Substrate film

Abstract

Provided is a substrate film for a tape used in a manufacturing process of a semiconductor. The substrate film has a base layer and an antistatic layer. The antistatic layer is laminated to the base layer. The difference between the maximum value of the arithmetic average roughness (Ra) and the minimum value of the arithmetic average roughness (Ra) on the surface of the antistatic layer side is 1.1 μm or less.

Description

Technical Field

[0001] This invention relates to substrate films, and more particularly to substrate films for tapes used in semiconductor manufacturing processes. Background Technology

[0002] In the manufacturing processes of semiconductor wafers and semiconductor packages, various adhesive tapes with an adhesive layer laminated on at least one side of a substrate film are used. Examples of such tapes include dicing tapes and back-grinding tapes. Dicing tapes are applied to semiconductor wafers during the dicing process, which divides a semiconductor wafer into multiple semiconductor chips. Back-grinding tapes are applied to the patterned surface of a semiconductor wafer during the grinding process, which thins the semiconductor wafer.

[0003] Japanese Patent Application Publication No. 2018-125521 (Patent Document 1) discloses a substrate film for cutting tape. Japanese Patent Application Publication No. 2020-088231 (Patent Document 2) discloses a substrate film for back-grinding tape.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2018-125521 Patent Document 2: Japanese Patent Application Publication No. 2020-088231 Summary of the Invention

[0005] The problem that the invention aims to solve In semiconductor manufacturing processes, the surface resistivity of substrate films used in tapes (e.g., cutting tapes or back-grinding tapes) sometimes fluctuates significantly. Substrate films with large fluctuations in surface resistivity sometimes fail to meet quality standards and are considered defective. Neither Patent Document 1 nor Patent Document 2 discloses a solution to this problem.

[0006] This invention was made to solve this problem, and its purpose is to provide a substrate film with relatively small fluctuations in surface resistivity within the plane.

[0007] Technical solutions for solving the problem The substrate film of the present invention is a substrate film for adhesive tape used in semiconductor manufacturing processes. The substrate film has a base layer and an antistatic layer. The antistatic layer is laminated on the base layer. On the surface of the antistatic layer side, the difference between the maximum value and the minimum value of the arithmetic mean roughness (Ra) is 1.1 μm or less.

[0008] The inventors of this invention discovered a correlation between the surface roughness of the substrate film and the surface resistivity of the substrate film. Using this substrate film, the difference between the maximum and minimum arithmetic mean roughness (Ra) of the surface on the antistatic layer side is less than 1.1 μm, and the fluctuation of the surface roughness in the plane of the substrate film is relatively small. Therefore, the fluctuation of the surface resistivity in the plane can be suppressed.

[0009] On the surface of the antistatic layer side of the above-mentioned substrate film, the difference between the maximum value and the minimum value of the arithmetic mean roughness (Ra) can be less than 0.30 μm.

[0010] Using this substrate film, the difference between the maximum and minimum arithmetic mean roughness (Ra) on the surface of the antistatic layer side is less than 0.30 μm, and the fluctuation of the surface roughness in the plane of the substrate film is smaller. Therefore, the fluctuation of the surface resistance value in the plane can be further suppressed.

[0011] In the aforementioned substrate film, the maximum value of the arithmetic mean roughness (Ra) of the surface on the antistatic layer side divided by the thickness of the antistatic layer yields a result less than 1.0.

[0012] The inventors of this invention discovered that when the maximum value of the arithmetic mean roughness (Ra) of the surface on the antistatic layer side is divided by the thickness of the antistatic layer and the result is less than 1.0, the surface resistance value falls within the desired range (e.g., 10). 9 Ω / □ or higher and less than 10 10 (Ω / □). Using this substrate film, the maximum value of the arithmetic mean roughness (Ra) of the surface on the antistatic layer side divided by the thickness of the antistatic layer is less than 1.0. Therefore, the surface resistance value can be made to fall within the desired range.

