Circuit board housing container and method for manufacturing the same

Abstract

To provide a substrate housing container capable of preventing and removing a position deviation and a falling of a packing, a damage of a substrate, and an increase of dust, and provide a manufacturing method of the same.SOLUTION: In a substrate housing container nipping an endless packing 20 between an opening top part 2 of an outer box 1 for housing a semiconductor wafer and a top cover, an attachment groove 4 for the packing 20 is formed to a peripheral edge part 3 of the top part 2, a tightened hole 5 for the packing 20 is bored into the attachment groove 4, and the tightened hole 5 is divided into a narrower part 6 that is contacted to the attachment groove 4, a narrower part 7 of which a width is expanded so as to be contacted to the narrower part 6, and a width narrowest part 8 of which the width is narrowed so as to be contacted to the narrower part 7. The packing 20 is formed by: a base part 21 that is fitted to the attachment groove 4; a narrow part 22 that is tightly fitted to the narrower part 6 so as to be contacted to the base part 21; a width wide part 23 that is tightly fitted to the narrower part 7 so as to be contacted to the narrow part 22; and a narrowest width part 24 that is tightly fitted to the width narrowest part 8 so as to be contacted to the width wide part 23.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a substrate storage container for storing substrates such as semiconductor wafers and a method for manufacturing the same.

Background Art

[0002] Conventional substrate storage containers include, as shown in FIGS. 8 to 10, an outer box 1 capable of storing a plurality of semiconductor wafers, an upper lid 10 that fits and covers the open upper part 2 of the outer box 1, and an endless packing 30 sandwiched between the outer box 1 and the upper lid 10, and are used for storing, transporting, and shipping a plurality of semiconductor wafers (see Patent Document 1).

[0003] As shown in FIGS. 8 to 10, the outer box 1 is formed into a bottomed cylindrical top-open box using a molding material containing resin, and houses a cassette in which a plurality of semiconductor wafers are stored in an aligned manner. The outer box 1 has a mounting groove 4 for the packing 30 recessed in an endless frame shape at the peripheral portion 3 of the open upper part 2, and a plurality of locking projections 9 for the upper lid 10 are formed on the upper parts of the outer surfaces of both side walls.

[0004] As shown in FIG. 8, the upper lid 10 is formed into a substantially box shape with a low height using a molding material containing resin, and horizontally long locking pieces 11 that fit and lock to the locking projections 9 of the outer box 1 are formed on the lower parts of both side walls so as to be bendable.

[0005] As shown in FIGS. 9 and 10, the packing 30 is formed into an elastic deformable frame shape using a molding material containing resin, and is loosely fitted in the mounting groove 4 of the outer box 1 with a gap. The packing 30 is formed, for example, in a substantially h-shaped cross section, and the bifurcated lower portions 31 thereof contact the bottom surface of the mounting groove 4, a plate piece 32 extends horizontally inward from near the central portion and contacts the inner wall surface of the mounting groove 4 for positioning, and the standing upper portion 33 is pressed against the peripheral portion of the open lower part of the upper lid 10 and deformed. Such a packing 30 is loosely fitted in the mounting groove 4 of the outer box 1 through a gap after being molded, and is deformed between the upper part 2 of the outer box 1 and the upper lid 10 to exhibit a sealing effect, preventing the stored semiconductor wafers from being contaminated by external particles. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Utility Model Publication No. 2-106831 [Overview of the project] [Problems that the invention aims to solve]

[0007] Conventional substrate storage containers are constructed as described above, and are assembled by simply loosely fitting a separate gasket 30 into the mounting groove 4 of the outer box 1 with a clearance. As a result, the gasket 30 may rattle and shift position, which can lead to problems such as the gasket 30 easily coming off the mounting groove 4 of the outer box 1, or the gasket 30 coming off the mounting groove 4 of the outer box 1 and causing damage to the semiconductor wafer, or the sealing performance of the gasket 30 decreasing and an increase in external particles.

[0008] The present invention has been made in view of the above, and aims to provide a substrate storage container and a method for manufacturing the same that can prevent or eliminate the risk of misalignment or detachment of the packing, damage to the substrate, and increase in dust by reducing the gap between the outer box and the packing. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention involves inserting a packing between the opening of an outer box capable of housing a circuit board and the lid, A mounting groove for a gasket is formed in the peripheral edge of the opening of the outer box, and a tightly fitting hole for the gasket is formed in this mounting groove, and this tightly fitting hole is divided into a narrow part connected to the mounting groove, a wide part connected to the narrow part and widening, and a narrowest part connected to the wide part and narrowing, The packing is characterized by comprising a base portion that is attached to the mounting groove of the outer box, a narrow portion connected to the base portion that closely contacts the narrow portion of the hole to be fitted in the outer box, a wide portion connected to the narrow portion that closely contacts the wide portion of the hole to be fitted, and an extremely narrow portion connected to the wide portion that closely contacts the narrowest portion of the hole to be fitted.

