Sheet material, semiconductor chip holding member, and method for manufacturing semiconductor chip holding member

Abstract

The present invention provides a sheet material that achieves both semiconductor chip pickup performance and securing of a semiconductor chip holding force, a semiconductor chip holding member that achieves both semiconductor chip pickup performance and securing of a semiconductor chip holding force, and a method for manufacturing a semiconductor chip holding member that achieves both semiconductor chip pickup performance and securing of a semiconductor chip holding force. A sheet material according to the present invention is used for holding a semiconductor chip, and is characterized by: being composed of a material containing a thermoplastic elastomer; and having a tack force of 10 kPa or more when the thickness of the material constituting a portion for holding the semiconductor chip is set to 150 μm. Preferably, the material constituting the portion for holding the semiconductor chip is composed of a material containing the thermoplastic elastomer and polyolefin.

Description

Sheet material, semiconductor chip holding member, and method for manufacturing semiconductor chip holding member 【0001】 The present invention relates to a sheet material, a semiconductor chip holding member, and a method for manufacturing a semiconductor chip holding member. 【0002】 Conventionally, it is known to hold and handle individually separated semiconductor chips in a holding member such as a storage tray (see, for example, Patent Documents 1 and 2). 【0003】 The holding member disclosed in Patent Document 1 has an adhesive material having an adhesive surface to which a plurality of chips are adhered, and the plurality of chips are adhered at once by pressing the chips against the adhesive surface. 【0004】 Further, the holding member disclosed in Patent Document 2 includes a bottomed square cylindrical tray and a flexible adhesive film that removably holds microcomponents inside the tray, and the adhesive film is sucked by exhausting air from an exhaust hole provided at the bottom of the tray. 【0005】 When the holding force of the adhesive surface is too strong, it becomes difficult to pick up the chip, and in some cases, the chip may be damaged. 【0006】 On the other hand, when the holding force is too weak, the chip cannot be held continuously. For example, the chip may move during transportation and contact between adjacent chips may occur, resulting in damage to the chip. 【0007】 As described above, in the conventional sheet material for holding semiconductor chips and semiconductor chip holding members, it has been difficult to achieve both good pick-up performance of the semiconductor chips and ensuring the holding force of the semiconductor chips. 【0008】 Japanese Patent Application Laid-Open No. 2012-043914 Japanese Patent Application Laid-Open No. 2019-160934 【0009】The object of the present invention is to provide a sheet material that achieves both the pickability of semiconductor chips and the retention force of semiconductor chips, to provide a semiconductor chip holding member that achieves both the pickability of semiconductor chips and the retention force of semiconductor chips, and to provide a method for manufacturing a semiconductor chip holding member that achieves both the pickability of semiconductor chips and the retention force of semiconductor chips. 【0010】 These objectives are achieved by the following inventions (1) to (30): (1) A sheet material used for holding a semiconductor chip, comprising a material including a thermoplastic elastomer, characterized in that the tack force is 10 kPa or more when the material constituting the portion that holds the semiconductor chip has a thickness of 150 μm. 【0011】 (2) The sheet material described in (1) above, wherein the material constituting the portion that holds the semiconductor chip is composed of the thermoplastic elastomer and the polyolefin. 【0012】 (3) The sheet material described in (2) above, wherein the material constituting the portion that holds the semiconductor chip is composed of the thermoplastic elastomer and polypropylene. 【0013】 (4) The sheet material according to (2) or (3) above, in which the content of the thermoplastic elastomer in the material constituting the portion that holds the semiconductor chip is X1 [mass%] and the content of the polyolefin is X2 [mass%], the relationship 0.25 ≤ X1 / X2 is satisfied. 【0014】 (5) The sheet material according to any one of (1) to (4) above, wherein the thermoplastic elastomer comprises at least one selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, olefin copolymer, and hydrogenated styrene-based thermoplastic elastomer. 【0015】(6) A sheet material according to any one of (1) to (5) above, comprising a base material and a retaining layer provided on one side of the base material and composed of a material including at least the thermoplastic elastomer, for holding the semiconductor chip. 【0016】 (7) The sheet material according to (6) above, wherein the base material and the retaining layer contain the same type of material. 【0017】 (8) The sheet material according to (6) or (7) above, wherein the base material is made of a material containing polyolefin. 【0018】 (9) The sheet material described in (8) above, wherein the base material is made of a material containing polypropylene. 【0019】 (10) A sheet material according to any one of (6) to (9) above, where T1 [μm] is the thickness of the retaining layer and T2 [μm] is the thickness of the substrate, and the relationship 0.03 ≤ T1 / T2 ≤ 30 is satisfied. 【0020】 (11) The sheet material has a volume resistivity of 1.0 × 10 １５ A sheet material according to any of (1) to (10) above, having a density of (Ω・m) or less. 【0021】 (12) A semiconductor chip holding member used to hold a semiconductor chip, comprising a sheet material made of a material including a thermoplastic elastomer and a ring-shaped frame, wherein the sheet material is bonded to one side of the frame. 【0022】 (13) A semiconductor chip holding member used to hold a semiconductor chip, comprising a sheet material made of a material including a thermoplastic elastomer and a ring-shaped frame, wherein the sheet material is bonded to one side of the frame, and the tack force is 10 kPa or more when the material constituting the portion of the sheet material that holds the semiconductor chip is 150 μm thick. 【0023】(14) The semiconductor chip holding member according to (13) above, wherein the material constituting the portion that holds the semiconductor chip is composed of a material containing the thermoplastic elastomer and polyolefin. 【0024】 (15) The semiconductor chip holding member according to (14) above, wherein the material constituting the portion that holds the semiconductor chip is made of a material including the thermoplastic elastomer and polypropylene. 【0025】 (16) The semiconductor chip holding member according to (14) above, where X1 [mass%] is the content of the thermoplastic elastomer and X2 [mass%] is the content of the polyolefin in the material constituting the part that holds the semiconductor chip, and the relationship 0.25 ≤ X1 / X2 is satisfied. 【0026】 (17) The semiconductor chip holding member according to any one of (1) to (16) above, wherein the sheet material is bonded to one side of the frame via an adhesive layer. 【0027】 (18) The semiconductor chip holding member according to (17) above, wherein the adhesive layer includes an ultraviolet-curing adhesive. 【0028】 (19) The semiconductor chip holding member according to any one of (1) to (18) above, wherein the thermoplastic elastomer comprises at least one selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, olefin copolymer, and hydrogenated styrene-based thermoplastic elastomer. 【0029】 (20) The semiconductor chip holding member according to any one of (1) to (19) above, wherein the sheet material comprises a base material and a holding layer provided on one side of the base material and composed of a material including at least the thermoplastic elastomer, for holding the semiconductor chip. 【0030】 (21) The semiconductor chip holding member according to (20) above, wherein the substrate and the holding layer contain the same type of material. 【0031】(22) The semiconductor chip holding member according to (20) or (21) above, wherein the substrate is made of a material containing polyolefin. 【0032】 (23) The semiconductor chip holding member according to (22) above, wherein the base material is made of a material including polypropylene. 【0033】 (24) A semiconductor chip holding member according to any one of (20) to (23) above, where T1 [μm] is the thickness of the holding layer and T2 [μm] is the thickness of the substrate, and the relationship 0.03 ≤ T1 / T2 ≤ 30 is satisfied. 【0034】 (25) A method for manufacturing a semiconductor chip holding member used to hold a semiconductor chip, comprising the step of joining a sheet material made of a material containing a thermoplastic elastomer to one side of a ring-shaped frame. 【0035】 (26) A method for manufacturing a semiconductor chip holding member used to hold a semiconductor chip, comprising the step of joining a sheet material made of a material including a thermoplastic elastomer to one side of a ring-shaped frame, wherein the tack force of the material constituting the portion of the sheet material that holds the semiconductor chip is 10 kPa or more. 【0036】 (27) A method for manufacturing a semiconductor chip holding member according to (25) or (26), wherein the sheet material is joined to one side of the frame via an adhesive layer. 【0037】 (28) A method for manufacturing a semiconductor chip holding member according to (27), wherein the adhesive layer includes an ultraviolet-curing adhesive. 【0038】 (29) A method for manufacturing a semiconductor chip holding member according to (27) or (28), comprising the steps of: applying an adhesive in a ring shape to one side of the sheet material to form the adhesive layer; and joining the sheet material on which the adhesive layer is formed and the frame via the adhesive layer. 【0039】(30) A step of applying an adhesive to one surface side of the frame to form the adhesive layer; and a step of joining the frame having the adhesive layer formed thereon and the sheet material through the adhesive layer. The method for manufacturing a semiconductor chip holding member according to any one of (27) to (29) above. 