A STORAGE CONTAINER AND MANUFACTURING METHOD OF THE SAME

A storage container with improved strength and airtightness, and a method for manufacturing the storage container are provided. The storage container includes, as a functional resin member, an insert component for a container body insert-molded with a molding material containing predetermined resin. The functional resin member is a side wall plate with support pieces. The side wall plate has a thick portion having at least a thickness of a side wall of the container body, and a thin joint portion formed around the thick portion, to be interposed into and joined to a peripheral wall of the container body. Most of the peripheral wall and the thin joint portion are engaged and joined to enlarge their contact area to eliminate a decrease of the mechanical strength and leakage around the peripheral edge of the side wall plate and prevent the peripheral wall from parting from the side wall plate.

TECHNICAL FIELD

The present invention relates to a storage container used for storing, transporting, and preserving various kinds of substrates and the like, and a method for manufacturing the same.

BACKGROUND ART

Though not shown, the conventional storage container includes a container body for storing a plurality of semiconductor wafers and a removable lid that is fitted to the open front of the container body with an elastic sealing gasket therebetween, and functions as a FOUP for safely storing, transporting, and preserving a plurality of semiconductor wafers (see Patent Documents 1, 2, and 3).

The semiconductor wafer is of a silicon wafer with a diameter of 300 mm and is heated to a high temperature as needed. The container body is molded into a front open box using a molding material containing a specific resin. Formed on the inner surfaces of both side walls of the box are paired support pieces on left and right sides for horizontally supporting the semiconductor wafer. These paired left and right support pieces are arranged vertically at regular intervals so as to hold the sides of the peripheral edge of the semiconductor wafers. Further, the lid is formed in a substantially rectangular shape in front view and has front retainers that are attached to the interior surface opposing the rear wall of the container body, to hold the front of the peripheral edge of the semiconductor wafers with elastic pieces.

Incidentally, since the side walls of the container body and the surface of the support pieces may be damaged by sliding contact of the peripheral edge of the semiconductor wafers, it is desirable to provide excellent wear resistance and slidability in order to prevent occurrence of damage. In view of dealing with this demand, there has been a method developed and proposed, comprising the steps of: molding two container body's side walls with support pieces as primary insert components by using a molding material having excellent wear resistance and slidability; inserting both side walls molded as the primary insert components into the metal mold for molding the container body, then filling a molding resin for the container body in the metal mold to thereby integrate the both two side walls and the resin and form the second side container body by the insert molding.

PRIOR ART DOCUMENTS

Patent Documents

Patent Document 1 International Publication WO2009/107254Patent Document 2 International Publication WO2019/031142Patent Document 3 International Publication WO2006/120866

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

However, by use of the insert molding method for the container body, it is possible to impart excellent wear resistance and slidability to the side walls and the support pieces of the container body, but depending on the configuration of the side walls with support pieces as the insert components, there is a risk of the deterioration of the strength and leakage properties of the insert-molded container body. For example, when the peripheral edge of the side wall with support pieces is simply a flat surface, the flat surface of the peripheral edge and the molten resin for the container body do not bond sufficiently but separate from each other, which may cause the problem of the deterioration of the strength and leakage properties of the side walls of the insert molded container body.

The present invention has been devised in view of the above, and it is an object of the present invention to provide a storage container capable of improving the strength and airtightness of the container to be molded, as well as providing a method for manufacturing the same.

Means for Solving the Problems

In order to achieve the above object, the present invention provides a container using an insert component as a functional resin member for the container that is insert-molded with a resin-containing molding material, wherein the functional resin member comprises: a thick portion having a thickness equal to or greater than a thickness of a wall of the container; and a thin joint portion formed in the thick portion, and the thin joint portion is interposed into and joined to the wall of the container.

Here, a resin as the molding material is a thermoplastic resin, and the functional resin member can be molded with a resin having excellent heat resistance.

The resin having excellent heat resistance for the functional resin member may use at least one of a polyether ether ketone resin, a polycarbonate resin, and a cycloolefin polymer resin.

Further, the resin for the molding material is the thermoplastic resin, and the functional resin member can be molded with a resin having at least better heat resistance than the thermoplastic resin for the molding material.

