Tape for electronic component processing

Abstract

Tape for electronic component processing characterized by comprising a resin layer A, a primer layer, a resin layer B, and an adhesive layer in this order, wherein the primer layer contains an antistatic agent.

Description

Tape for processing electronic components

[0001] The present invention relates to a tape for processing electronic components.

[0002] In the processing of electronic components such as semiconductor wafers, tapes having an adhesive layer on the adhesive surface to which the electronic components are attached are used for surface protection. For example, in the processing of semiconductor wafers, after a pattern is formed on the surface of the semiconductor wafer, so-called backside grinding and polishing is performed, in which the backside of the semiconductor wafer is ground and polished to a predetermined thickness. In this process, a tape for processing electronic components is attached to the surface of the semiconductor wafer to protect the surface of the semiconductor wafer, and the backside of the semiconductor wafer is ground in this state.

[0003] When processing electronic components using an electronic component processing tape, static electricity is generated due to peeling electrification, frictional electrification, and spray electrification. For example, in processing semiconductor wafers, static electricity is generated on semiconductor elements when applying the electronic component processing tape to the semiconductor wafer, when cutting the semiconductor wafer with a dicing saw, when picking up the semiconductor elements in the pickup process, and when peeling the electronic component processing tape from the semiconductor elements. The generated static electricity can cause problems such as destruction of circuits formed on the semiconductor wafer (electrostatic breakdown of electronic components) and adhesion of foreign matter such as dust to the circuits.

[0004] As one of the countermeasures against static electricity generated during the processing of electronic components, studies have been conducted to impart antistatic properties to tapes for processing electronic components. For example, Patent Document 1 describes a surface protection film comprising a resin film on one side of which is formed an adhesive layer containing an antistatic agent and formed by crosslinking a specific acrylic polymer. Patent Document 2 describes an adhesive film for semiconductor wafer processing, which comprises, in this order, a substrate layer, an irregularity-absorbing resin layer, an antistatic layer, and an adhesive resin layer. Patent Document 3 describes an adhesive tape composed of a laminate including a substrate containing a resin material and a conductive material and having a surface resistivity and volume resistivity within a specific range, and an adhesive layer laminated on one side of the substrate, and which is used to temporarily fix at least one of a substrate and a component.

[0005] JP 2019-210479 A JP 2018-006540 ​​A JP 2021-015953 A

[0006] In recent years, a mounting method called flip-chip mounting has been adopted due to the trend toward thinner packaging and smaller chip mounting areas. Flip-chip mounting electrically connects the chip surface to the substrate without using wires, using ball-shaped or cylindrical bumps formed on the surface of a semiconductor wafer. Depending on the bump formation method, some of these bumps have a bump height (i.e., unevenness of the semiconductor wafer surface) exceeding 100 μm. Tapes for electronic component processing that are bonded to semiconductor wafers with such large surface unevenness require high conformability to uneven surfaces. Furthermore, with the need for higher bump density and narrower wiring pitches on semiconductor wafers, semiconductor wafers are more susceptible to static electricity than ever before, necessitating further improvements in antistatic performance.

[0007] One possible way to impart stronger antistatic properties to tapes for processing electronic components is to increase the concentration of the antistatic agent. However, the technology described in Patent Document 1, in which an antistatic agent is incorporated into the adhesive layer, raises concerns about the antistatic agent contaminating the adherend, such as a semiconductor wafer, to which the tape is attached. Similarly, the technology described in Patent Document 3, in which a conductive material serving as an antistatic agent is incorporated into the base layer, also raises concerns about the antistatic agent contaminating the equipment used in contact with the base layer. Furthermore, in the configuration of the adhesive film for semiconductor wafer processing described in Patent Document 2, the antistatic layer is disposed as an intermediate layer of the laminate, thereby solving the problem of the antistatic agent contaminating the adherend and the equipment. However, according to the inventors' studies, when the adhesive layer is thickened (e.g., greater than 100 μm) to achieve high conformability to the surface of an adherend with large surface irregularities, it has been found that the antistatic layer disposed as an intermediate layer is unable to exhibit the desired antistatic properties (see Comparative Examples 2 and 3 described below). Therefore, an object of the present invention is to provide a tape for processing electronic components that does not cause the problem of contamination by the antistatic agent of the adherend or device that comes into contact with the tape, and that can exhibit excellent antistatic performance on the adherend regardless of the thickness of the adhesive layer (whether the adhesive layer is thin or thick).

[0008] The above-mentioned object of the present invention has been achieved by the following means. <1> An electronic component processing tape comprising a resin layer A, a primer layer, a resin layer B, and an adhesive layer in this order, wherein the primer layer contains an antistatic agent. <2> The electronic component processing tape according to <1>, wherein the antistatic agent is an ionic liquid. <3> The electronic component processing tape according to <1> or <2>, wherein the adhesive constituting the primer layer is an acrylic adhesive or a polyester adhesive. <4> The electronic component processing tape according to any one of <1> to <3>, wherein the adhesive constituting the adhesive layer is an acrylic adhesive. <5> The electronic component processing tape according to any one of <1> to <4>, wherein the thickness of the primer layer is 1 to 55 μm. <6> The melting point Tm of the resin layer A Ａand the melting point Tm of the resin layer B Ｂ But, Tm Ａ ≧Tm Ｂ <7> The tape for processing electronic parts according to any one of <1> to <5>, wherein the melting point Tm of the resin layer A is Ａ <8> The tape for processing electronic parts according to any one of <1> to <6>, wherein the storage modulus of the resin layer B at 70°C is 3.0 × 10 ６ <7> The tape for processing electronic parts according to any one of <1> to <7>, wherein the elastic modulus is 0.05 Pa or less.

[0009] The tape for processing electronic components of the present invention does not cause the problem of contamination by the antistatic agent of the adherend or device that comes into contact with the tape, and can exhibit excellent antistatic performance on the adherend regardless of the thickness of the pressure-sensitive adhesive layer.

[0010] FIG. 1 is a schematic cross-sectional view showing one embodiment of the tape for processing electronic components of the present invention.

[0011] In the present invention, the surface of a semiconductor wafer refers to the uneven surface of the semiconductor wafer, i.e., the surface on which an integrated circuit (circuit pattern) is formed. The surface opposite this surface is referred to as the back surface. In the present invention, the unevenness difference refers to the distance from the highest point of a convex portion to the wafer surface or the distance from the deepest point of a concave portion to the semiconductor wafer surface. For example, when metal electrodes (bumps) are formed on a semiconductor wafer, the highest point is the top of the highest bump, and the distance from there to the semiconductor wafer surface, i.e., the height of the bump, is the unevenness difference. Alternatively, when scribe lines (dicing lines) are formed on a semiconductor wafer, the deepest point is the deepest position of the scribe lines, and the distance from there to the semiconductor wafer surface is referred to as the unevenness difference. In the present invention, a numerical range expressed using "to" means a range including the numerical values ​​written before and after "to" as the lower and upper limits. In the present invention, "(meth)acrylic" is used to mean either "acrylic" or "methacrylic," or both.

