Gasket for substrate storage container, manufacturing method thereof, and substrate storage container

Abstract

To provide a gasket for a substrate storage container, a manufacturing method thereof, and a substrate storage container, which can prevent fluid from leaking from inside a container body to the outside of a lid even when the inside of the substrate storage container is under a positive pressure, and which can be easily molded and manufactured.SOLUTION: An elastically deformable gasket 20 for a substrate storage container is interposed between the body 1 of the substrate storage container and a door set 10, and includes a base piece 21 interposed between the body 1 storing semiconductor wafers and the door set 10, a pair of lip pieces 30 and 31 extending from the base piece 21 and closely contacting the inner wall surface of the body 1, and a curved groove 40 contributing to the rocking of an outer base piece 23 relative to the inner base piece 22 of the base piece 21, and the pair of lip pieces 30 and 31 extends away from each other from the periphery of the outer base piece. Since there are multiple lip pieces 30 and 31, it is possible to prevent air or liquid from leaking out even when the substrate storage container is purged with nitrogen or filled with liquid such as pure water and moved.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a gasket for a substrate storage container that is interposed between a container body and a lid for storing substrates such as semiconductor wafers, a method for manufacturing the same, and a substrate storage container. [Background technology]

[0002] As shown in Figures 10 to 12, a conventional substrate storage container is configured as a FOSB type having a body 1 for storing semiconductor wafers, a door set 10 that is press-fitted into the open front of the body 1, and a gasket 20A for substrate storage containers that is interposed between the body 1 and the door set 10, and is used for transporting semiconductor wafers (see Patent Document 1).

[0003] The body 1 is molded as a front-open box with an opening at the front, and a pair of left and right teeth pieces (not shown) that support semiconductor wafers are provided on both sides of the inside, and the pair of left and right teeth pieces are arranged at a predetermined interval in the vertical direction. On the front side 2 of the peripheral wall of the body 1, a step receiving wall 6 that comes into contact with the gasket 20A for a substrate storage container is formed as shown in Figures 12 and 13, and the step receiving wall 6 is formed with a partition wall 7 that partitions the front of the body 1 and can come into contact with the door set 10.

[0004] 10 to 13, the door set 10 is configured to have a substantially rectangular shape on the front side, and an endless mounting fitting groove 13 into which the gasket 20A for the substrate storage container is fitted is formed near the peripheral edge of the back side. The door set 10 is fitted with a filter that filters the air outside the substrate storage container and allows it to flow inside.

[0005] 12 and 13, gasket 20A for a substrate storage container comprises base piece 21A that fits into mounting fitting groove 13 of door set 10, and lip piece 30A that extends from the peripheral edge of base piece 21A and contacts the inner peripheral surface of the step receiving wall of body 1, and is molded by injection molding using a molding material containing elastomer. This gasket 20A for a substrate storage container functions to ensure the airtightness of the substrate storage container and prevent contamination of semiconductor wafers.

[0006] In the above configuration, when transporting semiconductor wafers in a substrate storage container, multiple semiconductor wafers are aligned and stored inside body 1 in a clean room of a semiconductor manufacturing factory, door set 10 is press-fitted into the open front of body 1, and substrate storage container gasket 20A is inserted into the gap between the inner front periphery of body 1 and door set 10 and deformed, allowing the multiple semiconductor wafers to be shipped and transported in the substrate storage container.

[0007] When the door set 10 is fitted, air inside and outside the substrate storage container flows out and in (see arrows in Figure 13) before the lip piece 30A of the gasket 20A for the substrate storage container comes into contact with the inner surface of the step-receiving wall of the body 1 (see Figure 12).However, after the lip piece 30A of the gasket 20A for the substrate storage container comes into contact (see Figure 14), the inside and outside of the substrate storage container are blocked off, so that inflow and outflow are regulated (see arrows in Figure 14).

[0008] Semiconductor wafers are transported by truck or rail, but when they are transported by air, the air pressure inside the aircraft is low when the aircraft takes off, so the inside of the substrate storage container becomes relatively positive pressure (see FIG. 15). When the inside of the substrate storage container becomes positive pressure, the door set 10 and the gasket 20A for the substrate storage container float up (see the thick arrow in FIG. 15), and clean air inside the substrate storage container flows out to the outside (see the thin arrow in the same figure). However, although the clean air inside the substrate storage container flows out to the outside, air outside the substrate storage container does not flow into the substrate storage container, so contamination of the semiconductor wafers does not occur.

