Thin film photomask and method for manufacturing thin film photomask

Abstract

The invention relates to a thin film photomask and a manufacturing method of the thin film photomask. A thin film photomask, which is used in an exposure process for manufacturing a mask strip constituting an open metal mask, includes: a first thin film provided with one or more first transmissive portions arranged in a width direction, the length of the first thin film in the longitudinal direction being greater than the length of the first thin film in the width direction; and a second film provided with a second transmissive portion corresponding to the first transmissive portion. By joining the second film on at least one of both ends of the first film in the longitudinal direction, it is possible to continuously connect the first transmissive portion and the second transmissive portion and thereby form a pattern corresponding to the shape of the mask strip.

Description

Technical Field

[0001] The invention relates to a thin film photomask and a method for manufacturing the thin film photomask. Background Art

[0002] With the development of science, a variety of display devices have emerged, and recently, display devices using semiconductors have emerged. As one of them, the organic light emitting diode (OLED) can be taken as an example. OLED is driven by organic matter and can emit light by the organic matter itself without the need for a separate light source. The traditional display device, the liquid crystal display (LCD), requires a backlight, but the organic light emitting diode does not require a backlight, so it can be made lighter and thinner. In addition, compared with LCD, OLED has the advantages of faster response speed and lower power consumption.

[0003] The process of manufacturing the latest display devices including organic light emitting diodes (OLEDs) includes a deposition process, which involves evaporating a substance to be deposited into a gas form and adhering the gas form to a substrate surface in the form of a thin film.

[0004] In the deposition process, an open metal mask is used when forming an organic common layer on a substrate. The open metal mask can be made into an integrated type or assembled from a plurality of mask strips.

[0005] The mask strips are made by performing a photolithography process on a material with a very low coefficient of thermal expansion, such as Invar, and a thin film photomask may be used during the exposure process of the photolithography process.

[0006] Compared with the case of using an integrated open metal mask, multiple display devices and larger display devices can be manufactured by using mask strips. The mask strip is manufactured using a thin film material sheet for a photomask. The thin film material sheet for a photomask is manufactured and sold by only a few companies in limited sizes, and the length of the mask strip is limited to the length of the thin film material sheet for the mask. Although the length of the mask strip is limited by the length of the thin film material sheet for the photomask, because the display device is gradually becoming larger and the number of display devices produced using a mother substrate to increase the yield is also increasing, the size of the mask strip required in the project also needs to be gradually increased. Finally, a technical issue of providing a mask strip with a larger size or length that is not limited by the size or length of the thin film material sheet for the photomask is derived. The following prior art document 1, Korean registered patent No. 10-2427523, records a method of manufacturing an open metal mask using a mask strip, but does not propose the use of a thin film material sheet for a photomask with a limited size to manufacture a larger mask strip.

[0007] In addition, Japanese Patent Laid-Open No. 11-30851, a prior art document 2, discloses a structure for producing a thin-film type photomask by forming a pattern on a photomask thin-film material sheet, but does not propose the production of a mask strip.

[0008] In the prior art, there is a problem that it is impossible to use a photomask thin film material sheet with a limited size to produce an opening metal mask for forming a substrate and an organic common layer that are gradually getting larger.

[0009] Prior art literature

[0010] Patent Literature

[0011] (Patent Document 0001) Korean Registered Patent No. 10-2427523

[0012] (Patent Document 0002) Japanese Patent Laid-Open No. 11-30851 Summary of the invention

[0013] In order to solve the problems mentioned above, the present invention discloses a thin film photomask used in an exposure process for manufacturing a mask strip constituting an open metal mask, the thin film photomask comprising: a first film, provided with one or more first transparent portions arranged along the width direction, the length of the first film in the length direction being greater than the length in the width direction; and a second film, provided with a second transparent portion corresponding to the first transparent portion; by bonding the second film at at least one of the two ends in the length direction of the first film, the first transparent portion and the second transparent portion can be continuously connected to thereby form a pattern corresponding to the shape of the mask strip.

