Substrate housing container

Abstract

To provide a substrate housing container capable of wiping a risk of leaking or entering of an outside air between a body and a door even when a pressure inside or outside the body is high, and eliminating a risk of part of a seal gasket being turned up.SOLUTION: A substrate housing container comprises: a semiconductor wafer housing body 1; a door set 10 fitted to a front surface part 2 of the body 1; and a seal gasket 20 interposed to between the body 1 and the door set 10. A seal forming surface 3 is formed in a front surface part inner periphery of the body 1. A mounting groove 13 is formed in a peripheral edge part of a back surface of the door set 10, and the seal gasket 20 includes: a gasket main body 21 fitted to the mounting groove 13; an extension piece 23 extending from the gasket main body 21; a first lip piece 24 in contact with an inner side of the seal forming surface, and a second lip piece 24A in contact with an outer side of the seal forming surface. The first and second lip pieces 24 and 24A are formed in an inverted L-shape in a cross section, and a bifurcated space 25 to be crushed when the door set 10 is fitted is formed therebetween.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a substrate storage container in which a seal gasket is interposed between a body that stores substrates such as semiconductor wafers and a door. [Background technology]

[0002] Substrate storage containers for storing semiconductor wafers come in two types: FOSB for transportation and FOUP for in-process transport, and both types require high performance. Specifically, improved sealing and cleanliness are required for FOSB for transportation, while improved purging functions are required for FOUP for in-process transport (see Patent Documents 1 and 2).

[0003] As shown in Figure 7, a conventional FOSB type substrate storage container comprises a body 1 for storing semiconductor wafers, a door set 10 that fits into the open front portion 2 of the body 1, and an endless seal gasket 30 that is interposed between the body 1 and the door set 10. To prevent gas from circulating between the body 1 and the door set 10 due to changes in air pressure during transportation, etc., there is a need to improve the sealing properties and cleanliness of the seal gasket 30.

[0004] The body 1 is formed as a front-open box capable of storing multiple semiconductor wafers in an aligned manner, with an open front portion 2 bulging outward, a step on the inner periphery of the front portion 2 forming a seal-forming surface 3, and an adjacent surface 4 bent adjacent to the seal-forming surface 3 forming the inner peripheral wall of the body 1. The door set 10 is configured in a size and shape corresponding to the front portion 2 of the body 1, and a mounting groove 13 is formed on the periphery of the back surface 12, into which a seal gasket 30 is fitted.

[0005] There are various types of seal gaskets 30, but for example, the type shown in Figure 7 is molded in a frame shape with a base 31 that is fitted into the mounting groove 13 of the door set 10, an extension piece 32 that extends outward in the width direction from this base 31, and a seal piece 33 that is curved at the tip of this extension piece 32 and extends outward, and a spherical protrusion 34 is formed at the tip of the seal piece 33 that presses against the seal forming surface 3 of the body 1 to form a seal.

[0006] When the door set 10 is pressed into the open front portion 2 of the body 1, the seal piece 33 of this seal gasket 30 bends outward, pressing the spherical protrusion 34 against the seal forming surface 3 of the body 1. This pressing forms a seal between the seal forming surface 3 and the door set 10, preventing outside air mixed with particles, etc. from flowing from the outside to the inside of the body 1. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-105931 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-017452 Summary of the Invention [Problem to be solved by the invention]

[0008] Although conventional substrate storage containers have a seal gasket 30 formed as described above and exhibit a predetermined effect, there is a concern that leaks or the intrusion of outside air may occur between the body 1 and the door set 10 if the pressure (air pressure) inside and outside the body 1 exceeds an expected value. For example, if the pressure inside the body 1 is higher than expected, the seal piece 33 and spherical protrusion 34 of the seal gasket 30 may succumb to the internal pressure and separate from the seal forming surface 3 of the body 1, resulting in a leak. Furthermore, in the case of the seal gasket 30 described in Patent Document 1, although excellent effects can be expected, the second seal piece protruding from near the middle of the extension piece 32 comes into contact with the adjacent surface 4 at a different position from the seal forming surface 3, and therefore there is a concern that the second seal piece may be turned up if the door set 10 is not fitted in the correct position.