[0013] In the aforementioned substrate film, the result obtained by dividing the maximum value of the arithmetic mean roughness (Ra) of the surface on the antistatic layer side by the thickness of the antistatic layer can be less than 0.16.

[0014] Using this substrate film, the maximum arithmetic mean roughness (Ra) of the surface on the antistatic layer side divided by the thickness of the antistatic layer yields a result less than 0.16. Therefore, the surface resistivity can be made to fall within the desired range (e.g., 10). 9 Ω / □ or higher and less than 8.9 × 10 9 Ω / □).

[0015] In the aforementioned substrate film, the surface resistivity can be 10. 9 Ω / □ or higher and less than 10 10 Ω / □.

[0016] Invention Effects Using this invention, a substrate film with relatively small fluctuations in in-plane surface resistivity can be provided. Attached Figure Description

[0017] Figure 1 This is a diagram showing a cross-section of the substrate film.

[0018] Figure 2 This is a diagram illustrating the configuration of a substrate film manufacturing apparatus. Detailed Implementation

[0019] Hereinafter, a specific embodiment of one aspect of the present invention (hereinafter also referred to as "this embodiment") will be described in detail using the accompanying drawings. In the drawings, the same or equivalent parts are referred to by the same reference numerals, and their descriptions are not repeated. Furthermore, in each drawing, objects are appropriately omitted or exaggerated schematically shown for ease of understanding.

[0020] [1. Composition of the substrate film] Figure 1 This is a schematic diagram showing a cross-section of the substrate film 10 according to this embodiment. Figure 1 As shown, the substrate film 10 includes a substrate layer 20 and an antistatic layer 30 laminated on the substrate layer 20. Because the antistatic layer 30 is laminated on the substrate layer 20, static electricity is less likely to be generated on the surface of the antistatic layer 30 side. Therefore, the substrate film 10 can be appropriately used as a substrate film for adhesive tapes (e.g., cutting tapes or back-grinding tapes) used in semiconductor manufacturing processes. The layers constituting the substrate film 10 will be described in detail below.

[0021] <1-1. Antistatic Layer> The antistatic layer 30 is composed of a resin composition containing at least a portion of a thermoplastic resin, a polymeric antistatic agent, and a thermoplastic elastomer. That is, the resin composition may, for example, contain a thermoplastic resin and a polymeric antistatic agent but not a thermoplastic elastomer, or it may contain all of the thermoplastic resin, the polymeric antistatic agent, and the thermoplastic elastomer. The components are described below.

[0022] (1-1-1. Thermoplastic resin) The thermoplastic resin contained in the antistatic layer 30 is not particularly limited, but is preferably selected from vinyl or acrylic resins. Examples of vinyl resins include polyethylene, branched low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-methyl acrylate copolymer (EMMA), ethylene-methacrylic acid copolymer (EMAA), and ionomer resins. Among these, LDPE and EMMA are preferred.

[0023] Examples of propylene-based resins include propylene-based binary copolymers and propylene-based terpolymers, which are mainly composed of propylene and have α-olefins as copolymerizing components. Among these, propylene-based terpolymers are preferred. Examples of α-olefins forming copolymerizing components include ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene. The ratio of α-olefins as copolymerizing components is preferably 1 to 10 mol%. In addition, propylene-based resins can be mixtures of different propylene-α-olefin random copolymers.

[0024] The resin composition constituting the antistatic layer 30 preferably contains 30% to 80% thermoplastic resin per 100% of the total layer, more preferably 35% to 75% by weight, and even more preferably 40% to 70% by weight.

[0025] (1-1-2. Polymer-type antistatic agent) Polymer-based antistatic agents impart the function of suppressing static electricity and preventing direct discharge to the substrate film 10 by adjusting the surface resistivity of the antistatic layer 30. Examples of polymer-based antistatic agents include polyether ester amide (PEEA) and hydrophilic olefin block copolymers. The resin composition constituting the antistatic layer 30 may contain any of these.

