JP4971654B2 - PCB cassette - Google Patents

Description

  The present invention relates to a substrate cassette, and more particularly to a substrate cassette for housing a substrate such as a large or ultra-large glass substrate in the field of electronics mounting technology. The substrate cassette of the present invention is particularly useful for accommodating thin-plate substrates such as glass substrates for liquid crystal displays, glass substrates for plasma displays, and glass substrates for thermal heads.

  In electronics packaging technology, using membrane technology and micro-connection technology, semiconductors, functional components, circuit components, etc. are placed on a wiring board and connected together with other components to assemble the desired electronic circuit. Is configured. As the substrate, for example, a glass substrate, a ceramic substrate, a silicon substrate, a composite substrate (for example, a resin / ceramic substrate, a resin / silicon substrate), a metal base / metal core substrate (insulating layer is glass, polyimide, etc.) The substrate is used.

  Various substrates such as these substrate materials, substrates on which conductor patterns are formed, and substrates incorporating high-functional elements such as thin film transistors (TFTs) (for example, glass substrates for liquid crystal displays) are manufacturing processes for mounting substrates and electronic circuit components. Etc., a plurality of sheets are collected together and accommodated in one substrate cassette for transport, storage, assembly work, and the like.

  The substrate cassette is required to have a structure that allows the substrates to be taken in and out so as not to contact each other and that the substrates can be supported and accommodated separately. Therefore, the substrate cassette is usually formed from a box-shaped frame, and has a structure in which grooved side plates are arranged on a pair of opposing side surfaces of the frame (Patent Documents 1 to 6). . Each substrate is accommodated between the corresponding grooves of the pair of side plates. As the shape of the grooved side plate, a shape in which a large number of rib-like shelf pieces protrude from the back portion of the side plate is generally used. A gap between adjacent shelf pieces becomes a groove, and a substrate is accommodated therein.

  A specific example of the substrate cassette having the above structure will be described with reference to FIGS. FIG. 1 is a front view of an example of a substrate cassette. The substrate cassette includes a bottom frame 1, an upper frame 2, two side plates 3, 3, a plurality of rib-like shelf pieces 4, 4,. 5 and 5. Between the adjacent rib-shaped shelf pieces becomes a groove, and the substrate A is accommodated therein.

  FIG. 2 is a perspective view of the substrate cassette. In the substrate cassette shown in FIG. 2, three grooved side plates 3 and 3 are arranged on each of a pair of side surfaces of the box-shaped frame body, but this number is appropriately changed according to the size of the substrate. can do. The bottom side frame 1 and the top side frame 2 are both formed in a lattice shape, but may have other shapes. Each of these members is generally manufactured by injection molding of a resin material and assembled into a box frame. For reinforcement, a substrate cassette in which a resin member and a metal member are combined is also used.

  As the size of the glass substrate increases, the flexure increases, so depending on the support method for supporting the glass substrate with the ribbed shelves on the grooved side plate, the glass substrate can be smoothly moved in and out unless the pitch between the shelves is significantly increased. The number of glass substrates that can be accommodated in one cassette is also reduced. Patent Document 4 proposes a cassette in which the length of the rib-like shelf piece of the side plate is significantly longer than before in order to cope with the increase in size of the glass substrate. If the length of the rib-shaped shelf is significantly increased, problems of charging and dust generation due to contact with the glass substrate are likely to occur.

  Conventionally, a tray-type cassette has been proposed as a substrate cassette that can cope with an increase in the size or size of a substrate (Patent Document 7). For example, as shown in FIG. 3, the substrate cassette disclosed in Patent Document 7 is a lattice having a basic structure including a peripheral frame 31 that forms a rectangular skeleton and a crosspiece 36 constructed between the peripheral frames 31. Tray-shaped cassette. Among the peripheral frames 31, the left peripheral frame 32, the right peripheral frame 34, and the rear peripheral frame 33 constitute a main frame, and the upper surfaces of these main frames are substantially in the same plane. The front peripheral frame 35 and the crosspiece 36 in the peripheral frame 31 constitute a sub-frame. The main frame has an overhanging member 37 protruding from the inner side surface of the main frame or the bottom surface of the main frame at a position lower than the upper surface. Resin pins 38, 38,... For supporting the substrate from below are projected on the extension member 37 and the subframe 36 attached to the main frame, and the upper ends of these resin pins 38 are It is substantially in the same plane at a lower position than the plane formed on the upper surface of the main frame. Further, the main frame has an intricate engagement structure that allows stacking of trays. Since the substrate cassette stably supports the substrate with a large number of resin pins, it can cope with an increase in the size of the substrate.

  In Patent Document 7, as the resin pin 38 in contact with the substrate, a dust-preventing resin (for example, polyether ether ketone, polyimide, polyether imide, polyacetal, polyamide, hard to generate dust due to friction with the substrate) is disclosed. It is desirable to use a molded body molded with ultrahigh molecular weight polyethylene, polytetrafluoroethylene, various elastomers), and at that time, it is described that molding is performed using a natural product substantially not containing a filler. .

However, a resin pin molded using a synthetic resin that does not substantially contain a filler such as a conductive filler is a highly insulating material, so that when it comes into contact with the glass substrate, the glass substrate is charged, Inconveniences such as damage to the circuit of the glass substrate occur. For example, when a glass substrate on which a thin film transistor is formed is accommodated in a substrate cassette, if the member in contact with the glass substrate is an insulator having a surface resistivity greater than 10 ¹⁴ Ω / □, the surface of the member is charged with static electricity. As a result, the circuit of the glass substrate is damaged, or dust floating in the air due to static electricity is adsorbed to the glass substrate.

  In Patent Document 5, a back portion and a tongue-shaped shelf provided on a substrate support side plate are formed of a resin body, a contact portion with a substrate is formed of a dust-proofing resin, and other portions are formed. A substrate supporting side plate formed of a conductive material-containing resin and a cassette using the same are disclosed. Since the shelf of this cassette is also made of a resin that does not contain a conductive substance, it has the same problems as described above.

On the other hand, when the surface resistivity of the cassette member in contact with the glass substrate is less than 10 ⁶ Ω / □, when the glass substrate comes into contact with the member, the glass substrate that has been electrocuted, leaked, or charged is rapidly discharged. The circuit may be damaged.

A cassette member that comes in contact with the glass substrate in terms of protecting the substrate from static electricity, maintaining an appropriate level of cleanness without bringing in dust, preventing sudden discharge, and not charging the glass substrate that is an insulator. It is desired to adjust the surface resistivity of the resin to a range of 10 ⁶ to 10 ¹⁴ Ω / □.