[0009] The present invention has been made in view of the above, and aims to provide a substrate storage container that can eliminate the risk of leaks or outside air intrusion between the body and the door even when the pressure inside and outside the body is high, and that can eliminate the risk of part of the seal gasket being turned over. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention provides a device comprising a body for storing a substrate, a door fitted into an opening of the body, and a deformable seal gasket interposed between the body and the door, A seal forming surface for a seal gasket is formed on either the inner periphery of the opening in the body or the periphery of the door, and an attachment groove for the seal gasket is formed on the other. The seal gasket comprises a gasket body that fits into the mounting groove, an extension piece that extends from the gasket body, a first lip piece that is formed on the extension piece and is capable of contacting the inside of the seal-forming surface, and a second lip piece that is formed on the extension piece and is capable of contacting the outside of the seal-forming surface, and is characterized in that the first and second lip pieces are each formed with a roughly L-shaped cross section, and a bifurcated space is formed between these first and second lip pieces that collapses when the door is fitted into the opening in the body.

[0011] The body is formed as a front-open box capable of storing a plurality of semiconductor wafers aligned in the vertical direction, and the open front part is formed to bulge outward in the width direction, and a step on the inner periphery of the front part is formed on the seal forming surface, It is preferable that the door has an endless mounting groove formed on the periphery of the rear surface, and the gasket body of the seal gasket is fitted into this mounting groove.

[0012] Preferably, the seal gasket is formed endlessly from a predetermined molding material, the gasket body is formed to have a substantially polygonal cross section, and a projection projects from the gasket body and contacts the inside of the mounting groove. In addition, the first and second lip pieces have a bent portion formed from the tip of the extension piece toward the seal forming surface, and a contact portion formed in this bent portion that contacts the seal forming surface, and it is preferable that the angle formed by this contact portion and the bifurcated space is between 70° and 90°.

[0013] The seal gasket may also include a gasket body that is fitted into the mounting groove of the door, an extension piece that extends from the gasket body in the inner circumferential direction of the opening in the body, a first lip piece that extends and bends from the tip of the extension piece to contact the inside of the seal-forming surface, and a second lip piece that extends and bends from the tip of the extension piece to contact the outside of the seal-forming surface, and the first and second lip pieces may each be bent into a substantially L-shaped cross section, and a bifurcated space that collapses when the door is fitted into the opening in the body may be defined between the first and second lip pieces.

[0014] Here, the substrates in the claims include semiconductor wafers, compound wafers, glass substrates, mask substrates, etc., each having a diameter of at least 300 mm or 450 mm. The body and door may be transparent, opaque, or translucent. The seal-forming surface for the seal gasket may be formed on the inner periphery of the opening in the body, or on the periphery of the door. The mounting groove for the seal gasket may be formed on the periphery of the door, or on the inner periphery of the opening in the body.

[0015] The term "approximately L-shaped cross section" includes not only an L-shape but also similar shapes (such as a J-shape) that do not result in any difference in the effects of the present invention. Furthermore, the up-down, front-rear, left-right directions of the substrate storage container according to the present invention are directions based on the drawings and can be appropriately changed as necessary. Furthermore, while the subject of the present invention is a substrate storage container, if the configuration of another application is the same as the configuration of the present invention and can be converted into a substrate storage container, and the effects of the present invention are achieved, the configuration of the other application falls within the technical scope of the present invention.