[0012] [Electronic component processing tape] The electronic component processing tape of the present invention comprises a resin layer A, a primer layer, a resin layer B, and a pressure-sensitive adhesive layer in this order, with the primer layer containing an antistatic agent. The electronic component processing tape of the present invention has a configuration in which the pressure-sensitive adhesive layer to be attached to an electronic component is laminated in this order: resin layer A, a primer layer containing an antistatic agent, resin layer B, and a pressure-sensitive adhesive layer, and can exhibit excellent antistatic performance regardless of the thickness of the pressure-sensitive adhesive layer. Preferred embodiments of the electronic component processing tape of the present invention are described below.

[0013] As shown in Figure 1, the tape (1) for electronic component processing of the present invention is an integrated tape in which a primer layer (3), a resin layer B (4), and a pressure-sensitive adhesive layer (5) are laminated in this order on a resin layer A (2). The tape (1) for electronic component processing may further include a release film (not shown in Figure 1) on the pressure-sensitive adhesive layer (5) to protect the pressure-sensitive adhesive layer (5). The tape (1) for electronic component processing of the present invention may also be in the form of a roll of a laminate of the resin layer A (2), the primer layer (3), the resin layer B (4), the pressure-sensitive adhesive layer (5), and the release film.

[0014] (Resin Layer A) The resin (in the present invention, the term "resin" includes elastomers) constituting the resin layer A (2) used in the tape for processing electronic components (1) of the present invention is not particularly limited, and plastics, rubbers, etc. commonly used as materials for constituting substrate films in the technical field to which the present invention pertains can be used. Examples of resins constituting the resin layer A (2) include polyolefin resins composed of homopolymers or copolymers of monomers containing ethylenically unsaturated groups, such as polyethylene (e.g., low-density polyethylene), polypropylene, ethylene-propylene copolymer, polybutene-1, poly-4-methylpentene-1, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-acrylic acid copolymer, and ionomers; engineering plastics such as polyester resins (e.g., polyethylene terephthalate and polyethylene naphthalate), polycarbonate resin, polyurethane resin, and polymethyl methacrylate resin; synthetic rubbers (e.g., styrene-ethylene-butene copolymer or styrene-ethylene-pentene copolymer); and thermoplastic elastomers (e.g., polyamide-polyol copolymer). The resin constituting the resin layer A(2) may be one of the above resins or a combination of two or more of them. The resin layer A(2) may be a single layer or multiple layers. In addition to the above resins, the resin layer A(2) may contain additives such as colorants and antioxidants as needed, provided that the additives do not affect the physical properties. The resin constituting the resin layer A(2) is preferably a polyolefin resin or a polyester resin.

[0015] Melting point Tm of resin layer A(2) Ａ The melting point Tm of the resin layer A(2) is usually 80°C or higher, preferably 80 to 265°C, more preferably 100 to 265°C, even more preferably 150 to 265°C, and particularly preferably 170 to 265°C. ＡWhen the temperature is 80°C or higher, the resin layer A (2) can be prevented from melting and fusing to devices and the like due to the temperature environment when the electronic component processing tape (1) of the present invention is laminated to electronic components or when the electronic components are processed in a laminated state. For example, when the electronic component processing tape of the present invention is used as an adhesive tape for protecting the surface of a semiconductor wafer or a dicing die bonding integrated film (DDF), it can be prevented from fusing to a laminating roller or a chuck table when heat lamination is performed under conditions of about 40°C to 70°C. Note that when the resin layer A (2) is a multilayer, the above-mentioned "melting point Tm of the resin layer A (2)" can be used. Ａ " means the melting point of the layer constituting the outermost layer opposite to the primer layer (3) among the layers constituting the resin layer A (2). Ａ is a value measured at a temperature rise rate of 10°C / min by DSC (differential scanning calorimetry) method based on JIS (Japanese Industrial Standards) K 7121 (1987) Method for measuring transition temperature of plastics.

[0016] The thickness of the resin layer A(2) is not particularly limited, but is, for example, preferably 25 to 150 μm, more preferably 40 to 120 μm, and even more preferably 50 to 100 μm. When the resin layer A(2) is a multi-layered layer, the above "thickness of the resin layer A(2)" means the total thickness of all layers constituting the resin layer A(2).

[0017] The surface of the resin layer A (2) on which the primer layer (3) is to be formed may be appropriately subjected to treatment such as corona treatment or the formation of a primer layer in order to improve adhesion to the primer layer (3).

[0018] (Primer Layer) The electronic component processing tape (1) of the present invention includes a primer layer (3) containing an antistatic agent. The primer layer (3) used in the electronic component processing tape (1) of the present invention functions as an adhesive layer bonding the resin layer A and the resin layer B and as a relaxation layer for suppressing warpage after backgrinding (thin film grinding) of the semiconductor wafer. The antistatic agent contained in the layer enables the electronic component processing tape (1) of the present invention to exhibit antistatic properties. The adhesive constituting the primer layer (3) can be, for example, an acrylic adhesive or a polyester adhesive, and is preferred. The definition of acrylic adhesive is synonymous with the acrylic adhesive in the adhesive layer described below.

[0019] Examples of the (meth)acrylic acid ester copolymer constituting the acrylic pressure-sensitive adhesive include (meth)acrylic acid ester copolymers composed of structural units derived from at least two of a (meth)acrylic acid ester monomer, a (meth)acrylic acid ester monomer substituted with a functional group such as a hydroxy group, and (meth)acrylic acid. Examples of the (meth)acrylic acid ester monomer include a cycloalkyl (meth)acrylic acid ester, a benzyl (meth)acrylic acid ester, and a (meth)acrylic acid alkyl ester in which the alkyl group has 1 to 18 carbon atoms (preferably 1 to 12, more preferably 1 to 8, and even more preferably 1 to 4). Examples of the (meth)acrylic acid ester monomer substituted with a functional group such as a hydroxy group include a (meth)acrylic acid ester monomer in which the cycloalkyl group, benzyl group, or alkyl group constituting the ester in the (meth)acrylic acid ester is substituted with a hydroxy group. Hydroxyalkyl (meth)acrylates are preferred, such as 2-hydroxyethyl (meth)acrylate.

[0020] The acrylic adhesive used in the primer layer (3) preferably contains a crosslinking agent selected from polyisocyanate compounds, polyepoxy compounds, polyaziridine compounds, chelate compounds, etc., and more preferably a polyisocyanate compound. The polyisocyanate compound is not particularly limited, and examples thereof include aromatic isocyanates such as 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, 4,4'-diphenyl ether diisocyanate, and 4,4'-[2,2-bis(4-phenoxyphenyl)propane]diisocyanate, as well as hexamethylene diisocyanate, 2,2,4-trimethyl-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, lysine diisocyanate, and lysine triisocyanate. Commercially available crosslinking agents can also be used, such as Coronate L (manufactured by Tosoh Corporation). Examples of polyvalent epoxy compounds include epoxy resins, such as ethylene glycol diglycidyl ether, terephthalic acid diglycidyl ester acrylate, and anilines in which two glycidyl groups are substituted on the N atom. TETRAD-X (trade name, manufactured by Mitsubishi Chemical Corporation) can also be used. Examples of anilines include N,N'-tetraglycidyl-m-phenylenediamine. Examples of polyvalent aziridine compounds include tris-2,4,6-(1-aziridinyl)-1,3,5-triazine, tris[1-(2-methyl)-aziridinyl]phosphine oxide, and hexa[1-(2-methyl)-aziridinyl]triphosphatriazine. Examples of chelate compounds include ethyl acetoacetate aluminum diisopropylate and aluminum tris(ethyl acetoacetate).