[0009] In contrast, when the aircraft lands, the inside of the substrate storage container becomes relatively negative pressure (see FIG. 16). When the inside of the substrate storage container becomes negative pressure, the door set 10 and the gasket 20A for the substrate storage container sink (see the thick arrow in FIG. 16), and the lip piece 30A of the gasket 20A for the substrate storage container is strongly pressed against the inner peripheral surface of the step receiving wall of the body 1, thereby restricting the air outside the substrate storage container from flowing into the inside of the substrate storage container from between the body 1 and the door set 10 (see the thin arrow in the same figure).

[0010] However, although the inflow of air from outside the substrate storage container is restricted by the blocking action of gasket 20A for the substrate storage container, the air still flows through the filter and into the substrate storage container. This inflow makes the air pressure inside the substrate storage container equal to the air pressure on the ground, but the filtering action of the filter prevents contamination of the semiconductor wafers. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] JP 2013-105931 A Summary of the Invention [Problem to be solved by the invention]

[0012] Because the conventional gasket 20A for a substrate storage container is formed as described above, it is possible to ensure airtightness and prevent contamination of semiconductor wafers when the substrate storage container is transported by truck, rail, or air.

[0013] However, when the substrate storage container is purged with nitrogen, or when the substrate storage container is filled with liquid such as pure water for ion analysis or metal analysis work and rotated or rocked, the inside of the substrate storage container becomes positive pressure and a pressure equivalent to that during positive pressure acts on the gasket 20A for the substrate storage container, resulting in the problem that air and liquid flow sequentially through the inside of the body 1, the gap between the body 1 and the gasket 20A for the substrate storage container, and the peripheral wall of the door set 10, and then leak out to the outside.

[0014] One possible solution to this problem would be to change the shape of gasket 20A for the substrate storage container; however, if this method is adopted carelessly, it would require undercut processing when manufacturing gasket 20A for the substrate storage container, creating a major new problem in that it would become extremely difficult to mold gasket 20A for the substrate storage container.

[0015] The present invention has been made in consideration of the above, and aims to provide a gasket for a substrate storage container, a manufacturing method thereof, and a substrate storage container which can prevent fluid from leaking from inside the container body to the outside of the lid even when the inside of the substrate storage container is under positive pressure, and which can be easily molded and manufactured. [Means for solving the problem]

[0016] In order to solve the above-mentioned problems, the present invention includes a base piece interposed between a container body that stores a substrate and a lid body, a plurality of lip pieces extending from the base piece and capable of contacting the inner wall surface of the container body, and a curved groove that contributes to the oscillation of the remainder of the base piece relative to a portion of the base piece, and is characterized in that the plurality of lip pieces extend away from each other from the remainder of the base piece.

[0017] The container body is configured as a front-open box with a lid fitted to the open front, and a step receiving wall that contacts the lip piece is formed on the front side of the peripheral wall and a partition wall that divides the front and can contact the peripheral wall of the lid is formed on the step receiving wall. An endless groove for fitting the base piece is formed near the periphery of the rear surface of the cover, The base piece is formed endlessly and includes an inner base piece that is fitted into the mounting groove of the lid body, and an outer base piece that is formed on the inner base piece so as to be swingable and is exposed from the mounting groove of the lid body, The plurality of lip pieces are formed endlessly, including a first lip piece extending from an outer base piece peripheral edge portion of the base piece and capable of contacting an inner peripheral surface of the step receiving wall of the container body, and a second lip piece extending from a base portion of the first lip piece and capable of contacting either a front side of the peripheral wall of the container body or the inner peripheral surface of the step receiving wall, The inflection groove is preferably formed in the base piece and located near the boundary between the inner base piece and the outer base piece.

[0018] It is also preferable that the multiple lip pieces are arranged so that a first lip piece extends obliquely from the peripheral edge of the outer base piece and a second lip piece extends obliquely away from the first lip piece, and that these first and second lip pieces are arranged in a roughly L-shaped cross section.

