JP2004314994A - Board storage container and manufacturing method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a board storage container, whose electrification preventive layer does not weaken its function, come off, or bleed when washed with water or wiped, retains the level of electrification preventiveness at the time of manufacturing, and does not crack or peel when an external force, such as impact or vibration, acting on the layer changes, and to provide a manufacturing method for the storage container. <P>SOLUTION: The board storage container comprises an outer box 1 of a rectangular cylinder with a bottom, an inner box of a rectangular cylinder which stores a plurality of lined up semiconductor wafers and is housed in the outer box 1, a lid 5 which opens/closes the opening top face of the outer box 1 via a packing 4, and a holding body 6 which is fitted on the inner surface of the lid 5 to prevent the shakiness of the semiconductor wafers. The outer and inner boxes 1, 3, lid 5, and holding body 6 are molded using resin compositions, respectively, and each is coated with the transparent electrification preventive layer 7 containing at least π electron conjugated conductive polymers. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００６８】
【発明の効果】
以上のように本発明によれば、帯電防止層が水洗、拭き取られた後にも機能減衰、脱離、ブリードすることがなく、製造当初の帯電防止性を持続することができるという効果がある。また、衝撃や振動等の外部応力が作用しても、割れや剥離を抑制防止することができる。
【図面の簡単な説明】
【図１】本発明に係る基板収納容器の実施形態を示す斜視説明図である。
【図２】本発明に係る基板収納容器の実施形態を示す分解斜視説明図である。
【図３】本発明に係る基板収納容器の実施形態における傾斜的な帯電防止層を示す説明図である。
【図４】本発明に係る基板収納容器の第２の実施形態を示す斜視説明図である。
【符号の説明】
１ 外箱（容器）
２ リブ片（容器の一部）
３ 内箱（容器）
５ 蓋体（容器の一部）
５Ａ 蓋体（容器の一部）
６ 押さえ体（容器の一部）
７ 帯電防止層
１０ フロントオープンボックス（容器）
Ｗ 半導体ウェーハ（基板）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a substrate storage container used when transporting and storing semiconductor wafers and the like, and more particularly, when various external stresses act on an antistatic layer of the substrate storage container, there is no cracking or peeling, and the substrate is washed with water. The present invention relates to a substrate storage container capable of maintaining excellent antistatic performance without losing function, detaching, or bleeding during wiping, and a method for manufacturing the same.
[0002]
[Prior art]
The substrate storage container used in the semiconductor manufacturing process is not shown, but generally a resin composition having excellent moldability, for example, polypropylene, polycarbonate, polybutylene terephthalate, polybutylene naphthalate, polyetherimide, polyetheretherketone, It is formed of fluororesin or the like.
However, substrate storage containers using these resins have a serious problem that they are easily charged with static electricity because of their high surface resistance. The substrate storage container charged with static electricity induces crystal defects and loss of electrical characteristics of the semiconductor wafer, and attracts minute foreign matters floating in the atmosphere. This will contaminate the surface. Therefore, in order to prevent these problems, a substrate storage container having an antistatic function is required.
[0003]
Conventionally, as a method of adding an antistatic function to a substrate storage container, a method of adding conductive carbon black fibers to polypropylene (see Patent Document 1) and a method of adding carbon fibers to polybutylene terephthalate (see Patent Document 2) A method of adding conductive carbon black to polyetheretherketone (see Patent Document 3) and a method of adding carbon black to aliphatic polyketone (see Patent Document 4) have been proposed.
[0004]
By adding such conductive material such as carbon black, carbon fiber, or conductive metal powder to the substrate container, antistatic properties can be achieved. However, the conductive material added to the resin composition of the substrate container may be used. The conductive material scatters, peels off, and falls off from the surface of the substrate storage container, becomes a new generation source of fine foreign matter, and newly raises a large problem of increasing dust generation. Further, organic substances and ionic residual substances contained in the conductive material leak and cause contamination of the surface of the semiconductor wafer, which is not preferable. Furthermore, since the color tone of the resin composition becomes black and the substrate storage container becomes opaque due to the addition of the conductive material, the semiconductor wafer in the substrate storage container may not be recognized or identified.
[0005]
A method of adding a conductive polymer as a conductive material to a resin composition of a substrate storage container has been proposed (see Patent Document 5). However, since a conductive polymer is used as a conductive filler, conductive carbon is used. It is not preferable for the same reason as when black, carbon fiber, or conductive metal powder is added. Also, when molding the substrate storage container, the material resin is melted near the melting point using an injection molding machine, and the molten material resin is injected into a lower temperature mold, cooled and solidified to obtain a product. Although a molding method is mainly adopted, a problem arises in that the conductive polymer is decomposed at the time of the injection molding and the function of the conductive material is impaired.