[0014] In addition, the present invention discloses a method for manufacturing a thin film photomask used in an exposure process for manufacturing a mask strip constituting an open metal mask, the manufacturing method comprising: a process for manufacturing a first thin film equipped with one or more first transparent portions arranged along a width direction, the length of the first thin film in a longitudinal direction being greater than the length in the width direction; and a process for manufacturing a second thin film equipped with a second transparent portion corresponding to the first transparent portion; the manufacturing method also comprises: a process for bonding the second thin film at at least one of the two ends in the longitudinal direction of the first thin film to continuously connect the first transparent portion and the second transparent portion and thereby form a pattern corresponding to the shape of the mask strip.

[0015] That is, an object of the present invention is to provide a photomask and a method for manufacturing a photomask in which a mask bar having a length greater than that of one photomask film material sheet is manufactured by bonding mutually different first and second films.

[0016] In order to achieve the above-mentioned purpose, according to an embodiment of the present invention, a thin film photomask used in an exposure process for manufacturing a mask strip constituting an open metal mask, the thin film photomask may include: a first film, provided with one or more first transparent portions arranged along the width direction, the length of the first film in the longitudinal direction is greater than the length in the width direction; and, a second film, provided with a second transparent portion corresponding to the first transparent portion; the second film is joined at least one of the two ends in the longitudinal direction of the first film, so as to continuously connect the first transparent portion and the second transparent portion and thereby form a pattern corresponding to the shape of the mask strip.

[0017] Furthermore, the second film may be in a rectangular shape.

[0018] Furthermore, the second film may have a protruding portion in the longitudinal direction at at least one of both ends in the width direction where the second transmission portion is not provided.

[0019] Furthermore, the first film may be in a rectangular shape.

[0020] Furthermore, the first film may have a shape in which one or more corners of the rectangular shape are chamfered.

[0021] In addition, the first film and the second film may be bonded by an adhesive or an adhesive tape.

[0022] Furthermore, the first film and the second film may be provided with alignment marks, respectively.

[0023] Furthermore, the first thin film and the second thin film may be obtained from the same sheet of thin film material for a photomask.

[0024] In addition, the length of the pattern corresponding to the shape of the mask stripe in the longitudinal direction may be 2.8 to 3.2 m.

[0025] In addition, the photomask thin film material sheet used to manufacture the first thin film or the second thin film may be in a rectangular shape, and the length of one side of the rectangular shape may be 1612 to 2450 mm.

[0026] Furthermore, according to another embodiment of the present invention, a method for manufacturing a thin film photomask used in an exposure process for manufacturing a mask strip constituting an open metal mask may include: a process of manufacturing a first thin film equipped with one or more first transparent portions arranged along a width direction, the length of the first thin film in a longitudinal direction being greater than the length in the width direction; and a process of manufacturing a second thin film equipped with a second transparent portion corresponding to the first transparent portion; the manufacturing method also includes: a process of bonding the second thin film at at least one of the two ends in the longitudinal direction of the first thin film to continuously connect the first transparent portion and the second transparent portion and thereby form a pattern corresponding to the shape of the mask strip.

[0027] Furthermore, the second film may be in a rectangular shape.

[0028] Furthermore, the second film may have a protruding portion in the longitudinal direction at at least one of both ends in the width direction where the second transmission portion is not provided.

[0029] Furthermore, the first film may be in a rectangular shape.

[0030] Furthermore, the first film may have a shape in which one or more corners of the rectangular shape are chamfered.

[0031] In addition, the first film and the second film may be bonded by an adhesive or an adhesive tape.

[0032] Furthermore, the first film and the second film may be provided with alignment marks, respectively.

[0033] In addition, the process of manufacturing the first thin film may further include: a step of arranging the length direction of the first thin film along the diagonal direction of the photomask thin film material sheet.

[0034] Furthermore, the process of manufacturing the second thin film may further include the step of disposing the second thin film in the remaining area of ​​the photomask thin film material sheet except for the first thin film.

[0035] In addition, the length of the pattern corresponding to the shape of the mask stripe in the longitudinal direction may be 2.8 to 3.2 m.

[0036] In addition, the process of manufacturing the first thin film or the process of manufacturing the second thin film may further include: manufacturing the first thin film or the second thin film from a photomask thin film material sheet having a side length of 1612 to 2450 mm.