  2. Description of the Related Art Conventionally, a molded product formed from a resin composition in which an antistatic agent or a filler having a low electrical resistance (conductive filler) is blended with a synthetic resin has been used as a member of a substrate cassette. However, a molded product formed from a resin composition containing an antistatic agent is not sufficient for long-term antistatic properties. That is, the antistatic agent present on the surface of the molded product is removed by washing with water, rubbing or the like, and eventually the antistatic effect is lost. In order to maintain the antistatic effect over a long period of time, when the blending ratio of the antistatic agent is increased, a large amount of the antistatic agent bleeds on the surface of the molded product, and dust adheres to the surface. There was a problem that the surrounding environment was polluted by the elution and volatilization of.

  As a specific example of a cassette for a substrate molded using a resin composition containing a conductive filler, a resin composition containing a metal fiber and a whisker-like conductive material in a resin component is melt-molded. Substrate cassette (Patent Document 3), substrate cassette using a member formed by molding a resin composition containing a resin component containing a conductive material such as metal fiber, metal particle, carbon fiber, carbon black, graphite, etc. (Patent Document 4), for a substrate in which a portion other than the contact portion with the substrate is formed of a resin composition containing a conductive substance (metal fiber, metal particle, carbon fiber, carbon black, graphite, ionic polymer) A cassette (Patent Document 5) has been proposed.

However, if molding is performed using a resin composition composed of a resin component made of an electrically insulating synthetic resin and a conductive filler, the electrical resistivity of the conductive filler and the resin component is significantly different from each other, or conductive filling Even if it is difficult to uniformly disperse the material, the electrical resistivity of the obtained molded product changes rapidly even with a slight change in the content of the conductive filler. In particular, when the surface resistivity required for the substrate cassette is in the range of 10 ⁶ to 10 ¹⁴ Ω / □, the surface resistivity varies rapidly. Moreover, the surface resistivity of the molded product formed by molding the resin composition varies greatly depending on the location.

Therefore, when the resin composition containing the synthetic resin and the conductive filler as described above is used, a molded product having a desired surface resistivity value within the range of 10 ⁶ to 10 ¹⁴ Ω / □ is stabilized. It is extremely difficult to mold. In addition, in the conventional technology using a resin composition containing a conductive filler, there is a large variation in surface resistivity depending on the location of the molded product. Therefore, for any substrate that exhibits a certain antistatic property and surface resistivity regardless of the location. It is difficult to manufacture a cassette and its components.

  On the other hand, Patent Document 8 proposes a cassette for a substrate formed from a resin composition in which a blend of polyarylene sulfide and polysulfone is blended with a carbon precursor and a conductive filler. Further improvements are required in terms of friction and wear resistance, dust prevention and the like.

JP-A-6-286812 Japanese Patent Laid-Open No. 6-247483 JP-A-5-147680 JP-A-9-36219 JP-A-8-46022 JP-A-8-310588 Japanese Patent Laid-Open No. 10-287382 JP 2002-80720 A

An object of the present invention is to stably control at least a member at a location in contact with a substrate to a desired value within a range of surface resistivity of 10 ⁶ to 10 ¹⁴ Ω / □, and to reduce variation in surface resistivity depending on the location. Another object of the present invention is to provide a substrate cassette formed of a resin member having excellent antistatic properties and frictional wear resistance.

Another object of the present invention is to stably control at least a member in contact with the substrate to a desired value within the range of the surface resistivity of 10 ⁶ to 10 ¹⁴ Ω / □, thereby improving antistatic properties and frictional wear resistance. An object of the present invention is to provide a substrate cassette which is an excellent protruding resin pin.

In particular, the subject of the present invention is a grid-like tray-shaped substrate cassette having a basic structure comprising a peripheral frame forming a rectangular skeleton as shown in FIG. 3 and a crosspiece spanned between the peripheral frames. In the substrate cassette having a structure in which the substrate is supported by the protruding resin pins arranged on the projecting member and the crosspiece (subframe) provided in the peripheral frame, at least the resin pins have a surface resistivity of 10 ^6. An object of the present invention is to provide a cassette for a substrate formed of a resin member that is stably controlled to a desired value within a range of -10 ¹⁴ Ω / □ and is excellent in antistatic properties and frictional wear resistance.

As a result of diligent research to solve the above problems, the present inventors have found that at least a member in contact with the substrate has a volume resistivity of 30 to 94% by weight of synthetic resin, 10 ² to 10 ¹⁰ Ω · cm. carbon precursor 5 to 40 wt%, and a resin member formed from a resin composition containing 1 to 30 wt% conductive filler guide having a volume resistivity of less than 10 ^2, and the potential of the resin member I have come up with a substrate cassette in which the static decay time until the voltage drops from 5000V to 50V is 2 seconds or less.

  In particular, when a resin pin for supporting a substrate is formed from the resin composition, it is possible to form a cassette for a substrate including a resin pin having excellent antistatic properties and frictional wear resistance. The antistatic property can be further improved by grounding. When a resin material with excellent heat resistance, mechanical properties, melt flowability, etc. is used as a synthetic resin, it has superior frictional wear resistance and dust prevention properties compared to the case where these resin materials are used alone. An improved resin member can be formed. The present invention has been completed based on these findings.

Thus, according to the present invention, in the substrate cassette, the synthetic resin 30 to 94 in which at least the member in contact with the substrate is a blend containing 5 to 95% by weight of polyethersulfone and 95 to 5% by weight of polyphenylene sulfide. ^wt%, 10 2 ^{to 10 10} Omega · cm carbon precursor 5 to 40 wt% having a volume resistivity of, and 10 resin composition containing 1 to 30 wt% conductive filler guide having a volume resistivity of less than ² (I) the resin member is a projecting resin pin that supports the substrate, and the resin pin has a grounded structure; (ii) the resin member the surface resistivity of the resin member ^is a ¹⁰ 6 ~10 ¹⁴ Ω / □ range, and, (iii) the static decay time until the potential of the resin member is lowered to 50V from 5000V Substrate cassette to equal to or less than 0.01 seconds is provided.

In particular, according to the present invention, the member in contact with at least a substrate, a cassette for a substrate is provided a resin pin projecting with excellent antistatic properties and abrasion wear resistance.