[0026] The resin composition constituting the antistatic layer 30 contains, relative to 100% by weight, at least 20% by weight and at least 40% by weight of the aforementioned polymeric antistatic agent, more preferably at least 25% by weight and at least 35% by weight, and even more preferably at least 27% by weight and at least 33% by weight. By ensuring that the content of a polymeric antistatic agent is above the aforementioned lower limit, sufficient antistatic function can be imparted to the antistatic layer 30. On the other hand, by ensuring that the content of a polymeric antistatic agent is below the aforementioned upper limit, the deterioration of the appearance of the substrate film 10 due to the aggregation of the polymeric antistatic agent and the fluctuation of the surface resistivity due to different positions can be suppressed.

[0027] (1-1-3. Thermoplastic elastomers) Examples of thermoplastic elastomers include hydrogenated styrene-based elastomers and their modifications. Thermoplastic elastomers improve the dispersibility of polymeric antistatic agents in the resin composition, which promote the formation of conductive circuits in the antistatic layer 30. Consequently, fluctuations in surface resistance due to location variations are suppressed in the antistatic layer 30, resulting in a better appearance. Defects in the appearance of the antistatic layer 30 include streaky opaque marks and cloudy, foggy appearances that impair the transparency of the substrate film 10. Such defects can be attributed to segregation of components in the resin composition.

[0028] The transparency of the substrate film 10 is required for the reasons described below. For example, in a semiconductor processing apparatus, if the semiconductor processing tape has an appearance defect, it may hinder proper control of the processing apparatus. Furthermore, in a dicing process, for example, a laser is irradiated onto a semiconductor wafer by means of a dicing tape attached to the wafer. If the semiconductor processing tape has an appearance defect, the laser transmittance through the dicing tape will be uneven, potentially resulting in poor dicing.

[0029] The resin composition constituting the antistatic layer 30 preferably contains 5% to 40% by weight of the aforementioned thermoplastic elastomer per 100% by weight of the entire layer, more preferably 10% to 35% by weight, and even more preferably 15% to 33% by weight. By ensuring that the content of the aforementioned thermoplastic elastomer is above the aforementioned lower limit, sufficient compatibility effect can be achieved. On the other hand, by ensuring that the content of the aforementioned thermoplastic elastomer is below the aforementioned upper limit, it is possible to avoid excessive compatibility promotion, which could damage the formation of conductive circuits due to the polymeric antistatic agent.

[0030] The thickness of the antistatic layer 30 is preferably 2 μm or more and 20 μm or less, more preferably 3 μm or more and 15 μm or less, and even more preferably 4 μm or more and 12 μm or less. By making the thickness of the antistatic layer 30 at or above the aforementioned lower limit, sufficient antistatic function can be imparted to the substrate film 10, while by making the thickness of the antistatic layer 30 at or below the aforementioned upper limit, the cost of the substrate film 10 can be suppressed.

[0031] <1-2. Matrix Layer> The substrate layer 20 is a layer containing thermoplastic resin as its main component, and it is the layer that dominates the room temperature expansion and uniform expansion properties described later. The substrate layer 20 can be composed of a single layer or multiple layers. In the substrate film 10 according to this embodiment, the substrate layer 20 includes a core layer 21, two adhesive layers 22 (adhesive layers 22A and 22B), and two surface layers 23 (surface layers 23A and 23B). Surface layers 23A and 23B respectively constitute the surface of the substrate layer 20. Adhesive layer 22A is stacked between the core layer 21 and the surface layer 23A, and adhesive layer 22B is stacked between the core layer 21 and the surface layer 23B. In the substrate layer 20, a symmetrical structure centered on the core layer 21 is formed, thus suppressing the occurrence of curling.

[0032] The thickness of the substrate layer 20 is preferably 40 μm or more and 200 μm or less, more preferably 45 μm or more and 190 μm or less, and even more preferably 50 μm or more and 180 μm or less.