[0021] The amount of the crosslinking agent to be added is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5.0 parts by mass, and even more preferably 0.5 to 4.0 parts by mass, per 100 parts by mass of the (meth)acrylic acid ester copolymer.

[0022] The polyester adhesive may be a copolymer made of a copolymerization component containing a polycarboxylic acid and a polyol. Examples of the polycarboxylic acid include dicarboxylic acids and polycarboxylic acids with a valence of three or more. Examples of the polyol component include dihydric alcohols and polyhydric alcohols with a valence of three or more. Commercially available polyester adhesives may be used, such as Nichigo Polyester LP (trade name) manufactured by Mitsubishi Chemical Corporation.

[0023] The adhesive constituting the primer layer (3) may be one of the above adhesives or a combination of two or more of them. The primer layer (3) may be a single layer or multiple layers. In addition to the above adhesives, the primer layer (3) may contain additives such as colorants and antioxidants as needed, as long as they do not affect the physical properties.

[0024] The antistatic agent contained in the primer layer (3) is not particularly limited, and any antistatic agent commonly used in electronic component processing tape applications can be used, as long as the electronic component processing tape (1) of the present invention can exhibit antistatic properties. In particular, when the antistatic agent is an ionic liquid, excellent antistatic properties can be exhibited on both the resin layer A (2) and the pressure-sensitive adhesive layer (5) of the electronic component processing tape (1) of the present invention. In the present invention, "ionic liquid" refers to a salt composed of an anion and a cation, and has a melting point of 30 to 80°C. The ionic liquid may be a quaternary ammonium salt-type ionic liquid containing an acryloyl group.

[0025] Examples of cations constituting the ionic liquid include nitrogen-containing onium cations such as pyridinium cation, imidazolium cation, pyrimidinium cation, pyrazolium cation, pyrrolidinium cation, and ammonium cation; phosphonium cation, and sulfonium cation. Examples of anions constituting the ionic liquid include hexafluorophosphate ion (PF ６ － ), thiocyanate ion (SCN －), alkylbenzenesulfonate ion (RC ６ H ４ SO ３ － ), perchlorate ion (ClO ４ － ), tetrafluoroborate ion (BF ４ － ), F-containing imide ion (R Ｆ ２ N － , as will be described in detail later.) and other inorganic or organic anions are examples. Preferred ionic liquids are compounds having at least one of the above cations and anions, with compounds having the above cations and anions being more preferred. The ionic liquid is preferably solid at room temperature (30°C), and by selecting the chain length of the alkyl group, the position and number of substituents, and the like, it is possible to obtain an ionic liquid having a melting point of 30 to 80°C. The cation constituting the ionic liquid is preferably a quaternary nitrogen-containing onium cation, and examples thereof include quaternary pyridinium cations such as 1-alkylpyridinium ions (carbon atoms at positions 2 to 6 may be substituted or unsubstituted), quaternary imidazolium cations such as 1,3-dialkylimidazolium ions (carbon atoms at positions 2, 4, and 5 may be substituted or unsubstituted), and acyclic quaternary ammonium cations such as tetraalkylammonium ions. The melting point of the ionic liquid is preferably 30 to 49°C.

[0026] Examples of quaternary ammonium salt-type ionic liquids containing an acryloyl group include those in which the cation constituting the ionic liquid is a ((meth)acryloyloxyalkyl)trialkylammonium ion [R ３ N ＋ -C ｎ H ２ｎ -OC(=O)CQ=CH ２ , where Q=H or CH ３ , R = alkyl)], and the anion constituting the ionic liquid is a hexafluorophosphate ion (PF ６ － ), thiocyanate ion (SCN － ), organic sulfonate ions (RSO３ － ), perchlorate ion (ClO ４ － ), tetrafluoroborate ion (BF ４ － ), F-containing imide ion (R Ｆ ２ N － ) and other inorganic or organic anions. Ｆ ２ N － ) in R Ｆ Examples of the F-containing imide ion include perfluoroalkanesulfonyl groups such as trifluoromethanesulfonyl and pentafluoroethanesulfonyl groups, and fluorosulfonyl groups. Examples of the F-containing imide ion include bis(fluorosulfonyl)imide ions [(FSO ２ ) ２ N － ], bis(trifluoromethanesulfonyl)imide ion [(CF ３ SO ２ ) ２ N － ], bis(pentafluoroethanesulfonyl)imide ion [(C ２ F ５ SO ２ ) ２ N － ] and the like.

[0027] Preferred specific examples of the ionic liquid include 1-octylpyridinium hexafluorophosphate, 1-nonylpyridinium hexafluorophosphate, 2-methyl-1-dodecylpyridinium hexafluorophosphate, 1-octylpyridinium dodecylbenzenesulfonate, 1-dodecylpyridinium thiocyanate, 1-dodecylpyridinium dodecylbenzenesulfonate, and 4-methyl-1-octylpyridinium hexafluorophosphate. Specific examples of the quaternary ammonium salt ionic liquid containing an acryloyl group include ((meth)acryloyloxymethyl)trimethylammonium hexafluorophosphate [(CH ３ ) ３ N ＋ CH ２ OC(=O)CQ=CH２ ・PF ６ － , where Q=H or CH ３ ], ethyl(2-(meth)acryloylethyl)trimethylammonium=bis(trifluoromethanesulfonyl)imide salt [(CH ３ ) ３ N ＋ (CH ２ ) ２ OC(=O)CQ=CH ２ ・(CF ３ SO ２ ) ２ N － , where Q=H or CH ３ ], ((meth)acryloyloxymethyl)trimethylammonium bis(fluorosulfonyl)imide salt [(CH ３ ) ３ N ＋ CH ２ OC(=O)CQ=CH ２ ・(FSO ２ ) ２ N － , where Q=H or CH ３ ] etc.

[0028] The content of the antistatic agent in the primer layer (3) is usually 1 to 20% by mass, which is sufficient to exhibit antistatic performance, with 1 to 15% by mass being preferred, 3 to 10% by mass being more preferred, and 4 to 10% by mass being even more preferred. Furthermore, the thickness of the primer layer (3) is preferably 1 to 55 μm, more preferably 5 to 55 μm, even more preferably 10 to 55 μm, and particularly preferably 15 to 55 μm, from the viewpoint of being able to fully exhibit antistatic performance. Considering the possibility of blade contamination during circle cutting, the upper limit of the thickness of the primer layer (3) is preferably 50 μm or less, more preferably 45 μm or less. When the primer layer (3) is a multilayered layer, the "thickness of the primer layer (3)" refers to the total thickness of all layers constituting the primer layer (3). In the tape for processing electronic components (1) of the present invention, when the thickness of the primer layer (3) is 10 to 55 μm and the content of the antistatic agent in the primer layer (3) is 4 to 10 mass %, excellent antistatic performance can be exhibited on both the resin layer A (2) and the pressure-sensitive adhesive layer (5) located on the back surface of the tape for processing electronic components (1) of the present invention, which is more preferable.