According to the present invention, at least the member in contact with the substrate is stably controlled to a desired value within the range of the surface resistivity of 10 ⁶ to 10 ¹⁴ Ω / □, and the variation in the surface resistivity depending on the location is small. Furthermore, there is provided a substrate cassette formed of a resin member having excellent antistatic properties and frictional wear resistance. According to the present invention, there is provided a substrate cassette in which the resin member is a resin pin for supporting a substrate.

1. Synthetic resin The synthetic resin to be used is not particularly limited. For example, polyamide, polyacetal, polybutylene terephthalate, polyethylene terephthalate, polyethylene, polypropylene, polyisobutylene, polyisoprene, polybutene, poly-p-xylene, polyvinyl chloride, polyvinyl chloride. Vinylidene, polycarbonate, modified polyphenylene ether, polyurethane, polydimethylsiloxane, polyvinyl acetate, polystyrene, polymethyl acrylate, polymethyl methacrylate, ABS resin, polyphenylene sulfide, polyether ether ketone, polyether ketone, polyphenylene sulfide ketone, polyphenylene Sulfide sulfone, polyether nitrile, wholly aromatic polyester, fluororesin, polyarylate, polysulfone, Examples include polyethersulfone, polyetherimide, polyamideimide, polyimide, polyaminobismaleide, triazine resin, epoxy resin, phenol resin, diallyl terephthalate resin, and modified products thereof .

  The fluororesin includes tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, polychlorotrifluoroethylene, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene / tetrafluoroethylene copolymer. Polymer, polyvinyl fluoride, ethylene / tetrafluoroethylene copolymer, ethylene / chlorotrifluoroethylene copolymer, propylene / tetrafluoroethylene copolymer, tetrafluoroethylene / perfluoroalkyl perfluorovinyl ether copolymer, Vinylidene fluoride / hexafluoropropylene copolymer, vinylidene fluoride / chlorotrifluoroethylene copolymer, tetrafluoroethylene / ethylene / isobutylene copolymer Ethylene / hexafluoropropylene copolymer and tetrafluoroethylene / ethyl vinyl ether copolymer. These synthetic resins can be used alone or in combination of two or more.

  Of these synthetic resins, thermoplastic resins are preferred. Preferred thermoplastic trees include, for example, polyarylene sulfides such as polyphenylene sulfide; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyolefins such as polyethylene and polypropylene; polyamides, polyacetals, polycarbonates, polyvinyl chloride, polyetherimides, poly Examples thereof include ether sulfone and polyether ether ketone.

  A more preferred synthetic resin is at least one synthetic resin selected from the group consisting of polyetheretherketone, polyethersulfone, polyphenylene sulfide, polyetherimide, polycarbonate, and polybutylene terephthalate. By using a resin composition containing a combination of a carbon precursor and a conductive filler in these synthetic resins, compared to the case of using a synthetic resin not containing a carbon precursor or a conductive filler, A molded product (resin member) having improved frictional wear can be obtained.

  When the resin member in contact with the substrate of the substrate cassette is subjected to friction due to contact with the substrate and is worn, powder such as resin powder drops and contaminates the substrate. From the viewpoint of hardly generating such falling powder, it is particularly preferable to use at least one synthetic resin selected from the group consisting of polyether ether ketone, polyether sulfone, and polybutylene terephthalate.

  In order to stably support the substrate and prevent the substrate from being deformed, the various resin members constituting the substrate cassette are required to have a high degree of dimensional accuracy. Polyethersulfone is excellent in moldability in addition to generating less falling powder, and can provide a molded product with high dimensional accuracy even if the annealing step of the molded product is omitted.

  Resin composition of polyethersulfone and at least one synthetic resin selected from the group consisting of polyetheretherketone, polyphenylene sulfide, polyetherimide, polycarbonate, and polybutylene terephthalate has the ability to prevent falling powder (preventing dust generation) ), Because it is excellent in formability and dimensional accuracy.

The resin composition preferably contains 5 to 95% by weight of polyethersulfone and 95 to 5% by weight of other synthetic resin, and 20 to 80% by weight of polyethersulfone and 80 to 20% by weight of other synthetic resin. It is more preferable to contain 30 to 70% by weight of polyethersulfone and 70 to 30% by weight of other synthetic resins. Among the resin compositions, a blend of polyethersulfone and polyphenylene sulfide is preferable. In the present invention, a synthetic resin which is a blend containing 5 to 95% by weight of polyethersulfone and 95 to 5% by weight of polyphenylene sulfide is used.

  It is important that the resin member constituting the substrate cassette is excellent in antistatic properties. The antistatic property of a molded product (resin member) formed from a resin composition containing a carbon precursor and a conductive filler can be evaluated by a static decay time described later. The resin composition containing polyether ether ketone, polyether sulfone, polyether sulfone, and polysulfone as synthetic resins in that the static decay time until the potential of the resin member decreases from 5000 V to 50 V is extremely short. Butylene terephthalate is preferred, and polyether ether ketone, polyether sulfone, and polyether sulfone-containing resin compositions are more preferred.

  From the viewpoint that a molded product (resin member) formed from a resin composition in which a carbon precursor and a conductive filler are blended is not easily charged to the substrate by contact with the substrate, polyether ether ketone is used as a synthetic resin. , Polyethersulfone, polyethersulfone-containing resin composition, polyetherimide, and polybutylene terephthalate are preferable, and a resin composition containing polyethersulfone such as a resin composition of polyethersulfone and polyphenylene sulfide is more preferable.

The blending ratio of the synthetic resin in the resin composition is 30 to 94% by weight, preferably 40 to 92% by weight, more preferably 50 to 87% by weight, and particularly preferably 60 to 80% by weight. If the blending ratio of the synthetic resin is too large, the blending ratio of the carbon precursor and the conductive filler becomes too small, so that the surface resistivity of the molded product (resin member) cannot be sufficiently lowered, and the desired half It becomes difficult to obtain a resin member having a surface resistivity (10 ⁶ to 10 ¹⁴ Ω / □) of the conductive region. If the blending ratio of the synthetic resin is too small, the blending ratio of the carbon precursor and the conductive filler becomes excessive, and mechanical properties such as tensile elongation of the molded product (resin member) are deteriorated.

2. Carbon Precursor A carbon precursor having a volume resistivity in the range of 10 ² to 10 ¹⁰ Ω · cm used in the present invention is obtained by firing an organic substance at a temperature of 400 ° C. to 900 ° C. in an inert atmosphere. be able to. Such carbon precursors are, for example, (1) heating pitches and tars such as petroleum tar, petroleum pitch, coal tar, coal pitch, aromatization and polycondensation, and if necessary, in an oxygen atmosphere Oxidation and infusibilization, and further heating and firing in an inert atmosphere, (2) thermoplastic resin such as polyacrylonitrile and polyvinyl chloride is infusible in an oxygen atmosphere, and further heated in an inert atmosphere -The method to bake, (3) It can manufacture by the method of heating and baking in inert atmosphere after heat-hardening thermosetting resins, such as a phenol resin and a furan resin. The carbon precursor means a substance that is not completely carbonized with a carbon content of 97% by weight or less by these treatments.

