding. In the bonding process, the alignment marks 12 formed on the mask substrate 110 may be used to align the positions of the mask substrate 110 and the support substrate 120.

[0027] The support substrate 120 preferably has a sufficiently low coefficient of linear expansion. The coefficient of linear expansion of the support substrate 120 is, for example, smaller than that of the mask substrate 110. The coefficient of linear expansion of the support substrate 120 is, for example, composed of an alloy containing nickel and cobalt, and the coefficient of linear expansion is, for example, 0.5×10 -6 ( / °C) or less. The support substrate 120 is, for example, made of invar. The support substrate 120 may also be composed of a ceramic composite material containing amorphous silicon and titanium or crystalline silicon, and the coefficient of linear expansion may be 0.5×10 -6 ( / °C) or less.

[0028] In one example, the support substrate 120 may be composed of, for example, a 32Ni - 5Co alloy. In this case, the coefficient of linear expansion is 0.2×10 -6 ( / °C). When the temperature of the evaporation mask rises by 30°C, the expansion amount per 100 mm is 0.2×10 -6 ( / °C)×30(°C)×100(mm) = 0.0006 mm = 0.6 μm. That is, in the manufacture of an OLED panel with a pixel size of 10 μm or less, evaporation can be performed with sufficient positional accuracy.

[0029] The support substrate 120 may have: a plurality of first openings OP1 for exposing the plurality of pattern regions PR in the laminate ST respectively; and a plurality of second openings OP2 for observing the plurality of alignment marks 12. The plurality of pattern regions PR may be exposed through the plurality of first openings OP1; the plurality of alignment marks 12 may be exposed through the plurality of second openings OP2.

[0030] The bonding process is carried out without heating or cooling. In other views, the bonding process can be carried out within a temperature range of 7°C or higher and 39°C or lower. In terms of such conditions, it is advantageous to limit the warpage of the laminate ST or the evaporation mask after the bonding process within an allowable range.

[0031] In Figure 1G , the thinning process is schematically shown. The thinning process can be carried out between the bonding process and the subsequent processing process. In the thinning process, the mask substrate 110 can be thinned so that the plurality of grooves 13 are changed into a plurality of through holes. In the thinning process, for example, the mask substrate 110 can be thinned by grinding or etching the second surface S2 (the surface opposite to the first surface S1) of the mask substrate 110.

[0032] In Figure 1H , the processing process is schematically shown. In the processing process, the mask substrate 110 can be processed so that the plurality of pattern regions PR (masks) in the laminate ST and the plurality of members 16 including the respective alignment marks 12 are separated from each other. More specifically, in the processing process, separation grooves 15 can be formed between the plurality of pattern regions PR and the plurality of members 16 in such a manner that the plurality of pattern regions PR (masks) and the plurality of members 16 are separated from each other. Thereby, the evaporation mask M is completed. Regarding the separation grooves 15, it is difficult to bring the influence of the deformation of the plurality of pattern regions PR caused by temperature change to the support substrate 120, and it is also difficult to bring the influence of the deformation of the support substrate 120 caused by temperature change to the plurality of pattern regions PR. After the separation process, the plurality of pattern regions PR separated from each other are supported by the support substrate 120. Regarding the width of the separation grooves 15 (the width in the direction orthogonal to the direction in which the separation grooves 15 extend along the edge of the pattern region PR in the region between the adjacent pattern regions PR), it is preferably larger than the width of the plurality of grooves 13 (the width in the above-mentioned direction).

[0033] Regarding the evaporation mask M that can be connected as described above, it is suitable for the manufacture of display devices. Such a method for manufacturing a display device may include: an evaporation process of evaporating on a substrate using the evaporation mask M; a processing process of processing the substrate that has undergone the evaporation process to obtain a display device. In the evaporation process, for example, an organic EL light-emitting material can be evaporated onto the substrate through the plurality of through holes of the evaporation mask.

[0034] In one example, the thickness of the mask substrate 110 before the thinning process is 775 μm; the thickness of the mask substrate 110 after the thinning process is 30 μm. In this case, in the patterning process, for example, the plurality of grooves 13 can be formed in such a manner that the depth is increased by 10% of the thickness of the mask substrate 110 after the thinning process (that is, 30 μm × (100 + 10) / 100 = 33 μm).

