Photomask container

Abstract

The present application provides a photomask container which can firmly hold a photomask substrate, inhibit dew condensation in a photomask substrate storage portion, has excellent cleanliness, is not easy to attach dirt (particles) to the surface of the photomask substrate, has a light weight, and has excellent mechanical strength. The photomask container is used to store and transport a photomask substrate in a state where the photomask substrate is stored in a photomask substrate storage portion formed by a container main body and a lid, and is characterized in that the container main body is a box-shaped body formed of a high-density polyethylene resin having a melt flow rate (MFR) of 0.6 (g / 10 minutes) or less, and is composed of a flat plate-shaped base portion and a side wall portion provided in a direction at a right angle from the end portion of the base portion, and the container main body is a double-layer hollow structure composed of an inner wall and an outer wall.

Description

Technical Field

[0001] This invention relates to photomask containers for storing and transporting photomask substrates. Background Technology

[0002] In recent years, when manufacturing display devices such as liquid crystal display panels, photomask substrates are made in cleanroom factories and then transported to the next process factory to manufacture display devices such as liquid crystal display panels.

[0003] Display devices such as liquid crystal display panels are precision equipment. If the substrate circuit or the substrate itself is damaged due to dirt (particles) or electrical damage during the transportation of the photomask substrate, it may become impossible to manufacture the display device.

[0004] Furthermore, due to the need for larger screen sizes in display devices such as LCD panels, or to increase productivity and save labor by sintering multiple display devices at once, photomask substrates are required to be enormous (large in area), needing to be 750×750mm or larger. In addition, due to globalization, the manufacturing of photomask substrates and the production of final products such as LCD panels are no longer carried out in a single factory, but rather in relatively distant locations both domestically and internationally. Therefore, photomask substrates are stored in photomask containers and transported by truck, ship, airplane, etc.

[0005] Therefore, it is desirable that the aforementioned photomask container can firmly hold the photomask substrate, be transported without contaminants (particles) adhering to its surface, and without damage, while also being lightweight and possessing excellent mechanical strength. Furthermore, when transported by air, which involves decompression or low temperatures, it is desirable that the photomask substrate or photomask container is not subjected to unnecessary stress, that condensation is suppressed in the photomask substrate storage area of ​​the photomask container, and that it maintains excellent cleanliness.

[0006] Therefore, various photomask containers suitable for transportation have been proposed. For example, the following solutions have been proposed: "A photomask box for transporting photomask substrates while they are being held, characterized in that it comprises: a holding means for holding the photomask substrate, a base provided with the holding means, and a cover portion that is detachably mounted on the base and covers the photomask substrate." (For example, see Patent Document 1); "A large precision sheet (semi-)finished product sealing container, comprising a main body and a cover portion having a generally symmetrical structure with sealing peripheral portions connected to each other, for storing large precision sheet finished or semi-finished products (hereinafter collectively referred to as "precision sheet (semi-)finished products"), characterized in that the main body and the cover portion are composed of multiple antistatic resin plates, each of which extends along a plane and is joined to each other through an intermediate connecting portion, having a structure in which a metal reinforcing strip is airtightly bolted to the resin plate from the outside along the joining portion, in the main body..." The bottom of the body has a fixed support structure capable of fixing and supporting the precision sheet (semi-finished product) in mutually perpendicular X, Y, and Z directions (i.e., the length, width, and thickness directions of the precision sheet (semi-finished product). The fixed support structure has at least one set of: a support portion for placing the precision sheet (semi-finished product) on the fixed support structure, and a fixed support tool for applying a pressing force at least in the thickness direction to the end edge of the precision sheet (semi-finished product) placed on the support portion. The fixed support tool has: a leg portion fixed to the bottom of the body portion; and a movable portion that can pivot rotatably between an inverted position where the leg portion applies a pressing force at least in the thickness direction to the end edge of the precision sheet (semi-finished product) placed on the support portion to fix and support the precision sheet (semi-finished product), and a flip-open position where the precision sheet (semi-finished product) can be placed on the support portion. (See, for example, Patent Document 2).