[0019] In order to solve the above problems, the present invention provides a method for producing a gasket for a substrate storage container according to claim 1 or 2, comprising the steps of: The method is characterized in that a molding material containing an elastomer is filled into a clamped mold with a slide mechanism to form a gasket for a substrate storage container in which a portion of a base piece has multiple lip pieces and the remaining portion is inclined near the inflection groove, the gasket for the substrate storage container is cooled and hardened, and the mold with the slide mechanism is opened to remove the gasket for the substrate storage container.

[0020] In addition, in order to solve the above-mentioned problems, the present invention provides a container body capable of storing a plurality of semiconductor wafers in an aligned manner, a lid body that is fitted to the open front surface of the container body (by pushing in with pressure), and a gasket for a substrate storage container as described in claim 1 or 2 that is interposed between the inner front periphery of the container body and the lid body, and is characterized in that the container body is used for transporting semiconductor wafers.

[0021] Here, the substrate in the claims includes at least various semiconductor wafers, glass substrates, mask substrates, etc. In addition, the term "approximately V-shaped cross section" of the multiple lip pieces includes not only a V-shaped cross section, but also similar shapes that do not cause a difference in the effect of the present invention (such as an approximately inverted L-shaped cross section or an approximately V-shaped cross section).

[0022] The top, bottom, front, back, left and right directions of the gasket for substrate storage containers according to the present invention are directions based on the drawings, and can be appropriately changed as necessary. The subject of the present invention is a gasket for substrate storage containers, but if the configuration for other uses is the same as the configuration of the present invention and can be converted to a gasket for substrate storage containers, and the function and effect of the present invention are achieved, the configuration for other uses falls within the technical scope of the present invention. Furthermore, although the substrate storage container is mainly of the FOSB type, this does not particularly exclude the FOUP type.

[0023] According to the present invention, by increasing the number of lip pieces and bringing the increased lip pieces into contact with the wall of the container body when the inside of the substrate storage container is under positive pressure and the outside is under negative pressure, it is possible to restrict the outflow of fluid from the inside of the substrate storage container to the outside. Also, when molding the gasket for the substrate storage container, the remaining part of the base piece is molded in a bent position, and the positions of the multiple lip pieces during molding are changed to positions that make it easier to mold, so molding the gasket for the substrate storage container becomes easier. Effect of the Invention

[0024] According to the present invention, even if the inside of the substrate storage container is under positive pressure, it is possible to effectively prevent fluid from leaking from inside the container body to outside the lid body. Also, it is possible to easily mold and manufacture the gasket for the substrate storage container.

[0025] According to the invention described in claim 2, when the outside of the substrate storage container is under positive pressure, even if the fluid outside the substrate storage container attempts to flow into the container body from between the step receiving wall of the container body and the lid, the first lip piece comes into contact with the inner circumferential surface of the step receiving wall of the container body, so the inflow is restricted by the first lip piece. Also, when the inside of the substrate storage container is under positive pressure, even if the fluid inside the substrate storage container attempts to flow out of the container body from between the step receiving wall of the container body and the lid, the second lip piece comes into contact with either the front side of the peripheral wall of the container body or the inner circumferential surface of the step receiving wall, so the second lip piece restricts the outflow.

[0026] According to the invention described in claim 3, the first and second lip pieces are arranged in an approximately V-shaped cross section and the second lip piece is shorter than the first lip piece, so that the multiple lip pieces can be brought into contact with the inner surface of the step receiving wall of the container body and the front side of the peripheral wall of the container body at approximately the same time, making handling easy.

[0027] According to the invention described in claim 4, when molding a gasket for a substrate storage container, a portion of the gasket for a substrate storage container can be inclined relative to the remaining portion, and multiple lip pieces can be molded to extend away from each other diagonally to the side, making it possible to easily mold and manufacture a gasket for a substrate storage container. [Brief description of the drawings]