【0040】 According to the present invention, it is possible to provide a sheet material that achieves both good pick-up property of a semiconductor chip and ensuring the holding force of the semiconductor chip, a semiconductor chip holding member that achieves both good pick-up property of a semiconductor chip and ensuring the holding force of the semiconductor chip, and a method for manufacturing a semiconductor chip holding member that achieves both good pick-up property of a semiconductor chip and ensuring the holding force of the semiconductor chip. 【0041】 FIG. 1 is a cross-sectional view showing one configuration example of the sheet material of the present invention. FIG. 2 is a cross-sectional view showing another configuration example of the sheet material of the present invention. FIG. 3 is a view showing one configuration example of the semiconductor chip holding member of the present invention, where (a) is a plan view and (b) is a cross-sectional view. FIG. 4 is a cross-sectional view showing an example of the manufacturing method of the semiconductor chip holding member of the present invention. FIG. 5 is a cross-sectional view showing an example of a method for forming an adhesive layer on one surface side of the sheet material. FIG. 6 is a cross-sectional view showing another example of the manufacturing method of the semiconductor chip holding member of the present invention. 【0042】 Hereinafter, preferred embodiments of the present invention will be described in detail. [1] Sheet Material First, the sheet material of the present invention will be described. 【0043】 FIG. 1 is a cross-sectional view showing one configuration example of the sheet material of the present invention. FIG. 2 is a cross-sectional view showing another configuration example of the sheet material of the present invention. 【0044】 The sheet material 1 of the present invention is a sheet material used for holding a semiconductor chip, is composed of a material containing a thermoplastic elastomer, and has a tack force of 10 kPa or more when the thickness of the material constituting the portion 1a for holding the semiconductor chip is 150 μm. 【0045】 Thereby, the sheet material 1 of the present invention can preferably achieve both good pick-up property of the semiconductor chip and ensuring the holding force of the semiconductor chip. 【0046】 More specifically, when the material composed of a material containing a thermoplastic elastomer and forming the portion 1a that holds the semiconductor chip has a thickness of 150 μm, the tack force is 10 kPa or more. As a result, the portion 1a that holds the semiconductor chip has appropriate tackiness, and it becomes possible to achieve both the pick-up property of the semiconductor chip and the securing of the holding force of the semiconductor chip. 【0047】 In other words, in the sheet material 1, the portion 1a that holds the semiconductor chip exhibits a suitable holding force with respect to the semiconductor chip, and at the time of pick-up, it can exhibit tackiness such that suitable peelability is exhibited between the sheet material 1 and the semiconductor chip. 【0048】 Also, a sheet material manufactured in a long shape is generally conveyed and stored in a state of being wound into a roll. However, even in such a case where the sheet material is wound into a roll, in the sheet material 1 of the present invention, it is possible to suitably prevent the sticking of the sheet materials 1 to each other when the sheet material 1 is wound, and it can be suitably pulled out during use (for example, during the manufacture of the semiconductor chip holding member 10). 【0049】 In the present invention, "elastomer" is a general term for polymer materials that have viscoelasticity and small intermolecular interactions, and thus have a small Young's modulus and a large fracture strain compared to other materials. In particular, "thermoplastic elastomer" refers to a polymer material that softens when heated and returns to a rubbery state when cooled. 【0050】 Also, in this specification, "tack" refers to the stickiness of an adhesive surface. Also, "tack force" refers to how instantaneously a material adheres when in contact, or the resistance force when pulled away immediately after contact. 【0051】 And in this specification, the tack force of the material constituting the portion 1a that holds the semiconductor chip is a value measured by a method conforming to JIS Z0237:2022. 【0052】Specifically, the test is performed using a tacking test machine TAC-1000 manufactured by Resca, Inc., with a Constant Load function that pushes the probe in to a set pressure value and maintains that pressure value until a set time has elapsed. A SUS probe with a diameter of 5.0 mm is brought into contact with the upper side of a test specimen formed from the material into a 150 μm thick sheet. The speed at which the probe is brought into contact with the test specimen is set to 1 mm / sec, the contact load to 200 gf, the contact time to 1 second, and the probe temperature and plate temperature to 25°C. After that, the probe is peeled upward at a peeling speed of 10 mm / sec, and the force required to peel it off is measured as the "tack force". 【0053】 Furthermore, in this specification, the thickness "150 μm" refers to the thickness of a test specimen prepared when measuring the tack force of the material constituting the semiconductor chip holding portion 1a, and not to the thickness of the "semiconductor chip holding portion 1a" that the sheet material 1 possesses. 【0054】 The excellent effects of the present invention are obtained when the sheet material 1 has the above-described configuration, and cannot be obtained when it does not have the above-described configuration. 【0055】 For example, if the part 1a that holds the semiconductor chip does not contain a thermoplastic elastomer, it is not possible to set the tack force of the material constituting the part 1a that holds the semiconductor chip to an appropriate level. Specifically, it becomes difficult to set the tack force of the material constituting the part 1a that holds the semiconductor chip to a range of 10 kPa or more when the thickness of the material is 150 μm. 【0056】 Furthermore, for example, if the tack force of the material constituting the part 1a that holds the semiconductor chip is less than 10 kPa, the holding force of the semiconductor chip will be insufficient. 【0057】In the sheet material 1 of the present invention, when the material constituting the portion 1a that holds the semiconductor chip has a thickness of 150 μm, the tack force should be 10 kPa or more, but preferably 20 kPa or more, and more preferably 30 kPa or more. This makes the effects of the present invention described above even more pronounced. 【0058】 Furthermore, in the sheet material 1 of the present invention, when the material constituting the portion 1a that holds the semiconductor chip has a thickness of 150 μm, the upper limit of the tack force is not particularly limited, but is preferably 125 kPa or less, more preferably 100 kPa or less, and even more preferably 75 kPa or less. 【0059】 This makes the effects of the present invention described above even more pronounced. In particular, the pickup properties of semiconductor chips can be made more favorable. Furthermore, the sheet material 1 can be suitably formed into a film, and adhesion between the sheet materials 1 when the sheet material 1 is wound into a roll can be more effectively suppressed. 【0060】 The sheet material of the present invention may have any portion made of a material containing a thermoplastic elastomer, and may consist only of a retaining layer 3 made of a material containing at least a thermoplastic elastomer, as shown in the sheet material 1 in Figure 1. However, the sheet material 1 shown in Figure 2 has a base material 2 and a retaining layer 3 provided on one side of the base material 2, which is made of a material containing at least a thermoplastic elastomer and holds a semiconductor chip. 【0061】 In the sheet material 1 shown in Figures 1 and 2, the surface of the retaining layer 3 becomes the portion 1a that holds the semiconductor chip. 【0062】By providing a base material 2 that supports the retaining layer 3, in addition to a portion (retaining layer 3) made of a material containing at least a thermoplastic elastomer, it is possible to more effectively prevent the sheet materials 1 from sticking together when, for example, the sheet material 1 is wound into a roll. Furthermore, since the material constituting the base material 2, in other words, the resin material described later, is generally less expensive than the thermoplastic elastomer constituting the retaining layer 3, it also contributes to reducing the overall cost of the sheet material 1. 【0063】 [1-1] Base material The base material 2 is in the form of a sheet and has the function of supporting the retaining layer 3. The base material 2 is usually composed of a material that mainly contains a resin material. 【0064】 [1-1-1] The resin material constituting the resin material substrate 2 is not particularly limited as long as it has good compatibility with the thermoplastic elastomer, but examples of thermoplastic resins include polyolefin resins, polyvinyl chloride resins, polystyrene resins, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polyester resins (ester polymers) such as polyester thermoplastic elastomers, polyurethane, polyimide, polyamide, polyether ketones such as polyether ether ketone, polyether sulfone, fluororesin, silicone resin, cellulose resin, acrylic resin, polyvinyl isoprene, polycarbonate (carbonate polymer), etc., and one or more selected from these can be used in combination. 【0065】 In particular, it is preferable that the base material 2 is composed of a material containing a polyolefin resin. This makes the effects described above even more pronounced. 【0066】The polyolefin resin is not particularly limited, but examples include polyethylene resins such as polypropylene, linear low-density polyethylene, low-density polyethylene, and ultra-low-density polyethylene; polyethylene copolymers such as ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-methacrylate copolymer (EMAA), and ionomers such as ethylene-based ionomers as zinc ion crosslinks, sodium ion crosslinks, or potassium ion crosslinks. One or more of these can be selected and used in combination, and it is preferable to include polypropylene. This can further enhance the effects described above. 【0067】 [1-1-2] Other components The base material 2 may contain components other than those described above (hereinafter referred to as "other components" in this section). 