When the organic substance is heated and fired in an inert atmosphere, the carbon content of the fired body obtained increases as the firing temperature rises. The carbon content of the carbon precursor can be easily controlled by appropriately setting the firing temperature. The carbon precursor having a volume resistivity of 10 ² to 10 ¹⁰ Ω · cm used in the present invention has a carbon content usually in the range of 85 to 97% by weight and is not completely carbonized. It can be obtained as a carbon material.

If the carbon content of the carbon precursor is too small, the volume resistivity increases, and it becomes difficult to reduce the surface resistivity of the resulting resin member. If the carbon content of the carbon precursor is too high, the volume resistivity becomes small, the surface resistivity of the resulting molded product (resin member) becomes too small, and even a slight change in the blending ratio of the carbon precursor can be obtained. The surface resistivity of the resin member to be changed abruptly. Therefore, when such a carbon precursor is used, it is difficult to stably produce a resin member having a surface resistivity of a desired semiconductive region with good reproducibility. The volume resistivity of the carbon precursor is preferably 10 ³ to 10 ⁹ Ω · cm, more preferably 10 ⁴ to 10 ⁸ Ω · cm.

  Carbon precursors are usually used in the form of particles or fibers. The average particle diameter of the carbon precursor particles used in the present invention is preferably 1 mm or less. When the average particle diameter of the carbon precursor particles is too large, it is difficult to obtain a molded article having a good appearance when the resin composition is molded. The average particle diameter of the carbon precursor particles is usually 0.1 μm to 1 mm, preferably 1 μm to 0.1 mm, more preferably 5 to 500 μm. In many cases, good results can be obtained by using carbon precursor particles having an average particle diameter of about 5 to 50 μm. The average particle diameter of the carbon precursor can be measured by a sieve separation method (micromesh sieve, standard sieve).

  The average diameter of the carbon precursor fiber used in the present invention is preferably 0.1 mm or less. If the average diameter of the carbon precursor fibers exceeds 0.1 mm, it is difficult to obtain a molded article having a good appearance when the resin composition is molded. The lower limit of the average diameter of the carbon precursor fiber is about 1 μm. The carbon precursor fibers are preferably short fibers having an average fiber length of usually 100 mm or less, and in many cases 50 mm or less, from the viewpoint of dispersibility. The lower limit of the average fiber length of the carbon precursor fiber is usually 5 μm, and in many cases about 10 μm.

The compounding ratio of the carbon precursor having a volume resistivity in the range of 10 ² to 10 ¹⁰ Ω · cm in the synthetic resin composition is 5 to 40% by weight, preferably 7 to 35% by weight, more preferably 10 to 10%. 30% by weight, particularly preferably 15 to 25% by weight. When the compounding ratio of the carbon precursor is too large, the tensile elongation of the obtained molded product (resin member) is lowered, and the mechanical properties are deteriorated. If the proportion of the carbon precursor is too small, it will be difficult to sufficiently reduce the surface resistivity of the resin member, or it will be difficult to control the surface resistivity to a semiconductive region.

3. Conductive filler Examples of the conductive filler having a volume resistivity of less than 10 ² Ω · cm used in the present invention include carbon fiber, conductive carbon black, graphite, and metal powder. Among these, from the viewpoint of controllability and reproducibility of the surface resistivity, conductive carbon materials such as carbon fiber, conductive carbon black, graphite, and a mixture thereof are preferable, and carbon fiber is more preferable. The conductive carbon material used in the present invention is in the form of short fibers or granules (including powders and scales).

Examples of the carbon fiber used in the present invention include cellulose-based carbon fiber, polyacrylonitrile (PAN) -based carbon fiber, lignin-based carbon fiber, and pitch-based carbon fiber (coal pitch-based carbon fiber and petroleum pitch-based carbon fiber). It is done. Of these, PAN-based carbon fibers, pitch-based carbon fibers, and mixtures thereof are preferable. The volume resistivity of the carbon fiber is usually about 10 ⁻¹ Ω · cm to about 10 ⁻³ Ω · cm.

  The average diameter of the carbon fibers is preferably 0.1 mm or less. If the average diameter of the carbon fibers is too large, it is difficult to obtain a molded product having a good appearance and mold transferability. The lower limit of the average diameter of the carbon fibers is usually 5 μm, and in many cases about 10 μm. The carbon fiber preferably has an average fiber length of 50 μm or more and is a short fiber. When the average fiber length of the carbon fibers is 50 μm or more, the effect of improving mechanical properties such as creep characteristics, elastic modulus, and strength becomes remarkable. The upper limit of the average fiber length before mixing of carbon fibers is about 80 mm. The upper limit of the average fiber length of the carbon fibers in the resin composition after mixing and extrusion is about 1000 μm.

Examples of the conductive carbon black used in the present invention include acetylene black, oil furnace black, thermal black, and channel black. Among these, acetylene black and oil furnace black which are conductive grades are preferable. The volume resistivity of the conductive grade carbon black is usually about 10 ⁻¹ Ω · cm to about 10 ⁻² Ω · cm. These conductive carbon blacks can be used alone or in combination of two or more.

Examples of the graphite used in the present invention include artificial graphite obtained by graphitizing coke, tar, pitch and the like at high temperature; natural graphite such as flake graphite, scaly graphite, and earth graphite. The volume resistivity of graphite is usually about 10 ⁻² Ω · cm.

The volume resistivity of the conductive filler used in the present invention is less than 10 ² Ω · cm, and the lower limit is usually the volume resistivity of a metal material such as metal powder or metal fiber.

The blending ratio of the conductive filler having a volume resistivity of less than 10 ² Ω · cm is 0.5 to 30% by weight, preferably 1 to 25% by weight, more preferably 3 to 20% by weight, and particularly preferably 5 to 5% by weight. 15% by weight. If the blending ratio of the conductive filler is too large, the surface resistivity of the obtained molded product (resin member) becomes too low, and it becomes difficult to control the surface resistivity to a desired semiconductive region. If the blending ratio of the conductive filler is too small, it will be difficult to sufficiently reduce the surface resistivity of the resulting molded product, or it will be difficult to control the surface resistivity to a desired semiconductive region. If the blending ratio of the conductive filler is reduced and the blending ratio of the carbon precursor is increased, the mechanical properties of the molded product (resin member) are lowered or the surface potential of the glass substrate cannot be sufficiently lowered. .