[0037] The present invention can manufacture a mask strip that is longer than the length of a thin film material sheet used for a photomask. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 (a) shows an integrated opening metal mask, and Figure 1 (b) shows an open metal mask assembled from a plurality of mask strips.

[0039] Figure 2 (a) shows a first film having a rectangular shape, and Figure 2 (b) shows a first film having a rectangular shape with one or more corners chamfered.

[0040] Figure 3 (a) shows a second film having a rectangular shape, and Figure 3 (b) shows a second film having a protruding portion in the longitudinal direction at least one of both ends in the width direction where the second transmission portion is not provided.

[0041] Figure 4 2 shows a state where the first thin film and the second thin film are arranged on the same photomask thin film material sheet.

[0042] Figure 5 FIG. 4 shows a thin film photomask for bonding a first thin film to two second thin films.

[0043]

Explanation of symbols

[0044] 101: Integrated open metal mask

[0045] 102: Open metal mask assembled from multiple mask strips

[0046] 110: Mask strip

[0047] 111: Active part

[0048] 112: Grip

[0049] 114: Framework

[0050] 201: The First Film

[0051] 202: The First Film

[0052] 203: First transmission part

[0053] 301: Second film

[0054] 302: Second film

[0055] 303: Second transmission part

[0056] 304: protrusion

[0057] 401: Thin film material sheet for photomask

[0058] 501: Thin Film Photomask

[0059] 502: Through the boundary DETAILED DESCRIPTION

[0060] The thin film photomask and the method for manufacturing the thin film photomask according to the present invention can be applied to various embodiments, and the thin film photomask and the method for manufacturing the thin film photomask according to the present invention will be described in detail below. In addition, the drawings will be referred to for description when necessary.

[0061] When manufacturing a display device using a semiconductor such as an OLED, a deposition process may be used. In the deposition process, an open metal mask 101, 102 may be used to form a common layer. The open metal mask may include an integrated type (see Figure 1 (a)) and the morphology formed by the combination of mask strips (see Figure 1 (b)). By manufacturing the open metal mask 102 in the form of a combination of mask strips 110, a deposition process for forming a larger organic common layer can be performed compared to the case of using an integrated open metal mask 101. However, in the process of manufacturing the mask strips 110, the horizontal length of the largest photomask thin film material sheet used in photolithography is only 2450 mm and the vertical length is only 1612 mm. Currently, there is no photomask thin film material sheet larger than the above values. Therefore, it is impossible to manufacture the mask strips with a length of 2.8 to 3.2 m in the longitudinal direction at one time as currently required.

[0062] Therefore, the above-mentioned problems are solved by bonding a plurality of separate thin films to produce a thin film photomask for mask stripe production.

[0063] Specifically, the first films 201, 202 and the second films 301, 302 can be bonded so that the first transparent portions 203 of the first films 201, 202 and the second transparent portions 303 of the second films 301, 302 are continuously connected, thereby forming a pattern corresponding to the shape of the mask strip, and using the pattern to manufacture the mask strip 110. The pattern is formed according to the shape of the mask strip and can be formed in the exposure process. As an example, the pattern can be formed on a photosensitive composition coated on the surface of a metal foil such as Invar used to make the mask strip.

[0064] The photomask film material sheet 401 may be in a rectangular shape. The material of the photomask film material sheet 401 is preferably polyethylene terephthalate (PET). For example, as the photomask film material sheet 401, a product of AGFA Company, which is in a rectangular shape and has a side length of 1612 to 2450 mm, a thickness of 175 μm, and is made of PET, may be used.

[0065] The photomask film material sheet 401 can be used to manufacture first films 201, 202 and second films 301, 302 of different shapes. Next, the first films 201, 202 and the second films 301, 302 will be described.

[0066] See also Figure 2 , the first films 201 and 202 will be described. The first films 201 and 202 may include one or more first transparent portions 203 arranged along the width direction. The width of the first transparent portion 203 depends on the specification of the mask strip 110 to be produced. The width of the first transparent portion 203 may be 200 μm.

[0067] The length of the first film 201, 202 in the longitudinal direction may be greater than the length in the width direction. Figure 2 The horizontal direction of the first film 201, 202, and the width direction refers to Figure 2 The vertical direction of the first films 201 and 202.