[0006]
As another method, a method has been proposed in which an alkylphosphonate compound is added as an internally added antistatic agent to a resin composition of a substrate container (see Patent Document 6).
However, low-molecular-weight antistatic agents such as alkyl phosphonate compounds have excellent antistatic performance, but have poor water resistance, so they are easily detached and bleed out by washing and wiping the substrate storage container. The effect is diminished. Also, the leaked low-molecular-weight antistatic agent is not preferable because it causes surface contamination of the semiconductor wafer.
[0007]
For the low-molecular-weight antistatic agent, a high-molecular-weight antistatic agent such as polyetherester, polyetheramide, polyetheresteramide, or polyetheramideimide is added to the resin composition as an internally added antistatic agent. A method (see Patent Document 7) has been proposed.
However, these polymer type antistatic agents are excellent in antistatic performance, but are inferior in heat resistance and cause discoloration of the resin composition during molding. Furthermore, since the polymer type antistatic agent has poor compatibility with the resin composition, there is a concern that the polymer composition may lower excellent physical properties such as mechanical properties of the resin composition.
[0008]
In contrast to the above-described method of kneading an antistatic agent into the resin composition of the substrate storage container, a method of applying a conductive paint to the resin composition has also been proposed. As a method using a conductive paint, there is proposed a method in which an antistatic coating liquid composition in which a π-electron conjugated conductive polymer is dispersed in a self-emulsifying polyester resin is prepared and applied to the resin (see Patent Document 8). However, since a water-soluble resin or a water-absorbing resin is used as the binder resin, the water resistance is very poor. A conductive paint in which an epoxy-containing alkoxysilane compound is added to a conductive paint for the purpose of improving the adhesion of a π-electron conjugated conductive polymer (see Patent Document 9) has also been proposed. As a result, the conductive paint gels and the long-term storage stability is impaired. In addition, there is room for doubt about the water resistance of the coating film.
[0009]
Further, a water-soluble compound having an amide bond or a hydroxyl group and an epoxy-containing alkoxysilane compound are added to an aqueous dispersion of a conductive polymer and a self-emulsifying polyester resin to form a coating film having excellent adhesion and water resistance. (See Patent Document 10) has also been proposed.
However, in the case of this configuration, since the resin composition and the coating film are simply in contact with each other, the resin composition is very fragile, and has an external stress such as impact or vibration, and further, a difference in linear expansion coefficient between the resin composition and the binder resin. There is a problem that cracking and peeling easily occur.
[0010]
[Patent Document 1]
JP-A-6-291177
[0011]
[Patent Document 2]
JP-A-8-88266
[0012]
[Patent Document 3]
JP-A-9-36216
[0013]
[Patent Document 4]
JP-A-11-3931
[0014]
[Patent Document 5]
JP-A-8-293536
[0015]
[Patent Document 6]
JP-A-62-230835
[0016]
[Patent Document 7]
JP-A-6-57153
[0017]
[Patent Document 8]
JP-A-6-295016
[0018]
[Patent Document 9]
JP-A-6-73271
[0019]
[Patent Document 10]
JP-A-2002-60736
[0020]
[Problems to be solved by the invention]
Since the conventional substrate storage container is configured as described above, if the antistatic layer is washed or wiped off, attenuation, desorption, and bleeding of the function occur, and the excellent antistatic performance at the beginning of manufacturing is obtained. There is a problem that it is difficult to sustain. Furthermore, when impacts, vibrations, and the like act, there are many possibilities that cracks or peeling may occur.
[0021]
The present invention has been made in view of the above, and even when washing and wiping the antistatic layer, the function does not decay, desorb, or bleed, so that the antistatic performance at the beginning of the production can be maintained, and further, the external stress It is an object of the present invention to provide a substrate storage container which does not crack or peel even if the change occurs, and a method of manufacturing the same.
[0022]
[Means for Solving the Problems]
In the present invention, in order to achieve the above object, in a container made of a resin composition, a substrate is stored,
It is characterized by comprising a substantially transparent antistatic layer formed in a container and at least a π-electron conjugated conductive polymer contained in the antistatic layer.
Incidentally, a gradient can be given to the component concentration of the antistatic layer, and the components of the antistatic layer can be gradually made into the resin composition of the container.
[0023]
Further, a binder resin can be contained in the antistatic layer.
Further, the total light transmittance can be 80% or more, and the haze value (cloudiness value) can be 10% or less.