[0035] In one example, before the bonding process is carried out, a metal film 131, 132 such as titanium can be formed on the mask substrate 110 and the support substrate 120 by sputtering or evaporation in a vacuum chamber with a vacuum pressure of 1×10 -4 Pa or less. The thickness of the metal films 131, 132 can be, for example, in the range of 0.3 to 5 nm.

[0036] Typically, the mask substrate 110 and the support substrate 120 are made of different materials. In one example, the mask substrate 110 is made of silicon and the support substrate 120 is made of an alloy of 32Ni - 5Co. In this case, the coefficient of linear expansion of the mask substrate 110 is 2.6×10 -6 ( / ℃), and the coefficient of linear expansion of the support substrate 120 is 0.2×10 -6 ( / ℃). Additionally, in one example, the size of the pattern region PR after the processing step can be 25.4 mm × 25.4 mm. In this example, the difference in the amount of expansion between the mask substrate 110 and the support substrate 120 per 1℃ increase in temperature is (2.6×10 -6 - 0.2×10 -6 ) × 1 × 25.4 = 0.00006096 mm = 0.061 μm. As an evaporation mask for manufacturing an OLED panel with a pixel size of 10 μm or less, it is desirable to control the difference in the amount of expansion within 10% of this pixel size, that is, 1 μm or less. In the case of this example, it is desirable to control the temperature difference to 10×10 -3 ×0.1÷(0.061×10 -3 ) = 16.4℃. Thus, if the set temperature in a general clean room is 23℃, then 23 ± 16.4℃, that is, 7 to 39℃, is the temperature suitable for the bonding process. The greater the difference between the temperature during the bonding process and the temperature after the bonding process, the greater the warpage amount of the laminate ST or the evaporation mask M after the bonding process, and it becomes impossible to maintain the distance between the pattern region PR and the wafer constant or to bring the two into contact. Therefore, the bonding process is preferably carried out in the range of 7 to 39℃.

[0037] In Figure 2 , a schematic plan view of the evaporation mask M manufactured by the above manufacturing method as viewed from the support substrate 120 side is shown. In Figure 3, a schematic plan view showing the evaporation mask M as viewed from the pattern region PR side. The evaporation mask M may include: a support substrate 120 having a plurality of first openings OP1 and a plurality of second openings OP2; a plurality of pattern regions PR (masks) supported by the support substrate 120; and a plurality of members 16 supported by the support substrate. Each pattern region PR (mask) may include a pattern region PR exposed through any one of the plurality of first openings OP1. All or part of the plurality of members 16 may include alignment marks 12 exposed through any one of the plurality of second openings OP2.

[0038] A metal film 131, 132 (see Figure 1H ) may be disposed between the support substrate 120 and the pattern region PR (mask), and between the support substrate 120 and the plurality of members 16. For the support substrate 120, for example, it is made of an alloy containing nickel and cobalt, and for example, the linear expansion coefficient may be 0.5×10 -6 ( / °C) or less. For the plurality of pattern regions PR (masks), for example, they may be silicon substrates or glass substrates.

[0039] As Figure 4 schematically shown, for the plurality of pattern regions PR (masks), they are arranged with respect to a lattice L defined by a plurality of alignment marks 12 respectively provided on the plurality of members 16. The number of the plurality of members 16 is less than the number of the plurality of pattern regions PR (masks).

[0040] The invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the appended claims are provided to disclose the scope of the invention.

Claims

1. A method for manufacturing an evaporation mask, comprising: A patterning step of patterning the mask substrate in such a manner that a plurality of pattern regions are formed on the mask substrate; A bonding step of bonding the mask substrate to a support substrate to form a laminate; And A processing step of processing the mask substrate in such a manner that the plurality of pattern regions in the laminate are separated from each other.

2. The manufacturing method of the evaporation mask according to claim 1, wherein, The bonding step is carried out without heating or cooling.

3. The manufacturing method of the evaporation mask according to claim 1, wherein, The bonding step is carried out within a temperature range of 7°C or higher and 39°C or lower.