[0007] However, since the photomask container has a large number of components, it will consume a lot of time to manufacture each component, and therefore has the following disadvantages: there are limits to improving production efficiency, maintaining quality stability requires a lot of time, and it is heavy and not easy to handle. Existing technical documents Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2008-32915 Patent Document 2: Japanese Patent No. 4476727 Summary of the Invention The technical problem to be solved by the present invention

[0009] In view of the above-mentioned problems, the purpose of the present invention is to provide a photomask container that is lightweight and has excellent mechanical strength, can firmly hold the photomask substrate, suppress condensation in the photomask substrate storage part, has excellent cleanliness, makes it difficult for dirt (particles) to adhere to the surface of the photomask substrate, is safe and easy to transport, is easy to manufacture, has high production efficiency and quality stability, and is inexpensive. Technical means to solve technical problems

[0010] That is, the present invention relates to the following: (1) A photomask container, wherein the photomask substrate storage portion of the photomask container is formed by a container body and a cover, the photomask container is used to store and transport the photomask substrate in the state of being stored in the photomask substrate storage portion, the photomask container is characterized in that the container body is a box-shaped body formed by a high-density polyethylene resin with a melt flow rate (MFR) of 0.6 (g / 10 min) or less, consisting of a flat base and a side wall portion provided at a right angle from the end of the base, and the container body is a double-layer hollow structure consisting of an inner wall and an outer wall. (2) The photomask container according to (1) is characterized in that the container body is integrally formed by blow molding. (3) The photomask container according to (1) or (2) is characterized in that a photomask substrate holding portion for holding and fixing the photomask substrate is formed on the base. (4) The photomask container according to any one of (1) to (3) is characterized in that the sidewall portion has a hollow portion and the thickness of the sidewall portion is greater than the thickness of the base portion. (5) The photomask container according to any one of (1) to (4) is characterized in that the inner wall of the base and / or the inner wall of the side wall are deformed toward the photomask substrate receiving portion (above or inside) to integrally form a photomask substrate holding portion having a hollow portion. (6) The photomask container according to any one of (1) to (5) is characterized in that the cover is a box-shaped body formed of a high-density polyethylene resin with a melt flow rate (MFR) of 0.6 (g / 10 min) or less, consisting of a flat base and a side wall portion provided at a right angle from the end of the base, and the cover is a double-layer hollow structure consisting of an inner wall and an outer wall. (7) The photomask container according to any one of (1) to (6) is characterized in that the upper end of the side wall portion of at least one of the container body and the cover extends laterally to form a handle portion. (8) The photomask container according to any one of (1) to (7) is characterized in that at least one of the container body and the cover is provided with a through hole, and a filter is provided on the through hole, thereby forming an air extraction section. (9) The photomask container according to any one of (1) to (8) is characterized in that a plurality of ribs are formed on the base. (10) The photomask container according to any one of (1) to (9), characterized in that the inherent surface resistivity is 10 Ω. 8 Ω or higher and less than 10 10 Ω. (11) The photomask container according to any one of (1) to (10) is characterized in that an antistatic sheet or an antistatic molded body is laminated on the photomask substrate receiving portion side of the inner wall of the base. Invention Effects

[0011] The photomask container of the present invention is constructed as described above. The photomask container is easy to manufacture and inexpensive, lightweight, and possesses excellent mechanical strength. It can firmly hold the photomask substrate and can be stored and transported without surface contaminants (particles) or deformation. Therefore, even when stored or transported under reduced pressure or low temperature, unnecessary stress is not applied to the photomask substrate or the photomask container. Condensation in the photomask substrate storage section of the photomask container is suppressed, resulting in excellent cleanliness. Therefore, it is suitable for air transport by aircraft. Attached Figure Description

[0012] Figure 1 A schematic cross-sectional view illustrating an example of the photomask container of the present invention. Figure 2 A plan view illustrating an example of the container body of the photomask container of the present invention. Figure 3 for Figure 2 AA cross-section view. Figure 4 for Figure 2 BB cross-section. Figure 5 A plan view illustrating different examples of the container body of the photomask container of the present invention. Figure 6 for Figure 5 CC cross-section view. Detailed Implementation

[0013] In the photomask container of the present invention, a photomask substrate storage part is formed by a container body and a cover. The photomask container is used to store and transport the photomask substrate in the state of being stored in the photomask substrate storage part. The photomask container is characterized in that the container body is a box-shaped body formed by a plate-shaped base and a side wall portion provided at a right angle from the end of the base, which is made of high-density polyethylene resin with a melt flow rate (MFR) of 0.6 (g / 10 min) or less. The container body is a double-layer hollow structure composed of an inner wall and an outer wall.