[0024]
Further, according to the present invention, in order to achieve the above object, a method for manufacturing a container containing a substrate,
The container is treated with a coating liquid composed of an organic solvent capable of dissolving the resin composition of the container and the π-electron conjugated conductive polymer, and the π-electron conjugated conductive polymer is dissolved and adhered to the resin composition of the container. To form a substantially transparent antistatic layer.
[0025]
Here, the container in the claims is a type that accommodates at least an inner box for storing a substrate in an outer box, a process cassette type, an open cassette type, a carrier type, a front open box type (for example, FOSB or FOUP), and a mask case. , A liquid crystal cell case, etc., with or without a lid. The opening of this container may be only the upper and lower surfaces, the front and rear surfaces, the upper surface, or only the front surface. The opening of the container may or may not be opened and closed by the lid, but when it is opened and closed by the lid, the lid can incorporate a locking latch mechanism. The substrate includes at least one or more semiconductor wafers (for example, 6-inch, 8-inch, and 12-inch silicon wafers), photomask glass, and the like.
[0026]
The antistatic layer can be applied and formed on the surface of the container, but can also be formed on a part of the container if the object can be achieved. Substantially transparent of the antistatic layer includes both transparent and translucent. This antistatic layer is preferably free from cracks and peeling after the water resistance test JIS K 5400 8.19 at 25 ° C. for 24 hours, and the rate of increase in surface resistance is preferably less than 10 times. Further, it is preferable that there is no crack or peeling in the water resistance test JISK 5400 8.32. "Grading the component concentration of the antistatic layer to gradually make the components of the antistatic layer into the resin composition of the container" means that the components of the antistatic layer are formed with a gradient, in other words, It means that the concentration distribution of the components of the prevention layer has gradation.
[0027]
According to the present invention, an antistatic layer is formed on at least a part of the container, and at least the antistatic layer contains a π-electron conjugated conductive polymer having an antistatic function, and the concentration of the component in the antistatic layer is reduced. To gradually reduce the components of the antistatic layer to the resin composition of the container, so that even if the antistatic layer is washed with water or wiped off, it is possible to suppress functional attenuation, desorption, and bleeding. . In addition, even if external stress such as impact or vibration acts on the container, cracking and peeling can be suppressed by making the component concentration of the antistatic layer gradient.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, a substrate storage container according to the present embodiment includes A plurality of inch-sized semiconductor wafers are aligned and stored via rib pieces 2, and a rectangular cylindrical inner box 3 removably housed in the outer box 1, and an upper surface of the opening of the outer box 1 via an endless packing 4. A lid 5, which is mounted on the inner surface of the lid 5 to prevent rattling of the semiconductor wafer. The outer box 1, the inner box 3, the lid 5, and the retainer 6 Each of them is formed of a resin composition, and a transparent antistatic layer 7 is formed on the surface (inner surface and / or outer surface) of each of these 1, 3, 5, and 6, and each antistatic layer 7 exhibits an antistatic function. Including π-electron conjugated conductive polymer That.
[0029]
The substrate storage container, in other words, the outer box 1, the inner box 3, the lid 5, and the pressing body 6 are usually formed by an injection molding method, and the outer box 1, the inner box 3, and the lid 5 are transparent or translucent. It is said. As a specific injection molding method, a resin composition of a material is heated and melted to a melting point or higher using an injection molding machine, and the melted resin composition is poured into a lower temperature mold and cooled and solidified. Is a method of obtaining a predetermined product by using The substrate storage container formed by such a method is subjected to a surface treatment with a coating liquid containing an organic solvent (organic solvent) capable of dissolving the resin composition and a π-electron conjugated conductive polymer, and the π-electron conjugated The transparent antistatic layer 7 is formed by the conductive polymer being dissolved and adhered to the resin composition.
[0030]
As the resin composition of the outer box 1, the inner box 3, the lid 5, and the pressing body 6, a resin excellent in mechanical strength, moldability, transparency, heat resistance, and dimensional stability is preferable. For example, polypropylene, polyethylene, polyolefins such as polybutylene, polyethylene terephthalate, polybutylene terephthalate, polyesters such as polycarbonate, polyethylene sulfide, polythioethers such as polyphenylene sulfide, polyether ketone, polyether sulfone, polyether ether ketone, etc. Polyketones, phenol resins, melamine resins, urea resins, fluorine resins, liquid crystal polymers, and the like.