[0028] [Figure 1] 1 is a front view illustrating a schematic diagram of an embodiment of a gasket for a substrate storage container according to the present invention. [Diagram 2] FIG. 2 is an explanatory diagram of line II-II in FIG. [Diagram 3] 3 is an explanatory side view showing an enlarged view of a portion III in FIG. 2. [Figure 4] 1 is an enlarged cross-sectional view illustrating a state in which the inside of a substrate storage container in an embodiment of a gasket for a substrate storage container according to the present invention is under negative pressure. FIG. [Diagram 5] 1 is an enlarged cross-sectional view illustrating a state in which the inside of a substrate storage container in an embodiment of a gasket for a substrate storage container according to the present invention is under positive pressure. FIG. [Figure 6]1 is an enlarged cross-sectional view illustrating a gasket for a substrate storage container according to an embodiment of the present invention, the gasket being expressed using the quadrant method with the vicinity of the base of multiple lip pieces as the origin. FIG. [Figure 7] 1 is a cross-sectional explanatory view that illustrates a relationship between a die with a slide mechanism and a gasket for a substrate storage container in an embodiment of a gasket for a substrate storage container and a manufacturing method thereof according to the present invention. FIG. [Figure 8] FIG. 2 is a cross-sectional explanatory view that illustrates a schematic relationship between a general mold and a gasket for a substrate storage container in an embodiment of a gasket for a substrate storage container and a manufacturing method thereof according to the present invention. [Figure 9] FIG. 1 is an explanatory diagram showing the procedure for attaching a gasket for a substrate storage container to a door set in an embodiment of the gasket for a substrate storage container according to the present invention, where (a) is a cross-sectional explanatory diagram showing the stage before the gasket for the substrate storage container comes into contact with the mounting fitting groove of the door set, (b) is a cross-sectional explanatory diagram showing the state where the gasket for the substrate storage container begins to come into contact with the mounting fitting groove of the door set, (c) is a cross-sectional explanatory diagram showing the state where the gasket for the substrate storage container comes into contact with the mounting fitting groove of the door set and the outer base piece swings, (d) is a cross-sectional explanatory diagram showing the state where the gasket for the substrate storage container comes into contact with the mounting fitting groove of the door set and the outer base piece swings completely, and (e) is a cross-sectional explanatory diagram showing the state where the gasket for the substrate storage container is fully inserted into the mounting fitting groove of the door set. [Figure 10] FIG. 2 is an exploded perspective view illustrating a substrate storage container. [Figure 11] FIG. 2 is an exploded side view illustrating a substrate storage container; [Figure 12] 11 is a cross-sectional explanatory view showing a state in which a door set is press-fitted into a body of a substrate storage container; FIG. [Figure 13] 13 is an enlarged cross-sectional view illustrating a schematic view of a portion XIII in FIG. 12. [Figure 14] 11 is a cross-sectional explanatory view showing a schematic state in which the door set is press-fitted into the body of the substrate storage container; FIG. [Figure 15] 11 is an enlarged cross-sectional explanatory diagram showing a schematic state in which the inside of a substrate storage container is under positive pressure when an aircraft takes off; FIG. [Figure 16] 11 is an enlarged cross-sectional explanatory diagram showing a state in which the inside of a substrate storage container becomes negative pressure when an aircraft lands; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] A preferred embodiment of the present invention will now be described with reference to the drawings. A gasket 20 for a substrate storage container in this embodiment is a dedicated elastically deformable gasket that is interposed between the body 1 and door set 10 of a substrate storage container known as a FOSB, as shown in FIGS. 1 to 11. The gasket 20 is endlessly molded to include a base piece 21 that is interposed between the body 1 and door set 10 and is capable of storing semiconductor wafers in an aligned manner, a pair of lip pieces 30 / 31 that extend from the base piece 21 and are capable of contacting the inner surface of the wall of the body 1, and a curved groove 40 that contributes to the oscillation of an outer base piece 23 having a pair of lip pieces 30 / 31 relative to an inner base piece 22 that is a part of the base piece 21, thereby contributing to the achievement of Goal 9 of the SDGs adopted at the United Nations Summit.

[0030] 10 and 11, the body 1 is injection molded into a front-open box with an opening at the front, and a pair of left and right teeth pieces (not shown) that support the semiconductor wafer horizontally are provided opposite each other on both sides of the interior, i.e., on the inner surfaces of both side walls 4, and the pair of left and right teeth pieces are arranged at a predetermined interval in the vertical direction, and each teeth piece is formed into a long, thin, curved plate extending in the front-to-back direction. The semiconductor wafers, although not shown, are made of thin, brittle, high-quality silicon wafers, for example, φ300 mm, which are stored inside the body 1, and multiple sheets (25 sheets) are aligned at a predetermined interval in the vertical direction.