[0014] The container body is preferably integrally formed by blow molding, resulting in high mechanical strength to prevent deformation or damage during transportation or storage. Therefore, the container body is made of high-density polyethylene resin. The high-density polyethylene resin is polymerized under medium and low pressure and has a density of 0.945~0.965 g / cm³. 3 Polyethylene resin can also be copolymerized with trace amounts of α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, and 1-octene.

[0015] The high-density polyethylene resin described above has a low melt flow rate (MFR), resulting in excellent film formability, particularly suitable for blow molding, and also exhibits excellent mechanical strength. Therefore, the melt flow rate (MFR) is 0.6 (g / 10 min) or less, preferably 0.2 (g / 10 min) or less, and more preferably 0.01 to 0.1 (g / 10 min). Furthermore, MFR is an indicator representing the melt viscosity of thermoplastic resins as specified in JIS K 7210.

[0016] Furthermore, when the weight-average molecular weight of the aforementioned high-density polyethylene resin is less than 100,000, its mechanical strength or creep resistance decreases; conversely, if it is greater than 500,000, its melt viscosity increases, its thermoforming properties decrease, and it becomes difficult to obtain a uniform container body. Therefore, a weight-average molecular weight of 100,000 to 500,000 is preferred. Additionally, in this invention, the weight-average molecular weight is a value determined by gel permeation chromatography (GPC).

[0017] In the above-mentioned high-density polyethylene resin, a small amount of medium-density polyethylene resin, low-density polyethylene resin, linear low-density polyethylene resin, polypropylene resin, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylate copolymer, ethylene-vinyl chloride copolymer, ethylene-propylene-butene copolymer, and other olefin resins may be added without reducing mechanical strength or other physical properties.

[0018] In addition, heat stabilizers, heat resistance modifiers, light stabilizers, ultraviolet absorbers, antioxidants, antistatic agents, impact modifiers, antifogging agents, flame retardants, colorants, etc., can be added to the above-mentioned high-density polyethylene resin as needed.

[0019] Because the container body is made of high-density polyethylene resin, it is prone to becoming charged and attracting contaminants (particles). Therefore, since the surface of the photomask substrate is easily contaminated by contaminants (particles), it is preferable to add an antistatic agent, and its inherent surface resistivity is preferably 10 Ω·cm. 8 Ω or higher and less than 10 10 Ω.

[0020] Examples of antistatic agents include glycerol fatty acid ester surfactants, organoboron antistatic agents, and carbon black, which are currently used in plastics processing.

[0021] As the above-mentioned antistatic agent, organoboron-based antistatic agents are preferred. For example, donor-acceptor molecular compound type antistatic agents represented by general formula (1) can be listed. [Chemical Formula 1]

[0022] In equation (1), R 1 R 2 Each is independently an acyl group or H with 12 to 22 carbon atoms, and R 1 R 2 At least one of them is an acyl group having 12 to 22 carbon atoms, R 3 R 4 R 5 Each of the following is independently CH3, C2H5, CH2OH, C2H4OH, CH2CH(CH3)OH, an alkyl or alkenyl group with 12 to 22 carbon atoms, an acyloxyalkyl group with a total of 13 to 25 carbon atoms, or an amidealkyl group with a total of 14 to 25 carbon atoms, and R 3 R 4 R 5 At least one of them is an alkyl or alkenyl group with 12 to 22 carbon atoms, an acyloxyalkyl group with a total carbon number of 13 to 25, or an acylaminoalkyl group with a total carbon number of 14 to 25.

[0023] As a specific example of an antistatic agent represented by general formula (1), it is represented by, for example, the following chemical formulas (2) to (12). [Chemical Formula 2]

[0024] [Chemical Formula 3]

[0025] [Chemical Formula 4]

[0026] [Chemical Formula 5]

[0027] [Chemical Formula 6]

[0028] [Chemical Formula 7]

[0029] [Chemical Formula 8]

[0030] [Chemical Formula 9]

[0031] [Chemical Formula 10]

[0032] [Chemical Formula 11]

[0033] [Chemical Formula 12]

[0034] The donor-acceptor molecular compound type antistatic agent represented by the above general formula (1) can be adsorbed onto the surface of inorganic filler powder to form a powdered antistatic agent. As for the inorganic filler powder, there is no particular limitation as long as it is an inorganic filler powder used in existing plastic molded bodies, such as calcium carbonate, magnesium carbonate, aluminum oxide, magnesium oxide, titanium oxide, magnesium hydroxide, talc, mica, clay, etc.