[0010] Furthermore, the outer box can be a top-opening box with an opening at the top. Furthermore, the outer box can be molded using a molding material containing thermoplastic resin, and the packing can be molded using a molding material containing a thermosetting resin with excellent elasticity. Furthermore, the cross-sections of the narrow, wide, and narrowest parts of the packing can be made roughly polygonal, and the narrowest part can be made sharp and oriented inward.

[0011] Furthermore, in order to solve the above problems, the present invention provides a method for manufacturing a substrate storage container as described in claim 1 or 2, The method is characterized by forming a packing from a molding material containing an elastic thermosetting resin, inserting this packing into a mold for forming the outer box and clamping it, filling the mold with a molding material containing a thermoplastic resin, and then cooling and solidifying this molding material to form the outer box.

[0012] Here, the substrate in the claims includes at least φ125mm, 150mm, 200mm, and 300mm semiconductor wafers, rectangular quartz glass photomask material, liquid crystal substrates, etc. The outer box and lid can be formed transparent, opaque, or translucent as needed. The contact holes in the outer box can be formed with a cross-section that is approximately polygonal, approximately elliptical, approximately track-shaped, approximately arrowhead-shaped, etc. The narrow, wide, and narrowest parts of the packing can also be formed with a cross-section that is approximately polygonal, approximately elliptical, approximately track-shaped, approximately arrowhead-shaped, etc.

[0013] According to the present invention, the narrow, wide, and narrowest parts of the packing are fitted into the tightly fitting holes in the opening of the outer box with virtually no gaps, thus preventing the packing from rattling and shifting position. [Effects of the Invention]

[0014] According to the present invention, the gap between the outer box and the packing can be reduced, which has the effect of preventing or eliminating the risk of the packing shifting or falling off, damage to the circuit board, and an increase in dust.

[0015] According to the invention described in claim 2, when a packing is inserted into a mold for forming an outer box and the outer box is formed afterward, since the packing is made of a thermosetting resin, it is possible to prevent the thermoplastic resin of the molding material that forms the outer box from welding to the packing.

[0016] According to the invention described in claim 3, when the packing has a substantially polygonal cross-section, and in particular when the narrowest, widest, and narrowest parts of the packing have a substantially pentagonal or deformed substantially rhombic cross-section, it is possible to suppress interference with the flow of the thermoplastic resin forming the outer box. Furthermore, since the narrowest part of the packing faces inward, that is, in the direction from which the thermoplastic resin forming the outer box flows, the narrowest part is less affected by the resin pressure of the thermoplastic resin forming the outer box and is less likely to move. Therefore, the holes to be closely fitted in the outer box can be formed in the vicinity of the packing with substantially no gaps and in the same shape.

[0017] According to the invention described in claim 4, the packing is pre-formed and inserted into the mold for forming the outer box, and the outer box with the packing is formed, making it possible to continuously form a narrow part and a wide part of different widths in the contact hole of the outer box. Furthermore, in view of the undercut of the contact hole of the outer box, it is possible to eliminate the trouble of dividing the mold for forming the outer box and providing special mechanisms such as a sliding mechanism, and to simplify the structure of the mold. [Brief explanation of the drawing]

[0018] [Figure 1] This is a partially cross-sectional perspective view showing the outer box in an embodiment of the substrate storage container and its manufacturing method according to the present invention. [Figure 2]It is a cross-sectional perspective view partially showing the upper peripheral portion of the outer box and the packing in an embodiment of a substrate storage container and a method for manufacturing the same. [Figure 3] It is a cross-sectional explanatory view partially showing the upper peripheral portion of the outer box and the packing in an embodiment of a substrate storage container and a method for manufacturing the same. [Figure 4] It is a cross-sectional explanatory view showing a state in which the packing used during manufacturing is pulled out from the upper peripheral portion of the outer box in an embodiment of a substrate storage container according to the present invention. [Figure 5] It is a cross-sectional explanatory view showing a state in which a new unused packing is inserted into the upper peripheral portion of the outer box in an embodiment of a substrate storage container according to the present invention. [Figure 6] It is a cross-sectional perspective view showing a state in which a new unused packing is inserted into the upper peripheral portion of the outer box in an embodiment of a substrate storage container according to the present invention. [Figure 7] It is a cross-sectional perspective view showing the relationship between the upper peripheral portion of the outer box and the new packing in an embodiment of a substrate storage container according to the present invention. [Figure 8] It is a perspective explanatory view showing a substrate storage container. [Figure 9] It is a cross-sectional perspective view partially showing the outer box of the substrate storage container of FIG. 8. [Figure 10] It is a cross-sectional perspective view partially showing the mounting groove and the packing of the outer box of FIG. 9.