[0029] (Resin Layer B) The resin layer B (4) used in the tape for processing electronic components (1) of the present invention is a layer that enhances conformability to the unevenness of electronic components when the tape for processing electronic components (1) of the present invention is attached to the electronic components. Since the resin layer B (4) is not intended to be adhesive, it is preferably non-adhesive. Non-adhesive refers to a state where there is no stickiness at room temperature (25°C).

[0030] Examples of resins (including rubbers and elastomers) constituting the resin layer B(4) include resins made of ethylene-based copolymers, which are copolymers of ethylene with at least one comonomer selected from the group consisting of a radically polymerizable acid comonomer, an acrylic acid ester comonomer, a methacrylic acid ester comonomer, and a carboxylic acid vinyl ester comonomer; resins made of homopolymers or copolymers of monomers (α-olefins) containing ethylenically unsaturated groups, such as ionomers (excluding the above-mentioned resins made of ethylene-based copolymers); resins made of polyethylene (e.g., low-density polyethylene); and thermoplastic elastomers such as olefin-based thermoplastic elastomers having polyolefins such as polyethylene, polypropylene, polybutene-1, and poly-4-methylpentene-1 as hard segments and rubber components such as ethylene-propylene copolymers as soft segments. The resin layer B(4) may contain one of these resins alone or in combination of two or more. The resin layer B(4) may also have two or more layers.

[0031] Specific examples of the radically polymerizable acid comonomer include α,β-unsaturated dicarboxylic acids or anhydrides thereof, such as maleic acid, fumaric acid, citraconic acid, and itaconic acid, and unsaturated monocarboxylic acids, such as acrylic acid, methacrylic acid, crotonic acid, vinylacetic acid, and pentenoic acid, with maleic anhydride, acrylic acid, and methacrylic acid being preferred.Specific examples of the acrylic acid ester comonomer include methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate, with methyl acrylate, ethyl acrylate, and butyl acrylate being preferred.

[0032] Specific examples of the methacrylic acid ester comonomer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate, with methyl methacrylate and ethyl methacrylate being preferred.Specific examples of the carboxylic acid vinyl ester comonomer include vinyl formate, vinyl acetate, vinyl propionate, and vinyl butyrate, with vinyl acetate being preferred.

[0033] Specific examples of ethylene-based copolymers include binary copolymers such as ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-maleic anhydride copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, and ethylene-vinyl acetate copolymer. Ternary copolymers include ethylene-acrylic acid-methyl acrylate copolymer, ethylene-acrylic acid-ethyl acrylate copolymer, ethylene-acrylic acid-vinyl acetate copolymer, ethylene-methacrylic acid-methyl methacrylate copolymer, ethylene-methacrylic acid-ethyl methacrylate copolymer, ethylene-methacrylic acid-vinyl acetate copolymer, ethylene-maleic anhydride-methyl acrylate copolymer, ethylene-maleic anhydride-ethyl acrylate copolymer, ethylene-maleic anhydride-methyl methacrylate copolymer, ethylene-maleic anhydride-methyl methacrylate copolymer, ethylene-maleic anhydride-methyl methacrylate copolymer, and ethylene-maleic anhydride-vinyl acetate copolymer. Furthermore, quaternary or higher multi-component copolymers combining the above-mentioned comonomers are also included. Among the above copolymers, particularly preferred are ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-maleic anhydride-methyl acrylate copolymer, ethylene-maleic anhydride-ethyl acrylate copolymer, ethylene-maleic anhydride-methyl methacrylate copolymer, and ethylene-maleic anhydride-ethyl methacrylate copolymer, and more preferred are ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, and ethylene-butyl acrylate copolymer.

[0034] The proportion of the comonomer in the total mass of ethylene and the comonomer used in the synthesis of the ethylene copolymer is preferably 10% by mass to 50% by mass, more preferably 15% by mass to 40% by mass.

[0035] The resin constituting the resin layer B(4) may be one of the above resins or a combination of two or more of them. The resin layer B(4) may be a single layer or multiple layers.

[0036] Melting point Tm of resin layer B(4) Ｂ is the melting point Tm of the resin layer A (2) Ａ Between Ａ ≧Tm Ｂ It is preferable that Tm Ａ ≧Tm Ｂ If Ｂ More than Tm Ａ By laminating the tape (1) for electronic component processing of the present invention to an electronic component such as a semiconductor wafer while applying heat of less than 1000 kJ / cm2, the possibility of the back surface of the resin layer A (2) melting and fusing with a lamination roller, chuck table, or other device is reduced, and the tape can be laminated with good conformity to the irregularities of the semiconductor wafer. Furthermore, since the tape is cooled after lamination, the adhesive layer is fixed in a state where it is in close contact with the irregular surface of the electronic component such as a semiconductor wafer, thereby preventing dust from entering. The melting point Tm of the resin layer B (4) Ｂ Generally, the melting point Tm of the resin layer B(4) is 95°C or less, preferably 40 to 95°C, more preferably 40 to 80°C, and even more preferably 40 to 70°C. Ｂ " means the melting point of the layer constituting the outermost layer opposite to the pressure-sensitive adhesive layer 5 among the layers constituting the resin layer B(4). Ｂ is a value measured at a temperature rise rate of 10°C / min by DSC (differential scanning calorimetry) method based on JIS (Japanese Industrial Standards) K 7121 (1987) Method for measuring transition temperature of plastics.

[0037] The storage modulus of the resin layer B(4) at 70°C is, for example, 6.0 × 10 ６ Pa or less, and ６ Pa or less, and ３ ~3.0 x 10 ６ Pa, more preferably 1.0 × 10 ３ ~1.0 x 10 ６Pa, more preferably 1.0 × 10 ４ ~5.0 x 10 ５ It is particularly preferable that the storage modulus at 70°C of the resin layer B(4) is within the above-mentioned preferred range, it is possible to reliably ensure conformability to the uneven surface of an electrical component such as a semiconductor wafer. When the resin layer B(4) is a multi-layered layer, the above "storage modulus at 70°C of the resin layer B" means the "storage modulus at 70°C of the resin layer B" for each layer constituting the resin layer B(4). That is, the storage modulus at 70°C of the resin layer B(4) is 6.0 x 10 ６ When the storage modulus is "not more than 6.0 x 10 Pa," it means that each layer constituting the resin layer B(4) has a storage modulus of 6.0 x 10 Pa or less at 70°C. ６ This means that the storage modulus at 70°C is equal to or less than 100 Pa. The storage modulus at 70°C is a value measured using a dynamic viscoelasticity measuring device under the conditions described in the Examples. The storage modulus can be adjusted to a desired value by adjusting the amount of curing agent in the resin layer B(4), the molecular weight of the polymer, the content of comonomer, the glass transition point of the polymer, the addition of additives such as plasticizers, etc.

[0038] The thickness of the resin layer B (4) is preferably greater than the unevenness of the surface of an electronic component, such as a semiconductor wafer, to which the tape for processing electronic components (1) of the present invention is bonded. From the standpoints of manufacturability and thickness accuracy, a thickness of 100 μm to 400 μm is preferred. Taking a semiconductor wafer as an example, if the thickness is thinner than the unevenness of the semiconductor wafer, the adhesive layer 5 will not adhere sufficiently to the semiconductor wafer, resulting in dust intrusion and wafer cracking. The thickness of the resin layer B (4) used in the tape for processing electronic components (1) of the present invention is preferably 10 μm to 30 μm thicker than the unevenness of the electronic component, such as a semiconductor wafer. If the resin layer B (4) is too thick, the thickness accuracy of the semiconductor wafer may deteriorate and manufacturing costs may increase. Furthermore, when manufacturing the bump portion of a bumped semiconductor wafer, an error of approximately 10 μm occurs, so a thickness of 10 μm in addition to the average bump height allows for ample tracking. When the resin layer B(4) is a multi-layered layer, the "thickness of the resin layer B(4)" means the total thickness of all layers constituting the resin layer B(4).