The resin having at least better heat resistance than that of the thermoplastic resin for the molding material can use at least one of the polyether ether ketone resin and the cycloolefin polymer resin.

The container may be given in the form of a front open box container body capable of arranging and storing a plurality of substrates.

The functional resin member may be a side wall plate in which a plurality of support pieces are arranged adjacent to one another, each support piece being capable of supporting a side of a peripheral edge of a substrate.

The functional resin member may be a window plate that forms a rear portion of the container body and allows a stored substrate to be seen.

The thin joint portion of the functional resin member is preferably a rib protruding from a peripheral edge of the thick portion of the functional resin member.

The rib of the thin joint portion may be formed with a bulging portion protruded at least in a direction crossing a protruding direction of the rib.

Further, a molding material flow hole may be formed in the rib of the thin joint.

Further, the molding material flow hole may be formed in at least one of the rib and the bulging portion of the thin joint.

In order to achieve the above object, the present invention provides a manufacturing method for the storage container according to any one of claims1to7, the method comprising the steps of:

inserting a functional resin member into a mold for molding the container; and,

filling the mold with a resin-containing molding material to form the container by integrating the functional resin member with the molding material.

Here, the molding material within the scope of the claims can contain various fillers in addition to the resin, as required. The resin for the molding material and the resin for the functional resin member may have good compatibility or poor compatibility. Further, an insert molding may include two-color molding (also referred to as multicolor molding or different material molding). The container may be a front open box such as FOUP or FOSB, a top open box, a bottom open box, a cassette having openings at top and bottom, or the like, and various items other than substrates may be stored. The wall of the hollow container depends on the type of the container, but examples include a peripheral wall of the container, for example, a base plate, a ceiling plate, a front wall, a rear wall, and a side wall of the container.

For example, the functional resin member that is an insert component is used for a necessary number of positioning tools and the like that are used for positioning and formed directly or indirectly as a wall plate with support pieces, a window plate with support pieces, and a bottom plate with support pieces of the container. The functional resin member may mainly use resins such as polyether ether ketone resin, polycarbonate resin, and cycloolefin polymer resin, but not particularly limited, and various resins may be selected depending on the configuration and application of the container so as to improve the strength and airtightness of the container.

A plurality of support pieces on the side wall plate can be arranged with a groove therebetween. Further, the thin joint portion of the functional resin member may have a cross section of, for example, a substantially I-shape, a substantially L-shape, a substantially T-shape, a substantially mushroom shape, a substantially cross shape, a substantially trapezoidal shape, a substantially arrow shape, or the like. The thin joint portion may be partially thicker than the thick portion. The thin joint portion is interposed into the wall of the container, and the interposed state may include a state of being engaged with the wall of the container, a state of being inserted in the wall of the container, and a state of being fitted in the wall of the container. Further, the substrate may include at least a semiconductor wafer, a glass substrate, a mask substrate, a liquid crystal glass, a reticle and the like, each of which has 300 mm or 400 mm in diameter.

According to the present invention, when a container is insert molded, the flat surface of the container wall and the flat surface of the functional resin member are not merely butted and joined, but the container wall and the thin joint portion of the functional resin member are joined into a bonded state in which the two components get entangled mechanically, so that the contact area between the wall of the container and the thin joint portion of the functional resin member can be enlarged.

Advantages of the Invention

According to the present invention, since the thin joint portion of the functional resin member is interposed into the wall of the container and joined, it is possible to improve the strength and airtightness of the container to be molded.

According to the invention of claim2, since the container comprises a front open box container body capable of arranging and storing a plurality of substrates, it is possible to safely store and preserve the plurality of substrates side by side.

According to the invention of claim3, when the functional resin member is given as a side wall plate in which a plurality of support pieces capable of supporting the sides of the peripheral edge of a substrate are arranged, it is possible to prevent reduction of the mechanical strength and airtightness around the peripheral edge of the side wall plate in the side wall of the container body.

According to the invention of claim4, when the functional resin member is given as a window plate that forms the rear portion of the container body and allows the stored substrates to be seen, it is possible to prevent reduction of the mechanical strength and airtightness around the peripheral edge of the window plate in the rear wall of the container body.