[0031] As shown in Figures 4 and 5, on the front side 2 of the peripheral wall of the body 1, i.e., the front side of the bottom plate 3, the front sides of both side walls 4, and the front side of the ceiling plate 5, a step receiving wall 6 that comes into contact with a gasket 20 for a substrate storage container is formed protruding in an endless, approximately frame-like shape, and at the end of this step receiving wall 6, a partition wall 7 that divides the front of the body 1 into an approximately rectangular shape and is capable of coming into contact with the peripheral wall of the door set 10 is integrally formed in an endless, approximately frame-like shape.

[0032] As shown in Figures 4, 5, 9 to 11, the door set 10 is configured in a generally rectangular shape from the front, and comprises a door main body 11 that is press-fitted into the open front of the body 1 and engaged with the partition wall 7 and the step receiving wall 6, and a pair of door covers 12 that are detachably attached to both sides of the open front of the door main body 11. A locking mechanism that is rotated from outside the door covers 12 is built in between the door main body 11 and the pair of door covers 12.

[0033] A plurality of filtration filters that filter dirty air outside the substrate storage container and introduce it into the inside are removably attached to this door set 10. In addition, an endless frame-shaped mounting fitting groove 13 that faces the step receiving wall 6 of the body 1 from the lateral direction is formed near the peripheral edge of the back surface 11a of the door main body 11 that faces the body back wall, and a separate substrate storage container gasket 20 is removably fitted into this mounting fitting groove 13.

[0034] As shown in Figures 1 to 7 and 9, the base piece 21 of the gasket 20 for a substrate storage container is formed in an endless frame shape comprising an inner base piece 22 that is deeply inserted into the mounting fitting groove 13 of the door set 10, and a swingable outer base piece 23 that is integrally formed on the peripheral portion of the inner base piece 22. When the gasket 20 for a substrate storage container is not fitted into the mounting fitting groove 13, the outer base piece 23 inclines upwardly in Figure 9 relative to the inner base piece 22, and when the gasket 20 for a substrate storage container is fitted into the mounting fitting groove 13, the outer base piece 23 inclined relative to the inner base piece 22 swings downwardly in Figure 9 and bends.

[0035] The base piece 21 has an inner base piece 22 and an outer base piece 23, each formed as a long, horizontal plate with a polygonal cross-section, with the outer base piece 23 surrounding the inner base piece 22, and this outer base piece 23 is formed to be larger and longer than the inner base piece 22, and when the gasket 20 for the substrate storage container is not engaged with the mounting engagement groove 13, it inclines diagonally upward at an angle θ1 of 25° or more and 50° or less, preferably 30° or more and 45° or less, and more preferably 32° or more and 40° or less (see Figure 7).

[0036] When the gasket 20 for a substrate storage container is fitted into the mounting fitting groove 13 of the door set 10, the surface 22a of the inner base piece 22 contacts the back surface 11a of the door body 11, and the back surface 22b contacts the inner surface of the mounting fitting groove of the door body 11. In contrast, when the gasket 20 for a substrate storage container is fitted into the mounting fitting groove 13 of the door set 10, the surface 23a of the outer base piece 23 contacts the back surface 11a of the door body 11, and part of the back surface 23b contacts the inner surface of the mounting fitting groove of the door body 11 to be aligned flush with the back surface 22b of the inner base piece 22, and most of the remaining back surface 23b is exposed to the outside from the mounting fitting groove 13.

[0037] As shown in Figures 3 to 7 and 9, the pair of lip pieces 30, 31 are formed in an endless frame shape with a first lip piece 30 extending from the outer peripheral edge of the outer base piece 23 of the base piece 21 and bendably fitted in close contact with the inner peripheral surface of the step receiving wall of the body 1, and a second lip piece 31 extending from the outer peripheral edge of the outer base piece 23 and bendably fitted in close contact with the front side 2 of the peripheral wall of the body 1, and function to regulate the flow of gas and liquid between the inside and outside of the substrate storage container.