[0039] The surface of the resin layer B (4) on which the pressure-sensitive adhesive layer (5) is provided may be appropriately treated by corona treatment, by providing a primer layer, or the like in order to improve adhesion to the pressure-sensitive adhesive layer (5). The surface of the resin layer B (4) on which the primer layer (3) is provided may also be appropriately treated by corona treatment, by providing a primer layer, or the like.

[0040] (Adhesive Layer) The adhesive layer (5) used in the electronic component processing tape (1) of the present invention may be any layer containing an adhesive, and may be formed using, for example, an adhesive composition. When the electronic component processing tape (1) of the present invention is applied to an electronic component, the adhesive layer (5) is attached to the uneven surface of the electronic component. An acrylic adhesive is preferably used as the adhesive constituting the adhesive layer (5). In the present invention, the term "acrylic adhesive" refers to an adhesive containing a copolymer having a (meth)acrylic acid ester as a constituent component (hereinafter referred to as "(meth)acrylic acid ester copolymer") as the main polymer (adhesive base polymer). In addition to the (meth)acrylic acid ester copolymer, the adhesive may also contain a crosslinking agent, as described below. Here, "containing a (meth)acrylic acid ester copolymer as the main component" means that the content of the (meth)acrylic acid ester copolymer in the polymer or resin constituting the base resin of the adhesive is at least 50% by mass, preferably 80% by mass or more (100% by mass or less).

[0041] The adhesive constituting the adhesive layer (5) may be a radiation-curable adhesive that cures upon irradiation with radiation, or a non-radiation-curable adhesive that does not cure upon irradiation with radiation. Examples of the radiation-curable adhesive include the radiation-curable adhesives described in paragraphs

[0035] to

[0076] of International Publication No. 2018 / 181240 and the radiation-curable adhesives described in paragraphs

[0031] to

[0050] of JP-A No. 2022 / 109374.

[0042] The non-radiation-curable pressure-sensitive adhesive is preferably a non-radiation-curable acrylic pressure-sensitive adhesive, and examples of the pressure-sensitive adhesive base polymer in the non-radiation-curable acrylic pressure-sensitive adhesive include a (meth)acrylic acid ester monomer or a (meth)acrylic acid ester copolymer composed of a structural unit derived from a (meth)acrylic acid ester monomer and (meth)acrylic acid. Here, examples of the (meth)acrylic acid ester monomer that can be used include the (meth)acrylic acid ester monomer used in the primer layer (3) described above and a (meth)acrylic acid ester monomer substituted with a functional group such as a hydroxyl group.

[0043] The non-radiation-curable pressure-sensitive adhesive composition may optionally contain a crosslinking agent. The crosslinking agent is a compound selected from polyisocyanate compounds, melamine-formaldehyde resins, and epoxy resins, and may be used alone or in combination of two or more. The crosslinked structure formed as a result of the reaction with the (meth)acrylic copolymer can improve the cohesive strength of the pressure-sensitive adhesive after application. The polyisocyanate compound is not particularly limited, and for example, the polyisocyanate compounds used in the aforementioned primer layer (3) can be used. Specific examples of commercially available products include Coronate L (product name, manufactured by Tosoh Corporation). Specific examples of commercially available melamine-formaldehyde resins include Nikalac MX-45 (manufactured by Sanwa Chemical Co., Ltd.) and Melan (product name, manufactured by Hitachi Chemical Co., Ltd.). Furthermore, examples of epoxy resins that can be used include TETRAD-X (product name, manufactured by Mitsubishi Chemical Corporation).

[0044] The amount of crosslinking agent added can be adjusted appropriately to obtain the desired adhesive properties relative to 100 parts by mass of the adhesive base polymer; for example, it is preferably 0.1 to 20 parts by mass, and more preferably 0.1 to 5 parts by mass.

[0045] In addition, the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer (5) may contain, as necessary, a release agent, a tackifier, a viscosity adjuster, a surfactant, or other modifiers, etc. Furthermore, it may contain an inorganic compound filler.

[0046] The thickness of the pressure-sensitive adhesive layer (5) can be, for example, 5 to 150 μm, preferably 10 to 150 μm, more preferably 50 to 150 μm, even more preferably more than 100 μm but not more than 150 μm, and also preferably 105 to 140 μm. In particular, the tape for processing electronic components (1) of the present invention can exhibit excellent antistatic performance even when the pressure-sensitive adhesive layer (5) is made thicker than 100 μm from the viewpoint of improving conformability to the irregularities of the surface of the adherend.

[0047] (Release Film) In the electronic component processing tape (1) of the present invention, a release film is optionally provided on the adhesive layer (5). The release film, also known as a separator, release layer, or release liner, is provided for the purpose of protecting the adhesive layer (5) and smoothing the adhesive layer (5). Examples of materials for the release film include synthetic resin films such as polyethylene, polypropylene, and polyethylene terephthalate, as well as paper. The surface of the release film may be subjected to a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment to enhance releasability from the adhesive layer (5). Furthermore, if necessary, an ultraviolet protection treatment may be applied to prevent the adhesive layer (5) from reacting due to unintended exposure to ultraviolet light, such as environmental ultraviolet light. The thickness of the release film is typically 10 to 100 μm, preferably 25 to 50 μm.

[0048] (Method for Manufacturing the Electronic Component Processing Tape of the Present Invention) The method for manufacturing the electronic component processing tape of the present invention is not particularly limited and can be produced by conventional methods. The resin layer A (2) and the resin layer B (4) can be produced by conventional methods such as extrusion, inflation, and casting. Alternatively, an independently formed film can be bonded to another film with an adhesive or the like to form a multilayer resin layer A (2) or a multilayer resin layer B (4). The primer layer (3) and the pressure-sensitive adhesive layer (5) can be formed by applying a composition for forming the primer layer (3) (primer composition) or a composition for forming the pressure-sensitive adhesive layer (5) (pressure-sensitive adhesive composition) to a release film or a film-like resin layer A (2) or resin layer B (4) and drying the composition. The obtained primer layer (3) and the pressure-sensitive adhesive layer (5) can be laminated as layers constituting the electronic component processing tape of the present invention by laminating or transferring them with other layers according to the laminate structure to be incorporated into the electronic component processing tape of the present invention. Examples of methods for manufacturing the electronic component processing tape of the present invention include the following methods. However, the manufacturing method of the electronic component processing tape of the present invention is not limited to the following. A primer composition is applied to a film-like resin layer A (2) and dried. Then, a film-like resin layer B (4) is laminated to the layer obtained by applying and drying the primer composition, thereby obtaining an adhesive film 1. Separately from the adhesive film 1, a pressure-sensitive adhesive composition is applied to the release-treated surface of a release film and dried to produce an adhesive layer (5). The resulting adhesive layer (5) is then laminated to the surface of the resin layer B (4) of the adhesive film 1, and the adhesive layer (5) is transferred to obtain an electronic component processing tape. The release film used to prepare the adhesive layer (5) may remain attached to the electronic component processing tape. However, when using the electronic component processing tape of the present invention, the release film is peeled off from the adhesive layer (5) before use.