[0035] Furthermore, there is no particular limitation on the method for preparing inorganic filler powder with the above-mentioned antistatic agent adsorbed on its surface. For example, the following method can be listed: supplying inorganic filler powder to an organic solvent in which the antistatic agent is dissolved, stirring and mixing, and allowing the antistatic agent to be adsorbed on the surface of the inorganic filler powder, and then evaporating the organic solvent.

[0036] As for the aforementioned organic solvent, there are no particular limitations as long as it is an organic solvent capable of dissolving the aforementioned antistatic agent. Examples include lower alcohols such as methanol, ethanol, propanol, isopropanol, and butanol; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; esters such as ethyl acetate and isopropyl acetate; and tetrahydrofuran.

[0037] The amount of donor-acceptor molecular compound type antistatic agent represented by the above general formula (1) is usually preferably 0.01 to 1.0 parts by weight relative to 100 parts by weight of high-density polyethylene resin.

[0038] Next, the photomask container of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a schematic cross-sectional view illustrating an example of the photomask container of the present invention. In the figure, 1 is the container body, and 2 is the lid. The container body 1 and the lid 2 together are box-shaped bodies. By covering the container body 1 with the lid 2, a photomask substrate storage portion 3 is formed. 4 and 4 are photomask substrate support and fixing portions, formed on the photomask substrate storage portion 3 side of the container body 1 and the lid 2, and formed such that when the lid 2 is covered on the container body 1, the photomask substrate support and fixing portions 4 of the container body 1 and the photomask substrate support and fixing portions 4 of the lid 2 face each other. In addition, 5 is a handle portion.

[0039] When housing and fixing the photomask substrate 6 in the aforementioned photomask container, for example, the container body 1 with the cover 2 removed is placed horizontally, and the photomask substrate 6 is placed on the photomask substrate support and fixing part 4 of the container body 1. Next, the cover 2 is placed in a manner that forms the photomask substrate housing part 3, and the photomask substrate 6 is clamped and fixed by the photomask substrate support and fixing part 4 of the container body 1 and the photomask substrate support and fixing part 4 of the cover 2. Finally, it is fixed by binding with a strip made of synthetic resin, a strip made of metal, or by fixing with a fastener such as a draw latch or a ratchet buckle.

[0040] When transporting the photomask container 1 containing the photomask substrate 6, it can be transported directly in a horizontal position, or rollers can be installed on the photomask container 1 and the container can be erected with the rollers facing down, so that the photomask substrate 6 is transported in an upright position.

[0041] Figure 2 This is a plan view illustrating an example of the container body 1 of the photomask container of the present invention. Figure 3 for Figure 2 AA section view, Figure 4 for Figure 2 The figure shows a BB cross-sectional view. In the figure, 1 represents the container body, which is a box-shaped body consisting of a flat base 11 and sidewalls 12 extending perpendicularly from the ends of the base 11. The base 11 is a double-layered hollow structure consisting of an inner wall 111 and an outer wall 112, with ribs 13 provided by forming a hollow portion 113 locally between the inner wall 111 and the outer wall 112. Alternatively, the base 11 can also be a double-layered structure in which the inner wall 111 and the outer wall 112 are tightly fitted together.

[0042] Furthermore, the side wall portion 12 is a double-layered hollow structure consisting of an inner wall 111 and an outer wall 112, with a hollow portion 113 formed between the inner wall 111 and the outer wall 112. Its thickness is greater than that of the base portion for the purpose of weight reduction and reinforcement.

[0043] Furthermore, 5, 5 are handle portions for inserting fingers to move the photomask container, and multiple such handle portions are formed on the upper end of the side wall portion 12. The handle portion 5 is formed by providing a through hole in the side edge portion, which is provided to extend laterally along the upper end of the side wall portion 12.

[0044] In the figure, 4 and 4 are photomask substrate support and fixing parts made of solid columnar bodies such as olefin resin and ABS resin, used to place, support and fix the photomask substrate. They are fixed to the photomask substrate storage part 3 of the base 11 by bolts 41.

[0045] Additionally, 42, located between bolt 41 and base 11, serves as a sealing packing to tightly secure the two together, while 43 is an insert nut fixed to the lower interior of the photomask substrate support and fixing part 4. It is connected to bolt 41 via a thread to secure base 11 and photomask substrate receiving part 3. For the aforementioned photomask substrate support and fixing part 4, any existing known support holding means or positioning holding means can be used simultaneously (e.g., see Patent Documents 1 and 2).