[0038] The first lip piece 30 extends obliquely from the outer peripheral edge of the outer base piece 23 toward the inner peripheral surface of the step receiving wall, and functions to prevent gas or liquid from flowing from the outside of the substrate storage container to the inside when the outside of the substrate storage container is under positive pressure. In contrast, the second lip piece 31 extends obliquely from the base of the first lip piece 30 to a short length away from the first lip piece 30, and functions to prevent gas or liquid from flowing from the inside of the substrate storage container to the outside when the inside of the substrate storage container is under positive pressure. The first and second lip pieces 30 and 31 are arranged in a generally V-shaped cross section away from each other, and form an angle θ2 of 80° to 125°, preferably 85° to 110°, and more preferably 87° to 95° (see FIG. 7).

[0039] 3 to 7 and 9, in order to facilitate deformation of the gasket 20 for a substrate storage container, the inflection groove 40 is formed in a generally mountain-shaped cross section on the rear surface of the base piece 21, and is also formed in an endless frame shape near the boundary between the inner base piece 22 and the outer base piece 23 of the base piece 21, and functions to control the position and attitude of the outer base piece 23 and the pair of lip pieces 30, 31. When the gasket 20 for a substrate storage container is not fitted into the mounting fitting groove 13, the inflection groove 40 maintains the generally mountain-shaped cross section as shown in Fig. 3, and when the gasket 20 for a substrate storage container is fitted into the mounting fitting groove 13, the inflection groove 40 is crushed by the swinging of the outer base piece 23 as shown in Figs. 4 and 5, facilitating swinging.

[0040] Such a gasket 20 for a substrate storage container is injection molded from a molding material containing an elastomer, and has a hardness of A40 or more and A90 or less when measured with a type A durometer. The elastomer of the molding material is not particularly limited, but examples thereof include inexpensive polyester resin, polyethylene resin, polyolefin resin, fluororubber, etc., which are excellent in weather resistance, etc.

[0041] The surface hardness of the gasket 20 for a substrate storage container, when measured with a type A durometer, is preferably A40 to A90, more preferably A50 to A90, and even more preferably A60 to A90, from the viewpoint of facilitating the swinging of the outer base piece 23. The measurement with a type A durometer is performed under pressing conditions of 1 second or less according to the JIS K6253 standard.

[0042] When the gasket 20 for a substrate storage container is represented by the quadrant method with the vicinity of the base portions of the pair of lip pieces 30 and 31 as the origin, when the gasket 20 for a substrate storage container is manufactured or when the gasket 20 for a substrate storage container is not fitted into the mounting fitting groove 13, the first lip piece 30 is in the first quadrant and the second lip piece 31 is in the fourth quadrant in order to facilitate demolding of the gasket 20 for a substrate storage container. In contrast, when the gasket 20 for a substrate storage container is fitted into the mounting fitting groove 13, the first lip piece 30 is in the fourth quadrant and the second lip piece 31 is in the third quadrant.

[0043] In the above configuration, when manufacturing gasket 20 for a substrate storage container, lower die 51 and upper die 52 of mold 50 with a slide mechanism prepared as shown in Figure 7 are clamped, and molten elastomer-containing molding material is filled into this clamped mold 50 with a slide mechanism to injection mold gasket 20 for a substrate storage container in which outer base piece 23 is inclined at the boundary of inflection groove 40 relative to inner base piece 22.

[0044] The mold 50 with a slide mechanism is preferably a dedicated type with a slide mechanism having multiple parting lines PL. This is because, for example, when the gasket 20 for a substrate storage container is injection molded using a general simple mold, an undercut portion UC shown in Fig. 8 is generated, making it extremely difficult to remove the gasket 20 for a substrate storage container from the mold.

[0045] Furthermore, in order to facilitate undercut processing, it is preferable that the gasket 20 for a substrate storage container is injection molded so that the base piece 21 is bent in a generally inverted V-shape rather than having a generally plate-like cross section extending horizontally. This is because if the outer base piece 23 is injection molded so that it is inclined obliquely upward from the vicinity of the inflection groove 40 relative to the inner base piece 22 and the first and second lip pieces 30, 31 extend vertically while moving away from each other diagonally to the sides, the core 53 of the slide mechanism can be slid to facilitate demolding after injection molding.