【0068】 Examples of such components include conductive materials, softeners such as mineral oil, fillers such as calcium carbonate, silica, talc, mica, and clay, antioxidants, light stabilizers, lubricants, dispersants, neutralizing agents, and colorants. One or more of these can be selected and used in combination. 【0069】 Of these, by including a conductive material in the base material 2, the conductive material can function as an antistatic agent, effectively suppressing or preventing the generation of static electricity in the semiconductor element during handling and pickup. Therefore, it is possible to effectively suppress or prevent damage to the semiconductor element caused by the discharge of static electricity, which would result in a decrease in the characteristics of the semiconductor element. 【0070】 The conductive material is not particularly limited as long as it is conductive, but examples include surfactants, permanent antistatic polymers (IDPs), metal materials, metal oxide materials, and carbon-based materials, and one or more selected from these can be used in combination. 【0071】However, the content of other components in the base material 2 is preferably 30.0% by mass or less, more preferably 25.0% by mass or less, and even more preferably 20.0% by mass or less. 【0072】 [1-1-3] Other conditions: In sheet material 1, even if the materials constituting the retaining layer 3 are the same, by changing the thickness of the base material 2, the overall heat resistance, dimensional stability, prevention of roll twisting during film formation, and cost reduction of the sheet material 1 can be improved. 【0073】 The thickness of the substrate 2 is preferably 5 μm or more and 300 μm or less, more preferably 10 μm or more and 250 μm or less, and even more preferably 15 μm or more and 200 μm or less. 【0074】 This allows for a more optimal tack force for the sheet material 1 as a whole. Furthermore, it enables the base material 2 to function more reliably, allowing for more efficient handling of semiconductor chips. Additionally, it allows for more precise pickup of semiconductor chips. 【0075】 The base material 2 may be composed of a laminate (multilayer) made up of multiple layers of different materials stacked together. 【0076】 [1-2] Retaining layer The retaining layer 3 is made of a material that includes at least a thermoplastic elastomer and constitutes a portion 1a in the sheet material 1 that holds the semiconductor chip. 【0077】 In the following explanation, the material constituting the part 1a that holds the semiconductor chip will be described as the material constituting the holding layer 3. 【0078】 The retaining layer 3 (the part that holds the semiconductor chip) is made of a material containing at least a thermoplastic elastomer, but it is preferable that it is made of a material containing both a thermoplastic elastomer and a polyolefin. This makes it possible to more favorably achieve the tack force conditions described above. 【0079】[1-2-1] Thermoplastic Elastomers Examples of thermoplastic elastomers include styrene-based thermoplastic elastomers, ethylene-based thermoplastic elastomers, olefin-based thermoplastic elastomers such as polypropylene-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, olefin-based copolymers, etc. One or more selected from these can be used in combination, but it is preferable that at least one selected from the group consisting of styrene-based thermoplastic elastomers, ethylene-based thermoplastic elastomers, and olefin-based copolymers be used. This makes the above-mentioned effects more pronounced. 【0080】 Examples of styrene-based thermoplastic elastomers (TPS) include hydrogenated styrene-based thermoplastic elastomers such as partially hydrogenated styrene-butadiene-styrene block copolymer (SBS), fully hydrogenated styrene-butadiene-styrene block copolymer (SBS), styrene-butadiene-styrene block copolymer (SBS), styrene-isobutylene-styrene block copolymer (SIBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene-styrene (SIS), and styrene-ethylene-propylene-butylene block copolymer (SEPS). 【0081】 Examples of ethylene-based thermoplastic elastomers include ethylene-vinyl acetate copolymer (EVA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl acrylate copolymer (EAA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), and ethylene-butyl acrylate copolymer (EBA). 【0082】 Examples of olefin copolymers include ethylene copolymers, propylene copolymers, and butene copolymers, and more specifically, ethylene-butene copolymers and propylene-butene copolymers. 【0083】 The retaining layer 3 preferably contains at least one thermoplastic elastomer selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, olefin copolymer, and hydrogenated styrene-based thermoplastic elastomer, among the compounds described above. This can further enhance the effects described above. 【0084】 The content of thermoplastic elastomer in the retaining layer 3 is preferably 20% by mass or more and 100% by mass or less, more preferably 25% by mass or more and 90% by mass or less, and even more preferably 30% by mass or more and 80% by mass or less. This makes the above-mentioned effects more pronounced. 【0085】 [1-2-2] The polyolefin constituting the polyolefin retaining layer 3 is not particularly limited, but examples include polyethylene resins such as polypropylene, linear low-density polyethylene, low-density polyethylene, and ultra-low-density polyethylene, polyethylene copolymers such as ethylene-methacrylate copolymers (EMAA), and ionomers such as ethylene-based ionomers as zinc ion crosslinks, sodium ion crosslinks, or potassium ion crosslinks. One or more selected from these can be used in combination, but polypropylene is preferred. 【0086】 In other words, it is preferable that the material constituting the retaining layer 3 is composed of a material containing thermoplastic elastomer and polypropylene. This can further enhance the effects described above. 【0087】 The polyolefin content in the retaining layer 3 is preferably 0% by mass or more and 90% by mass or less, more preferably 10% by mass or more and 80% by mass or less, and even more preferably 20% by mass or more and 70% by mass or less. This makes the above-mentioned effects more pronounced. 【0088】By adjusting the content of thermoplastic elastomer and polyolefin in the retaining layer 3, the tack force of the semiconductor chip-holding portion 1a can be suitably controlled. 【0089】 In the retaining layer 3 (the part that holds the semiconductor chip), when the content of thermoplastic elastomer is X1 [mass%] and the content of polyolefin is X2 [mass%], it is preferable that the relationship 0.25 ≤ X1 / X2 is satisfied, more preferably that 0.5 ≤ X1 / X2 is satisfied, and even more preferably that 0.75 ≤ X1 / X2 is satisfied. This makes the above-mentioned effects even more pronounced. 【0090】 In the sheet material 1, it is preferable that the base material 2 and the retaining layer 3 contain the same type of material. More specifically, it is more preferable that the base material 2 is composed of a material containing polyolefin and the retaining layer 3 is composed of a material containing thermoplastic elastomer and polyolefin, and even more preferable that the base material 2 is composed of a material containing polypropylene and the retaining layer 3 is composed of a material containing thermoplastic elastomer and polypropylene. 【0091】 This results in better adhesion between the base material 2 and the retaining layer 3, and also allows for better overall tack strength of the sheet material 1. 【0092】 In this specification, "same type" means any material having a common repeating chemical structure (unit structure). For example, if both the substrate 2 and the retaining layer 3 are composed of polypropylene, they are considered to be the same type of material, even if their weight-average molecular weight, glass transition temperature, softening point, and other conditions differ. 【0093】 [1-2-3] The other component retaining layer 3 may contain components other than those described above (hereinafter referred to as "other components" in this section). 【0094】Examples of such components include conductive materials, tackifiers, anti-aging agents, tack modifiers, fillers, colorants, flame retardants, softeners, antioxidants, and surfactants. One or more of these can be selected and used in combination. 【0095】 Of these, the conductive material is not particularly limited as long as it has conductivity, but a material similar to the conductive material described above for the base material 2 can be suitably used. 【0096】 The inclusion of such conductive materials allows them to function as antistatic agents, effectively suppressing or preventing static electricity from being generated in semiconductor devices during handling and pickup. Therefore, damage to semiconductor devices caused by static discharge, resulting in a decrease in the properties of the semiconductor devices, can be effectively suppressed or prevented. 【0097】 However, the content of other components in the retaining layer 3 is preferably 30.0% by mass or less, more preferably 25.0% by mass or less, and even more preferably 20.0% by mass or less. 【0098】 [1-2-4] Other conditions: In sheet material 1, even if the material constituting the retaining layer 3 is the same, the tack force of the sheet material 1 as a whole can be adjusted by changing the thickness of the retaining layer 3. 【0099】 In the sheet material 1, the thickness of the retaining layer 3 is preferably 1 μm or more and 300 μm or less, more preferably 2 μm or more and 250 μm or less, and even more preferably 3 μm or more and 200 μm or less. This makes it possible to make the overall tack strength of the sheet material 1 more favorable. 【0100】 Furthermore, even if the materials constituting the base material 2 and the retaining layer 3 are the same in the sheet material 1, the overall tack force of the sheet material 1 can be adjusted by changing the ratio of the thickness of the retaining layer 3 to the thickness of the base material 2. 【0101】In the sheet material 1, when the thickness of the retaining layer 3 is T1 [μm] and the thickness of the base material 2 is T2 [μm], it is preferable that the relationship 0.03 ≤ T1 / T2 ≤ 30 is satisfied, more preferably that the relationship 0.04 ≤ T1 / T2 ≤ 25 is satisfied, and even more preferably that the relationship 0.05 ≤ T1 / T2 ≤ 20 is satisfied. 【0102】 This makes it possible to further optimize the tack strength of the sheet material 1 as a whole. 