[0049] (Uses of the Electronic Component Processing Tape of the Present Invention) The electronic component processing tape of the present invention can be suitably used for processing electronic components, for example, by adhering it to the uneven surface of the electronic component having an uneven surface. In particular, it exhibits excellent unevenness-following ability and is suitable for use with electronic components having a large unevenness difference. An example of the use of the electronic component processing tape of the present invention is a semiconductor processing adhesive tape used in semiconductor wafer processing. For example, it can be suitably used as a semiconductor processing surface protection adhesive tape that is adhered to the uneven surface of a semiconductor wafer in a semiconductor chip manufacturing method in which a semiconductor wafer is diced into chips by backgrinding. It is also suitable as a DDF.

[0050] [Method for Processing Semiconductor Wafers] Hereinafter, a method for processing semiconductor wafers will be described as an example of a method for processing electronic components using the tape for processing electronic components of the present invention, although the application of the tape for processing electronic components of the present invention is not limited to this use.

[0051] The tape (1) for processing electronic parts of the present invention may be used in any step of the semiconductor wafer processing process, such as a back grinding step, a dicing step, and a dicing die bonding step.

[0052] The electronic component processing tape (1) of the present invention can be applied to the surface of a semiconductor wafer having a surface unevenness of 20 μm or more (height of the bumps (electrodes) or depth of the scribe lines), and is preferably applied to semiconductor wafers having a surface unevenness of 200 μm or more, more preferably 200 to 400 μm. As described in the examples below, the electronic component processing tape (1) of the present invention can exhibit good conformability to the surface unevenness even on semiconductor wafers having a surface unevenness of more than 100 μm. The types of bumps and electrodes on the semiconductor wafer are not particularly limited. For example, the tape can exhibit good conformability to bumps formed by any of the plating bump method, screen printing method, and ball mounting method.

[0053] The arrangement density (high density) of the bumps on the surface of the semiconductor wafer is not particularly limited. For example, it can be applied to bumps with a pitch (distance from the apex of a bump in the height direction to the apex of the next bump in the height direction) of 0.5 to 3 times or less, preferably 1 to 2 times or less, the height of the bumps. It can also be used for semiconductor wafers with bumps arranged uniformly over the entire surface.

[0054] The thickness of the semiconductor wafer before backgrinding is not particularly limited, and may be, for example, 500 to 800 μm. Furthermore, the thickness of the semiconductor wafer after backgrinding using the tape for processing electronic components (1) of the present invention can also be made to a desired thickness, for example, 20 to 500 μm, preferably 50 to 200 μm, and more preferably 80 to 200 μm.

[0055] In the method for processing a semiconductor wafer using the tape for processing electronic components (1) of the present invention, it is preferable to include a step of laminating the tape for processing electronic components (1) of the present invention, in which the pressure-sensitive adhesive layer (5) is a radiation-curable type, to a semiconductor wafer, and then irradiating the tape with radiation (preferably ultraviolet light) to peel off the tape for processing electronic components.

[0056] For example, the electronic component processing tape (1) of the present invention is first laminated to the circuit pattern surface (front surface) of a semiconductor wafer with the adhesive layer (5) facing the wafer. Next, the side of the semiconductor wafer opposite the circuit pattern is ground until the semiconductor wafer reaches a predetermined thickness, e.g., 10 to 200 μm. The electronic component processing tape is then placed on a heating and adsorption platform with the adhesive side facing down, and a dicing / die-bonding film may be laminated to the ground surface of the semiconductor wafer. After the dicing process, a heat-sealing or adhesive release tape is adhered to the back surface of the resin layer A (2) of the electronic component processing tape (1), and the electronic component processing tape (1) is then peeled from the semiconductor wafer. When peeling the electronic component processing tape (1), if the adhesive layer (5) is radiation-curable, it is preferable that the adhesive layer (5) be cured by irradiation with radiation (preferably ultraviolet light) to reduce its adhesive strength.

[0057] The present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[0058] <Resin Layer A> (Film A1) As Film A1, a 50 μm thick polyethylene terephthalate (PET) film that had been subjected to corona treatment on one side was prepared. (Film A2) As Film A2, a 50 μm thick polypropylene (PP) film that had been subjected to corona treatment on one side was prepared. (Film A3) Melting point Tm Ａ A low-density polyethylene resin (LDPE) having a melting point Tm of 105°C was extruded to a thickness of 100 μm to form a film, and one side of the obtained film was subjected to a corona treatment to obtain Film A3. (Film A4) Ａ Ethylene-vinyl acetate copolymer resin (EVA) having a viscosity of 90° C. was extruded to form a film having a thickness of 100 μm, and one side of the obtained film was subjected to a corona treatment to obtain film A4.

[0059] <Resin Layer B> (Film B1) Melting Point Tm Ｂ The storage modulus at 70°C is 1.4 × 10 ５ Ethylene-vinyl acetate copolymer (EVA) of 1000 Pa was extruded to a thickness of 350 μm to form a film, and both sides of the obtained film were subjected to corona treatment to obtain Film B1. (Film B2) Melting point Tm Ｂ The storage modulus at 70°C is 8.5 × 10 ４ An olefin-based thermoplastic elastomer (TPO) having a melting point of 100 Pa was extruded to a thickness of 350 μm to form a film, and both surfaces of the obtained film were subjected to a corona treatment to obtain Film B2. (Film B3) Melting point Tm Ｂ The storage modulus at 70°C is 2.8 × 10 ６ A poly-α-olefin having a melting point Tm of 100 Pa was extruded to form a film having a thickness of 350 μm, and both surfaces of the obtained film were subjected to a corona treatment to obtain Film B3. (Film B4) Melting point Tm Ｂ at 90°C, and the storage modulus at 70°C is 3.9 × 10 ６The poly-α-olefin Pa was extruded to a thickness of 350 μm to form a film, and both surfaces of the obtained film were subjected to corona treatment to obtain film B4.

[0060] <Primer Composition> (Preparation of Primer Composition 1) 1.0 part by mass of Coronate L (trade name, manufactured by Tosoh Corporation) and 5.0 parts by mass of an ionic liquid (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Elexel MP-402A) as an antistatic agent were added to 100 parts by mass of a copolymer consisting of 80 parts by mass of ethyl acrylate, 15 parts by mass of 2-hydroxyethyl acrylate, and 5 parts by mass of methacrylic acid, and mixed to obtain Primer Composition 1. (Preparation of Primer Composition 2) 1.0 part by mass of Coronate L (trade name, manufactured by Tosoh Corporation) and 5.0 parts by mass of an ionic liquid (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Elexel MP-402A) as an antistatic agent were added to 100 parts by mass of a polyester-based pressure-sensitive adhesive (manufactured by Mitsubishi Chemical Corporation, trade name: Nichigo Polyester LP-011S50EO), and mixed to obtain Primer Composition 2. (Preparation of Primer Composition 3) Primer composition 3 was obtained by adding 1.0 part by mass of Coronate L (trade name, manufactured by Tosoh Corporation) to 100 parts by mass of a copolymer consisting of 80 parts by mass of ethyl acrylate, 15 parts by mass of 2-hydroxyethyl acrylate, and 5 parts by mass of methacrylic acid and mixing them.