[0031]
The resin composition is required to reduce as much as possible organic substances and ionic residual substances which become a contamination source of the semiconductor wafer. For this reason, it is important to remove and purify the remaining reaction catalyst and volatile organic components such as oligomers from the viewpoint of quality characteristics. In the resin composition, various additives such as an antioxidant, a neutralizer, a plasticizer, a flame retardant, and an ultraviolet absorber, and a reinforcing filler can be used as a resin modifier. However, in order to prevent contamination of the semiconductor wafer, it is preferable to keep the amount to the minimum necessary for exhibiting the resin modification characteristics.
[0032]
An organic solvent that dissolves the resin composition, that is, a good solvent, must be appropriately selected depending on the type of the resin composition used. Specifically, halogenated hydrocarbons such as methylene chloride and chloroform; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethers such as diethyl ether and tetrahydrofuran; esters such as ethyl acetate and butyl acetate; , Xylene, aromatic hydrocarbons such as benzene, nitriles such as acetonitrile, N-methylpyrrolidone, dimethylsulfoxide, dimethylsulfoxide, dimethylformamide, dimethylacetamide, etc., and these can be used alone or in combination. it can.
[0033]
In order to control the dissolution rate of the resin composition, the organic solvent used may be a mixture of a good solvent having a high solubility in the resin composition and a poor solvent having a low solubility in the resin composition. When a mixture of a good solvent and a poor solvent is used, the antistatic layer 7 can be provided uniformly and accurately without impairing the mechanical properties of the resin composition. The poor solvent also needs to be appropriately selected depending on the type of the resin composition to be used. For example, alcohols such as meteranol, ethanol, and isopropyl alcohol, and glycols such as ethylene glycol and diethylene glycol can be used.
[0034]
Here, as an example of a parameter that defines a good solvent and a poor solvent of the resin composition, that is, a solubility, there is a solubility parameter (SP value) δ shown in Expression 1. Polar resin compositions tend to be soluble in polar solvents and less soluble in non-polar solvents, whereas non-polar resin compositions tend to be the opposite. A parameter for determining the strength of the affinity is the SP value. Generally, the closer the SP value of the resin composition and the solvent molecule is, the higher the solubility tends to be.
[0035]
δ ² = ΔE / V (ΔE is the cohesive energy of liquid molecules, V is the molar volume) (Equation 1)
[0036]
For example, when a polycarbonate having a polar group is used as the resin composition, the polycarbonate has poor solvent resistance and easily becomes cloudy and deforms when contacted with the organic solvent. In other words, by preparing a coating solution using an organic solvent having a similar SP value, the antistatic layer 7 can be dissolved and adhered to the surface of the polycarbonate.
[0037]
When polyetheretherketone, polyetherketone, or the like is used as the resin composition, it has a hydrophobic non-polar group and is excellent in solvent resistance. Therefore, as a good solvent, N-methylpyrrolidone, dimethylformamide, dimethyl Although it is limited to acetamide or the like, since the dissolution rate of the resin composition is easily controlled, the antistatic layer 7 can be uniformly and accurately formed. The dissolution rate of the resin composition by the coating liquid for forming the antistatic layer 7 is controlled by the immersion time with the coating liquid, the ambient temperature, the mixing ratio of the good solvent to the poor solvent, and the like.
[0038]
The time for bringing the coating liquid into contact with the resin composition is optimally 3 to 600 seconds, preferably 5 to 60 seconds. This is because, if the contact time is shorter than 3 seconds, the coating liquid is insufficiently dissolved in the resin composition, and the uniform and accurate antistatic layer 7 cannot be formed. Conversely, if the contact time is longer than 600 seconds, the base material is deformed or the production capacity is reduced, which is not preferable. The mixing ratio of the poor solvent in the present invention is preferably 0 to 95% of the total solvent including the good solvent and the poor solvent. The dissolution rate can also be controlled by adjusting the SP value by mixing a plurality of good solvents.
[0039]
In addition to these, the dissolution rate is controlled by performing a surface modification treatment of the resin composition in advance using a known method, such as surface roughening, corona treatment, plasma treatment, primer treatment, or anchor coat treatment. It is also possible. Activating the surface of the resin composition using external energy such as ultrasonic waves is also effective in controlling the dissolution rate. When applying to a resin composition having poor wettability, a coating liquid may be repelled on the surface of the resin composition and pinholes may be generated. In this case, improvement can be achieved by adding a binder resin or a surfactant to the coating liquid. As the binder resin, the above resin composition can be used, and the same material as the substrate storage container or a different material can be used. The solvent for dissolving the binder may be the same as or different from the solvent for dissolving the conductive polymer, but it is necessary that the conductive polymer and the binder resin be compatible.