【0103】 The retaining layer 3 may also be composed of a laminate (multilayer) made up of multiple layers of different materials stacked together. 【0104】 [1-3] Other conditions: The volume resistivity of sheet material 1 is 1.0 × 10 １５ It is preferable that it is less than or equal to (Ω·m), and 1.0 × 10 １４ It is more preferable that it is less than or equal to (Ω·m), and 1.0 × 10 １３ It is even more preferable that it is less than or equal to (Ω・m). 【0105】 This effectively suppresses or prevents the generation of static electricity in semiconductor elements during handling and pickup. Consequently, it effectively suppresses or prevents damage to semiconductor elements caused by static discharge, which would result in a decrease in the characteristics of the semiconductor elements. 【0106】 [2] Method for manufacturing sheet material Next, the method for manufacturing sheet material as described above will be explained. 【0107】 A method for manufacturing a sheet material includes at least a step of forming a portion made of a material containing a thermoplastic elastomer. More specifically, for example, it includes a step of forming a retaining layer 3 made of a material containing at least a thermoplastic elastomer on one side of a substrate 2. 【0108】 The process of forming the retaining layer 3 includes, for example, a retaining layer forming composition preparation step of preparing a retaining layer forming composition containing the materials that constitute the retaining layer 3, and a composition application step of forming the retaining layer 3 by applying the retaining layer forming composition to one side of the substrate 2. 【0109】Specifically, for example, in the step of preparing the composition for forming the retaining layer, the composition for forming the retaining layer is prepared by mixing the materials constituting the retaining layer 3, for example, a thermoplastic elastomer and a polyolefin. 【0110】 Then, in the step of applying the retaining layer-forming composition, the retaining layer-forming composition can be applied to one side of the substrate 2 using known methods such as extrusion lamination or dry lamination to form the retaining layer 3. 【0111】 Prior to forming the retaining layer 3, a surface treatment such as corona treatment may be applied to the surface of the substrate 2 to improve adhesion with the retaining layer 3. Alternatively, the film may be formed by co-extruding the substrate forming composition and the retaining layer forming composition. 【0112】 [3] Semiconductor Chip Holding Member Next, the semiconductor chip holding member of the present invention will be described. Figure 3 is a diagram showing one example of the configuration of the semiconductor chip holding member of the present invention, where (a) is a plan view and (b) is a cross-sectional view. 【0113】 In the semiconductor chip holding member 10 shown in Figure 1, the sheet material 1' comprises a base material 2 and a holding layer 3' provided on one side of the base material 2, which is made of a material containing at least a thermoplastic elastomer and holds the semiconductor chip. However, the semiconductor chip holding member 10 of the present invention may also comprise a sheet material 1' which is made of a material containing at least a thermoplastic elastomer, has a holding layer 3' for holding the semiconductor chip, and does not have a base material 2 (see Figure 2). 【0114】 The semiconductor chip holding member 10 is used to hold a semiconductor chip. The semiconductor chip holding member 10 has a sheet material 1' made of a material including a thermoplastic elastomer and a ring-shaped frame 11, with the sheet material 1' being joined to one side of the frame 11. 【0115】 With this configuration, the semiconductor chip holding member 10 can achieve both high pickability for semiconductor chips and sufficient holding force for semiconductor chips. 【0116】In particular, if the tack force of the material constituting the portion 1a of the sheet material 1' that holds the semiconductor chip is 150 μm thick is 10 kPa or more, the semiconductor chip holding member 10 will have more appropriate tack properties, and will be able to more favorably achieve both semiconductor chip pickability and securing of semiconductor chip holding force. 【0117】 [3-1] Sheet material The sheet material 1' is made of a material including a thermoplastic elastomer. By providing the semiconductor chip holding member 10 with a sheet material 1' made of such a material, it is possible to achieve both good semiconductor chip pickability and secure semiconductor chip holding force. 【0118】 The sheet material 1' may be composed of a material containing a thermoplastic elastomer, but it is preferable that the tack force is 10 kPa or more when the material constituting the semiconductor chip holding portion 1a has a thickness of 150 μm. In other words, it is preferable that the sheet material 1' is the aforementioned sheet material 1. To put it another way, it is preferable that the holding layer 3' is the aforementioned holding layer 3. 【0119】 As a result, the portion 1a that holds the semiconductor chip has more suitable tackiness, and it is possible to more favorably achieve both the pickability of the semiconductor chip and the securing of the semiconductor chip's holding force. 【0120】 In other words, in the sheet material 1', the portion 1a that holds the semiconductor chip can exhibit a more suitable holding force with respect to the semiconductor chip, and at the time of pickup, it can exhibit a degree of tackiness that allows for more suitable peelability between the sheet material 1' and the semiconductor chip. 【0121】 The sheet material 1' is not particularly limited as long as it is composed of a material containing a thermoplastic elastomer, but it is preferable that it satisfies the favorable conditions described in [1] above. This will result in the effects described above. 【0122】 [3-2] The frame semiconductor chip holding member 10 has a ring-shaped frame 11, and a sheet material 1' is bonded to one side of this frame 11. 【0123】As the ring-shaped frame 11, for example, one used in dicing sheets can be used. 【0124】 As shown in Figure 3, the frame 11 is a frame having an opening 12 in the center, and is a molded body made of, for example, metal such as stainless steel or plastic. 【0125】 The thickness of the frame 11 is not particularly limited, but can be 1.0 mm or more and 1.5 mm or less. 【0126】 The external shape of the frame 11 is not limited to a circular shape, but may also be polygonal. Similarly, the shape of the opening 12 is not limited to a circular shape. 【0127】 Furthermore, the frame 11 may have notches or the like (not shown) formed therein for aligning the orientation and position of semiconductor chips during manufacturing and inspection. 【0128】 The sheet material 1' and the frame 11 can be joined by placing the frame 11 on the surface that constitutes the portion 1a of the sheet material 1' that holds the semiconductor chip, in other words, on the tacky surface and pressing it down. However, in the semiconductor chip holding member 10 shown in Figure 3, the sheet material 1' is joined to one side of the frame 11 via an adhesive layer 13. This allows for a stronger bond between the sheet material 1' and the frame 11. 【0129】 The shape of the sheet material 1' is not particularly limited as long as it can cover the opening 12 of the frame 11, but it is preferably circular. 【0130】 [3-3] Adhesive layer The adhesive layer 13 serves to join the sheet material 1' and the frame 11. In this specification, the term "adhesive layer" is a concept that includes both an adhesive layer and an adhesive layer. 【0131】 The adhesive that constitutes the adhesive layer 13 is not particularly limited, but it is preferable that the adhesive layer 13 includes an ultraviolet-curing adhesive. 【0132】UV-curing adhesives have sufficient adhesive strength before the curing reaction by UV light, but their adhesive strength decreases after the curing reaction. 【0133】 As a result, after use, by irradiating the adhesive layer 13 of the semiconductor chip holding member 10 with ultraviolet light, the ultraviolet-curable adhesive layer 13 is cured, reducing its adhesive strength, which allows for a suitable separation of the sheet material 1' and the frame 11. 【0134】 The following explanation will primarily focus on the case where the adhesive layer 13 is an adhesive layer containing an ultraviolet-curing adhesive, but it is not limited to this case. 【0135】 Such an adhesive layer is composed of a resin composition containing either (1) an adhesive base resin or (2) a curable resin for curing the adhesive layer, with the latter being the main material. 【0136】 The following describes in detail each component contained in this resin composition. 【0137】 [3-3-1] Base resin The base resin is tacky and is included in the resin composition to impart tackiness to the sheet material 1' and frame 11 to the adhesive layer. 【0138】 Examples of such base resins include acrylic resins (adhesives), silicone resins (adhesives), polyester resins (adhesives), polyvinyl acetate resins (adhesives), polyvinyl ether resins (adhesives), styrene elastomer resins (adhesives), polyisoprene resins (adhesives), polyisobutylene resins (adhesives), and urethane resins (adhesives), but among these, acrylic resins are preferred. 【0139】 Acrylic resins are preferred as base resins because they have excellent heat resistance and are relatively easy and inexpensive to obtain. 【0140】 Acrylic resins refer to polymers (homopolymers or copolymers) whose base polymer is a polymer in which (meth)acrylic acid ester is the main monomer component. 【0141】 The (meth)acrylic acid ester is not particularly limited, but alkyl (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and octyl (meth)acrylate are preferred. 【0142】 Alkyl (meth)acrylates are particularly excellent in heat resistance and are relatively easy and inexpensive to obtain. 【0143】 Acrylic resins preferably have functional groups (reactive functional groups) that are reactive to crosslinking agents and photopolymerization initiators, such as hydroxyl groups and carboxyl groups (especially hydroxyl groups). 【0144】 As a result, the crosslinking agent and photopolymerization initiator are linked to the acrylic resin, which is the polymer component, and the leakage of these crosslinking agents and photopolymerization initiators from the adhesive layer can be effectively suppressed or prevented. Consequently, irradiation of the adhesive layer with ultraviolet light reliably reduces the adhesiveness of the adhesive layer to the frame 11. 