[0068] The first thin films 201 and 202 can be used to produce the active portion 111 of the mask strip 110. The active portion 111 of the mask strip 110 is a portion of the organic common layer of the substrate that is directly formed by a deposition process, and requires strict precision. Therefore, it is preferable that the first thin films 201 and 202 used to form the active portion 111 of the mask strip 110 are made from one sheet of thin film material 401 for a photomask. In addition, it is preferable that the first thin films 201 and 202 ensure sufficient length in the longitudinal direction, so they can be made in a manner that the length direction of the sheet of thin film material 401 for a photomask is the length direction of the first thin films 201 and 202. More preferably, a step of arranging the length direction of the first thin films 201 and 202 along the diagonal direction of the sheet of thin film material 401 for a photomask can be included to produce the first thin films 201 and 202. By arranging the length direction of the first films 201 and 202 along the diagonal direction of the photomask film material sheet 401 , the first films 201 and 202 can be manufactured using the longest length of the photomask film material sheet 401 .

[0069] The first film 201 is as follows Figure 2 The rectangular shape shown in (a) is preferred. Since the first film 201 is produced by cutting the photomask film material sheet 401, the cutting process is relatively simple when the first film 201 is in a rectangular shape, so the first film 201 can be produced more easily.

[0070] In addition, the first film 202 is as follows Figure 2 The shape in which one or more corners are chamfered on a rectangular shape as shown in (b) is preferred. In this way, the first film 202 can be manufactured by making full use of the diagonal direction of the photomask film material sheet 401. Specifically, the active portion 111 of the mask strip 110 is manufactured in a manner corresponding to the first transparent portion 203 of the first film 201, 202, and because the first transparent portion 203 is formed inside the first film 201, 202, when the first film 201, 202 is manufactured by making use of the diagonal of the photomask film material sheet 401, when the first film 202 is in a shape in which one or more corners are chamfered on a rectangular shape, the length of the first transparent portion 203 of the first film 202 can be made greater than the length of the first transparent portion 203 when the first film 201 is in a rectangular shape. Compared with the case where the first film is in a rectangular shape, in the case in which one or more corners are chamfered on a rectangular shape, the first transparent portion 203 can be made closer to the corner of the photomask film material sheet 401.

[0071] See also Figure 3 , the second films 301 and 302 will be described. The second films 301 and 302 may include one or more second transparent portions 303 arranged along the width direction. The second transparent portions 303 correspond to the first transparent portions 203. For example, when the number of the first transparent portions 203 and the second transparent portions 303 is the same, or the width direction lengths of the first transparent portions 203 and the second transparent portions 303 are the same, or when the first transparent portions 203 and the second transparent portions 303 are overlapped, the width direction ends of the first transparent portions 203 and the second transparent portions 303 are continuous with each other along the length direction, it can be said that the second transparent portion corresponds to the first transparent portion.

[0072] The lengths of the second films 301 and 302 in the longitudinal direction and the lengths in the width direction can be freely determined. However, it is preferable that the lengths of the second films 301 and 302 in the width direction are the same as the lengths of the first films 201 and 202 in the width direction. This is because when the first films 201 and 202 are bonded to the second films 301 and 302, the lengths of the film mask 401 in the width direction are the same in all longitudinal directions, which is convenient for the management and use of the film mask 501.

[0073] The second film 301, 302 may be used to produce the gripping portion 112 of the mask strip 110. The gripping portion 112 of the mask strip 110 may include a portion that is joined to the frame 114 when the mask strip 110 is stretched and joined to the frame 114 of the open metal mask 102, or is clamped by the stretching machine for stretching the mask strip 110. Therefore, strict precision is not required like the active portion 111 of the mask strip 110. The gripping portion 112 of the mask strip 110 may include a portion of the mask strip formed by the transparent portion boundary 502 of the thin film photomask 501. The transparent portion boundary 502 of the thin film photomask 501 may include a boundary where the first transparent portion 201, 202 contacts the second transparent portion 301, 302 in the thin film photomask 501 formed by bonding the first film 201, 202 and the second film 301, 302. Thus, even though a step difference may be formed due to the transparent portion boundary 502 , since the gripping portion 112 of the mask strip 110 does not require strict precision, the mask strip 110 can be assembled into the open metal mask 102 and a mask strip 110 with good quality can be manufactured.