According to the invention of claim5, since the thin joint portion of the functional resin member is a rib projected from the peripheral edge of the thick portion of the functional resin member, the wall of the container can be easily and surely joined by interposing the thin joint portion.

According to the invention of claim6, since the rib of the thin joint portion is formed with the bulging portion protruded at least in the direction crossing the projected direction of the rib, the thin joint portion of the functional resin member interposed into the wall of the container becomes hard to separate from the container wall.

According to the invention of claim7, since the molding material of the container flows into the molding material flow hole and solidifies therein, the wall of the container and the functional resin member are firmly bonded so that it is possible to prevent a decrease of the mechanical strength and airtightness around the peripheral edge of the functional resin member.

According to the invention of claim8, since the container is insert-molded, it is possible to easily integrate even different molding materials and improve the joint strength between the container and the functional resin member as well as the durability of the container. Further, since it is possible to omit the work of fastening the container wall and the functional resin member with fasteners, the manufacturing steps of the container can be reduced and the positional accuracy of the functional resin member can be improved.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. As shown inFIGS.1to11, a storage container of the present embodiment is a FOUP, which includes, as functional resin members, insert components in a container body1that is insert-molded by using a molding material containing specific resin. The functional resin members constitute part of a peripheral wall2of the container body1, specifically, side wall plates20that form most part of side walls11to provide a supporting function of semiconductor wafers. In the storage container, a thin joint portion22of the side wall plate20is mechanically joined.

As shown inFIGS.8,10, and11, the container body1is made by insert molding with a predetermined resin-containing molding material. The container body1is a front open box capable of storing a plurality of semiconductor wafers in alignment. A lid with a built-in locking mechanism is detachably fitted to the opened front8with a frame-shaped sealing gasket inserted therebetween. Examples of the specific resin in the molding material of the container body1include thermoplastic resins such as polycarbonate (PC) resin, cycloolefin polymer (COP) resin, cycloolefin copolymer (COC) resin, polypropylene (PP) resin, and polyetherimide (PEI) resin, polyether ketone (PEK) resin, polyether ether ketone (PEEK) resin, polybutylene terephthalate (PBT) resin, polyacetal (POM) resin, liquid crystal polymers, and alloys of these.

As the molding material of the container body1, in addition to the above resin, conductive substances such as carbon black, acetylene black, carbon fiber, carbon powder, carbon nanotubes, conductive polymers as well as various anti-static agents such as, anion, cation, non-ion, are added as necessary. Further, benzotriazole-based, salicylate-based, cyanoacrylate-based, oxalic acid anilide-based, and hindered amine-based ultraviolet absorbers are added. Also, glass fibers and others that improve rigidity may be selectively added.

Though not illustrated, the semiconductor wafer is, for example, a thin and brittle high-quality silicon wafer having a diameter of 300 mm, and 25 wafers are housed inside the container body1, being arranged in the vertical direction at a predetermined interval. The peripheral edge of the semiconductor wafer may be formed angularly with straight sides but is generally formed in a round R-shape, C-shape, round shape, or the like by chamfering the peripheral side. Further, the semiconductor wafer is heated to a high temperature as necessary in the manufacturing process.

Though not shown, the lid is formed in a substantially rectangular shape when viewed from the front, having a locking mechanism by combining a plurality of parts, and has a vertically long front retainer that hold the semiconductor wafers at the front peripheral edge by laterally long elastic pieces, attached in a middle part on a back side that opposes the rear wall10of the container body1. The lid and the locking mechanism are molded using a molding material substantially the same as the molding material of the container body1.

As shown inFIGS.8and10, percolation filters4are mounted on both sides of the front portion of a base plate3of the container body1, and these paired filters4on the left and right sides functions to make the pressures inside and outside the container body1uniform. Attached horizontally to the undersurface of the base plate3of the container body1is a resin bottom plate5by a plurality of fasteners. Positioning tools for positioning the container to a processing device or the like are formed and arrayed on both sides of the front portion of the bottom plate5and at the rear center thereof while an RF tag or the like opposing the lower part of the rear wall10of the container body1is optionally erected at the rear end portion of the bottom plate5.