[0016] According to the present invention, when the internal pressure of the body is high, gas inside the body tries to flow between the body and the door, but the first lip piece of the seal gasket remains in close contact with the seal-forming surface without separating from it, thereby restricting the flow of gas inside the body.In contrast, when the external pressure of the body is high, gas outside the body tries to flow between the body and the door, but the second lip piece of the seal gasket remains in close contact with it without separating from it, thereby restricting the inflow of gas outside the body. [Effects of the Invention]

[0017] According to the present invention, even when the pressure inside and outside the body is high, it is possible to eliminate the risk of leakage or the intrusion of outside air between the body and the door. It is also possible to eliminate the risk of a portion of the seal gasket being turned over. Furthermore, when the substrate storage container is a transport container for semiconductor wafers, it is expected to have improved sealing properties and cleanliness, and when it is an in-process transport container for semiconductor wafers, it is expected to have improved purging functions.

[0018] According to the invention of claim 2, even when the pressure inside and outside the body that stores multiple semiconductor wafers in an aligned manner is high, it is possible to eliminate the risk of leakage between the body and the door or the intrusion of outside air. In addition, since both the first and second lip pieces of the seal gasket come into contact with the seal-forming surface on the inner periphery of the front part of the body, it is possible to eliminate the risk of part of the seal gasket being turned up.

[0019] According to the invention of claim 3, the seal gasket is not formed as multiple pieces but as a single endless piece, thereby improving workability and ease of handling. Also, the gasket body of the seal gasket is formed as a substantially polygonal shape rather than a circular cross section, giving it directionality, making it easier to align the extension piece, first lip piece, and second lip piece. According to the invention described in claim 4, the angles formed by the contact portions of the first and second lip pieces and the bifurcated space are each between 70° and 90°, so that improved adhesion of the contact portions to the seal forming surface can be expected. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a perspective overall view schematically showing an embodiment of a substrate storage container according to the present invention. [Figure 2] 1 is an exploded perspective view schematically showing an embodiment of a substrate storage container according to the present invention. [Figure 3] FIG. 2 is a cross-sectional explanatory view of a main part that schematically shows the relationship between a body, a door set, and a seal gasket in an embodiment of a substrate storing container according to the present invention. [Figure 4] 10 is a cross-sectional explanatory view of a main part, schematically showing a state in which a door set is fitted to a front portion of a body in an embodiment of a substrate storing container according to the present invention. FIG. [Figure 5] 10 is a cross-sectional explanatory view of a main part, schematically showing a state in which a door set begins to be pulled out from a front part of a body in an embodiment of a substrate storing container according to the present invention. FIG. [Figure 6] 5 is a cross-sectional explanatory view of a main part, schematically showing a state in which the door set in FIG. 4 is further pulled out and the seal gasket is separated from the seal forming surface of the body. FIG. [Figure 7] FIG. 10 is a cross-sectional explanatory view schematically showing the relationship between a body, a door set, and a seal gasket of a conventional substrate storing container. DETAILED DESCRIPTION OF THE INVENTION

[0021] A preferred embodiment of the present invention will now be described with reference to the drawings. As shown in FIGS. 1 to 6 , the substrate storage container in this embodiment is a FOSB for transport, which includes a body 1 for storing semiconductor wafers as substrates, a door set 10 that is detachably fitted into the open front portion 2 of the body 1, and a deformable seal gasket 20 that is interposed between the body 1 and the door set 10. The seal gasket 20 is formed from a gasket main body 21 that is fitted into the mounting groove 13 of the door set 10, an extension piece 23 that extends from the gasket main body 21, and first and second lip pieces 24 / 24A that bifurcate from the extension piece 23 and come into contact with the seal-forming surface 3 of the body 1, thereby contributing to the achievement of Goal 9 of the SDGs adopted at the United Nations Summit.

[0022] The semiconductor wafers are thin, brittle, high-quality silicon wafers (not shown), for example, 300 mm in diameter, and 25 wafers are successively stored in and extracted from the body 1 by a dedicated robot (not shown).