[0033] (1-2-1. Surface layer) Surface layer 23 is the layer constituting the surface of substrate layer 20. In substrate film 10, an antistatic layer 30 is laminated on surface layer 23B. Surface layer 23 contains, for example, a thermoplastic resin. The thermoplastic resin contained in surface layer 23 can be the same as the thermoplastic resin contained in antistatic layer 30. Surface layer 23 can contain, for example, the vinyl resin or acrylic resin described in one aspect of antistatic layer 30. Among these, LDPE is preferred as the thermoplastic resin contained in surface layer 23. For example, when the thermoplastic resin contained in antistatic layer 30 is the same as the thermoplastic resin contained in surface layer 23, the uneven flow rate during co-extrusion of the resin composition constituting these layers is suppressed, and as a result, the adverse effects on the appearance of substrate film 10 are suppressed. Furthermore, in this case, the interlayer compatibility is improved, and therefore the interlayer adhesive strength is improved.

[0034] The thickness of the surface layer 23 is preferably 5 μm or more and 40 μm or less, more preferably 8 μm or more and 35 μm or less, and even more preferably 10 μm or more and 30 μm or less.

[0035] (1-2-2. Adhesive layer) The adhesive layer 22 is used to bond the core layer 21 to the surface layer 23. The adhesive layer 22 is, for example, composed of a resin composition containing, for example, an ethylene-based resin, an propylene-based resin, or an amorphous olefin-based resin as described in the antistatic layer 30. The resin composition constituting the adhesive layer 22 may also contain two or more of these.

[0036] Examples of amorphous olefin resins include amorphous polypropylene (also known as flexible polypropylene) obtained by homopolymerization of propylene using a prescribed catalyst, and copolymers obtained by copolymerization of at least one of propylene and 1-butene with α-olefins having 2 to 20 carbon atoms (excluding propylene and 1-butene) using a prescribed catalyst. The polymerization ratio of propylene or 1-butene is preferably 50% by weight or more, more preferably 60% by weight or more, further preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more.

[0037] The resin composition constituting the adhesive layer 22 is preferably a mixture of LDPE and LLDPE. The LDPE and LLDPE used in the adhesive layer 22 may be the same as or different from the LDPE and LLDPE used in the surface layer 23.

[0038] The thickness of the adhesive layer 22 is preferably 2 μm or more and 20 μm or less, more preferably 3 μm or more and 15 μm or less, and even more preferably 4 μm or more and 12 μm or less.

[0039] (1-2-3. Core layer) The core layer 21 is the thickest layer in the substrate film 10. The core layer 21 is, for example, composed of a resin composition containing at least one of the ethylene resin and propylene resin described in the antistatic layer 30 and the amorphous olefin resin described in the adhesive layer 22.

[0040] The thickness of the core layer 21 is preferably 30 μm or more and 160 μm or less, more preferably 40 μm or more and 150 μm or less, and even more preferably 50 μm or more and 140 μm or less.

[0041] [2. Various parameters involved in the substrate film] <2-1. Arithmetic Mean Roughness (Ra)> As described above, the substrate film 10 is used as a substrate for tapes (e.g., cutting tapes or back-grinding tapes) used in semiconductor manufacturing processes. It is assumed that if the in-plane surface resistivity of the substrate film 10 fluctuates significantly, the substrate film 10 may be considered a defective product.

[0042] The inventors of this invention have discovered a correlation between the surface roughness of the substrate film 10 and the surface resistance value of the substrate film 10. Specifically, the inventors of this invention have discovered a trend in which a larger surface roughness value of the substrate film 10 results in a larger measured surface resistance value, and a smaller surface roughness value of the substrate film 10 results in a smaller measured surface resistance value.