[0046] In the figure, 7 is the air extraction section, which connects the inside and outside of the photomask substrate housing section 3, and the gas inside and outside can move. The air extraction section can be used to maintain the same temperature, humidity, pressure, etc. inside and outside. The air extraction section 7 is provided with a through hole 71 in such a way that a step portion 72 is formed between the inner wall 111 and the outer wall 112 of the base 11, and a filter 73 is stacked on the step portion 72 to block the through hole 71. The filter 73 is fixed to the base 11 by an annular fixing tool 74.

[0047] By forming the above-mentioned air extraction section 7, the internal and external gases of the photomask substrate storage section 3 are connected, and the air pressure, humidity and temperature inside and outside the photomask substrate storage section 3 become indistinguishable. This can suppress the deformation and damage of the photomask container caused by the air pressure difference during transportation by aircraft, and can suppress the condensation that occurs inside the photomask substrate storage section 3 due to temperature difference.

[0048] In the figure, 8 is a viewing window, which is used to observe the inside of the photomask substrate storage section 3 and the stored photomask substrate 6. The viewing window 8 is formed by passing through a hole in the base 11 and embedding a transparent resin plate such as polycarbonate resin, ABS resin, or glass.

[0049] In the figure, 9 is an O-ring, which is used to securely seal the photomask substrate storage portion 3 when the cover 2 is covered on the container body 1 to form the photomask substrate storage portion 3. The O-ring 9 is embedded in a groove formed on the upper surface of the side wall portion 12 of the container body 1. The O-ring 9 is preferably made of an elastic resin such as silicone rubber, fluororubber, urethane rubber, or norbornene rubber.

[0050] In the figure, 13, 13 are ribs provided on the base 11 for reinforcing the container body 1. Ribs 13 are formed by providing a hollow portion 113 between the inner wall 111 and the outer wall 112. Alternatively, ribs 13 can be formed by bending the inner wall 111 and / or the outer wall 112 to form the hollow portion 113, or by not forming a hollow portion 113. Furthermore, it is preferable to provide multiple ribs 13, and they can also be provided on the side wall portion 12.

[0051] In the figure, 14 and 14 are notches located near the upper end of the side wall portion 12 for setting a fixing clamp (e.g., a hook and loop fastener, ratchet lock, etc.). This fixing clamp is used to seal and fix the photomask container formed by covering the container body 1 with the cover 2 to form a photomask substrate storage portion. In addition, when sealing and fixing the photomask container, a rope or strip made of synthetic resin or metal can be used for binding.

[0052] Figure 5 Plan views illustrating different examples of the container body of the photomask container of the present invention, Figure 6 for Figure 5 CC cross-sectional view. 1 is the container body. The container body 1 is a box-shaped body formed by blow molding, consisting of a flat base 11 and a side wall portion 12 provided at a right angle from the end of the base 11. The base 11 and the side wall portion 12 are partially hollow double-layered hollow structures formed by an inner wall 111 and an outer wall 112.

[0053] In the figure, 12 is a sidewall portion provided at a right angle from the end of the base 11. The sidewall portion 12 is a hollow double-layer structure with a hollow portion 113 formed inside by the inner wall 111 and the outer wall 112. Since the sidewall portion 12 is a hollow double-layer structure, its thickness is greater than that of the base 11. A groove is formed on the upper surface of the sidewall portion 12, and an O-ring 9 is embedded in the groove.

[0054] In the figure, 4 and 4 are photomask substrate support and fixing parts for mounting and supporting the photomask substrate. The photomask substrate support and fixing part 4 is formed by deforming the inner wall 111 of the base 11 and / or the inner wall 111 of the side wall 12 toward the photomask substrate receiving part (above or inside), forming a hollow part 113 between the inner wall 111 and the outer wall 112 of the base 11 and the side wall 12, and integrally forming it with the base 11 and the side wall 12.

[0055] The photomask substrate support and fixing part 4 forms a lower inner step portion through the hollow part 113. The lower inner side of the step portion is the upper surface of the lower step portion, which is the photomask substrate mounting part 44, and the higher outer side of the step portion is the lateral positioning part 45. That is, while the photomask substrate for storage and transportation is placed on the photomask substrate mounting parts 44 at its ends, it is also positioned and firmly fixed by the lateral positioning parts 45.

[0056] The container body 1 described above is preferably formed by blow molding. Blow molding refers to the process of extruding thermoplastic resin in a molten state to form a cylindrical preform, then feeding the obtained preform into a molding metal mold, injecting gas into the preform, and simultaneously closing the molding metal mold to manufacture the molded body.