Embodiments for Carrying Out the Invention

[0019] A preferred embodiment of the present invention will now be described with reference to the drawings. As shown in Figures 1 to 8, the substrate storage container in this embodiment comprises an outer box 1 for storing semiconductor wafers which are substrates, a cassette stored in the outer box 1, a top lid 10 that detachably fits and covers the open top 2 of the outer box 1, a retainer that holds the upper peripheral edge of the semiconductor wafer stored in the cassette, and an endless packing 20 sandwiched between the outer box 1 and the top lid 10. By inserting the pre-formed packing 20 when molding the outer box 1 with a mold for molding the outer box, and insert molding the outer box 1 with the packing 20, the container contributes to achieving Goal 9 of the SDGs (Sustainable Development Goals, which are the United Nations' international goals for sustainable development and consist of 17 global goals and 169 targets (achievement criteria)) adopted at the UN Summit.

[0020] As shown in Figures 1 to 3, 6 and 7, the outer box 1 is injection molded from a thermoplastic resin-containing molding material into a bottomed rectangular tubular top-open box with an open top 2, and detachably houses a rectangular tubular cassette containing multiple semiconductor wafers (for example, φ200 mm silicon wafers). The thermoplastic resin used to mold this outer box 1 is not particularly limited, but examples include polypropylene resin, polycarbonate resin, polyetherimide resin, polyetheretherketone resin, and polybutylene terephthalate resin.

[0021] The molding material may consist solely of the thermoplastic resin mentioned above, but conductive materials such as carbon fibers, carbon nanotubes, and conductive polymers, various antistatic agents such as anionic, cationic, and nonionic types, glass fibers or carbon fibers to improve rigidity, and ultraviolet absorbers may be added as needed.

[0022] The outer box 1 has an endless, frame-shaped recessed mounting groove 4 for the packing 20 formed in the peripheral edge portion 3 of the open upper part 2, and a tightly fitting hole 5 for the packing 20 is drilled in this mounting groove 4. Multiple locking protrusions 9 for the top cover 10 are formed in a row on the upper part of the outer surfaces of both side walls. As shown in Figures 2 and 3, the tightly fitting hole 5 of the outer box 1 is formed in a polygonal cross-section (pentagon, deformed rhombus, etc.) or arrowhead shape, comprising a narrowed portion 6 connected to the center of the bottom surface of the mounting groove 4, a wide portion 7 connected to the narrowed portion 6 that widens as it extends downwards, and a narrowest portion 8 connected to the wide portion 7 that narrows as it extends downwards. The narrowest portion 8 is formed in a sharp, lead-in shape and is angled inward towards the outer box 1.

[0023] As shown in Figure 8, the top lid 10 is injection-molded into a low, roughly box-shaped form using a thermoplastic resin-containing molding material. Horizontally elongated locking pieces 11, which engage with the locking projections 9 of the outer box 1, are integrally formed on the lower part of both side walls, and each locking piece 11 is formed in a striped pattern. The thermoplastic resin used to mold the top lid 10 is not particularly limited, but examples include polycarbonate resin and polypropylene resin. Similar to the outer box 1, conductive substances, antistatic agents, glass fibers, carbon fibers, and ultraviolet absorbers are selectively added to the molding material. A retainer for reelastically holding the upper edge of the semiconductor wafer with multiple flexible holding materials is detachably mounted on the internal ceiling of the top lid 10.