4. The method for manufacturing an evaporation mask according to any one of claims 1 to 3, wherein, In the patterning step, a plurality of grooves are formed on the mask substrate in such a manner that through holes are not formed in the mask substrate. Between the bonding step and the processing step, a thinning step is carried out of thinning the mask substrate in such a manner that the plurality of grooves are changed into a plurality of through holes.

5. The manufacturing method of an evaporation mask according to any one of claims 1 to 4, wherein, The bonding step is carried out after the patterning step.

6. The method for manufacturing an evaporation mask according to any one of claims 1 to 5, wherein, The support substrate is made of an alloy containing nickel and cobalt, and has a linear expansion coefficient of 0.5×10 -6 ( / ℃) or less.

7. The method for manufacturing an evaporation mask according to any one of claims 1 to 5, wherein, The support substrate is made of a ceramic composite material containing amorphous silicon and titanium or crystalline silicon, and has a linear expansion coefficient of 0.5×10 -6 ( / °C) or less.

8. The method for manufacturing an evaporation mask according to any one of claims 1 to 7, wherein, The mask substrate is a silicon substrate or a glass substrate.

9. The method for manufacturing an evaporation mask according to any one of claims 1 to 8, wherein, In the patterning step, alignment marks are formed on the mask substrate. In the bonding step, the mask substrate and the support substrate are position-aligned using the alignment marks.

10. The method for manufacturing an evaporation mask according to claim 9, wherein The support substrate has: a plurality of first openings for respectively exposing the plurality of pattern regions in the laminate; and a second opening for observing the alignment marks.

11. The method for manufacturing an evaporation mask according to any one of claims 1 to 10, wherein Patterning for forming the plurality of pattern regions is carried out on the first surface of the mask substrate. In the bonding step, the support substrate is bonded to the first surface side of the mask substrate.

12. The manufacturing method of the evaporation mask according to claim 11, wherein, In the bonding step, the first surface side of the mask substrate and the support substrate are bonded via a metal film.

13. The method for manufacturing an evaporation mask according to any one of claims 1 to 12, wherein, The bonding step is a bonding of the mask substrate and the support substrate by atomic diffusion bonding.

14. The method for manufacturing an evaporation mask according to any one of claims 1 to 13, wherein, The patterning step includes: A coating step of coating a photoresist on the mask substrate to form a photoresist film; A transfer step of sequentially transferring the pattern of a master to a plurality of pattern formation regions of the photoresist film using an exposure apparatus; A developing step of developing the photoresist film to form a resist pattern; And An etching step of etching the mask substrate through the openings of the resist pattern to thereby form the plurality of pattern regions.

15. The method for manufacturing an evaporation mask according to any one of claims 1 to 14, wherein, The processing step includes a step of forming separation grooves for separating the plurality of pattern regions from each other.

16. The manufacturing method of the evaporation mask according to claim 4, wherein, The processing step includes a step of forming separation grooves for separating the plurality of pattern regions from each other. The width of the separation grooves is larger than the width of the plurality of grooves.

17. A method for manufacturing a display device, comprising: An evaporation step of evaporating a substrate using an evaporation mask manufactured by the manufacturing method according to any one of claims 1 to 16; and A processing step of processing the substrate that has undergone the evaporation step to obtain a display device.

18. An evaporation mask, comprising: A support substrate having a plurality of first openings and a plurality of second openings; A plurality of masks supported by the support substrate; and A plurality of members supported by the support substrate Each mask includes a pattern region exposed through any one of the plurality of first openings. Each member includes an alignment mark exposed through any one of the plurality of second openings.

19. The evaporation mask according to claim 18, wherein, A metal film is disposed between the support substrate and the plurality of masks, and between the support substrate and the plurality of members.

20. The evaporation mask according to claim 18 or 19, wherein, The support substrate is made of an alloy containing nickel and cobalt, and has a linear expansion coefficient of 0.5×10 -6 ( / °C) or less.

21. The evaporation mask according to any one of claims 18 to 20, wherein The plurality of masks are silicon substrates or glass substrates.

22. The evaporation mask according to any one of claims 18 to 21, wherein The plurality of masks are arranged with respect to a lattice defined by the plurality of alignment marks respectively provided in the plurality of members.

23. The evaporation mask according to any one of claims 18 to 22, wherein The number of the plurality of members is smaller than the number of the plurality of masks.

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