[0040]
Examples of the surfactant include anionic surfactants such as sodium alkylbenzene sulfonate, sodium alkyl sulfonate, and sodium alkyl sulfate, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenolate, polyoxyethylene / polyoxypropylene glycol, and the like. And non-ionic surfactants and fluorine-based surfactants such as fluoroalkyl carboxylic acid, perfluoroalkyl carboxylic acid, perfluoroalkyl benzene sulfonic acid, perfluoroalkyl quaternary ammonium, and perfluoroalkyl polyoxyethylene ethanol. Can be Preferably, a nonionic surfactant having a low ionic residue is selected.
[0041]
The π-electron conjugated conductive polymer contained in the antistatic layer 7 is a polymer having a conjugated double bond in the molecular structure, and has a stable conductive structure even with a change in humidity because the conductive mechanism is not ionic conductive. Conductivity can be obtained. Further, since it is an organic compound, it is softer than an inorganic conductive material, and has a feature that the base sheet is not damaged. Examples of the monomer before polymerization of the conductive polymer include aniline derivatives such as aniline, sulfonated aniline, and alkylated aniline, and a 5-membered heterocyclic compound.
[0042]
The 5-membered heterocyclic ring includes pyrrole, thiophene, furan, indole and derivatives thereof, for example, N-methylpyrrole, N-ethylpyrrole, 3-methylpyrrole, 3-methoxypyrrole, 3-octylpyrrole, 3-octylpyrrole, Decylpyrrole, 3,4-dimethylpyrrole, 3-hexylpyrrole, methyl 3-methyl-4-pyrrolecarboxylate, 3-methylthiophene, 3-methoxythiophene, 3-butylthiophene, 3,4-dimethylthiophene, 3- Dodecylthiophene, 3-thiophene-β-ethanesulfonate, 2,3-dihydrothieno (3,4-b) -1,4-dioxin, 3-methylfuran, 3-methylindole, and the like, The present invention is not limited to these, and a single or multiple monomers may be copolymerized and used. It is. In particular, a derivative having a long side chain of 3 or more carbon atoms at the β-position of the 5-membered heterocyclic compound is not highly conductive, but has excellent compatibility.
[0043]
The monomer before polymerization of the conductive polymer is polymerized into a polymer having a degree of polymerization of about 10 to 1000 using an oxidation polymerization catalyst. If the degree of polymerization is low, the conductivity is low, so that a large amount of a conductive polymer is required as the antistatic layer 7, and the transparency is deteriorated. Conversely, if the degree of polymerization is high, the compatibility with the organic solvent decreases, so the above range is appropriate. Oxidation polymerization catalysts used for these include chlorides of transition metals such as ferric chloride, cupric chloride and stannic chloride, hydrogen peroxide, peroxides such as ozone and benzoyl peroxide, and silver oxide. Such as metal oxides, inorganic acids and salts thereof such as permanganic acid, chromic acid and hypochlorous acid, perchlorates such as ferric perchlorate and cupric perchlorate, ammonium persulfate and persulfuric acid Persulfides such as sodium.
[0044]
Since the polymerization catalyst is an ionic residual substance, it is necessary to remove the polymerization catalyst by ion exchange, dialysis or the like after completion of the polymerization. When it is desired to improve the conductivity of the π-electron conjugated polymer, a dopant may be added. For this, organic electron-donating compounds such as fullerene, tetracyanoquinodimethane, and tetracyanotetraazanaphthalene can be used, which is very preferable because there is no ionic residual substance.
[0045]
The π-electron conjugated conductive polymer must be dissolved in a solvent or binder resin that dissolves the resin composition in order to improve transparency. Since the organic conductive polymer is generally an insoluble and infusible polymer, a coating liquid in which a π-electron conjugated conductive polymer is dispersed and blended as conductive fine particles is inferior in transparency and haze value, and is therefore preferable. Absent. When a binder resin is added to improve wettability, depending on the type of the binder, even if the π-electron conjugated conductive polymer is solubilized due to its polarity, intermolecular force, etc., it may be separated and aggregated. There is something to do. This case can be solved by using a compatibilizer or a surfactant.
[0046]
The content of the π-electron conjugated conductive polymer in the coating liquid for forming the antistatic layer 7 is such that the resistance value of the surface of the antistatic layer 7 is 10%. ⁵ -10 ¹² The content is 0.01 to 20% by mass in the coating liquid so as to be Ω / □. This is because if it is less than 0.01% by mass, sufficient conductivity cannot be obtained, and if it exceeds 20% by mass, transparency, especially the haze value is adversely affected. Even when the antistatic layer 7 contains a binder resin, the surface resistance of the antistatic layer 7 is 10 ⁵ -10 ¹² However, if the binder resin content exceeds 20% by mass as a solid content in the coating solution, the antistatic layer 7 cannot be formed uniformly and accurately. If the thickness is too thick, the dimensions of the resin composition will be too large. Therefore, it is preferable to suppress the content to 20% by mass or less.