[0024] As shown in Figures 1 to 3, the packing 20 is molded into an elastically deformable frame shape from a molding material containing a thermosetting resin, and is detachably fitted into the mounting groove 4 and contact hole 5 of the outer box 1. A thermosetting resin is used as the molding material for the packing 20 because if a thermoplastic resin were used, it would become compatible with the molding material of the outer box 1 during molding, making it impossible to remove the packing 20 later. The thermosetting resin used as the molding material for the packing 20 is not particularly limited, but an elastomer that allows for the removal and replacement of the packing 20, specifically urethane rubber or fluororubber with excellent heat resistance and elasticity, is used. In addition to the thermosetting resin, various fillers are selectively added to the molding material.

[0025] The packing 20 comprises a plate-shaped base portion 21 that fits into the mounting groove 4 of the outer box 1, a narrow portion 22 connected to the lower surface of the base portion 21 that fits into and makes tight contact with the narrow portion 6 of the contact hole 5 of the outer box 1, a wide portion 23 connected to the narrow portion 22 that fits into and makes tight contact with the wide portion 7 of the contact hole 5, and a narrowest portion 24 connected to the wide portion 23 that fits into and makes tight contact with the narrowest portion 8 of the contact hole 5. The narrow portion 22, wide portion 23, and narrowest portion 24 are formed in the same polygonal cross-section (pentagon, deformed rhombus, etc.) or arrowhead shape as the contact hole 5 of the outer box 1 to prevent gaps from forming, and function to prevent rattling, misalignment, and falling out of the contact hole 5.

[0026] As shown in Figure 2, the narrowest portion 22, wide portion 23, and narrowest portion 24 of the packing 20 are formed such that the narrowest portion 24 is sharply shaped in a lead-in form, and at least the narrowest portion 24 is tilted and oriented in the inward direction of the packing 20, in other words, in the direction in which the thermoplastic resin that forms the outer box 1 flows during molding (see arrow in Figure 2).

[0027] The hardness of packing 20, when measured with a Type A durometer, should preferably be between A70° and A90°, more preferably between A80° and A90°, and more preferably between A85° and A90°. This is because if the hardness of packing 20 is within the range of A70° to A90°, it will be easier to remove and replace packing 20.

[0028] In the above configuration, when manufacturing the outer box 1 of the substrate storage container, first, a molding material containing a thermosetting resin with excellent heat resistance and elasticity is prepared, this molding material is filled into a high-temperature mold for packing molding that has been clamped, the molding material is cooled and solidified to form the packing 20, and then the mold is opened and the packing 20 is demolded.

[0029] Next, after the packing 20 is molded, it is inserted into the mold for forming the outer box and clamped. The reason for pre-injecting the packing 20 and inserting it into the mold for forming the outer box is that if the outer box 1 were to be molded using a normal injection molding method without using the packing 20, the recessed portion (between the multiple dotted lines in Figure 3) between the narrow part 6 and the wide part 7 of the contact hole 5 of the outer box 1 would become an undercut, making it extremely difficult to mold and demold the outer box 1 unless the mold for forming the outer box is divided and a special mechanism such as a sliding mechanism is installed.

[0030] After clamping the mold for forming the outer box, molten molding material containing thermoplastic resin is injected and filled into the mold, and after the molten molding material is filled in and the molding material is cooled and solidified to form the outer box 1 having mounting grooves 4 and contact holes 5, the mold is opened and the outer box 1 is demolded, thereby manufacturing the outer box 1 having the packing 20 open at the top 2.

[0031] In this case, since the packing 20 is molded from a thermosetting resin rather than a thermoplastic resin, it prevents the thermoplastic resin of the molding material forming the outer box 1 from welding to the packing 20, and the packing 20 can be removed and replaced later. Also, since the narrowest part 24 of the packing 20 is tilted and oriented in the direction from which the thermoplastic resin forming the outer box 1 flows, resistance is reduced, and the narrowest part 24 is not affected by the resin pressure of the thermoplastic resin forming the outer box 1 and does not wobble. Therefore, the packing 20 can be used as a mold to appropriately form mounting grooves 4 and contact holes 5 around it later.

[0032] If the packing 20 used during manufacturing deteriorates or becomes damaged after long-term use of the circuit board housing, the packing 20 used during manufacturing can be removed by pinching it from the top 2 of the outer box 1 (see Figure 4). Since the packing 20 has excellent elasticity, it can be easily pulled out and removed. After removing the packing 20 used during manufacturing, an unused packing 20A can be tightly fitted into the sealing hole 5 of the outer box 1 to ensure a tight seal without any gaps (see Figures 5 to 7).