[0046] After the gasket 20 for the substrate storage container is injection molded, the gasket 20 for the substrate storage container is cooled and hardened, and the lower die 51 and upper die 52 of the mold 50 with a slide mechanism are opened, and then the gasket 20 for the substrate storage container is demolded and removed, thereby manufacturing the gasket 20 for the substrate storage container.

[0047] Next, when attaching the manufactured gasket 20 for a substrate storage container to the door set 10, the frame-shaped gasket 20 for a substrate storage container is stretched and spread out as shown in Figure 9, and the gasket 20 for a substrate storage container is gradually inserted into the mounting fitting groove 13 of the door set 10 from the outside, thereby attaching the gasket 20 for a substrate storage container.

[0048] At this time, in the initial stage, the base piece 21 of the substrate storage container gasket 20 is deformed into a generally inverted V-shaped cross section (see FIG. 9(a)), but when the surface 23a of the outer base piece 23 of the base piece 21 begins to contact the door main body back surface 11a of the door set 10, the outer base piece 23 gradually swings (see FIGS. 9(b) and (c)). Then, when the surface 23a of the outer base piece 23 completely contacts the door main body back surface 11a of the door set 10, the back surface 22b of the inner base piece 22 and the back surface 23b of the outer base piece 23 are aligned flush, and the inflection groove 40 between the inner base piece 22 and the outer base piece 23 is crushed (see FIGS. 9(d) and (e)).

[0049] Next, when semiconductor wafers are stored in a substrate storage container for transportation, a plurality of semiconductor wafers are sequentially stored and aligned inside body 1 in a clean room of a semiconductor manufacturing factory, door set 10 is press-fitted into the open front of body 1 with an opener, and substrate storage container gasket 20 is inserted into the gap between the front inner periphery of body 1 and door set 10 and deformed, whereby a plurality of semiconductor wafers can be shipped and transported in the substrate storage container. When substrate storage container gasket 20 deforms, the first lip piece 30 of the pair of lips 30, 31 presses against the inner periphery of the step receiving wall of body 1, and the second lip piece 31 presses against the peripheral wall front side 2 of body 1.

[0050] Semiconductor wafers are shipped and transported by truck, rail, or air, and during transportation, the inside of the substrate storage container may become negative pressure and the outside of the substrate storage container may become positive pressure. In this case, air outside the substrate storage container tries to flow into the inside of the body 1 from between the step receiving wall 6 of the body 1 and the door set 10 (see FIG. 4), but since the long first lip piece 30 is pressed against and in close contact with the inner peripheral surface of the step receiving wall of the body 1, the outflow is blocked by the first lip piece 30. Therefore, it is possible to effectively restrict dirty air outside the substrate storage container from flowing into the inside of the body 1 from between the body 1 and the door set 10.

[0051] In addition, during transportation of semiconductor wafers, during nitrogen purging of the substrate storage container, during ion analysis or metal analysis, etc., the inside of the substrate storage container may become positive pressure and the outside of the substrate storage container may become negative pressure. In this case, air or liquid inside the substrate storage container tries to flow out of the body 1 between the step receiving wall 6 of the body 1 and the door set 10 (see FIG. 5), but since the short second lip piece 31 is pressed against and tightly attached to the peripheral wall front side 2 of the body 1, the outflow is blocked by the second lip piece 31. Therefore, the air or liquid inside the substrate storage container does not leak out to the outside by sequentially flowing through the inside of the body 1, the gap between the body 1 and the substrate storage container gasket 20, and the peripheral wall of the door set 10.

[0052] According to the above configuration, the number of lip pieces of gasket 20 for a substrate storage container is increased to multiple pieces and configured to accommodate the negative and positive pressures of the substrate storage container, so that air and liquid can be effectively prevented from leaking out even when the substrate storage container is purged with nitrogen or filled with liquid such as pure water for ion analysis or metal analysis and moved. Also, when molding gasket 20 for a substrate storage container, base piece 21 is molded in a bent position with a substantially inverted V-shape in cross section, and the molding positions of first and second lip pieces 30 and 31 are changed and shifted, so that undercut processing is facilitated and gasket 20 for a substrate storage container can be easily molded.