[0023] 1 to 6, the body 1 is injection-molded from a resin-containing molding material into a front-open box capable of storing a plurality of semiconductor wafers aligned vertically, with an open front portion 2 bulging outward in the width direction, a step on the inner periphery of this front portion 2 forming a flat, front-frame-shaped seal-forming surface 3, and an adjacent surface 4 located adjacent and substantially perpendicular to this flat seal-forming surface 3 forms the inner surface of the peripheral wall of the body 1 other than the front portion 2. The required number of intake and exhaust valves (for example, four) are attached to the front and rear of the bottom plate of this body 1, and these required number of intake and exhaust valves replace the air inside the body 1 with an inert gas such as nitrogen gas or clean dry air (CDA) to effectively prevent oxidation and deterioration of the surfaces of the semiconductor wafers.

[0024] Resins contained in the molding material of the body 1 include, for example, thermoplastic resins such as polycarbonate (PC) resin, cycloolefin polymer (COP) resin, cycloolefin copolymer (COC) resin, polypropylene (PP) resin, polyetherimide (PEI) resin, polyether ketone (PEK) resin, polyether ether ketone (PEEK) resin, polybutylene terephthalate (PBT) resin, polyacetal (POM) resin, and liquid crystal polymer, as well as alloys of these resins.

[0025] To these resins, conductive materials such as carbon fibers, carbon powder, carbon nanotubes, and conductive polymers, and various antistatic agents such as anionic, cationic, and nonionic antistatic agents may be added as needed. Also, ultraviolet absorbers such as benzotriazoles, salicylates, cyanoacrylates, oxalic acid anilides, and hindered amines may be added as needed, and glass fibers, carbon fibers, and the like may also be selectively added to improve rigidity.

[0026] 1 to 6, the door set 10 comprises a door body 11 having a generally tray-shaped cross section that is press-fitted into the open front portion 2 of the body 1, and a door plate 14 that covers the open surface (front) of the door body 11, and is configured to have a size and shape that corresponds to the front portion 2 of the body 1. Like the body 1, the door body 11 and door plate 14 of this door set 10 are each injection-molded from a resin-containing molding material. The door body 11 has a rear surface 12 whose peripheral edge faces the seal-forming surface 3 of the body 1, and the rear surface 12 has an endless frame-shaped mounting groove 13 formed around its peripheral edge, into which an elastic seal gasket 20 that presses against the seal-forming surface 3 is removably fitted.

[0027] The seal gasket 20 is molded into an elastically deformable endless frame shape using a predetermined molding material, and is subjected to surface treatment such as corona treatment as necessary. The predetermined molding material for this seal gasket 20 is not particularly limited, but examples include polybutylene terephthalate elastomers, polyolefin elastomers, urethane elastomers, fluororubber, etc.

[0028] 2 to 6, the gasket body 21 is formed in a rectangular polygonal cross section, and is removably fitted into the mounting groove 13 of the door set 10. A plurality of protrusions 22 that come into contact with the interior of the mounting groove 13 are formed on the opposing surface and inner peripheral surface of the gasket body 21 that face the inner surface of the mounting groove 13, and these multiple protrusions 22 are formed in a trapezoidal or rectangular cross section, etc., and the contact of the multiple protrusions 22 effectively prevents the gasket body 21 from shifting position or falling off.

[0029] 3 to 6, extension piece 23 extends linearly from the outer peripheral surface of gasket body 21 toward the inner peripheral direction of front portion 2 of body 1, with its tip facing seal-forming surface 3 of body 1 with a gap therebetween. First lip piece 24 has an inverted L-shaped cross section and includes a compressible bent portion 24a that is bent from the tip of extension piece 23 toward seal-forming surface 3 of body 1, and a contact portion 24b that is formed at the end of bent portion 24a and comes into contact with the inside of seal-forming surface 3, and functions to prevent inert gas or clean dry air from leaking from the inside of body 1 to the outside.

[0030] 3 to 6, the second lip piece 24A has an inverted L-shaped cross section and is provided with a compressible bent portion 24a that is bent from the tip of the extension piece 23 toward the seal-forming surface 3, and a contact portion 24b that is formed at the end of the bent portion 24a and comes into contact with the outside of the seal-forming surface 3, and is adjacent to the first lip piece 24. This second lip piece 24A functions to prevent outside air from flowing into the interior of the body 1 from the outside.