[0033] Since the unused new packing 20A in this case is unrelated to the molding of the outer box 1, it may be molded from a molding material containing an elastic thermosetting resin or from a molding material containing an elastic thermoplastic resin. Also, if the narrow portion 22, wide portion 23, and narrowest portion 24 of the packing 20A are the same shape, the base portion 21A of the packing 20A may be polygonal, or a deformable upright piece 25 may be formed by extending upward from the base portion 21A, and this upright piece 25 may be pressed against the peripheral edge portion of the lower part of the opening of the top lid 10.

[0034] As described above, the narrow portion 22, wide portion 23, and narrowest portion 24 of the packing 20 are tightly fitted without gaps into the tightly fitting hole 5 of the outer box 1, and the space between the narrow portion 22 and the wide portion 23 provides a gripping function, thus preventing the packing 20 from rattling and shifting position. Therefore, the risk of the packing 20 easily coming off the mounting groove 4 of the outer box 1, the risk of the packing 20 coming off the mounting groove 4 of the outer box 1 and causing damage to the semiconductor wafer, and the risk of the sealing performance of the packing 20 decreasing and an increase in external particles can be eliminated.

[0035] Furthermore, since the narrowest part 8 of the contact hole 5 and the narrowest part 24 of the packing 20 each have a tapered, sharp lead-in shape, the packing 20 can be easily inserted into the contact hole 5 of the outer box 1 afterwards. Also, instead of loosely fitting the packing 20 into the molded outer box 1 afterwards, the packing 20 is molded first and the outer box 1 is injection molded afterwards, so even if a complexly shaped contact hole 5 is molded in the upper peripheral portion 3 of the outer box 1, the outer box 1 can be easily demolded. Moreover, since the narrow part 22, wide part 23, and narrowest part 24 of the packing 20 have a pentagonal or deformed rhombic cross-section, they have a pointed, tapered shape and do not hinder the flow of the thermoplastic resin for the outer box 1.

[0036] In the above embodiment, the outer box 1 was injection molded into a top-opening box, but the invention is not limited to this. For example, it may be molded into a front-opening box container body that directly stores φ300mm silicon wafers in an aligned manner, and a mounting groove for a packing may be formed as an endless frame-shaped recess on the inner peripheral edge of the open front of the container body. In this case, the top lid 10 may be injection molded from a molding material containing thermoplastic resin into a roughly plate-shaped lid that can be detachably opened and closed on the open front of the container body. Furthermore, the up, down, front, back, left, and right directions of the substrate storage container in the above embodiment are directions based on the drawing and can be changed as needed. [Industrial applicability]

[0037] The substrate storage container and its manufacturing method according to the present invention are used in the fields of electrical, electronic, and semiconductor manufacturing. [Explanation of symbols]

[0038] 1 Outer box 2 Upper part (opening) 3. Peripheral portion 4. Mounting groove 5. Closely contacted hole 6 Narrow width part 7 Wide part 8 Narrowest part 10 Upper lid (lid body) 20 packing 20A packing 21 Base 21A base 22 Narrow part 23 Wide section 24 Narrowest part 25 Standing piece 30 packing

Claims

1. A circuit board storage container having a gasket placed between the opening of the outer box capable of housing the circuit board and the lid, A mounting groove for a gasket is formed in the peripheral edge of the opening of the outer box, and a tightly fitting hole for the gasket is formed in this mounting groove, and this tightly fitting hole is divided into a narrow part connected to the mounting groove, a wide part connected to the narrow part and widening, and a narrowest part connected to the wide part and narrowing, A substrate storage container characterized in that the packing includes a base portion that is attached to a mounting groove of the outer box, a narrow portion connected to the base portion that closely contacts the narrow portion of the hole to be closely fitted in the outer box, a wide portion connected to the narrow portion that closely contacts the wide portion of the hole to be closely fitted, and an extremely narrow portion connected to the wide portion that closely contacts the narrowest portion of the hole to be closely fitted.

2. A substrate storage container according to claim 1, wherein the outer box is molded from a molding material containing a thermoplastic resin, and the packing is molded from a molding material containing a thermosetting resin with excellent elasticity.

3. The substrate storage container according to claim 2, wherein the cross-sections of the narrow, wide, and narrowest parts of the packing are substantially polygonal, and the narrowest part is formed sharply and directed inward.

4. A method for manufacturing a substrate storage container according to claim 1 or 2, characterized in that a packing is formed from a molding material containing an elastic thermosetting resin, the packing is inserted into a mold for forming an outer box and clamped, a molding material containing a thermoplastic resin is filled into the mold, and the molding material is cooled and solidified to form an outer box.

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