4). Other fillers Various other fillers can be blended in the resin composition constituting the resin member of the substrate cassette of the present invention for the purpose of improving mechanical strength and heat resistance. Examples of other fillers include inorganic fiber materials such as glass fiber, asbestos fiber, silica fiber, alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber; stainless steel, aluminum, Metallic fibrous materials such as titanium, steel, brass, etc .: high melting point organic fibrous materials such as polyamide, fluororesin, polyester resin, and acrylic resin;

  Other fillers include, for example, mica, silica talc, alumina, kaolin, calcium sulfate, calcium carbonate, titanium oxide, ferrite, clay, glass powder, zinc oxide, nickel carbonate, iron oxide, quartz powder, magnesium carbonate, sulfuric acid Particulate or powder fillers such as barium can be mentioned. However, in order to control the surface resistivity of the molded product within a preferable range, it is desirable to use a non-conductive filler.

  Other fillers can be used alone or in combination of two or more. Other fillers may be treated with a sizing agent or a surface treatment agent as necessary. Examples of the sizing agent or surface treatment agent include functional compounds such as epoxy compounds, isocyanate compounds, silane compounds, and titanate compounds. These compounds may be used after subjecting the filler to a surface treatment or a focusing treatment in advance, or may be added simultaneously with other fillers in the preparation of the resin composition.

5. Other Additives In the substrate cassette of the present invention, as other additives other than those described above, for example, an impact modifier such as an epoxy group-containing α-olefin copolymer, a resin modifier such as ethylene glycidyl methacrylate. Further, a lubricant such as pentaerythritol tetrastearate, a flame retardant, a colorant such as a dye or a pigment, and the like can be appropriately added.

6). Resin Composition The resin composition used in the present invention can be prepared using equipment and methods generally used for preparing a resin composition. For example, each raw material component is premixed with a mixer such as a Henschel mixer or tumbler, and if necessary, other fillers such as glass fiber are added and further mixed, and then a single or twin screw extruder is used. And kneaded and extruded to form pellets for molding. A method of mixing a part of the required components into a master batch and then mixing with the remaining components. In addition, in order to improve the dispersibility of each component, a part of the raw materials to be used is pulverized, mixed with a uniform particle size, and melt extruded It is also possible to do.

7). PCB cassette
Board cassette, it member portion in contact with at least a substrate, a synthetic resin 30 to 94 ^wt%, the carbon precursor 5 to 40 wt% having a volume resistivity of 10 2 ^{to 10 10} Omega · cm, and 10 ² Static decay time until the potential of the resin member is reduced from 5000V to 50V, which is a resin member formed from a resin composition containing 1-30% by weight of a conductive filler having a volume resistivity of less than Is less than 2 seconds.

Static decay time of the resin member is preferably 1.5 seconds or less, more preferably Ru der than 1 second. As synthetic resins, polyether ether ketone, polyether sulfone, polyether sulfone-containing resin composition (e.g., a resin composition containing a polyether sulfone and polyphenylene sulfide), polycarbonate, and by using the polybutylene terephthalate, static Decay time can be reduced to 0.5 seconds or less. When polyether ether ketone, polyether sulfone, and polyether sulfone-containing resin composition are used, the static decay time can be shortened to 0.01 seconds or less. In this invention, it is 0.01 second or less.

The surface resistivity of the resin member formed from the resin composition of the present invention can be controlled to a desired value within the range of 10 ⁶ to 10 ¹⁴ Ω / □. The surface resistivity of the resin member is preferably 10 ⁶ to 10 ¹³ Ω / □, more preferably 10 ⁷ to 10 ¹² Ω / □. The variation in surface resistivity depending on the location of the resin member is extremely small. Further, the resin member formed from the resin composition of the present invention has remarkably suppressed chargeability to a substrate such as a glass substrate, and can maintain the surface potential of the substrate in contact with the resin member at a low level. Is possible. The resin member formed from the resin composition of the present invention is excellent in frictional wear resistance, and is less likely to cause falling powder upon contact with the substrate.

The tensile elongation (ASTM D638) of the resin member of the present invention is preferably 2.0% or more from the viewpoint of mechanical properties. If the tensile elongation of the resin member is too low, the flexibility is impaired and the resin member is easily damaged by an external force such as an impact. The upper limit of tensile elongation is usually about 10%, although it depends on the type of synthetic resin and the blending ratio of each component.
In the present invention, various properties such as static decay time, surface resistivity, and tensile elongation of the resin member are values measured by the measurement methods described in Examples described later.

  The substrate cassette of the present invention is not limited to one having a specific structure, but is usually formed from a box-shaped frame, and grooved side plates are arranged on a pair of opposing side surfaces of the frame. Has a structured. As described above, a specific example of such a substrate cassette has a structure as shown in FIGS.

  As shown in FIGS. 1 and 2, a typical substrate cassette includes a bottom frame 1, a top frame 2, a pair of side plates 3 and 3, and rib-like shelf pieces 4 provided on each of these side plates. 4 and receiving side frames 5 and 5. The rib-shaped shelf pieces are provided so that a large number of ribs protrude in parallel at a predetermined pitch from the back portion of the side plate. Between the adjacent rib-shaped shelf pieces becomes a groove, and the substrate A is accommodated therein. The shape and size of the grooved side plate can be variously changed as desired. Each of these members is usually manufactured by injection molding and then assembled into a box frame. Each member may be entirely molded from a resin composition, or may be a composite with a metal body such as a metal insert product or an outsert product.

  In the substrate cassette having such a structure, at least a portion in contact with the substrate is constituted by a resin member formed from the resin composition. All members may be formed from a resin composition. Examples of members that come into contact with the substrate include grooved side plates 3 and 3 and receiving side frames 5 and 5. In the grooved side plates 3 and 3, the side plate main body and the rib-shaped shelf piece may be integrally formed of a resin composition, or separately molded resin members may be assembled together. Further, the side plate main body may be formed by forming a skeleton of a metal and compounding a resin composition around it by insert or outsert molding. The receiving side frames 5 and 5 may be one, or may be two or more. Further, the receiving frame may be a flat plate shape, but may be provided with rib-shaped shelf pieces in the same manner as the grooved side plate.