[0061] <Adhesive Compositions> (Preparation of Adhesive Composition 1) 1.0 part by mass of Coronate L (trade name, manufactured by Tosoh Corporation) was added to 100 parts by mass of a copolymer consisting of 70 parts by mass of butyl acrylate, 28 parts by mass of 2-hydroxyethyl acrylate, and 2 parts by mass of methacrylic acid, and they were mixed to obtain Adhesive Composition 1. (Preparation of Adhesive Composition 2) 1.0 part by mass of Coronate L (trade name, manufactured by Tosoh Corporation) and 0.5 parts by mass of tetradecyldimethylbenzylammonium chloride (manufactured by NOF Corporation, trade name: NissanCation M2-100) as an ion-conductive additive were added to 100 parts by mass of a copolymer consisting of 70 parts by mass of butyl acrylate, 28 parts by mass of 2-hydroxyethyl acrylate, and 2 parts by mass of methacrylic acid, and they were mixed to obtain Adhesive Composition 2.

[0062] <Preparation of Tape for Electronic Component Processing> (Example 1) Primer composition 1 was applied to the corona-treated surface of film A1 as resin layer A so that the film thickness after drying would be 30 μm, and then dried. Immediately after drying, film B1 as resin layer B was laminated to the dried layer side of primer composition 1, thereby obtaining laminated film 1. Separately from the laminated film 1, pressure-sensitive adhesive composition 1 was applied to the release-treated surface of a 40 μm-thick polypropylene (PP) separator (also referred to as a release film) that had been release-treated on one side, so that the film thickness after drying would be 10 μm, and then dried to obtain a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer was then transferred by laminating it to the surface side of resin layer B of the laminated film 1, thereby obtaining the tape for electronic component processing of Example 1. The tape for processing electronic components (1) of Example 1 obtained in this manner has a structure in which a resin layer A (2), a primer layer (3), a resin layer B (4), and a pressure-sensitive adhesive layer (5) are laminated in this order, as shown in Figure 1, and a release film (not shown in Figure 1) is further laminated on the pressure-sensitive adhesive layer (5).

[0063] Examples 2 to 12 and Comparative Example 1 were prepared in the same manner as in the preparation of the electronic component processing tape of Example 1, except that the configuration of at least one of the resin layer A (2), primer layer (3), resin layer B (4), and adhesive layer (5) was changed to the configurations described in Tables 1-1 and 1-2 below. The electronic component processing tapes (1) of Examples 2 to 12 obtained in this manner have a structure in which, as shown in FIG. 1 , the resin layer A (2), primer layer (3), resin layer B (4), and adhesive layer (5) are laminated in this order, with a release film (not shown in FIG. 1 ) further laminated on the adhesive layer (5). The electronic component processing tape of Comparative Example 1 also has a structure in which the resin layer A (2), primer layer (3), resin layer B (4), and adhesive layer (5) are laminated in this order, with a release film further laminated on the adhesive layer (5).

[0064] (Comparative Example 2) The ethylene-vinyl acetate copolymer (EVA) used in producing film B1 was extruded to a thickness of 350 μm onto the corona-treated surface of film A1 as resin layer A to form resin layer B, and corona treatment was performed on the surface of the resin layer B side to obtain a laminated film 2. Separately from the laminated film 2, a 25 μm-thick polyethylene terephthalate (PET) separator (also referred to as a release film) with one side subjected to release treatment was coated on the release-treated surface with a conductive material containing polyethylene dioxythiophene / polystyrene sulfonic acid (PEDOT / PSS) (manufactured by Nagase ChemteX Corporation, product name: Denatron P-504CT) as an intermediate layer forming material so that the film thickness after drying would be 0.1 μm, and the laminated film 2 was bonded to the surface of resin layer B, and the PET separator was peeled off to transfer the intermediate layer, thereby obtaining a laminated film 3. Furthermore, separately from the above-mentioned laminating film 3, the pressure-sensitive adhesive composition 1 was applied to the release-treated surface of a 40 μm-thick polypropylene (PP) separator that had been subjected to a release treatment on one side, so that the film thickness after drying would be 120 μm, and then dried to obtain a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer was then transferred by laminating it to the surface of the intermediate layer of the above-mentioned laminating film 3, thereby obtaining a tape for processing electronic components of Comparative Example 2. The tape for processing electronic components of Comparative Example 2 obtained in this manner has a structure in which a resin layer A (2), a resin layer B (4), an intermediate layer, and a pressure-sensitive adhesive layer (5) are laminated in this order, and a release film is further laminated on the pressure-sensitive adhesive layer (5).

[0065] (Comparative Example 3, Reference Example 1) In the preparation of the tape for processing electronic components of Comparative Example 2, the configuration of the pressure-sensitive adhesive layer (5) was changed to the configuration described in Table 1-2 below, and the tapes for processing electronic components of Comparative Example 3 and Reference Example 1 were prepared in the same manner.

[0066] The obtained tape for processing electronic components was evaluated as follows. The melting points of the resin layer A (2) and the resin layer B (4), the storage modulus of the resin layer B (4), and the thickness of each layer (the resin layer A (2) and the resin layer B (4), the primer layer (3), and the pressure-sensitive adhesive layer (5)) were measured by the following methods. These results are shown in Tables 1-1 and 1-2 (collectively referred to as "Table 1").

[0067] [1. Evaluation Method of Antistatic Performance] A control tape containing no antistatic agent was prepared in the same manner as the above-mentioned electronic component processing tape, except that no antistatic agent was added. The surface resistivity of each resin layer A side of the electronic component processing tape and the control tape, as well as the adhesive layer side after the release film was peeled off from the electronic component processing tape and the control tape, was measured as follows. (Surface Resistivity) 10 x 10 cm test pieces cut from the electronic component processing tape and the control tape were stored for 24 hours at a temperature of 23°C and a relative humidity of 50%. Thereafter, the surface resistivity was measured at an applied voltage of 0.10 V, a temperature of 23°C, and a relative humidity of 50% using a digital ultra-high resistance / microcurrent meter (model number: 8340A) and a resistivity chamber (model number: R12704) manufactured by Advantest Corporation. Using each surface resistivity value measured as above, X 樹脂層Ａ面 = [surface resistivity of the resin layer A side of the control tape] / [surface resistivity of the resin layer A side of the tape for processing electronic components], and X 粘着剤層面 The value of the formula "surface resistivity of the adhesive layer surface of the control tape" divided by the value of the adhesive layer surface of the tape for processing electronic components" was calculated, and the antistatic performance was evaluated based on the following criteria: - antistatic performance - ⊚: X 樹脂層Ａ面 and X 粘着剤層面 The values ​​are all 10 or more, and sufficient antistatic effect is obtained on both sides. 樹脂層Ａ面 and X 粘着剤層面 Of these, one is 10 or more and has a sufficient antistatic effect, and the other is less than 10 and does not have a sufficient antistatic effect. 樹脂層Ａ面 and X 粘着剤層面 The values ​​are all less than 10, and neither side has a sufficient antistatic effect.