[0053] Furthermore, since the first and second lip pieces 30 and 31 are arranged in a generally V-shaped cross section and the second lip piece 31 is shorter than the first lip piece 30, the pair of lip pieces 30 and 31 can be simultaneously brought into close contact with the inner surface of the step receiving wall of the body 1 and the front side 2 of the peripheral wall of the body 1, making work and handling easier.

[0054] In addition, the inner base piece 22 and the outer base piece 23 of the gasket 20 for a substrate storage container in the above embodiment may be the same length or different lengths. For example, the inner base piece 22 may be longer. Furthermore, the first and second lip pieces 30 and 31 of the gasket 20 for a substrate storage container may each be tapered or curved, and a protrusion having a substantially circular cross section may be integrally formed at the tip portion. These first and second lip pieces 30 and 31 may be the same length or different lengths.

[0055] The second lip piece 31 may be extended from the outer peripheral edge of the outer base piece 23 and bendably fitted in close contact with the inner peripheral surface of the step receiving wall. A plurality of curved grooves 40 may be formed at predetermined intervals on the rear surface of the base piece 21. Furthermore, all of the technologies described in this specification may be subject to the acquisition of rights through amendments or divisional applications, etc. [Industrial Applicability]

[0056] The gasket for a substrate storage container and its manufacturing method, as well as the substrate storage container according to the present invention, are used in the fields of manufacturing semiconductor wafers and substrate storage containers. [Explanation of symbols]

[0057] 1 Body (container body) 2 Front side of surrounding wall 6. Step support wall (wall) 7 Compartment wall (wall) 10 Door set (lid) 13 Mounting groove 20 Gasket for substrate storage container 21 Base piece 22 Inner base piece (part) 23 Outer base piece (remainder) 30 First Lip Piece 31 Second Lip Piece 40 Inflection Groove 50 Mold 51 Lower mold 52 Upper mold 53 cores PL parting line

Claims

1. A gasket for a substrate storage container, comprising: a base piece interposed between a container body for storing substrates and a lid; a plurality of lip pieces extending from the base piece and capable of contacting the inner wall surface of the container body; and a curved groove contributing to the oscillation of the remainder of the base piece relative to a portion of the base piece, the plurality of lip pieces extending away from each other from the remainder of the base piece.

2. The container body is configured as a front open box with a lid fitted to the open front, and a step receiving wall that contacts the lip piece is formed on the front side of the peripheral wall and a partition wall that partitions the front and can contact the peripheral wall of the lid is formed on the step receiving wall. An endless groove for fitting the base piece is formed near the periphery of the rear surface of the cover, The base piece is formed endlessly and includes an inner base piece that is fitted into the mounting groove of the lid body, and an outer base piece that is formed on the inner base piece so as to be swingable and is exposed from the mounting groove of the lid body, The plurality of lip pieces are formed endlessly, including a first lip piece extending from an outer base piece peripheral edge portion of the base piece and capable of contacting an inner peripheral surface of the step receiving wall of the container body, and a second lip piece extending from a base portion of the first lip piece and capable of contacting either a front side of the peripheral wall of the container body or the inner peripheral surface of the step receiving wall, 2. The gasket for a substrate storage container according to claim 1, wherein the curved groove is formed in the base piece and positioned near the boundary between the inner base piece and the outer base piece.

3. 3. A gasket for a substrate storage container as described in claim 2, wherein the multiple lip pieces include a first lip piece extending obliquely from the peripheral edge of the outer base piece and a second lip piece extending obliquely away from the first lip piece, and the first and second lip pieces are arranged to form an approximately L-shaped cross section.

4. 3. A method for manufacturing a gasket for a substrate storage container as described in claim 1 or 2, characterized in that a molding material containing an elastomer is filled into a clamped mold with a slide mechanism to mold a gasket for a substrate storage container in which a portion of a base piece has multiple lip pieces and the remaining portion is inclined near the inflection groove, the gasket for the substrate storage container is cooled and hardened, and the mold with a slide mechanism is opened to remove the gasket for the substrate storage container.

5. 3. A substrate storage container comprising: a container body capable of storing a plurality of semiconductor wafers in an aligned manner; a lid body which is press-fitted into the open front surface of the container body; and a gasket for a substrate storage container according to claim 1 or 2 which is interposed between the inner front surface portion of the container body and the lid body, and which is used for transporting semiconductor wafers.

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