  As a preferred structure of the substrate cassette of the present invention, the resin member for supporting the substrate is constituted by a projecting resin pin. A typical example of a substrate cassette provided with resin pins is a grid-like tray-type substrate cassette having a basic structure consisting of a peripheral frame forming a rectangular skeleton and a crosspiece spanned between the peripheral frames. The substrate cassette has a structure in which the substrate is supported by protruding resin pins disposed on the overhang member provided on the peripheral frame and on the crosspiece (subframe).

  For example, as shown in FIG. 3, the substrate cassette provided with the resin pins is a lattice-shaped tray having a basic structure including a peripheral frame 31 forming a rectangular skeleton and a crosspiece 36 constructed between the peripheral frames 31. It is a cassette of shape. Among the peripheral frames 31, the left peripheral frame 32, the right peripheral frame 34, and the rear peripheral frame 33 constitute a main frame, and the upper surfaces of these main frames are substantially in the same plane. The front peripheral frame 35 and the crosspiece 36 in the peripheral frame 31 constitute a sub-frame. The main frame has an overhanging member 37 protruding from the inner side surface of the main frame or the bottom surface of the main frame at a position lower than the upper surface. Resin pins 38, 38,... For projecting the substrate from below are projected on the overhanging member 37 and the subframe 36 attached to the main frame. Since the substrate cassette stably supports the substrate with a large number of resin pins, it can cope with an increase in the size of the substrate. This tray-type cassette can be used by stacking a plurality of cassettes.

At least the resin pin 38 in contact with the substrate is formed of the resin composition. The resin pin and the overhang member, the resin pin and the overhang member and the peripheral frame, and the resin pin and the crosspiece may be integrally formed with the resin composition. In the substrate cassette of the present invention, the resin member constituting the substrate cassette is formed by a molded product that is stably controlled to a desired value within the range of the surface resistivity of 10 ⁶ to 10 ¹⁴ Ω / □. In addition to being excellent in frictional wear resistance, the anti-static property and the discharge property can be highly suppressed by grounding the resin pin in contact with the substrate by utilizing the semiconductivity. For the grounding of the resin pins, a conductive wire may be connected to an appropriate portion of the substrate cassette formed of a resin member and grounded. Such grounding of the resin pin is impossible with a resin pin made of a conventional natural product (synthetic resin molding containing no filler).

  An example of another preferred substrate cassette of the present invention is shown in FIG. The substrate cassette 41 shown in FIG. 4 is a substrate cassette made of a box-shaped frame, like the substrate cassette shown in FIGS. 1 and 2, and FIG. 4 is a front view thereof. A substrate cassette 41 shown in FIG. 4 includes a bottom frame 49, a top frame 48, a pair of side columns 42, 42, and support rods 43, 43,. -It is comprised from the receiving side pillar 45. FIG. The support rods 43, 43,... Are provided so as to protrude in parallel from the side columns 42, 42 at a predetermined pitch. Resin pins 44, 44,... Are arranged at the tip ends of the support bars 43, 43,.

  A pair of side pillars 42, 42 provided with support rods 43, 43,... On which such resin pins 44 are arranged is arranged in the depth direction by a necessary number (for example, 3 to 4 pairs). In this respect, in FIGS. 1 and 2, it is the same as that a plurality of pairs of side plates 3 and 3 having rib-like shelf pieces are arranged. The substrate is placed on the resin pins 44 and 44 of the pair of support bars 43 and 43 facing each other. Receiving side pillars 45, 45,... Are arranged behind the box frame. The receiving side pillars 45, 45,... Are also provided with receiving side support rods 46, 46,... Protruding forward, and resin pins 47, 47,. Is provided. By placing and placing the substrate on the resin pins of the receiving side support rod, it is possible to prevent sagging of the central portion of the substrate. A plurality (for example, 2 to 5) of receiving-side support bars can be arranged.

  The resin pins 44 and 47 are formed of the resin composition. The side columns 42 and 42, the support rods 43 and 43, the reception side columns 45 and 45, and the reception side support rods 46 and 46 can be made of a conductive material (for example, a metal such as stainless steel or aluminum). The bottom side frame 49 and the top side frame 48 can also be made of a conductive material. The resin pin can be grounded by grounding a side pillar or the like made of these conductive materials.

  As a substrate accommodated in the substrate cassette of the present invention, a glass substrate, a ceramic substrate, a silicon substrate, a composite substrate (for example, a resin / ceramic substrate, a resin / silicon substrate), a metal base / metal core substrate (the insulating layer is made of glass, And a thin plate-like substrate such as polyimide. Examples of applications of these substrates include glass substrates for liquid crystal displays, glass substrates for plasma displays, glass substrates for thermal heads, ceramic substrates for LSI packages, and ceramic substrates for hybrid ICs in the field of electronics packaging technology. The substrate cassette of the present invention is particularly suitable for housing a glass substrate such as a glass substrate for a liquid crystal display.

Hereinafter, the present invention will be described more specifically with reference to Examples , Reference Examples, and Comparative Examples, but the present invention is not limited to these Examples. The measurement methods of physical properties and characteristics are as follows.

(1) Surface resistivity When the surface resistivity of the sample is 1 × 10 ⁶ Ω / □ or more, a constant voltage device (300-1A type manufactured by Kikusui Co., Ltd.), an ammeter (616 type manufactured by Keithley Co., Ltd.) according to JIS K6911. And the surface resistivity was measured at an applied voltage of 100 V using a sample cell (Yokogawa, Hewlett-Packard 1608A type). When the surface resistivity of the sample was less than 1 × 10 ⁶ Ω / □, the sample was measured according to JIS K7194 using a Lorester HP manufactured by Mitsubishi Chemical Corporation. The surface resistivity of the sample represents the resistance per unit surface area. The unit of surface resistivity is Ω, but in order to distinguish from a simple resistance value, Ω / □ or Ω / sq. (Ohm par square).

(2) Measurement of surface potential of glass substrate After rubbing a sample (shape = 20 cm × 20 cm × 1 cm) with a glass substrate (shape = 6 cm × 4 cm × 0.05 cm) at a room temperature of 23 ° C. and a relative humidity of 50% The surface potential of the glass substrate was measured with a surface potential meter (trade name “Model 344” manufactured by Trek Japan). Friction was performed by placing a glass substrate on the sample, removing electricity with an ionizer, and then sliding the glass substrate 10 times by a person grounded with a wrist strap. After the slide, the surface potential of the glass substrate was measured. This surface potential (V) is an indicator of the chargeability of the sample with respect to the glass substrate, and the larger the surface potential, the stronger the tendency to be charged.