【0145】 [3-3-2] Curable resins Curable resins are those that have the property of curing by irradiation with ultraviolet light, for example. Through this curing, the base resin is incorporated into the cross-linked structure of the curable resin, and the adhesive strength of the adhesive layer decreases. 【0146】 As such a curable resin, for example, a low molecular weight compound having at least two polymerizable carbon-carbon double bonds as functional groups that can be three-dimensionally crosslinked by ultraviolet irradiation can be used. 【0147】 Such curable resins are not particularly limited, but it is preferable that they contain at least one of the following: an ester of (meth)acrylic acid and a polyhydric alcohol, a urethane acrylate, and a bisphenol A-based epoxy acrylate. This allows the curable resin to be cured more reliably by ultraviolet irradiation. 【0148】The curable resin is preferably blended in an amount of 30 to 200 parts by weight, and more preferably in an amount of 50 to 140 parts by weight, per 100 parts by weight of the base resin. 【0149】 This ensures that the functions exhibited by adding the curable resin and the base resin to the resin composition are reliably exerted by both the curable resin and the base resin. 【0150】 [3-3-3] The adhesive layer of the photopolymerization initiator loses its tackiness to the frame 11 when irradiated with ultraviolet light. It is preferable that the resin composition constituting the adhesive layer contains a photopolymerization initiator to facilitate the initiation of polymerization of the curable resin. 【0151】 Examples of photopolymerization initiators include 2-2-dimethoxy-1,2-diphenylethane-1-one, benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, and β-chloranthraquinone. One or more selected from these can be used in combination. 【0152】 The amount of photopolymerization initiator in the resin composition is preferably 0.1 parts by weight or more and 50 parts by weight or less, and more preferably 0.5 parts by weight or more and 10 parts by weight or less, per 100 parts by weight of the base resin. 【0153】 [3-3-4] Crosslinking agent The resin composition constituting the adhesive layer may contain a crosslinking agent. The inclusion of a crosslinking agent allows the adhesive layer to be adjusted to have a more suitable hardness. 【0154】Examples of crosslinking agents include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, urea resin-based crosslinking agents, methylol-based crosslinking agents, chelate-based crosslinking agents, aziridine-based crosslinking agents, melamine-based crosslinking agents, polyvalent metal chelate-based crosslinking agents, acid anhydride-based crosslinking agents, polyamine-based crosslinking agents, and carboxyl group-containing polymer-based crosslinking agents. One or more selected from these can be used in combination. Among these, isocyanate-based crosslinking agents are preferred. 【0155】 Examples of isocyanate-based crosslinking agents include polyisocyanate compounds of polyvalent isocyanates, trimers of polyisocyanate compounds, trimers of terminal isocyanate compounds obtained by reacting polyisocyanate compounds with polyol compounds, or blocked polyisocyanate compounds obtained by encapsulating terminal isocyanate urethane prepolymers with phenol, oximes, etc. One or more selected from these can be used in combination. 【0156】 The amount of crosslinking agent in the resin composition is preferably 0.01 parts by weight or more and 30 parts by weight or less, and more preferably 0.1 parts by weight or more and 20 parts by weight or less, per 100 parts by weight of the base resin. 【0157】 [3-3-5] Plasticizer The resin composition constituting the adhesive layer may contain a plasticizer. The inclusion of a plasticizer can more effectively improve the flexibility of the adhesive layer, which is susceptible to reduced adhesive strength due to ultraviolet irradiation. 【0158】 Examples of such plasticizers include phthalate ester plasticizers, aliphatic dibasic acid ester plasticizers, aromatic carboxylic acid ester plasticizers, trimellitic acid ester plasticizers, adipic acid ester plasticizers, and one or more of these can be used in combination. 【0159】 The plasticizer content in the resin composition is preferably 0.1 parts by weight or more and 5.0 parts by weight or less, and more preferably 0.5 parts by weight or more and 3.0 parts by weight or less, per 100 parts by weight of the base resin. This allows for a more favorable improvement in the flexibility of the adhesive layer. 【0160】 [3-3-6] Other components Furthermore, the resin composition constituting the adhesive layer may also contain components other than those described above (hereinafter referred to as "other components" in this section). 【0161】 Examples of such components include conductive materials, tackifiers, anti-aging agents, tack modifiers, fillers, colorants, flame retardants, softeners, antioxidants, and surfactants. One or more of these can be selected and used in combination. 【0162】 The conductive material is not particularly limited as long as it is conductive, but examples include surfactants, permanent antistatic polymers (IDPs), metal materials, metal oxide materials, and carbon-based materials, and one or more selected from these can be used in combination. 【0163】 The inclusion of such conductive materials allows the conductive materials to function as antistatic agents, thereby more effectively suppressing or preventing the generation of static electricity on semiconductor chips during handling and pickup. 【0164】 The tackifier is not particularly limited, but examples include rosin resin, terpene resin, coumarone resin, phenol resin, aliphatic petroleum resin, aromatic petroleum resin, aliphatic aromatic copolymer petroleum resin, etc., and one or more selected from these can be used in combination. 【0165】 [3-3-7] Other conditions The thickness of the adhesive layer 13 is not particularly limited, but is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 30 μm or less. 【0166】 This allows for a stronger bond between the sheet material 1' and the frame 11, and also enables a more reliable and preferable separation of the sheet material 1' and the frame 11 after use of the semiconductor chip holding member 10, while preventing adhesive residue. 【0167】Such a semiconductor chip holding member 10 is used, for example, in the manufacturing of semiconductor packages to hold semiconductor chips during inspection and other processing or transportation. 【0168】 In particular, in the manufacturing of semiconductor packages, by attaching a semiconductor chip to a sheet material 1' bonded to a frame 11, it can be suitably used as a holding member for holding a semiconductor chip during the lamination process of the package. 【0169】 In particular, the semiconductor chip holding member 10 exhibits a suitable holding force for the semiconductor chip and, during pickup, possesses sufficient tackiness to exhibit suitable peelability between the holding layer 3' and the semiconductor chip. 【0170】 After use of the semiconductor chip holding member 10, the adhesive layer 13 is cured by irradiating it with ultraviolet light, thereby reducing the adhesive adhesion of the adhesive layer 13 to the frame 11. 【0171】 This causes delamination to occur between the adhesive layer 13 and the frame 11, allowing the sheet material 1' and the frame 11 to be suitably separated. 【0172】 The peeled frame 11 can be reused, for example. On the other hand, the peeled sheet material 1' can be discarded, for example. 【0173】 [4] Method for Manufacturing a Semiconductor Chip Holding Member Next, the method for manufacturing a semiconductor chip holding member of the present invention will be described. Figure 4 is a cross-sectional view showing an example of the method for manufacturing a semiconductor chip holding member of the present invention. Figure 5 is a cross-sectional view showing an example of a method for forming an adhesive layer on one side of a sheet material. Figure 6 is a cross-sectional view showing another example of the method for manufacturing a semiconductor chip holding member of the present invention. 【0174】 The present invention relates to a method for manufacturing a semiconductor chip holding member, which is used to hold a semiconductor chip, and comprises a step (joining step) of joining a sheet material 1' made of a material containing a thermoplastic elastomer to one side of a ring-shaped frame 11. 【0175】 This makes it possible to suitably manufacture a semiconductor chip holding member 10 that achieves both high pickability for semiconductor chips and sufficient retention force for semiconductor chips. 【0176】 In the method for manufacturing a semiconductor chip holding member of the present invention, it is preferable that the tack force of the material constituting the portion of the sheet material 1' that holds the semiconductor chip is 10 kPa or more. In other words, the method for manufacturing a semiconductor chip holding member of the present invention is a method for manufacturing a semiconductor chip holding member 10 used to hold a semiconductor chip, comprising a step (joining step) of joining a sheet material 1' made of a material containing a thermoplastic elastomer to one side of a ring-shaped frame 11, and it is preferable that the tack force of the material constituting the portion 1a of the sheet material 1' that holds the semiconductor chip is 10 kPa or more. 【0177】 As a result, the portion 1a that holds the semiconductor chip has more suitable tackiness, and it is possible to more favorably achieve both the pickability of the semiconductor chip and the securing of the semiconductor chip's holding force. 【0178】 The sheet material 1' is not particularly limited as long as it is composed of a material containing a thermoplastic elastomer, but it is preferable that it satisfies the favorable conditions described in [1] above. This will result in the effects described above. 【0179】 [4-1] Bonding process In the bonding process, a sheet material 1' made of a material containing a thermoplastic elastomer is bonded to one side of the ring-shaped frame 11. 【0180】 The sheet material 1' and the frame 11 may be joined by any method, but it is preferable to join the sheet material 1' to one side of the frame 11 via an adhesive layer 13. This allows for a stronger bond between the sheet material 1' and the frame 11. The adhesive layer 13 preferably contains an ultraviolet-curing adhesive. 