As shown inFIGS.10and11, a flat rectangular robotic flange7is detachably attached as an option to the substantially center of the ceiling plate6of the container body1. This robotic flange7is held by an unillustrated overhead transfer mechanism in a factory. Further, as shown inFIGS.8,10and11, the front8of the container body1is formed via a step portion as it bends and stretches outward in the width direction from the peripheral wall2of the container body1. The flat shoulder surface of the step portion defines a seal forming surface for the sealing gasket of the lid. Locking holes9that engage the locking claws of the locking mechanism of the lid are hollowed at the top and bottom on both sides on the inner circumference of the front of the container body1, each locking hole9being formed in a rectangular shape in a plan view.

A transparent vertically long viewer window is optionally formed in the vicinity of the central of the slightly curved rear wall10of the container body1so that a plurality of stored semiconductor wafers can be seen from the outside. Further, on the inner surface of the rear wall10, a plurality of rear retainers that can interfere with the rear peripheral edge of the semiconductor wafer in an emergency are optionally formed and arrayed.

Most of the side walls11of the container body1are formed with the side wall plates20that are functional resin members, and the rest of the side walls11are formed of the solidified molding material of the container body1. As shown inFIGS.8,10, and11, a pair of left and right support pieces12opposing each other for horizontally supporting the semiconductor wafer are provided on inner surfaces of both side walls11of the container body1, at a predetermined interval in a vertical direction of the container body1. A U-shaped groove13having a substantially U-shaped cross section is formed between the vertically adjacent support pieces12. Each support piece12is provided in the form of an elongated substantially horizontal plate extending in the front-rear direction and supports the side peripheral edge of the semiconductor wafer.

As shown in the same figures, an operation handle plate14for gripping is detachably attached as an option to the outer surface of each of both side walls11of the container body1. Side rails for transportation are detachably attached, as required, to the outer lower portion of the side walls11, at a location under the operation handle plate14, each side rail being oriented horizontally in the front-rear direction of the container body1.

As shown inFIGS.1to11, each side wall plate20is composed of: a thick portion21having a thickness equal to or more than the thickness of the rest of the side wall11of the container body1; and a thin joint portion22which is formed along the peripheral edge of the thick portion21to be joined and interposed into the peripheral wall2of the container body1, thus forming most part other than the front and rear of the side wall11of the container body1. When the resin of the side wall plate20is demanded to be more excellent in wear resistance, slidability, heat resistance, and the like than the thermoplastic resin of the molding material of the container body1, the side wall plate20is formed into a bent plate with, for example, a polyether-ether-ketone (PEEK) resin or the like.

Further, when the resin of the side wall plate20is demanded to be more excellent in heat resistance, impact resistance, weather resistance, dimensional stability, transparency, and the like, the side wall plate20is formed into a bent plate with, for example, a polycarbonate resin, and the like. When the resin is demanded to be more excellent in heat resistance, transparency, precision moldability, and the like, the side wall plate20is formed into a bent plate with, for example, a cycloolefin polymer (COP) resin.

The thick portion21of the side wall plate20is formed in a vertically long plate having a wall thickness equal to, or greater than, that of the remaining part of the side wall11of the container body1so that the inner and outer surfaces of the side wall11of the container body1will not have unevenness. The side wall has a rear part bent inward of the container body1and a plurality of support pieces12arranged on the inner surface (surface) in the vertical direction at predetermined intervals. U-shaped grooves13extending in the front-rear direction are formed in such a state each groove is interposed between the vertically adjacent support pieces12.

The thickness of the thick portion21may be the same as the thickness of the remaining part of the side wall11of the container body1, but it is 0.05 mm thicker, more preferably about 0.1 mm thicker, than the thickness of the remaining part of the side wall11of the container body1, considering the shrinkage of the resin after cooling. Of the inner and outer surfaces of the thick portion21, at least the inner surface is formed to be flush with the inner surface of the remaining side wall11of the container body1at the time of insert molding of the container body1from the viewpoint of pertinent positioning and storage of semiconductor wafers.