[0074] The second film 301 is preferably rectangular in shape. Since the second film 301 is produced by cutting the photomask film material sheet 401, the cutting process is relatively simple when the second film 301 is rectangular in shape, so the second film 301 can be produced more easily.

[0075] The second film 302 preferably has a protrusion 304 in the length direction at at least one of the two ends in the width direction where the second transparent portion 303 is not provided. The protrusion 304 can increase the contact area between the first film 201, 202 and the second film 302 when bonding with the first film 201, 202, so as to more easily complete the bonding. In addition, since the protrusion 304 has nothing to do with the second transparent portion 303, it will not affect the quality of the mask strip 110.

[0076] The first films 201, 202 and the second films 301, 302 can be joined by an adhesive or an adhesive tape. In addition, a known adhesive and a known adhesive tape can be used simultaneously during the joining. The adhesive is preferably an adhesive for PET.

[0077] In the bonding process of the first film 201, 202 and the second film 301, 302, the alignment mark (not shown) marked on the first film 201, 202 and the alignment mark (not shown) marked on the second film 301, 302 can be used to minimize the bonding error. In the overlapping portion of the first film 201, 202 and the second film 301, 302, the alignment operation can be performed by the center of the alignment marks on both sides. That is, the step difference on the transparent portion 502 can be minimized by the alignment mark. It is preferable that the alignment mark is in the form of a hole. In the case where the alignment mark is in the form of a hole, the alignment mark can be made more easily, and it is easy to confirm whether the alignment operation has been completed correctly.

[0078] The first films 201, 202 and the second films 301, 302 may be obtained from the same photomask film material sheet 401. When the first films 201, 202 and the second films 301, 302 are respectively manufactured on different photomask film material sheets 401, it may cause a waste of resources and a problem of cutting each photomask film material sheet 401. However, by obtaining the first films 201, 202 and the second films 301, 302 from the same photomask film material sheet 401, the cutting process can be simplified and the waste of resources can be prevented. The process of manufacturing the first films 201, 202 preferably includes a step of arranging the length direction of the first films 201, 202 along the diagonal direction of the photomask film material sheet 401, and preferably includes a step of arranging the second films 301, 302 in the remaining area except for the first films 201, 202. This is because the length of the first thin films 201 and 202 in the longitudinal direction can be maximized, and the second thin films 301 and 302 can be obtained from one photomask thin film material sheet 401 .

[0079] Next, we will Figure 4 Provide explanation. Figure 4 4 shows a state where a cutting line indicating one first film 202 and two second films 302 are formed on a photomask film material sheet 401. By performing a cutting process along the cutting line, one first film 202 and two second films 302 can be obtained from one photomask film material sheet 401. As described above, by manufacturing the first film 202 and the second film 302 from one photomask film material sheet 401, a thin film photomask 502 can be efficiently produced. In addition, by arranging the first film 202 in the diagonal direction of the photomask film material sheet 401, a longer active portion of the mask strip 110 can be formed.

[0080] Next, we will Figure 5Provide explanation. Figure 5 2 shows a state where a thin film photomask 501 is formed by bonding a first film 201, 202 and two second films 302. The first films 201, 202 and the second films 302 can be made of a single photomask thin film material sheet 401 or a plurality of photomask thin film material sheets 401. In addition, the bonding force can be improved by the protrusion 304 of the second film 302, and a longer mask strip 110 can be manufactured by making the first transparent portion 203 and the second transparent portion 303 continuous compared to the limited photomask thin film material sheet 401.

[0081] As described above, the thin film photomask and the method for manufacturing the thin film photomask of the present invention can manufacture a mask strip longer than the thin film material sheet for the photomask and of good quality, thereby manufacturing an opening metal mask for forming a large-scale multiple organic common layers.

[0082] The above content describes the thin film photomask and the method for manufacturing the thin film photomask of the present invention. Practitioners in the technical field of the present invention should understand that the technical structure of the present invention described above can be implemented in other specific forms without changing the technical concept or essential features of the present invention.

[0083] Therefore, the embodiments described in the above content should be construed in all aspects only for the purpose of illustration and not limitation.