【0181】 UV-curing adhesives have sufficient adhesive strength before the curing reaction by UV light, but their adhesive strength decreases after the curing reaction. 【0182】This makes it possible to manufacture a semiconductor chip holding member 10 in which, after use, the adhesive layer 13 can be cured by irradiating it with ultraviolet light, thereby reducing the adhesive strength and allowing the sheet material 1' and the frame 11 to be suitably separated. The separated frame 11 can be suitably reused, for example, in the manufacture of a new semiconductor chip holding member 10. 【0183】 As an ultraviolet-curing adhesive, an ultraviolet-curing adhesive as described in [3-3] above can be used. This will provide the effects described above. 【0184】 The adhesive layer 13 can be formed, for example, by dissolving a resin composition, which is a constituent material of the adhesive layer 13, in a solvent to create a varnish-like liquid material, applying it to one side of the sheet material 1' or one side of the frame 11, and then allowing the solvent to evaporate. 【0185】 Examples of solvents include methyl ethyl ketone, acetone, toluene, ethyl acetate, and dimethylformaldehyde, and one or more of these can be selected and used in combination. 【0186】 Furthermore, the liquid material can be applied to the sheet material 1' or frame 11 using methods such as die coating, curtain die coating, gravure coating, comma coating, bar coating, and lip coating. 【0187】 The joining process includes, for example, the step of applying adhesive in a ring shape to one side of the sheet material 1' to form an adhesive layer 13, as shown in Figure 4, and the step of joining the sheet material 1' with the adhesive layer 13 formed thereon to the frame 11 via the adhesive layer 13. 【0188】 This method allows the sheet material 1' and the frame 11 to be suitably joined via the adhesive layer 13. 【0189】The method for applying the adhesive in a ring shape onto the sheet material 1' is not particularly limited, but examples include (1) a method of applying it partially in a ring shape, and (2) a method using a mask sheet. 【0190】 First, (1) as a method for partially applying adhesive in a ring shape onto the sheet material 1', for example, a method of applying the adhesive in a ring pattern using methods such as screen printing, gravure printing, or flexographic printing can be mentioned. 【0191】 Furthermore, in the manufacturing of the semiconductor chip holding member, it is preferable that the sheet material 1' is larger than the outer dimensions of the frame 11. This facilitates the application of adhesive. 【0192】 Next, (2) a method of applying adhesive in a ring shape onto the sheet material 1' using a mask sheet will be described. 【0193】 First, as shown in Figure 5(a), a mask sheet 20 having a ring-shaped opening 21 is placed on one side of the sheet material 1', in the configuration shown in the figure, on the retaining layer 3'. 【0194】 The mask sheet 20 is made of, for example, polyethylene terephthalate (PET). The opening 21 has a shape that corresponds to the shape of the frame 11. 【0195】 Next, as shown in Figure 5(b), adhesive 13a is applied to the mask sheet 20. 【0196】 Then, as shown in Figure 5(c), by peeling the mask sheet 20 from the sheet material 1', a ring-shaped adhesive layer 13 is formed on one surface of the sheet material 1'. 【0197】 Furthermore, the joining process may include, as shown in Figure 6, the steps of applying an adhesive to one side of the frame 11 to form an adhesive layer 13, and joining the frame 11 with the adhesive layer 13 formed thereon to the sheet material 1' via the adhesive layer 13. 【0198】 This method allows the sheet material 1' and the frame 11 to be suitably joined via the adhesive layer 13. 【0199】 After joining the sheet material 1' and the frame 11, the portion of the sheet material 1' that extends beyond the frame 11 may be cut to match the outer shape of the frame 11, for example, in a circular shape. 【0200】 This makes it possible to suitably manufacture a semiconductor chip holding member 10 as shown in Figure 3. 【0201】 [4-2] As described above, the semiconductor chip holding member 10 may be stored, distributed, and sold in a state in which the sheet material 1', which is made of a material including a thermoplastic elastomer, and the ring-shaped frame 11 are joined together. However, for example, the sheet material 1' and the frame 11, which is not joined to the sheet material 1', may be stored, distributed, and sold as a set. When the sheet material 1' and the frame 11, which is not joined to the sheet material 1', are stored, distributed, and sold as a set, users can join the sheet material 1' and the frame 11 together for use. 【0202】 As described above, when the sheet material 1' and the frame 11, which is not joined to the sheet material 1', are stored, distributed, and sold as a set, for example, a ring-shaped adhesive layer 13 may be formed on one side of the frame 11. 【0203】 In such cases, the adhesive layer 13 formed on the frame 11 may also be protected by a protective sheet made of polyethylene terephthalate (PET) or the like. When joining the frame 11 to the sheet material 1', the protective sheet can be peeled off to expose the adhesive layer 13. 【0204】 Alternatively, the sheet material 1' may be stored, distributed, and sold in a state where multiple frames 11 are joined to one side of the sheet material 1', without cutting the sheet material 1', in other words, with multiple semiconductor chip holding members 10 formed on the sheet. 【0205】 In this case, for example, when using the semiconductor chip holding member 10, the user separates the sheet material 1' to form individual semiconductor chip holding members 10. 【0206】 Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto. 【0207】 For example, the sheet material of the present invention may have a configuration other than those described above. 【0208】 Furthermore, for example, the semiconductor chip holding member of the present invention may have a configuration other than those described above. 【0209】 Furthermore, the sheet material of the present invention is not limited to those used in the manufacture of semiconductor chip holding members as described above. 【0210】 Furthermore, for example, the method for manufacturing the semiconductor chip holding member of the present invention may include steps other than those described above (e.g., pre-treatment steps, intermediate treatment steps, post-treatment steps, etc.). 【0211】 The present invention will be described in detail below based on specific examples, but the present invention is not limited thereto. In the following examples, processes and measurements where the temperature conditions are not specified were performed at room temperature (25°C). 【0212】 [5] Manufacturing of sheet materials 【0213】 (Example 1) A sheet material with a thickness of 150 μm was manufactured by extruding a composition for forming a sheet material, which included an ethylene-vinyl acetate copolymer (Evaflex EV360, manufactured by Mitsui Dow Polychemicals) as a thermoplastic elastomer. The extruded resin was cooled on a mirror-finished roll to form a chip-holding surface. 【0214】 In this example, the copolymerization ratio (%) of the ethylene-vinyl acetate copolymer used was ethylene / vinyl acetate = 75 / 25 in molar ratio. 【0215】 (Example 2) A sheet material was manufactured in the same manner as in Example 1, except that a sheet material forming composition was used, which contained 80% by mass of ethylene-vinyl acetate copolymer ("Evaflex EV360" manufactured by Mitsui Dow Polychemicals) and 20% by mass of polypropylene ("Noblen FS2011DG3" manufactured by Sumitomo Chemical Co., Ltd.) as thermoplastic elastomers. 【0216】 (Example 3) A sheet material was manufactured in the same manner as in Example 1, except that a sheet material forming composition containing ethylene-methyl methacrylate copolymer (EMMA) (Sumitomo Chemical Co., Ltd.'s "Aclift WH206-F") was used as the thermoplastic elastomer. 【0217】 In this example, the copolymerization ratio (%) of the ethylene-methyl methacrylate copolymer used was ethylene / methyl methacrylate = 80 / 20 in molar ratio. 【0218】 (Example 4) A sheet material was manufactured in the same manner as in Example 1, except that a sheet material forming composition containing an ethylene-butene copolymer ("Tafmer A4085S" manufactured by Mitsui Chemicals, Inc.) was used as the thermoplastic elastomer. 【0219】 (Example 5) A sheet material was manufactured in the same manner as in Example 1, except that a sheet material forming composition was used, which contained 60% by mass of a hydrogenated styrene-butadiene thermoplastic elastomer ("ToughTec H1221" manufactured by Asahi Kasei Corporation) and 40% by mass of polypropylene ("Noblen FS2011DG3" manufactured by Sumitomo Chemical Co., Ltd.) as the thermoplastic elastomer. 【0220】 In this example, the copolymerization ratio (%) of the hydrogenated styrene-butadiene thermoplastic elastomer used was styrene / butadiene = 12 / 88 in molar ratio. 【0221】 (Example 6) A sheet material was manufactured in the same manner as in Example 1, except that a sheet material forming composition was used, which contained 60% by mass of a hydrogenated styrene-butadiene thermoplastic elastomer ("ToughTec H1221" manufactured by Asahi Kasei Corporation), 15% by mass of polypropylene ("Noblen FS2011DG3" manufactured by Sumitomo Chemical Co., Ltd.), and 25% by mass of a polyether-based antistatic agent ("Pelektron PVL" manufactured by Sanyo Chemical Industries, Ltd.) as the thermoplastic elastomer. 【0222】 (Example 7) First, a polypropylene (PP) film with a thickness of 135 μm (Sumitomo Chemical's "Noblen FS2011DG3") was prepared as a base material. 【0223】Furthermore, a composition for forming a retaining layer was prepared by mixing 60% by mass of a hydrogenated styrene-butadiene thermoplastic elastomer ("ToughTec H1221" manufactured by Asahi Kasei Corporation) and 40% by mass of polypropylene ("Noblen FS2011DG3" manufactured by Sumitomo Chemical Co., Ltd.). 【0224】 A retaining layer-forming composition was applied to a substrate by an extrusion lamination method to form a retaining layer with a thickness of 15 μm, and a 150 μm sheet material was manufactured. 【0225】 In the obtained sheet material, the thickness ratio of the retaining layer to the total thickness was 10%, and the thickness ratio of the base material was 90%. 