[0043] In the substrate film 10, on the surface F1 on the side of the antistatic layer 30, the difference between the maximum and minimum arithmetic mean roughness (Ra) is less than 1.1 μm. Since the difference between the maximum and minimum arithmetic mean roughness (Ra) on the surface F1 on the side of the antistatic layer 30 is less than 1.1 μm, the surface roughness fluctuation within the surface of the substrate film 10 is relatively small, thus suppressing in-plane fluctuations in surface resistivity.

[0044] Furthermore, in the substrate film 10, the difference between the maximum and minimum arithmetic mean roughness (Ra) of the surface F1 on the antistatic layer 30 side is preferably 0.30 μm or less. When the substrate film 10 has a difference between the maximum and minimum arithmetic mean roughness (Ra) of the surface F1 on the antistatic layer 30 side of 0.30 μm or less, the surface roughness fluctuation within the surface of the substrate film 10 is smaller, thus further suppressing the in-plane fluctuation of the surface resistance value.

[0045] Arithmetic mean roughness (Ra) can be determined according to JIS B 0601:1994. For example, the arithmetic mean roughness (Ra) can be determined using a Retrofit 1400D-3DF manufactured by Tokyo Seimitsu Co., Ltd. (e.g., tip size: 5 μm; cutoff value: 0.08 mm; length: 1.2 mm; T-SPEED: 0.03 mm / s).

[0046] <2-2. Surface resistivity> The surface resistivity of the substrate film 10 is, for example, 10. 9 Ω / □ or higher and less than 10 10 Ω / □, preferably 10 9 Ω / □ or higher and less than 8.9 × 10 9 Ω / □. The surface resistance value can be determined according to JIS K6911:1995. For example, the surface resistance value can be determined using the HiRESTA UP MCP-450 model manufactured by Nitto Seiko Analytical Technology Co., Ltd. (e.g., probe: UR100, measurement mode: surface resistance, applied voltage: 500V, timer: 10 seconds).

[0047] <2-3. The result obtained by dividing the maximum value of the arithmetic mean roughness (Ra) by the thickness of the antistatic layer> The inventors of this invention discovered that when the maximum value of the arithmetic mean roughness (Ra) of the surface on the antistatic layer 30 side is divided by the thickness of the antistatic layer 30, the result is less than 1.0, and the surface resistivity of the substrate film 10 falls within the desired range (e.g., 10). 9 Ω / □ or higher and less than 10 10(Ω / □). In the substrate film 10, the maximum value of the arithmetic mean roughness (Ra) of the surface on the antistatic layer 30 side divided by the thickness of the antistatic layer 30 is less than 1.0. Therefore, by using the substrate film 10, the maximum value of the arithmetic mean roughness (Ra) of the surface on the antistatic layer 30 side divided by the thickness of the antistatic layer 30 is less than 1.0, thus enabling the surface resistivity of the substrate film 10 to fall within the desired range.

[0048] Furthermore, in the substrate film 10, the result obtained by dividing the maximum arithmetic mean roughness (Ra) of the surface F1 on the antistatic layer 30 side by the thickness of the antistatic layer 30 is preferably less than 0.16. At this time, using the substrate film 10, the result obtained by dividing the maximum arithmetic mean roughness (Ra) of the surface F1 on the antistatic layer 30 side by the thickness of the antistatic layer 30 is less than 0.16; therefore, the surface resistance value can fall within the desired range (e.g., 10). 9 Ω / □ or higher and less than 8.9 × 10 9 Ω / □).

[0049] <2-4. Room Temperature Expansion> The room-temperature extensibility of the substrate film 10 is evaluated, for example, by tensile elongation (%). For the MD (Machine Direction) and TD (Transverse Direction) of the substrate film 10, a film sample processed to a width of 15 mm and a clamping distance of 40 mm is stretched at a stretching speed of 200 mm / min and the elongation is measured. Preferably, the obtained tensile elongation is 100% or higher for both MD and TD. This is because when the tensile elongation is less than 100%, it can lead to cracking or wrinkling during expansion in the processing of semiconductor wafers, etc. Here, MD is the extrusion direction of the substrate film 10, which is the length direction. TD is the direction orthogonal to MD.