(3) Evaluation of static decay time (Static Decay Time) Static decay time from 5000V to 50V according to MIL-B-81705C using a static decay measuring instrument (trade name “STATIC DECAY METER-406C”) manufactured by ETS. Was measured. More specifically, a sample (shape = 12 cm × 10 cm × 0.3 cm) is placed on a charge plate monitor, charged up to 5000V, and then discharged through the sample until the potential of the sample reaches 50V. The time (seconds) was measured. The shorter the static decay time, the weaker the static electricity accumulation tendency.

(4) Friction and abrasion resistance A sample is pressed on a glass substrate (shape = 6 cm × 4 cm × 0.05 cm) on a sample (shape = 20 cm × 20 cm × 1 cm) by hand and is rubbed by friction 1000 times. The state of was visually evaluated in the following five stages.
A: Sample shaving is extremely small,
B: Sample shaving is small,
C: There is a little shaving of the sample,
D: Sample shaving is slightly noticeable,
E: The sample is extremely shaved.
(5) Tensile Elongation The tensile elongation of the sample was measured according to ASTM D638. If the tensile elongation is 2.0% or more, the practical mechanical properties are sufficient.

[Production Example 1] Production Example of Carbon Precursor A softening point of 210 ° C., a quinoline insoluble content of 1 wt%, an H / C atomic ratio of 0.63, a petroleum pitch of 68 kg, and naphthalene of 32 kg, an inner volume of 300 with a stirring blade The mixture was charged into a liter pressure vessel, heated to 190 ° C., dissolved and mixed, then cooled to 80 to 90 ° C. and extruded to obtain a string-like molded body having a diameter of about 500 μm. Next, the string-like molded body was pulverized so that the ratio of diameter to length was about 1.5, and the obtained pulverized product was heated to 93 ° C. with 0.53% polyvinyl alcohol (degree of saponification of 88 %) Dropped into an aqueous solution, stirred and dispersed, and cooled to obtain a spherical pitch formed body. Further, filtration was performed to remove moisture, and naphthalene in the pitch molded body was extracted and removed with about 6 times as much n-hexane as the spherical pitch molded body.

The spherical pitch molded body thus obtained was subjected to an oxidation treatment by holding it at 260 ° C. for 1 hour while passing heated air to obtain an oxidized pitch. This oxidized pitch was heat treated in a nitrogen stream at 580 ° C. for 1 hour and then pulverized to obtain carbon precursor particles having an average particle diameter of about 25 μm. The carbon content of the carbon precursor particles was 91% by weight. In order to examine the volume resistivity of this carbon precursor, 13 g of carbon precursor particles were filled in a cylindrical mold having a cross-sectional area of 80 cm ² and molded at a pressure of 196 MPa to obtain a molded body sample. When the volume resistivity of this sample was measured according to JIS K 7194, it was 5 × 10 ⁷ Ω · cm.

[ Reference Example 1]
72 parts by weight of polyetheretherketone (Victrex PEEK 150P), 16 parts by weight of the carbon precursor prepared in Production Example 1, and 12 parts by weight of carbon fiber (manufactured by Toho Rayon Co., Ltd., trade name “Besfight HTA3000”) After the part was uniformly dry blended with a Henschel mixer, the mixture was supplied to a 45 mmφ twin-screw kneading extruder (“PCM-45” manufactured by Ikekai Ironworks Co., Ltd.), and melt-extruded to produce pellets. After the obtained pellets were dried, a measurement sample (flat plate) was produced by an injection molding machine (IS-75 manufactured by Toshiba Machine Co., Ltd.). The results are shown in Table 1.

[ Example 1, Reference Examples 2 to 5 ]
A measurement sample was prepared in the same manner as in Reference Example 1 except that the type of synthetic resin and the blending ratio of each component were changed as shown in Table 1. The results are shown in Table 1.

[Comparative Examples 1-6]
A measurement sample was prepared in the same manner as in Reference Example 1 except that the type of synthetic resin and the blending ratio of each component were changed as shown in Table 1. The results are shown in Table 1.

(footnote)
(1) polyetheretherketone (150P manufactured by Victrex),
(2) Polyethersulfone (Sumitomo Chemical 3600P),
(3) Polyphenylene sulfide (Fortron KPS W-214 manufactured by Kureha Corporation),
(4) Polyetherimide (1000-1010 manufactured by GE Polymer Land Japan),
(5) Polycarbonate (Iupilon S-2000 manufactured by Mitsubishi Gas Chemical Company),
(6) Polybutylene terephthalate (Juranex 2002 manufactured by Polyplastics),
(7) Carbon precursor (volume resistivity 5 × 10 ⁷ Ω · cm, carbon content 91 wt%),
(8) PAN-based carbon fiber (Beast Fight HTA3000 manufactured by Toho Rayon Co., Ltd.),
(9) Regarding the value of the surface resistivity, for example, the notation 2E + 08 means 2 × 10 ⁸ .

<Discussion>
As is clear from the results in Table 1, when a synthetic resin, a carbon precursor, and a conductive filler are used in combination at specific ratios (Example 1 , Reference Examples 1 to 5 ), 10 ⁶ to 10 ¹⁴ Ω / □ A molded product that exhibits surface resistivity and has a static decay time of 2 seconds or less can be obtained. As synthetic resins, polyether ether ketone ( Reference Example 1), polyether sulfone ( Reference Example 2), polyether sulfone-containing resin composition (Example 1 ; resin composition containing polyether sulfone and polyphenylene sulfide), When polycarbonate ( Reference Example 4 ) and polybutylene terephthalate ( Reference Example 5 ) are used, the static decay time can be reduced to 0.5 seconds or less. When polyether ether ketone ( Reference Example 1), polyether sulfone ( Reference Example 2), and polyether sulfone-containing resin composition (Example 1 ) are used as synthetic resins, the static decay time is reduced to 0.01 seconds or less. can do.

The molded product formed using the resin composition of the present invention can suppress the glass substrate surface potential to a low level when it is rubbed with the glass substrate, and satisfies the required characteristics as a material for the substrate cassette. When a polyether ether ketone ( Reference Example 1), polyether sulfone ( Reference Example 2), a blend containing polyether sulfone (Example 1 ), and polybutylene terephthalate ( Reference Example 5 ) are used as synthetic resins, The surface potential of the substrate can be suppressed to a low level of 150 V or less. In particular, when a blend containing polyethersulfone (Example 1 ) is used, the surface potential of the glass substrate can be suppressed to a very low level.