【0226】 (Example 8) A sheet material was manufactured in the same manner as in Example 7, except that the base material was a low-density polyethylene film (R300, manufactured by Ube Maruzen Polyethylene Co., Ltd.) with a thickness of 135 μm. 【0227】 (Example 9) A sheet material was manufactured in the same manner as in Example 1, except that a sheet material forming composition was used, which contained 50% by mass of a hydrogenated styrene-butadiene thermoplastic elastomer (Dynalon 1320P, manufactured by ENEOS Material Corporation) and 50% by mass of polypropylene (Noblen FS2011DG3, manufactured by Sumitomo Chemical Co., Ltd.) as the thermoplastic elastomer. 【0228】 In this example, the copolymerization ratio (%) of the hydrogenated styrene-butadiene thermoplastic elastomer used was styrene / butadiene = 10 / 90 in molar ratio. 【0229】 (Example 10) A sheet material was manufactured in the same manner as in Example 7, except that the retaining layer forming composition used contained 50% by mass of a hydrogenated styrene-butadiene thermoplastic elastomer (Dynalon 1320P, manufactured by ENEOS Material Corporation) and 50% by mass of polypropylene (Noblen FS2011DG3, manufactured by Sumitomo Chemical Co., Ltd.). 【0230】(Comparative Example 1) A sheet material and a semiconductor chip holding member were manufactured in the same manner as in Example 1, except that a sheet material forming composition was used, which contained 50% by mass of ethylene-vinyl acetate copolymer ("Evaflex EV360" manufactured by Mitsui Dow Polychemicals) and 50% by mass of polypropylene ("Noblen FS2011DG3" manufactured by Sumitomo Chemical Co., Ltd.) as thermoplastic elastomers. 【0231】 (Comparative Example 2) A sheet material and a semiconductor chip holding member were manufactured in the same manner as in Example 1, except that a sheet material forming composition containing a propylene-butene copolymer ("Tafmer XM7080" manufactured by Mitsui Chemicals, Inc.) was used as the thermoplastic elastomer. 【0232】 (Comparative Example 3) A sheet material and a semiconductor chip holding member were manufactured in the same manner as in Example 1, except that a sheet material forming composition was used, which contained 20% by mass of a hydrogenated styrene-butadiene thermoplastic elastomer ("ToughTec H1221" manufactured by Asahi Kasei Corporation) and 80% by mass of polypropylene ("Noblen FS2011DG3" manufactured by Sumitomo Chemical Co., Ltd.) as the thermoplastic elastomer. 【0233】 (Comparative Example 4) A sheet material and a semiconductor chip holding member were manufactured in the same manner as in Example 7, except that the retaining layer forming composition used contained 20% by mass of a hydrogenated styrene-butadiene thermoplastic elastomer ("ToughTec H1221" manufactured by Asahi Kasei Corporation) and 80% by mass of polypropylene ("Noblen FS2011DG3" manufactured by Sumitomo Chemical Co., Ltd.). 【0234】 (Comparative Example 5) A sheet material and a semiconductor chip holding member were manufactured in the same manner as in Example 1, except that a sheet material forming composition was used, which contained 10% by mass of a hydrogenated styrene-butadiene thermoplastic elastomer (Dynalon 1320P, manufactured by ENEOS Material Corporation) and 90% by mass of polypropylene (Noblen FS2011DG3, manufactured by Sumitomo Chemical Co., Ltd.) as the thermoplastic elastomer. 【0235】(Comparative Example 6) A sheet material and a semiconductor chip holding member were manufactured in the same manner as in Example 7, except that a retaining layer forming composition was used, which contained 10% by mass of a hydrogenated styrene-butadiene thermoplastic elastomer (Dynalon 1320P, manufactured by ENEOS Material Corporation) and 90% by mass of polypropylene (Noblen FS2011DG3, manufactured by Sumitomo Chemical Co., Ltd.). 【0236】 [6] Evaluation [6-1] Measurement of tack force of the materials constituting the sheet material 【0237】 The tack force was measured for the sheet materials of each of the above embodiments and comparative examples. 【0238】 First, for each of the sheet materials in the above-mentioned examples and comparative examples, a 5.0 mm diameter SUS probe was brought into contact with the sheet material from above using a tacking tester TAC-1000 manufactured by Resca, in accordance with JIS Z0237:2022. The speed at which the probe was brought into contact with the sheet material was set to 1 mm / sec, the contact load to 200 gf, the contact time to 1 second, and the probe temperature and plate temperature to 25°C. Subsequently, the probe was peeled upward at a peeling speed of 10 mm / sec, and the force required to peel it off was measured as the tack force. 【0239】 Tables 1 and 2 show the evaluation results of the tack force for the sheet materials of each of the above embodiments and comparative examples. 【0240】 In each of the above embodiments, the tack force when the material thickness was 150 μm was 10 kPa or more in all cases. 【0241】 Furthermore, from the comparison between Example 1, Example 2, and Comparative Example 1, the comparison between Example 5, Comparative Example 3, and Example 9, it can be seen that the tack strength can be adjusted by changing the content ratio of thermoplastic elastomer to polypropylene. 【0242】 [6-2] Evaluation of the tack force of the sheet material as a whole The tack force of the sheet material as a whole was measured for each of the above examples and comparative examples. The tack force was measured in the same manner as described above. 【0243】 [6-3] Silicon Chip Holding Force A ring-shaped frame was joined to the sheet material of each of the above embodiments and comparative examples to obtain a semiconductor chip holding member. A silicon chip measuring 6 mm square in plan view was placed on the sheet material constituting these semiconductor chip holding members and pressed down to hold it on the surface of the sheet material. Five silicon chips were held in each member. 【0244】 Then, with the frame standing vertically, I lifted it by hand to a height of 100 cm above the desk and dropped it onto the desk to create an impact, repeating this action three times. 【0245】 Additionally, vibrations were applied by holding the frame horizontally and shaking it from side to side by hand. 【0246】 The subsequent condition of the semiconductor chip holder was visually observed and evaluated according to the following criteria. 【0247】 ○: All silicon chips remained in place. ×: One or more silicon chips fell off. 【0248】 [6-4] Peelability (Pickup) of Silicon Chips As described in [6-3] above, silicon chips measuring 6 mm square in plan view were placed on the sheet material constituting the semiconductor chip holding member according to each of the above embodiments and comparative examples and pressed down to be held on the surface of the sheet material. Ten silicon chips were held in each case. 【0249】 Then, the silicon tip was pushed up using four needles with a tip diameter of 100 μm, with a needle push-up amount of 500 μm. 【0250】 Next, while maintaining the upward thrust of the silicon tip by the needle, the silicon tip was picked up by suction using a vacuum collet. 【0251】 Through the above process, the pickup of silicon chips by adsorption was repeated 10 times for each of the sheet materials in the above-mentioned examples and comparative examples. 【0252】Then, for each of the above-mentioned examples and comparative examples, the success or failure of pickup by the adsorption of silicon chips (pickup capability) was observed and evaluated according to the following criteria. 【0253】 ◎: I was able to pick up 10 silicon chips. 〇: I was able to pick up 5 to 9 silicon chips. △: I was able to pick up 1 to 4 silicon chips. ×: I was unable to pick up any silicon chips. 【0254】 [6-5] Sheet Formability Approximately 5 m of the sheet material produced in each of the above examples and comparative examples was wound onto a core layer with a diameter of approximately 10 cm to form a roll, which was then unwound and evaluated according to the following criteria. 【0255】 ◎: Can be unwound without applying force. ○: Can be unwound with force. ×: Cannot be unwound even with force. These evaluation results are summarized in Tables 1 and 2. 【0256】 【0257】 【0258】 By comparing Example 5 with Example 7, Example 9 with Example 10, Comparative Example 3 with Comparative Example 4, and Comparative Example 5 with Comparative Example 6, it can be seen that even when using the same retaining layer forming composition, it is possible to adjust the tack force of the entire sheet material to a suitable range by introducing a base material. 【0259】 By comparing the above examples 6 to 8, it can be seen that even when using the same retaining layer forming composition, the tack force of the entire sheet material can be adjusted to a suitable range by changing the type of substrate. 【0260】Furthermore, even if the tack force of the sheet material as a whole is relatively small, if the tack force of the portion that holds the semiconductor chip, in other words, the material constituting the holding layer itself, is 10 kPa or more when the material has a thickness of 150 μm, the semiconductor chip can be held more effectively. 【0261】 Furthermore, the semiconductor chip holding members of each of the above embodiments were able to suitably pick up the held semiconductor chips. 【0262】 Furthermore, in each of the above embodiments, excellent sheet moldability was observed, and suitable sheet materials could be obtained. In particular, while the hydrogenated ethylene-butadiene thermoplastic elastomers used in Examples 5 to 10 were difficult to form films on their own, suitable films could be formed by mixing the ethylene-butadiene thermoplastic elastomers with polypropylene in a predetermined ratio. 【0263】 According to the present invention, it is possible to provide a sheet material that achieves both the pickability of semiconductor chips and the retention force of semiconductor chips, a semiconductor chip holding member that achieves both the pickability of semiconductor chips and the retention force of semiconductor chips, and a method for manufacturing a semiconductor chip holding member that achieves both the pickability of semiconductor chips and the retention force of semiconductor chips. Therefore, the present invention has industrial applicability. 【0264】 1, 1' Sheet material 1a Semiconductor chip holding portion 2 Substrate 3, 3' Holding layer 10 Semiconductor chip holding member 11 Frame 12 Opening 13 Adhesive layer 13a Adhesive 20 Mask sheet 21 Opening