[0050] <2-5. Uniform Expansion> The uniform expansion property of the substrate film 10 is evaluated, for example, by a 25% modulus ratio (MD / TD). For the MD and TD of the substrate film 10, a film sample with a width of 15 mm and a clamping distance of 40 mm is stretched at a stretching speed of 200 mm / min to obtain a stress-strain curve (SS curve). The ratio of the stress value of MD at 25% elongation to the stress value of TD at 25% elongation is calculated as the modulus ratio (MD / TD). The modulus ratio (MD / TD) is preferably less than 1.5. When the modulus ratio (MD / TD) is less than 1.5, due to the uniform expansion of the semiconductor processing tape, the monolithic semiconductor chips are uniform in width (cutting width), the semiconductor chips do not tilt, and the pick-up performance becomes good. On the other hand, when the modulus ratio (MD / TD) is 1.5 or higher, the cutting width becomes uneven, which may lead to misalignment of the semiconductor chips, collisions between semiconductor chips, and damage as a result.

[0051] [3. Method for manufacturing the substrate film] Figure 2 This is a schematic diagram illustrating the configuration of the manufacturing apparatus 50 for the substrate film 10. (See diagram below.) Figure 2 As shown, the manufacturing apparatus 50 includes a T-mold 500, casting rolls 510 and 520, and a take-up roll 530.

[0052] The T-die 500 is configured such that molten material is produced by heating and melting the material added to six material feeding sections (not shown), and the molten material is extruded. The first material feeding section contains the material constituting the surface layer 23A; the second material feeding section contains the material constituting the adhesive layer 22A; the third material feeding section contains the material constituting the core layer 21; the fourth material feeding section contains the material constituting the adhesive layer 22B; the fifth material feeding section contains the material constituting the surface layer 23B; and the sixth material feeding section contains the material constituting the antistatic layer 30.

[0053] Casting rollers 510 and 520 are configured to cool the extruded molten material and feed it downstream. The surface roughness of the substrate film 10 is caused, for example, by the surface roughness of the casting rollers 510 and 520. The take-up roller 530 is configured to draw and take up the molten material cooled by the casting rollers 510 and 520 at a predetermined speed. The wound body of the substrate film 10 is manufactured through the manufacturing process of the manufacturing apparatus 50.

[0054] For example, the temperature of the casting roller 510 is 10°C or higher and 80°C or lower, preferably 20°C or higher and 60°C or lower. Furthermore, for example, the specified speed at which the molten material is drawn using the take-up roller 530 is 3 m / min or higher and 30 m / min or lower, preferably 9 m / min or higher and 25 m / min or lower.

[0055] [4. Characteristics] As described above, the substrate film 10 according to this embodiment is a substrate film for adhesive tape used in semiconductor manufacturing processes. The substrate film 10 includes a substrate layer 20 and an antistatic layer 30. The antistatic layer 30 is laminated on the substrate layer 20. On the surface of the antistatic layer 30, the difference between the maximum and minimum arithmetic mean roughness (Ra) is less than 1.1 μm. Using the substrate film 10, since the difference between the maximum and minimum arithmetic mean roughness (Ra) on the surface of the antistatic layer 30 is less than 1.1 μm, the in-plane surface roughness fluctuation of the substrate film 10 is relatively small, thus suppressing in-plane fluctuations in surface resistivity.

[0056] [5. Other implementation methods] The ideas behind the above-described embodiments are not limited to those embodiments. Hereinafter, examples of other embodiments to which the ideas of the above-described embodiments can be applied will be described.

[0057] <5-1> In the substrate film 10 according to the above embodiments, the resin composition constituting the core layer 21, adhesive layer 22, surface layer 23 and antistatic layer 30 may contain additives such as antistatic agents other than polymeric antistatic agents, antioxidants, heat stabilizers, ultraviolet absorbers, light stabilizers, lubricants, flame retardants, antibacterial agents, fluorescent whitening agents, colorants, and fillers, without impairing the effects of the present invention.