[0031] The first and second lip pieces 24, 24A are arranged in a generally T-shaped cross section and are capable of contacting the inside and outside of the seal-forming surface 3, and a bifurcated space 25 is formed between adjacent bent portions 24a, 24a, which is crushed when the door set 10 is fitted into the front portion 2 of the body 1. As shown in Figures 4 to 6, this bifurcated space 25 is defined as a groove with a generally I-shaped cross section, for example, with a width of 0.8 mm to 1.2 mm, preferably around 1.0 mm, and a depth of 5 mm to 10 mm, and functions to absorb deformation of the first and second lip pieces 24, 24A and improve sealing performance.

[0032] As shown in Fig. 3, the surfaces of the contact portions 24b of the first and second lip pieces 24 and 24A form a predetermined angle θ with the bifurcated space 25. From the viewpoint of improving the adhesive strength to the seal-forming surface 3, this angle θ should be 70° or more and 90° or less, preferably 80° or more and 90° or less, more preferably 85° or more and 90° or less, and even more preferably 90°.

[0033] In the above configuration, when the door set 10 is pressed into the open front portion 2 of the body 1 by an opener, as shown in Figure 4, the seal gasket 20 is interposed between the body 1 and the door set 10, and the contact portion 24b of the first lip piece 24 forming this seal gasket 20 comes into close contact with the inside of the seal forming surface 3 of the body 1, and the contact portion 24b of the second lip piece 24A comes into close contact with the outside of the seal forming surface 3, causing the bifurcated space 25 to be crushed and the air therein to be exhausted (see the arrows in Figure 4).

[0034] This exhaust causes the contact portions 24b of the first and second lip pieces 24, 24A to tightly and firmly contact the inside and outside of the seal-forming surface 3 of the body 1 like suction cups, effectively blocking air flow between the body 1 and the door set 10. When air flow between the body 1 and the door set 10 is blocked in this way, the air inside the body 1 is replaced with inert gas or clean, dry air as needed by the intake and exhaust action of the intake and exhaust valve, creating a positive pressure inside the body 1.

[0035] In contrast, when the door set 10 begins to be pulled out with an opener to remove it from the front portion 2 of the body 1, the first and second lip pieces 24 and 24A and the bifurcated space 25 of the seal gasket 20 each return to their original shapes, as shown in Figure 5, but the sealing performance is maintained as long as the contact portions 24b of the first and second lip pieces 24 and 24A are in close contact with the seal-forming surface 3 of the body 1.

[0036] When the door set 10 is further pulled out and the contact portions 24b of the first and second lip pieces 24, 24A of the seal gasket 20 separate from the seal-forming surface 3 of the body 1, the inert gas and clean dry air inside the body 1 form an airflow that passes between the body 1 and the door set 10 and flows out of the body 1 (see the arrows in FIG. 6), as shown in FIG. 6. This outflow of airflow prevents the outside air, which may contain particles, from flowing between the body 1 and the door set 10.

[0037] Furthermore, if the pressure inside the body 1 is higher than expected, the inert gas or clean dry air inside the body 1 will attempt to pass between the body 1 and the door set 10, but even if the first lip piece 24 of the seal gasket 20 deforms and crushes the bifurcated space 25, it will not separate from the seal-forming surface 3 of the body 1, effectively eliminating the risk of leaks. On the other hand, if the pressure outside the body 1 is higher than expected, the outside air mixed with particles outside the body 1 will attempt to pass between the body 1 and the door set 10, but even if the second lip piece 24A of the seal gasket 20 deforms and crushes the bifurcated space 25, it will not separate from the seal-forming surface 3 of the body 1, effectively eliminating the risk of outside air entering.