As shown inFIG.9, the thin joint portion22is made in a shape having a substantially mushroom-shaped cross-section comprising: a rib23that protrudes outward from the peripheral edge of the thick portion21of the side wall plate20; and a bulging portion24at the distal end of the rib23, protruding in the direction (left-right direction inFIG.9) at least orthogonal to the protruding direction of the rib23. The thin joint portion22forms a boundary between the thick portion21and the peripheral wall2of the container body1, specifically, the base plate3, the ceiling plate6, and the remaining part of the side wall11, all of which are of the container body1.

As shown inFIG.9, in order to make the rib23secure and easy to be interposed and inserted into the peripheral wall2of the container body1, the rib23protrudes, with a thin-plate form, from the entire circumferential edge of the thick portion21, and surrounds the thick portion21endlessly. Further, the bulging portion24may have a substantially V-shaped cross-section, but in view of making it difficult to come off from the base plate3side portion of the container body1, the ceiling plate6side portion of the container body1, and the side wall11remaining portion of the container body1, and securing good formability and fastening strength, it is preferable that the bulging portion is formed in an endless undercut shape. Specifically, the bulging portion is formed so as to have a rounded substantially rhombus-shaped cross-section or a substantially circular-shaped cross-section. This thin joint portion22functions to join the thick portion21of the side wall plate20and the peripheral wall2of the container body1that are located opposite to each other, by using a board joint method (joining method in the construction field), specifically, a dovetail method in the board joint method.

In the above configuration, when manufacturing the container body1of the storage container, first, the side wall plate20on the primary side, which is a functional resin member, is injection molded. A pair of side wall plates20are inserted into the mold for molding of the container body1with its mold opened, then the mold is clamped. The clamped mold is injected and filled with a plasticized molding material to integrate the pair of side wall plates20and the molten molding material to complete insert molding of the container body1on the secondary side.

In this process, the molding material injected and filled in the mold stops flowing when the injection is completely filled, and is cooled and solidified as the mold deprives the molding material of heat, to form most of the peripheral walls2of the container body1. The opposing portions of the peripheral wall2of the container body1(base plate3side portion, ceiling plate6side portion, the remaining portion of the side wall11) that are located opposite to each of the side plates20are deformed into shapes having a substantially U-shaped section so as to interpose the thin joint portion22of each of the side wall plates20by shrinkage and robustly join and integrate the most part of the peripheral wall2of the container body1and side wall plates20(seeFIG.9). This joining completely forms both the side walls11of the container body1, and the peripheral wall2of the container body1takes a perfect configuration.

After insert molding the container body1on the secondary side, the container body1is left and cooled until the resin of the molding material acquires sufficient rigidity, and then the mold is opened and the container body1is removed by the push-out mechanism, whereby the container body1of the storage container can be manufactured by insert molding.

According to the above configuration, when the container body1is insert-molded, the flat surfaces of the peripheral wall2, which is the most part of the container body1, and the side wall plates20formed with support pieces12are not simply abutted and joined to each other. But the peripheral wall2forming the large part of the main body1and the thin joint portion22of the side wall plate20are meshed with each other and joined to expand the contact area therebetween. It is therefore possible to eliminate a decrease in mechanical strength and leakage performance around the peripheral edge of the side wall plates20in the side walls11of the container body1and prevent the peripheral wall2of the container body1from parting from the side wall plate20.

Further, since excellent wear resistance and slidability can be imparted to the side walls11of the container body1and the support pieces12, it is possible to prevent damage to the both side walls11of the container body1and the surface of support pieces12due to sliding their contact with the round peripheral edge of the semiconductor wafer, and generation of particles can be expectedly prevented. Further, correct selection of the resin of the side wall plate20can impart excellent heat resistance to the side walls11of the container body1and the support pieces12, so that even if the semiconductor wafers are heated to a high temperature, it can be expected to prevent deformation and melting of the support pieces12that come into contact with the wafers. For example, choice of a polycarbonate resin as the resin for the side wall plates20makes it possible to impart excellent heat resistance, impact resistance, weather resistance, dimensional stability, transparency, and the like to both side walls11of the container body1and the support pieces12.

Next,FIGS.12to15show the second embodiment of the present invention. In this case, the thin joint portion22of the side wall plate20is modified to enlarge the contact area with the molding material of the container body1.