[0058] <5-2> In the above embodiment, the antistatic layer 30 is laminated onto the substrate layer 20 by co-extrusion. However, the method of laminating the antistatic layer 30 onto the substrate layer 20 is not limited to this. The antistatic layer 30 may also be laminated onto the substrate layer 20 by coating, for example.

[0059] The embodiments of the present invention have been described above by way of example. That is, detailed descriptions and accompanying drawings have been provided for the purpose of illustration. Therefore, the constituent elements described in the detailed descriptions and accompanying drawings sometimes include constituent elements that are not essential to solving the problem. Therefore, one should not assume that these non-essential constituent elements are essential simply because they are described in the detailed descriptions and accompanying drawings.

[0060] Furthermore, the above embodiments are merely examples of the present invention in all respects. Various modifications and variations can be made to the above embodiments within the scope of the present invention. For example, at least a portion of the configuration of any one embodiment can be combined with at least a portion of the configuration of another embodiment. That is, when implementing the present invention, appropriate specific configurations can be adopted according to the embodiments.

[0061] Example Next, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments.

[0062] [1. Examples and Comparative Examples] Substrate films of Examples 1-9 and Comparative Examples 1-3 were prepared. Each substrate film of Examples 1-9 and Comparative Examples 1-3 had one of four six-layer structures: a surface layer, an adhesive layer, a core layer, an adhesive layer, a surface layer, and an antistatic layer, stacked sequentially. In the substrate films of Examples 1-9 and Comparative Examples 1-3, the thermoplastic resins used in the matrix layers were LDPE, LDPE, LDPE, LDPE, PP, EVA, ionomer, LDPE, ionomer, PP, LDPE, and ionomer, respectively. In the substrate films of Examples 1-9 and Comparative Examples 1-3, the thermoplastic resins used in the antistatic layers were LDPE, LDPE, LDPE, LDPE, PP, EVA, ionomer, LDPE, ethylene-methacrylic acid copolymer, PP, LDPE, and ionomer, respectively. An antistatic resin of a hydrophilic olefin block copolymer, comprising 30% by weight relative to the total weight of the layer, was added to impart antistatic properties. The thicknesses of the substrate films in Examples 1-9 and Comparative Examples 1-3 were 70 μm, 150 μm, 150 μm, 150 μm, 150 μm, 125 μm, 150 μm, 70 μm, 80 μm, 70 μm, 150 μm and 100 μm, respectively.

[0063] [2. Measurement of various parameters] <2-1. Surface Roughness (Rz)> The ten-point average roughness (Rz) was determined according to JIS B 0601:1994. For the ten-point average roughness (Rz) measurement, a Retrofit 1400D-3DF (e.g., tip size: 5 μm; cutoff value: 0.08 mm; length: 1.2 mm; T-SPEED: 0.03 mm / s) manufactured by Tokyo Seimitsu Co., Ltd. was used. A substrate film with a width of 600 mm and a length of 600 mm was prepared. Ten points were measured in the width direction at a pitch of 60 mm, starting 30 mm from the end. Similarly, ten points were measured in the length direction, for a total of 100 points, to determine the ten-point average roughness (Rz).

[0064] <2-2. Surface Roughness (Ra)> Arithmetic mean roughness (Ra) was determined according to JIS B 0601:1994. In the determination of arithmetic mean roughness (Ra), a Retrofit 1400D-3DF (e.g., tip size: 5 μm; cutoff value: 0.08 mm; length: 1.2 mm; T-SPEED: 0.03 mm / s) manufactured by Tokyo Seimitsu Co., Ltd. was used. A substrate film with a width of 600 mm and a length of 600 mm was prepared. Ten points were measured in the width direction at a pitch of 60 mm, starting 30 mm from the end, and ten points were also measured in the length direction, for a total of 100 points, to determine the arithmetic mean roughness (Ra).