[0047]
In order to form the antistatic layer 7 on the resin composition, coating can be performed by using a known coating method such as spray coating or dipping, and then drying is performed to obtain a predetermined antistatic layer 7. The thickness of one coating is preferably 0.1 to 100 μm. When the dissolution rate of the resin composition is high, thin coating may be performed several times and repeated until a desired surface resistance value is obtained. The drying time varies depending on the solvent used, but it needs about 10 to 600 seconds. Although the characteristics of the antistatic layer 7 do not vary depending on the drying conditions, it is necessary to completely volatilize and remove the solvent in the drying step. This is because, when the resin composition is in an incompletely dried state, the remaining solvent may unnecessarily penetrate the resin composition, causing cloudiness and deformation of the resin composition.
[0048]
The drying temperature varies depending on the type of the solvent and the heat resistance of the resin composition, but the most preferable method is to circulate hot air so that the temperature of the resin surface becomes 50 to 160 ° C. to quickly volatilize the solvent. Here, if the entire resin composition is heated at a high temperature in an oven or the like, the dissolution of the resin rapidly progresses, and the resin composition may be clouded or deteriorated. The thickness of the antistatic layer 7 which is melted and fused to the surface layer of the resin composition is 0.01 to 10 μm, preferably 0.1 to 1 μm.
[0049]
This is based on the reason that when the film thickness is smaller than 0.01 μm, a desired resistance value cannot be obtained, or a pinhole is generated during coating. Conversely, when the film thickness is more than 10 μm, it takes a long time for drying, it is difficult to control the contact time between the good solvent and the resin composition, and the film thickness tends to vary. The thickness of the antistatic layer 7 is preferably within the above-mentioned dimensional range in order to maintain dimensional accuracy after injection molding.
[0050]
The state of the minute interface between the surface of the resin composition and the antistatic layer 7 is such that the two layers are melt-fused and become compatible with each other, so that the antistatic layer 7 is inclined. Here, the term "gradient" means that the antistatic layer 7 is formed with a concentration gradient from the surface to the inside of the resin composition as shown in FIG. As a result, a substrate storage container having excellent water resistance and impact resistance can be obtained. In particular, since both layers are formed by compatibilization, the antistatic layer 7 does not peel off or bleed from the resin composition. This is preferable because there is no contamination of the semiconductor wafer. Regarding the characteristics, the water resistance can be evaluated based on JIS K 5400 8.19, and the impact resistance can be evaluated based on JIS K 5400 8.32 Dupont impact test.
[0051]
The substrate storage container is composed of a resin composition having excellent transparency and the antistatic layer 7, and has a total light transmittance of 80% or more and a haze value of 10% or less, preferably a total light transmittance of 90% or more and a haze value. 5% or less is good. This is because if the transmittance is less than 80% and the haze value is large, it is difficult to recognize and identify the contents stored through the substrate storage container, that is, the semiconductor wafer. The transparency can be measured using a transmittance meter or a haze meter based on JIS K 7105.
[0052]
According to the above configuration, a transparent antistatic layer 7 is formed on the surface of the outer case 1, the inner case 3, the lid 5, and the presser 6, and each antistatic layer 7 is made of a π-electron conjugated conductive polymer. The concentration of the components of the antistatic layer 7 is gradually increased and the components of the antistatic layer 7 are gradually thinned to obtain the resin composition of the outer box 1, the inner box 3, the lid 5, and the pressing body 6. Even if the antistatic layer 7 is washed or wiped off with water, the function does not attenuate, desorb, or bleed, and excellent antistatic properties at the beginning of the production can be maintained. In addition, the inclined antistatic layer 7 can prevent cracking and peeling even when external stress such as impact or vibration acts.
[0053]
In the above embodiment, a transparent antistatic layer 7 is formed on the surface of the outer case 1, the inner case 3, the lid 5, and the pressing body 6 constituting the container, and each antistatic layer 7 is provided with a π-electron conjugated conductive material. The conductive polymer is contained, but the present invention is not limited to this. For example, a transparent antistatic layer 7 may be formed on the surface of the inner box 3 and the pressing body 6 that directly contacts the semiconductor wafer, and the antistatic layer 7 may contain a π-electron conjugated conductive polymer.