As shown inFIG.15, the thin joint portion22in the present embodiment is formed to have a substantially cross-shaped cross section comprising: a rib23protruding outward from the peripheral edge of the thick portion21of the side wall plate20; and a plurality of bulging ribs24A protruding from both sides of the middle part of the rib23in the directions orthogonal to the protruding direction of the rib23. The thin joint portion22forms a boundary between the thick portion21and the peripheral wall2of the container body1, specifically the base plate3, ceiling plate6and the remaining part of the side walls11of the container body1.

The rib23is protruding, with a thin plate form, from the entire edge of the thick portion21, and surrounds the thick portion21endlessly. Further, a plurality of bulging ribs24A are arranged at a predetermined interval in the longitudinal direction of the ribs23. Each bulging rib24A is formed in a substantially rib shape with a rounded cross section, and is interposed between and covered by the opposing part of the peripheral wall2of the container body1, the opposing part being located opposite to each of the side wall plates20. The thickness of the bulging rib24A is thicker than the thickness of the rib23, and approximately the same as the wall thickness of the thick portion21. Since the other parts are the same as those in the above embodiment, the description is omitted.

Also in this embodiment, the same advantages as those in the above embodiment can be expected, and since the bulging rib24A is thick and is complicatedly interposed into the peripheral wall2of the container body1and is difficult to become detached, it is clear that the strength of the thin joint portion22can be increased and the mechanical strength near the peripheral edge of the side wall plate20can be improved.

Next,FIGS.16to18show a third embodiment of the present invention. Also in this case, the thin joint portion22of the side wall plate20is modified.

As shown inFIG.18, the thin joint portion22in the present embodiment comprises: a rib23protruding outward from the peripheral edge of the thick portion21of the side wall plate20; and a plurality of molding material passage holes25that are bored in the rib23to allow the molding material for the container body1to flow thereinto, thus forming a boundary between the thick portion21and the peripheral wall2of the container body, specifically the base plate3, ceiling plate6and the remaining part of the side walls11of the container body1.

The rib23protrudes, in a thin plate form, from the entire edge of the thick portion21and surrounds the thick portion21endlessly. Further, a plurality of molding material passage holes25are bored at a predetermined interval in the longitudinal direction of the ribs23. Each molding material passage hole25is formed in a circular or square shape. Since the other parts are the same as those in the above embodiments, the description is omitted.

Also in this embodiment, the same advantages as those in the above embodiments can be expected. Moreover, since the molding material for the container body1flows into the plurality of molding material passage holes25and solidifies therein, it is clear that the degree of integration of the container body1with the side wall plates20improves, and the mechanical strength and leakage properties near the peripheral edge of the side wall plate20can be prevented from decreasing.

Next,FIG.19shows a fourth embodiment of the present invention. In this case, a thin joint portion22of the side wall plate20is formed by combination of the above embodiments.

The thin joint portion22of the present embodiment comprises: an endless rib23A protruding outward from the peripheral edge of the thick portion21of the side wall plate20; a plurality of bulging ribs24A protruding on both sides of the middle part of the rib23A in the directions orthogonal to the protruding direction of the rib23A; and a plurality of molding material passage holes25that are bored in the rib23A to allow the molding material for the container body1to flow thereinto. The thin joint portion22forms a boundary between the thick portion21and the peripheral wall2of the container body, specifically the base plate3, ceiling plate6and the remaining part of the side walls11of the container body1.

The rib23A protrudes, in a thin plate form, from the entire edge of the thick portion21, but is extended longer than the rib23of the above embodiment. A plurality of bulging ribs24A and the plurality of molding material passage holes25are arrayed in an alternate manner along the longitudinal direction of the rib23A. Since the other parts are the same as those in the above embodiments, the description is omitted.

Also in this embodiment, the same advantages as those in the above embodiments can be expected, and since the bulging ribs24A are thick and complicatedly interposed into the peripheral wall2of the container body1and hard to become detached. Moreover, since the molding material for the container body1flows into the molding material passage holes25and solidifies therein, it is clear that the degree of integration of the container body1with the side wall plates20improves, and the mechanical strength and leakage properties near the peripheral edge of the side wall plate20can be prevented from decreasing.