Claims

1. A thin film photomask, the thin film photomask being used as a thin film photomask in an exposure process for manufacturing a mask strip constituting an opening metal mask, the thin film photomask comprising: A first film is provided with one or more first transmission parts arranged along the width direction, wherein the length of the first film in the longitudinal direction is greater than the length in the width direction; and A second film having a second transparent portion corresponding to the first transparent portion; The second film is bonded to at least one of both ends in the length direction of the first film, so that the first transmission portion and the second transmission portion are continuously connected to form a pattern corresponding to the shape of the mask stripe.

2. The thin film photomask according to claim 1, wherein: The second film is in a rectangular shape.

3. The thin film photomask according to claim 1, wherein: The second film has a protruding portion in the longitudinal direction at at least one of both ends in the width direction where the second transmission portion is not provided.

4. The thin film photomask according to any one of claims 1 to 3, wherein: The first film is in a rectangular shape.

5. The thin film photomask according to claim 4, wherein: The first film has a shape in which one or more corners of the rectangular shape are chamfered.

6. The thin film photomask according to any one of claims 1 to 3, wherein: The first film and the second film are bonded together by an adhesive or an adhesive tape.

7. The thin film photomask according to any one of claims 1 to 3, wherein: The first film and the second film are respectively provided with alignment marks.

8. The thin film photomask according to any one of claims 1 to 3, wherein: The first thin film and the second thin film are obtained from the same sheet of thin film material for photomask.

9. The thin film photomask according to any one of claims 1 to 3, wherein: The length of the pattern corresponding to the shape of the mask stripe in the longitudinal direction is 2.8 to 3.2 m.

10. The thin film photomask according to any one of claims 1 to 3, wherein: The photomask thin film material sheet used to manufacture the first thin film or the second thin film has a rectangular shape, and the length of one side of the rectangular shape is 1612 to 2450 mm.

11. A method for manufacturing a thin film photomask, the thin film photomask being used in an exposure process for manufacturing a mask strip constituting an opening metal mask, the manufacturing method comprising: A process of manufacturing a first film having one or more first transmission portions arranged in a width direction, wherein the length of the first film in a longitudinal direction is greater than the length in a width direction; and A process of manufacturing a second film having a second transmission portion corresponding to the first transmission portion; The second film is bonded to at least one of the two ends in the length direction of the first film to continuously connect the first transmission portion and the second transmission portion to form a pattern corresponding to the shape of the mask stripe.

12. The method for manufacturing a thin film photomask according to claim 11, wherein: The second film is in a rectangular shape.

13. The method for manufacturing a thin film photomask according to claim 11, wherein: The second film has a protruding portion in the longitudinal direction at at least one of both ends in the width direction where the second transmission portion is not provided.

14. The method for manufacturing a thin film photomask according to any one of claims 11 to 13, wherein: The first film is in a rectangular shape.

15. The method for manufacturing a thin film photomask according to claim 14, wherein: The first film has a shape in which one or more corners of the rectangular shape are chamfered.

16. The method for manufacturing a thin film photomask according to any one of claims 11 to 13, wherein: The first film and the second film are bonded together by an adhesive or an adhesive tape.

17. The method for manufacturing a thin film photomask according to any one of claims 11 to 13, wherein: The first film and the second film are respectively provided with alignment marks.

18. The method for manufacturing a thin film photomask according to any one of claims 11 to 13, wherein: The process of manufacturing the first thin film further includes: a step of arranging the length direction of the first thin film along the diagonal direction of the photomask thin film material sheet.

19. The method for manufacturing a thin film photomask according to claim 18, wherein: The process of manufacturing the second thin film further includes the step of disposing the second thin film in the remaining area of ​​the photomask thin film material sheet except for the first thin film.

20. The method for manufacturing a thin film photomask according to any one of claims 11 to 13, wherein: The length of the pattern corresponding to the shape of the mask stripe in the longitudinal direction is 2.8 to 3.2 m.

21. The method for manufacturing a thin film photomask according to any one of claims 11 to 13, wherein: The process of manufacturing the first thin film or the process of manufacturing the second thin film further includes: manufacturing the first thin film or the second thin film from a thin film material sheet for a photomask having a side length of 1612 to 2450 mm.

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