[0057] By using blow molding, a large container body 1 can be easily and integrally formed. The resulting container body 1 has a double-layer structure of inner and outer walls, with hollow parts in some areas, and is integrally formed without seams. It is lightweight and has excellent mechanical strength.

[0058] As long as it can function as the lid of the container body 1, the lid body 2 is not particularly limited. If the lid body 2 and the container body 1 have the same shape, then... Figure 1 As shown, the photomask substrate 6 can be easily housed and held within the photomask substrate housing 3, and is therefore preferred. Specifically, the cover is preferably a box-shaped body formed of a flat base and a sidewall portion perpendicularly disposed from the end of the base, made of high-density polyethylene resin with a melt flow rate (MFR) of 0.6 (g / 10 min) or less, and is a double-layer structure consisting of an inner wall and an outer wall.

[0059] In addition, to ensure that the inside of the photomask substrate housing is free of charge, antistatic sheets, antistatic molded bodies, etc., can be laminated on the inner wall of the base (photomask substrate housing side), or antistatic coatings can be applied or laminated. Industrial applicability

[0060] The photomask container of this invention is lightweight and has excellent mechanical strength, enabling it to firmly hold the photomask substrate and transport it without surface contaminants (particles) or deformation. Even during transport under reduced pressure or low temperature, it does not impose unnecessary stress on the photomask substrate or the photomask container, suppresses condensation in the photomask substrate storage area of ​​the container, and exhibits excellent cleanliness. Therefore, it is suitable for air transport by aircraft and can be used as a photomask container for storing and transporting photomasks. Explanation of reference numerals in the attached figures 1: Container body; 11: Base; 111: Inner wall; 112: Outer wall; 113: Hollow part; 12: Side wall; 13: Rib; 14: Notch / recess; 2: Cover; 3: Photomask substrate storage part; 4: Photomask substrate support and fixing part; 41: Bolt; 42: Sealing filler; 43: Embedded nut; 44: Photomask substrate mounting part; 45: Lateral positioning part; 5: Handle part; 6: Photomask substrate; 7: Vacuum part; 71: Through hole; 72: Step part; 73: Filter; 74: Fixing tool; 8: Viewing window; 9: O-ring.

Claims

1. A photomask container, wherein the photomask substrate storage portion of the photomask container is formed by a container body and a cover, the photomask container being used to store and transport the photomask substrate in a state of being stored in the photomask substrate storage portion, the photomask container being characterized in that the container body is a box-shaped body formed of high-density polyethylene resin with a melt flow rate (MFR) of less than 0.6 g / 10 min, consisting of a flat base and sidewalls provided at right angles from the ends of the base, and the container body is a double-layered hollow structure consisting of an inner wall and an outer wall.

2. The photomask container according to claim 1, characterized in that, The container body is integrally formed using blow molding.

3. The photomask container according to claim 1 or 2, characterized in that, A photomask substrate holding portion is formed on the base to hold and fix the photomask substrate.

4. The photomask container according to claim 1 or 2, characterized in that, The sidewall has a hollow portion, and the thickness of the sidewall is greater than the thickness of the base.

5. The photomask container according to claim 1 or 2, characterized in that, The inner wall of the base and / or the inner wall of the side wall are deformed toward the photomask substrate receiving portion, and a photomask substrate holding portion with a hollow portion is integrally formed.

6. The photomask container according to claim 1 or 2, characterized in that, The cover is a box-shaped body formed of a flat base and sidewalls arranged at right angles from the ends of the base, and is made of high-density polyethylene resin with a melt flow rate (MFR) of less than 0.6 g / 10 min. The cover is a double-layered hollow structure composed of an inner wall and an outer wall.

7. The photomask container according to claim 1 or 2, characterized in that, The upper end of the side wall of at least one of the container body and the lid extends laterally to form a handle.

8. The photomask container according to claim 1 or 2, characterized in that, A through hole is provided in at least one of the container body and the lid, and a filter is provided in the through hole, thereby forming an air extraction section.

9. The photomask container according to claim 1 or 2, characterized in that, Multiple ribs are formed at the base.

10. The photomask container according to claim 1 or 2, characterized in that, The surface inherent resistance value is 10 8 Ω or more and less than 10 10 Ω.

11. The photomask container according to claim 1 or 2, characterized in that, An antistatic sheet or an antistatic molded body is stacked on the inner wall of the base of the photomask substrate receiving part.

Images