[0038] According to the above configuration, the first and second lip pieces 24, 24A of the seal gasket 20 deform independently and, moreover, receive gas at their surfaces to block its flow, thereby eliminating the risk of leaks or the intrusion of outside air between the body 1 and the door set 10, improving sealing and purging performance, and maintaining cleanliness. Furthermore, because the first and second lip pieces 24, 24A are in close contact with the seal-forming surface 3 of the body 1, concerns about the first lip piece 24 or the second lip piece 24A being turned up can be effectively eliminated even if the door set 10 is not properly fitted.

[0039] While the above embodiment illustrates a FOSB for transportation, the present invention is not limited to this. A seal gasket 20 may be interposed between the body 1 of a FOUP for in-process transportation and the door set 10 to improve the purging mechanism. Furthermore, a mounting groove 13 may be formed on the inner periphery of the front portion 2 of the body 1 in the above embodiment, or a seal-forming surface 3 may be formed on a peripheral portion, such as the rear peripheral portion, of the door main body 11. A locking latch mechanism may also be interposed and installed between the door main body 11 and the door plate 14 of the door set 10.

[0040] In the above embodiment, the seal gasket 20 is formed into an endless frame shape, but this is not limited thereto, and the seal gasket 20 can be divided into two or three sections, etc. Furthermore, the protrusions 22 of the gasket body 21 in the above embodiment may have a rectangular cross section, but they can also have a substantially triangular, substantially polygonal, or substantially semicircular cross section, etc. Furthermore, the bifurcated space 25 can also be formed as a groove having a substantially V-shaped cross section, for example, with a width of 0.8 mm to 1.2 mm and a depth of 5 mm to 10 mm. Furthermore, all of the technologies described in this specification are subject to patent protection through amendments, divisional applications, etc. [Industrial Applicability]

[0041] The substrate storage container according to the present invention is used in the manufacturing field as a FOSB for transportation, a FOUP for in-process transport, and the like. [Explanation of symbols]

[0042] 1 Body 2 Front part (opening) 3 Seal forming surface 10 Door Set (Door) 12 Back side 13 Mounting groove 20 Sealing gasket 21 Gasket body 22 protrusions 23 Extension piece 24 First Lip Piece 24A Second Lip Piece 24a Bend part 24b Contact part 25 Bifurcated space

Claims

1. A substrate storage container comprising a body for storing substrates, a door fitted into an opening of the body, and a deformable seal gasket interposed between the body and the door, A seal forming surface for a seal gasket is formed on either the inner periphery of the opening in the body or the periphery of the door, and an attachment groove for the seal gasket is formed on the other. The sealing gasket comprises a gasket body that is fitted into the mounting groove, an extension piece that extends from the gasket body, a first lip piece that is formed on the extension piece and is capable of contacting the inside of the seal-forming surface, and a second lip piece that is formed on the extension piece and is capable of contacting the outside of the seal-forming surface, and the first and second lip pieces are each formed to have a substantially L-shaped cross section, and a bifurcated space that collapses when the door is fitted into the opening of the body is formed between the first and second lip pieces, characterized in that

2. The body is formed as a front-open box capable of storing a plurality of semiconductor wafers aligned in the vertical direction, and the open front part is formed to bulge outward in the width direction, and a step on the inner periphery of the front part is formed on the seal forming surface, 2. A substrate storage container according to claim 1, wherein the door has an endless mounting groove formed in the periphery of the rear surface, and the gasket body of the seal gasket is fitted into the mounting groove.

3. 3. A substrate storage container according to claim 1, wherein the sealing gasket is molded endlessly from a predetermined molding material, the gasket body is formed to have a substantially polygonal cross section, and a protrusion projects from the gasket body and contacts the inside of the mounting groove.

4. 3. A substrate storage container as described in claim 1 or 2, wherein the first and second lip pieces have a bent portion formed from the tip of the extension piece toward the seal forming surface, and a contact portion formed at this bent portion and contacting the seal forming surface, and the angle formed by this contact portion and the bifurcated space is 70° or more and 90° or less.

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