[0054]
Next, FIG. 4 shows a second embodiment of the present invention. In this case, a front open box 10 in which a plurality of 12-inch semiconductor wafers W are aligned and stored in a vertical direction via rib pieces 2 is provided. A lid 5A for opening and closing the open front of the front open box 10 via an endless packing 4. The front open box 10 and the lid 5A are formed of a resin composition, respectively. A transparent antistatic layer 7 is formed on the surface (inner surface and / or outer surface), respectively, and each antistatic layer 7 contains a π-electron conjugated conductive polymer. The other parts are the same as those in the above-described embodiment, and a description thereof will be omitted. It is apparent that the present embodiment can expect the same operation and effect as the above embodiment.
[0055]
【Example】
Hereinafter, examples of a substrate storage container and a method of manufacturing the substrate storage container according to the present invention will be described together with comparative examples.
In each of Examples 1 to 3 and Comparative Examples 1 to 3, substrate storage containers were prepared, and the transparency, surface resistance, appearance, and overall evaluation of each substrate storage container were evaluated based on the following evaluation methods. The results are summarized in Table 1. The storage test was evaluated after standing at 23 ° C. and 50% RH.
[0056]
Example 1
First, a polypropylene resin was selected as a resin composition, a resin temperature of 230 ° C., a mold temperature of 50 ° C., and an injection pressure of 1,500 kg / cm. ² To produce a substrate storage container. Then, the following coating solution A was provided in a thickness of 3 μm on the surface of the resin molded body of the substrate storage container by spray coating to obtain a substrate storage container of this example.
[0057]
Preparation of coating liquid A
Aniline and a sulfonating agent as a π-electron conjugated conductive polymer, and dodecylbenzenesulfonic acid as a compatibilizer were added, and ammonium persulfate was gradually added as an oxidation polymerization catalyst while stirring at a low temperature to prepare a uniform aqueous polyaniline solution. Methanol was added to this aqueous solution to precipitate polyaniline. The precipitate is repeatedly washed with pure water to eliminate ionic residual substances, and then the precipitate is dissolved in toluene and methyl ethyl ketone (mixing ratio 50:50) to prepare a toluene / methyl ethyl ketone solution of 5.0 mass% polyaniline in toluene / methyl ethyl ketone. did.
[0058]
Example 2
First, a polyetheretherketone resin is selected as a resin composition, and a resin 400 ° C., a mold temperature 170 ° C., an injection pressure 1,500 kg / cm. ² To produce a substrate storage container. Then, the following coating liquid B was provided on the surface of the resin molded body of the substrate storage container by spray coating to a thickness of 0.5 μm to obtain a substrate storage container of this example.
[0059]
Preparation of coating liquid B
As a π-electron conjugated conductive polymer, an aqueous solution of polydioxythiophene (trade name: ORGACON, manufactured by Agfagewald) subjected to ion exchange and dialysis to remove ionic residual substances is used, and this aqueous solution is subjected to N, N-dimethylacetamide. A DMAC solution containing 1.0% by mass of polydioxythiophene solvent-substituted with the following (DMAC) was prepared. Here, in order to control the dissolution rate, a DMAC solution of polydioxythiophene containing 1.0% by mass of ethanol as a poor solvent was added to obtain a solution of 0.5% by mass of DMAC / ethanol (50:50) of polydioxythiophene, A dark blue transparent coating solution B that was uniformly dissolved was prepared.
[0060]
Example 3
A polycarbonate resin was selected as the resin composition, and the resin was 260 ° C., the mold temperature was 100 ° C., and the injection pressure was 1,200 kg / cm. ² To produce a substrate storage container. Then, the following coating liquid C was applied by spray coating to a thickness of 1 μm on the surface of the resin molded body of the substrate storage container to obtain a substrate storage container of this example.
[0061]
Preparation of Coating Liquid C
As a π-electron conjugated conductive polymer, an aqueous solution of polydioxythiophene (trade name ORGAGON, manufactured by Agfagewald) subjected to ion exchange and dialysis to remove ionic residual substances was used, and this aqueous solution was solvent-substituted with DMAC. A DMAC solution containing 1.0% by mass of polydioxythiophene was prepared. Separately from this, a binder resin solution prepared by dissolving polyethersulfone as a binder resin in DMAC and having a solid content of 8.18% by mass is prepared in advance, and a DMAC solution of polydioxythiophene and a binder resin are prepared. By mixing equal amounts of the solution, a DMAC solution of polydioxythiophene / polyethersulfone (solid content: 5% by mass, polydioxythiophene: polyethersulfone = 1: 99) was prepared.
[0062]
Comparative Example 1
The precipitate of polyaniline produced in Example 1 was molded into a shape suitable for injection molding by a press or the like. A composite material in which polyaniline was mixed with polypropylene resin so as to be 10% by mass was injection-molded in the same manner as in Example 1 to obtain a substrate storage container of this comparative example.