Next,FIG.20shows a fifth embodiment of the present invention. In this case, the structure and arrangement of bulging ribs24A of a thin joint portion22are modified.

The thin joint portion22of the present embodiment comprises: an endless rib23A protruding outward from the peripheral edge of the thick portion21of the side wall plate20; a number of bulging ribs24A protruding on both sides of the middle part of the rib23A in the directions orthogonal to the protruding direction of the rib23A; and a number of molding material passage holes25that are bored in the rib23A to allow the molding material for the container body1to flow thereinto. The thin joint portion22forms a boundary between the thick portion21and the peripheral wall2of the container body1, specifically the base plate3, ceiling plate6and the remaining part of the side walls11of the container body1.

The rib23A protrudes in a thin plate form from the entire edge of the thick portion21, but is extended longer than the rib23of the above embodiments. A number of the bulging ribs24A are formed on both sides of the middle portion of the rib23A but at different positions in a staggered manner. Specifically, a plurality of bulging ribs24A arranged on one side of the middle portion of the rib23A at a predetermined pitch, and a plurality of bulging ribs24A arranged on the other side of the middle portion of the rib23A at the predetermined pitch, but are arranged so as to be shifted in the longitudinal direction of the ribs23A, and each bulging rib24A being formed to be smaller than the bulging rib24A of the above embodiments.

A large number of the molding material passage holes25are arranged alternately with a number of the bulging ribs24A. Each molding material passage hole25is bored in a round hole having a diameter smaller than that of the molding material passage hole25of the above embodiment, as is required. Since the other parts are the same as those in the above embodiments, the description is omitted.

Also in this embodiment, the same advantages as those in the above embodiments can be expected, and since a large number of bulging ribs24A are arranged in the staggered manner, the contact area between the container body1and the thin joint portion22of the side wall plate20is enlarged so it can be greatly expected that the degree of integration further improves, and the mechanical strength and leakage properties near the peripheral edge of the side wall plate20can be prevented from decreasing.

Additionally, the container body1in the above embodiment may have, on the rear side of the base plate3, a plurality of air supply valves for supplying purge gas such as nitrogen gas from the outside to the inside, and on both sides in the front part of the base plate3, a plurality of exhaust valves for exhausting air from the inside to the outside. Further, in the above embodiment, the functional resin member is used for the side wall plates20, but the present invention is not limited to this.

For example, the functional resin member may be a transparent vertically long window plate that forms most of the rear wall10of the container body1. This window plate is used as a viewing window so as to allow a plurality of semiconductor wafers housed in the container body1to be seen. In this case, when the container body1is manufactured, a substantially rectangular window plate as the functional resin member is injection-molded, and the window plate on the primary side is inserted into the mold for molding the container body1with its mold opened, then the mold is clamped. The thus clamped mold is injected and filled with a plasticized molding material to integrate the peripheral edge or the thin joint portion22of the window plate with the molten molding material to manufacture the container body1on the secondary side by insert molding. In this way, advantages substantially similar to the above advantages can be obtained.

Further, the molding resin of the side wall plate20may be a combination of a polyether ether ketone resin and a polycarbonate resin, or a combination of a polyether ether ketone resin and a cycloolefin polymer resin. Further, in the above embodiments, U-shaped grooves13are formed between the neighboring upper and lower support pieces12on the side wall plate20, but V-grooves may be formed instead of the U-shaped grooves13.

Moreover, each support piece12may have a substantially I-shaped cross section, a substantially wedge-shaped cross section, or the like. Further, if necessary, a thin joint portion22can be formed in part on the peripheral edge of the thick portion21of the side wall plate20. Further, it is possible to bore a required number of molding material passage holes25in at least one of the rib23A and the bulging rib24A of the thin joint portion22. Furthermore, the bulging portion24of the thin joint portion22may have a cross section of a substantially elliptical shape, a substantially semi-elliptical shape, a substantially semi-circular shape, or the like.

INDUSTRIAL APPLICABILITY

The storage container and the manufacturing method thereof according to the present invention are used in the field of manufacturing storage containers for storing substrates such as semiconductor wafers.

DESCRIPTION OF REFERENCE NUMERALS