Claims

1. A sheet material used for holding semiconductor chips, characterized in that it is composed of a material containing a thermoplastic elastomer, and the tack force is 10 kPa or more when the material constituting the portion that holds the semiconductor chip has a thickness of 150 μm.

2. The sheet material according to claim 1, wherein the material constituting the portion that holds the semiconductor chip is composed of a material containing the thermoplastic elastomer and polyolefin.

3. The sheet material according to claim 2, wherein the material constituting the portion that holds the semiconductor chip is composed of a material including the thermoplastic elastomer and polypropylene.

4. The sheet material according to claim 2 or 3, wherein the content of the thermoplastic elastomer in the material constituting the portion that holds the semiconductor chip is X1 [mass%] and the content of the polyolefin is X2 [mass%], and the relationship 0.25 ≤ X1 / X2 is satisfied.

5. The sheet material according to claim 1 or 2, wherein the thermoplastic elastomer comprises at least one selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, olefin copolymer, and hydrogenated styrene-based thermoplastic elastomer.

6. The sheet material according to claim 1, comprising a base material and a retaining layer provided on one side of the base material and composed of a material containing at least the thermoplastic elastomer, for holding the semiconductor chip.

7. The sheet material according to claim 6, wherein the base material and the retaining layer contain the same type of material.

8. The sheet material according to claim 6 or 7, wherein the base material is made of a material containing polyolefin.

9. The sheet material according to claim 8, wherein the base material is made of a material containing polypropylene.

10. The sheet material according to claim 6 or 7, wherein when the thickness of the retaining layer is T1 [μm] and the thickness of the substrate is T2 [μm], the relationship 0.03 ≤ T1 / T2 ≤ 30 is satisfied.

11. The sheet material has a volume resistivity of 1.0 × 10 １５ The sheet material according to claim 1 or 2, wherein the density is less than or equal to (Ω・m).

12. A semiconductor chip holding member used to hold a semiconductor chip, comprising a sheet material made of a material including a thermoplastic elastomer and a ring-shaped frame, wherein the sheet material is bonded to one side of the frame.

13. A semiconductor chip holding member used to hold a semiconductor chip, comprising a sheet material made of a material including a thermoplastic elastomer and a ring-shaped frame, wherein the sheet material is bonded to one side of the frame, and the tack force is 10 kPa or more when the material constituting the portion of the sheet material that holds the semiconductor chip is 150 μm thick.

14. The semiconductor chip holding member according to claim 13, wherein the material constituting the portion that holds the semiconductor chip is composed of a material containing the thermoplastic elastomer and polyolefin.

15. The semiconductor chip holding member according to claim 14, wherein the material constituting the portion that holds the semiconductor chip is composed of a material including the thermoplastic elastomer and polypropylene.

16. The semiconductor chip holding member according to claim 14, wherein the content of the thermoplastic elastomer in the material constituting the portion that holds the semiconductor chip is X1 [mass%] and the content of the polyolefin is X2 [mass%], and the relationship 0.25 ≤ X1 / X2 is satisfied.

17. The semiconductor chip holding member according to claim 12 or 13, wherein the sheet material is bonded to one side of the frame via an adhesive layer.

18. The semiconductor chip holding member according to claim 17, wherein the adhesive layer includes an ultraviolet-curing adhesive.

19. The semiconductor chip holding member according to claim 12 or 13, wherein the thermoplastic elastomer comprises at least one selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, olefin copolymer, and hydrogenated styrene-based thermoplastic elastomer.

20. The semiconductor chip holding member according to claim 12 or 13, wherein the sheet material comprises a base material and a holding layer provided on one side of the base material and composed of a material including at least the thermoplastic elastomer, for holding the semiconductor chip.

21. The semiconductor chip holding member according to claim 20, wherein the substrate and the holding layer contain the same type of material.

22. The semiconductor chip holding member according to claim 20, wherein the substrate is made of a material containing polyolefin.

23. The semiconductor chip holding member according to claim 22, wherein the base material is made of a material including polypropylene.

24. The semiconductor chip holding member according to claim 20, wherein when the thickness of the holding layer is T1 [μm] and the thickness of the substrate is T2 [μm], the relationship 0.03 ≤ T1 / T2 ≤ 30 is satisfied.

25. A method for manufacturing a semiconductor chip holding member used to hold a semiconductor chip, characterized by comprising the step of joining a sheet material made of a material containing a thermoplastic elastomer to one side of a ring-shaped frame.

26. A method for manufacturing a semiconductor chip holding member used to hold a semiconductor chip, comprising the step of joining a sheet material made of a material containing a thermoplastic elastomer to one side of a ring-shaped frame, characterized in that the tack force of the material constituting the portion of the sheet material that holds the semiconductor chip is 10 kPa or more.

27. The method for manufacturing a semiconductor chip holding member according to claim 25 or 26, wherein the sheet material is joined to one side of the frame via an adhesive layer.

28. The method for manufacturing a semiconductor chip holding member according to claim 27, wherein the adhesive layer includes an ultraviolet-curing adhesive.

29. A method for manufacturing a semiconductor chip holding member according to claim 27, comprising the steps of: applying an adhesive in a ring shape to one side of the sheet material to form the adhesive layer; and joining the sheet material on which the adhesive layer is formed and the frame via the adhesive layer.

30. A method for manufacturing a semiconductor chip holding member according to claim 27, comprising the steps of: applying an adhesive to one side of the frame to form the adhesive layer; and joining the frame on which the adhesive layer is formed and the sheet material via the adhesive layer.

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