[0063]
Comparative Example 2
A substrate storage container was injection-molded in the same manner as in Example 2, and the following coating liquid D was provided on the surface of the substrate storage container by spray coating to a thickness of 1 μm to obtain a substrate storage container of this comparative example.
Preparation of coating liquid D
As a π-electron conjugated conductive polymer, a water / isopropyl alcohol solution of polydioxythiophene (trade name: Denatron P-502S, manufactured by Nagase & Co., Ltd.) is subjected to ion exchange and dialysis to remove ionic residual substances. The conductive polymer was adjusted to be 1.2% by mass to prepare a uniform light blue transparent coating solution D.
[0064]
Comparative Example 3
A substrate storage container was injection-molded in the same manner as in Example 3, and the following coating solution E was provided on the surface of the substrate storage container by spray coating to a thickness of 2 μm to obtain a substrate storage container of this comparative example.
Preparation of coating liquid E
100 parts of a polyester emulsion (manufactured by Toyobo Co., Ltd., trade name: Vinaroll MD-1200, solid content: 34% by mass) are ion-exchanged and dialyzed as a π-electron conjugated conductive polymer to remove ionic residual substances. An aqueous solution of oxythiophene (trade name: ORGACON, manufactured by Agfagewald) was added so that the π-electron conjugated conductive polymer became 1.0% by mass, and a pale navy blue transparent coating solution E uniformly dissolved was prepared.
[0065]
Evaluation method
(1) Measurement of transparency
The measurement was performed using HR-100 manufactured by Murakami Color Research Laboratory.
A: Total light transmittance
B: Haze
(2) Surface resistance
The surface resistance before and after the water resistance test (implemented at 25 ° C. for 24 hours in accordance with JIS K 5400 8.19) was measured using Hiresta UP manufactured by Diamond Instruments (measured voltage: 100 V).
[0066]
(3) Appearance
The impact resistance test was performed according to JIS K 5400 8.32 Dupont type impact test (φ1 / 2 inch, 500 g, 50 cm), and the surface state after the test was observed.
：: No cracking or peeling of antistatic layer
×: Cracking and peeling occurred in the antistatic layer
(4) Comprehensive evaluation
Based on the results of the above evaluations, the suitability as a substrate storage container was evaluated according to the following criteria.
：: Excellent characteristics as a substrate storage container.
：: Can be used as a substrate storage container.
X: Not suitable as a substrate storage container.
[0067]
[Table 1]

[0068]
【The invention's effect】
As described above, according to the present invention, the antistatic layer is washed with water, and even after being wiped off, there is no effect of functional attenuation, desorption, and bleeding, and the antistatic property of the initial production can be maintained. . Further, even if external stress such as impact or vibration acts, cracking and peeling can be suppressed and prevented.
[Brief description of the drawings]
FIG. 1 is an explanatory perspective view showing an embodiment of a substrate storage container according to the present invention.
FIG. 2 is an exploded perspective view showing an embodiment of the substrate storage container according to the present invention.
FIG. 3 is an explanatory view showing a tilted antistatic layer in the embodiment of the substrate storage container according to the present invention.
FIG. 4 is an explanatory perspective view showing a second embodiment of the substrate storage container according to the present invention.
[Explanation of symbols]
1 outer box (container)
2 rib pieces (part of container)
3 inner box (container)
5 Lid (part of container)
5A Lid (part of container)
6 Holding body (part of container)
7 Antistatic layer
10 Front open box (container)
W Semiconductor wafer (substrate)

Claims (5)

A container containing a resin composition, a substrate storage container for storing a substrate,
A substrate storage container comprising: a substantially transparent antistatic layer formed on a container; and at least a π-electron conjugated conductive polymer contained in the antistatic layer. 2. The substrate storage container according to claim 1, wherein a gradient is given to the component concentration of the antistatic layer, and the components of the antistatic layer are gradually made into the resin composition of the container. 3. The substrate container according to claim 1, wherein the antistatic layer contains a binder resin. 4. The substrate storage container according to claim 1, wherein the total light transmittance is 80% or more and the haze value is 10% or less. A method for manufacturing a substrate storage container for storing a substrate in a container, comprising: treating the container with a coating liquid comprising an organic solvent capable of dissolving the resin composition of the container and a π-electron conjugated conductive polymer; A method for producing a substrate storage container, comprising forming a substantially transparent antistatic layer by dissolving and bonding a conjugated conductive polymer to a resin composition of a container.

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