[0065] <2-3. Surface resistivity> The surface resistivity of the substrate film was determined according to JIS K6911:1995. For the surface resistivity measurement, a HiRESTA UP MCP-450 model (e.g., probe: UR100, measurement mode: surface resistivity, applied voltage: 500V, timer: 10 seconds) manufactured by Nitto Seiko Analytical Technology Co., Ltd. was used. A substrate film with a width of 600 mm and a length of 600 mm was prepared and placed overnight in an environment with a temperature of 23±2℃ and a humidity of 50±10%. Then, under the same conditions, 10 points were measured in the width direction at 60 mm intervals, starting 30 mm from the end, and 10 points were measured in the length direction, for a total of 100 points.

[0066] <2-4. Room Temperature Expansion> The room temperature expansion property of the substrate film was evaluated using tensile elongation (%). For the MD and TD of the substrate film, film samples with a width of 15 mm and a clamping distance of 40 mm were stretched at a stretching speed of 200 mm / min, and the tensile elongation (%) was measured.

[0067] <2-5. Uniform Expansion> The uniform expansion property of the substrate film was evaluated using the 25% modulus ratio (MD / TD). For the MD and TD of the substrate film, film samples with a width of 15 mm and a clamping distance of 40 mm were stretched at a stretching speed of 200 mm / min to obtain stress-strain curves (SS curves). The ratio of the stress value of MD at 25% elongation to the stress value of TD at 25% elongation was calculated as the modulus ratio (MD / TD).

[0068] <2-6. Antistatic layer thickness> To determine the thickness of the antistatic layer, a cross-sectional photograph of the substrate film was taken using a VK-X100 laser microscope manufactured by KEYENCE, thereby measuring the thickness of the antistatic layer.

[0069] [3. Measurement Results] The test results for each item are shown in Table 1 below. In Table 1, "AS layer" represents the antistatic layer.

[0070] [Table 1] As shown in Table 1, the substrate films of Examples 1-9 and Comparative Examples 1-3 exhibited good extensibility. Compared to the substrate films of Comparative Examples 1-3, the difference between the maximum and minimum surface roughness values ​​of the substrate films of Examples 1-9 was smaller, therefore, the difference between the maximum and minimum surface resistivity values ​​was also smaller. Furthermore, unlike the substrate films of Comparative Examples 1-3, the maximum surface resistivity value of the substrate films of Examples 1-9 was less than 10. 10 Ω / □.

[0071] Symbol Explanation 10: Substrate film; 20: Base layer; 21: Core layer; 22: Adhesive layer; 23: Surface layer; 30: Antistatic layer; 50: Manufacturing device; 500: T-die; 510, 520: Casting roller; 530: Winding roller; F1: Surface.

Claims

1. A substrate film, which is a substrate film for adhesive tape used in a semiconductor manufacturing process, characterized in that it has: base layer, and An antistatic layer laminated on the substrate layer. On the surface of the antistatic layer side, the difference between the maximum and minimum arithmetic mean roughness (Ra) is less than 1.1 μm.

2. The substrate film as described in claim 1, characterized in that: On the surface of the antistatic layer side, the difference between the maximum and minimum arithmetic mean roughness (Ra) is less than 0.30 μm.

3. The substrate film as described in claim 1, characterized in that: The maximum value of the arithmetic mean roughness (Ra) of the surface on the side of the antistatic layer divided by the thickness of the antistatic layer yields a result less than 1.

0.

4. The substrate film as described in claim 3, characterized in that: The maximum value of the arithmetic mean roughness (Ra) of the surface on the antistatic layer side divided by the thickness of the antistatic layer yields a result less than 0.

16.

5. The substrate film according to any one of claims 1 to 4, characterized in that: Surface resistivity is 10 9 Ω / □ or higher and less than 10 10 Ω / □.

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