In contrast, when a synthetic resin not containing a carbon precursor and a conductive filler is used (Comparative Examples 1 to 6), the surface resistivity of the molded product is as large as 10 ¹⁵ Ω / □ or more. Thus, the static decay time is as long as 60 seconds or longer and the antistatic function does not work. Moreover, the molded articles of Comparative Examples 1 to 6 do not satisfy the required level for the cassette for substrates because the surface potential of the glass substrate is raised to 1000 V or more by friction.

Molded articles (Example 1 ) formed using the resin composition of the present invention and Reference Examples 1 to 5 were respectively molded articles of comparative examples (Comparative Examples 1 to 6) formed using corresponding synthetic resins. In comparison, the friction and wear resistance is improved. For example, compared to a molded article using only polyetheretherketone (Comparative Example 1), a molded article ( Reference Example 1) formed from a resin composition in which a polyether precursor ketone is blended with a carbon precursor and carbon fiber is used. Despite the inclusion of these fillers, the evaluation of frictional wear resistance is improved from B to A. The same tendency is shown in the comparison result between Reference Example 2 and Comparative Example 2, the comparison between Reference Example 3 and Comparative Example 4, the comparison between Reference Example 4 and Comparative Example 5, and the comparison result between Reference Example 5 and Comparative Example 6. In both cases, moldings formed from a resin composition in which a carbon precursor and carbon fiber are blended with a synthetic resin are more resistant to moldings formed from a synthetic resin that does not contain these fillers. Friction wear is improved.

In particular, as a synthetic resin, a molded product (Example 1 ) formed using a resin composition containing polyethersulfone and polyphenylene sulfide was used as a polyethersulfone molded product (Comparative Example 2) and a polyphenylene sulfide molded product (Comparative). Compared to Example 3), the frictional wear resistance is significantly improved.

  The molded product (resin member) formed from the resin composition of the present invention does not adsorb dust or the like floating in the air, and does not cause the circuit of the glass substrate incorporating the thin film transistor to be destroyed.

[Comparative Examples 7 to 10]
A measurement sample was prepared in the same manner as in Example 1 except that the type of the synthetic resin and the blending ratio of each component were changed as shown in Table 2. The results are shown in Table 2.

(footnote)
(1) polyetheretherketone (150P manufactured by Victrex),
(2) Carbon precursor (volume resistivity 5 × 10 ⁷ Ω · cm, carbon content 91% by weight),
(3) PAN-based carbon fiber (Beast Fight HTA3000 manufactured by Toho Rayon Co., Ltd.),
(4) Regarding the value of the surface resistivity, for example, the notation 2E + 08 means 2 × 10 ⁸ .

<Discussion>
A molded product (Comparative Example 7) formed from a resin composition in which a PAN-based carbon fiber alone is blended with polyether ether ketone has a surface resistivity that is too low, and the surface potential of the glass substrate is sufficiently low. Is difficult. When the blending ratio of the PAN-based carbon fiber is decreased (Comparative Example 8), the static decay time is increased and the surface potential of the glass substrate is significantly increased.

  A molded article (Comparative Example 9) formed from a resin composition obtained by blending a large amount of a carbon precursor alone with polyether ether ketone has a small tensile elongation and is inferior in mechanical properties. If the blending ratio of the carbon precursor is reduced (Comparative Example 10), the tensile elongation can be improved, but the static decay time is increased, and the surface potential of the glass substrate is significantly increased.

  The substrate cassette of the present invention is useful as a cassette for various substrates such as glass substrates for liquid crystal displays, glass substrates for plasma displays, glass substrates for thermal heads, ceramic substrates for LSI packages, and ceramic substrates for hybrid ICs in the electronics packaging technology field. It is. The substrate cassette of the present invention can be used as a cassette for a large substrate having a structure provided with resin pins.

FIG. 1 is a front view showing an example of a substrate cassette. FIG. 2 is a perspective view showing an example of the substrate cassette. FIG. 3 is a perspective view showing an example of a grid-like tray-type substrate cassette. FIG. 4 is a front view showing another example of the substrate cassette.

Explanation of symbols

1: bottom side frame,
2: Top side frame,
3: Side plate,
4: Ribbed shelf
5: receiving frame,
A: substrate
31: A perimeter frame forming a rectangular skeleton,
32: Left peripheral frame,
33: rear peripheral frame,
34: Right frame,
35: Front perimeter frame,
36: pier (sub-frame),
37: Overhang member,
38: Resin pin,
41: substrate cassette
42: Side pillar,
43: Support rod,
44: Resin pin,
45: Receiving side pillar,
46: receiving support rod,
47: Resin pin,
48: Upper side frame,
49: Bottom side frame.

Claims (8)

In the substrate cassette, at least a member in contact with the substrate is 30 to 94% by weight of a synthetic resin, which is a blend containing 5 to 95% by weight of polyethersulfone and 95 to 5% by weight of polyphenylene sulfide , and 10 ² to 10 ^10. a resin member formed from a carbon precursor 5 to 40 wt%, and 10 resin composition containing 1 to 30 wt% conductive filler guide having a volume resistivity of less than ² having a volume resistivity of Omega · cm And (i) the resin member is a projecting resin pin that supports a substrate, and the resin pin has a grounded structure, and (ii) the surface resistivity of the resin member is: 10 ⁶ ~10 ¹⁴ Ω / □ by weight, and, (iii) that the static decay time until the potential of the resin member is lowered to 50V from 5000V is less than 0.01 seconds Cassette for the substrate to be characterized.   2. The cassette for substrates according to claim 1, wherein the tensile elongation of the resin member is 2.0% or more. The cassette for a substrate according to claim 1 or 2 , wherein the cassette is a lattice-like tray-shaped cassette having a basic structure including a peripheral frame forming a rectangular skeleton and a crosspiece spanned between the peripheral frames. The carbon precursor has a carbon content of 85 to 97 wt%, fully substrate cassette according to any one of claims 1 to 3 is a carbon material that is not carbonized. The cassette for substrates according to claim 4 , wherein the carbon precursor is particles having an average particle diameter of 0.1 µm to 1 mm. Conductive filler, a substrate cassette according to any one of claims 1 to 5 carbon fibers. The cassette for substrates according to claim 6 , wherein the carbon fibers are short fibers having an average diameter of 0.1 mm or less and an average fiber length of 50 µm to 80 mm. The substrate cassette according to any one of claims 1 to 7 , wherein the substrate cassette is a cassette for accommodating a glass substrate.

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