[0068] [2. Evaluation method for conformability to irregularities] The above-prepared tape for processing electronic components was laminated to the bump-bearing surface of an 8-inch diameter semiconductor wafer having solder ball-shaped bumps with a ball width of approximately 230 μm on its surface at a height (distance from the surface of the semiconductor wafer substrate to the highest point of the bump) of 200 μm and a pitch (distance between the tops of the bumps) of 400 μm, using a BG (back grinding) tape laminator (manufactured by Lintec Corporation, product name: RAD3510F / 8) at a lamination table temperature of 70° C., a roller temperature of 65° C., a roll pressure of 0.3 MPa, and a roll speed of 3 mm / sec, and circle cutting was then performed. The thickness of the semiconductor wafer laminated with the electronic component processing tape was measured using a spindle-type dial gauge (manufactured by Mitutoyo Corporation) from the non-bumped surface of the semiconductor wafer (starting point) to the end point of the resin layer A (2) of the electronic component processing tape that was not in contact with the primer layer (3), with the dial gauge's measuring probe facing the electronic component processing tape. Specifically, the thickness at the center of the semiconductor wafer (the center of the circle) was measured as α, and the thickness at the edge of the semiconductor wafer (the portion without bumps) as β. Insufficient conformability results in a large α due to the formation of gaps between the electronic component processing tape and the semiconductor wafer. A sample satisfying α-β≦60 μm was evaluated as having good conformability and marked with a "Good", a sample satisfying 60 μm<α-β≦85 μm was evaluated as having good conformability and marked with a "Good", and a sample satisfying 85 μm<α-β was evaluated as an "Poor".

[0069] (Melting points of resin layers A and B) Melting point Tm of resin layer A (2) Ａ and the melting point Tm of the resin layer B(4) Ｂ was measured at a heating rate of 10°C / min using a high-sensitivity differential scanning calorimeter (manufactured by Hitachi High-Tech Science Corporation, trade name: DSC7000X) in accordance with JIS (Japanese Industrial Standards) K 7121 (1987) Method for measuring transition temperature of plastics.

[0070] (Storage modulus of resin layer B) The storage modulus of resin layer B (4) at 70 ° C. was measured using a dynamic viscoelasticity measuring device (manufactured by Thermo Fisher Scientific, trade name: HAAKE MARS iQ rheometer) by the following method. That is, a measurement sample having a thickness of 1000 μm was prepared using the resin constituting resin layer B (4), and the temperature was raised from room temperature (25 ° C.) to 100 ° C. at a heating rate of 10 ° C. / min while applying a shear strain of 1 Hz frequency, and the storage modulus at 70 ° C. was measured. In the table, the storage modulus at 70 ° C. is simply referred to as "elastic modulus at 70 ° C."

[0071] (Thickness of Each Layer) The thickness of each layer was measured on a surface plate using a spindle type dial gauge (manufactured by Mitutoyo Corporation).

[0072]

[0073]

[0074] The films, primer compositions, and adhesive compositions listed in the columns for Resin Layer A and B are as described at the beginning of each example. (Resin Layer A) PET: polyethylene terephthalate PP: polypropylene LDPE: low-density polyethylene EVA: ethylene-vinyl acetate copolymer (Primer Layer) Ionic liquid: Elexel MP-402A (trade name) manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. (Resin Layer B) EVA: ethylene-vinyl acetate copolymer TPO: olefin-based thermoplastic elastomer (Intermediate Layer) P-504CT: conductive material containing polyethylenedioxythiophene / polystyrene sulfonate (PEDOT / PSS) (manufactured by Nagase ChemteX Corporation, trade name: Denatron P-504CT) "-": indicates that the component and / or layer is not present. Content: For the primer layer, this refers to the content of the antistatic agent in the layer, and for the adhesive layer, this refers to the content of the ion-conductive additive in the layer.

[0075] The results in Table 1 reveal the following: The electronic component processing tape of Comparative Example 1 does not contain an antistatic agent and therefore does not exhibit antistatic properties. The electronic component processing tapes of Comparative Examples 2 and 3 and Reference Example 1 are different from the electronic component processing tape of the present invention in that they include a resin layer A, a resin layer B, an intermediate layer made of a conductive material, and an adhesive layer, in that order. Thus, in an electronic component processing tape in which the layer adjacent to the adhesive layer is an intermediate layer made of a conductive material, as shown in Reference Example 1, when the adhesive layer is as thin as 40 μm, antistatic properties are exhibited on one side of the tape, but when the adhesive layer is as thick as 120 μm, antistatic properties are not exhibited on either side of the tape, as shown in Comparative Example 2. The content of the conductive material (antistatic agent) in the intermediate layer of the electronic component processing tapes of Comparative Examples 2 and 3 is nearly 100%, and the content of the conductive material cannot be increased. On the other hand, increasing the thickness of the intermediate layer to improve antistatic properties results in a decrease in conformity to uneven surfaces and is not practical from the standpoints of productivity and cost. Furthermore, even when an ion-conductive additive, which is described in Patent Document 2 as improving antistatic performance, was further added to the adhesive layer, when the adhesive layer was as thick as 120 μm, sufficient antistatic performance was not exhibited on either the front or back surface of the tape, as shown in Comparative Example 3. In contrast, Examples 1 to 12, which are tapes for processing electronic components as defined in the present invention, were able to maintain sufficient antistatic performance regardless of the thickness of the adhesive layer, in a thickness range of 10 to 120 μm.

[0076] While the present invention has been described in connection with embodiments thereof, we do not intend to limit our invention to any of the details of the description unless otherwise specified, and believe that the claims should be construed broadly without departing from the spirit and scope of the invention as set forth in the appended claims.

[0077] This application claims priority based on Japanese Patent Application No. 2024-054431, filed on March 28, 2024, the contents of which are incorporated herein by reference as part of the present specification.

[0078] REFERENCE SIGNS LIST 1 Tape for processing electronic components 2 Resin layer A 3 Primer layer 4 Resin layer B 5 Pressure-sensitive adhesive layer

Claims

1. A tape for processing electronic components, comprising a resin layer A, a primer layer, a resin layer B, and an adhesive layer in this order, wherein the primer layer contains an antistatic agent.

2. The tape for processing electronic components according to claim 1, wherein the antistatic agent is an ionic liquid.

3. The tape for processing electronic components according to claim 1 or 2, wherein the adhesive constituting the primer layer is an acrylic adhesive or a polyester adhesive.

4. The tape for processing electronic components according to any one of claims 1 to 3, wherein the adhesive constituting the adhesive layer is an acrylic adhesive.

5. The tape for processing electronic parts according to any one of claims 1 to 4, wherein the thickness of the primer layer is 1 to 55 μm.

6. Melting point Tm of the resin layer A Ａ and the melting point Tm of the resin layer B Ｂ But, Tm Ａ ≧Tm Ｂ The tape for processing electronic parts according to any one of claims 1 to 5, wherein the above formula (1) is satisfied.

7. Melting point Tm of the resin layer A Ａ The tape for processing electronic parts according to any one of claims 1 to 6, characterized in that the temperature is 80°C or higher.

8. The storage modulus of the resin layer B at 70°C is 3.0 x 10 ６ The tape for processing electronic parts according to any one of claims 1 to 7, characterized in that it has a viscosity of 100 Pa or less.

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