Electronic component processing tape

Abstract

To provide an electronic component processing tape that does not cause a problem of contamination by an antistatic agent on an adherend or device that comes into contact with the tape, and that can achieve both good conformability to the irregularities on the surface of electronic components and excellent antistatic performance even when the thickness of the adhesive layer is increased.SOLUTION: An electronic component processing tape (1) includes a resin layer A (2), a primer layer (3), a resin layer B (4), and an adhesive layer (5) in this order, and the primer layer (3) contains an antistatic agent. There are no particular restrictions on the antistatic agent contained in the primer layer (3), as long as the tape for processing electronic components (1) can exhibit antistatic properties.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] 2. Description of the Related Art In the processing of electronic components such as semiconductor wafers, tapes having an adhesive layer on the adhesive surface that adheres to the electronic components 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, the backside of the semiconductor wafer is ground and polished to a predetermined thickness (so-called backside grinding and polishing). At this time, in order to protect the surface of the semiconductor wafer, a tape for processing electronic components is attached to 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 the semiconductor elements when the electronic component processing tape is applied to the semiconductor wafer, when the semiconductor wafer is cut using a dicing saw, when the semiconductor elements are picked up in the pickup process, and when the electronic component processing tape is peeled off from the semiconductor elements. The generated static electricity can cause problems such as destruction of circuits formed on the semiconductor wafer (electrostatic destruction 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 as described above, studies have been made 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 a pressure-sensitive 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 that is composed of a laminate comprising 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 is used to temporarily fix at least one of a substrate and a component. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-210479 [Patent Document 2] Japanese Patent Application Publication No. 2018-006540 [Patent Document 3] Japanese Patent Publication No. 2021-015953 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, with the trend toward thinner packaging and smaller chip mounting areas, a mounting method known as flip-chip mounting has been adopted. 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 the semiconductor wafer. Depending on the bump formation method, these bumps can have a bump height (the difference in unevenness on the semiconductor wafer surface) of over 100 μm. Tapes for electronic component processing that are bonded to semiconductor wafers with such large surface unevenness are required to have high conformability to uneven surfaces. Furthermore, with the need for higher bump density and narrower wiring pitch on semiconductor wafers, semiconductor wafers are becoming more susceptible to static electricity than ever before, and further improvements in anti-static performance are required.

[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 of incorporating an antistatic agent into the adhesive layer described in Patent Document 1 raises concerns about the antistatic agent contaminating adherends, such as semiconductor wafers, to which the tape is attached. Similarly, the technology of incorporating a conductive material as an antistatic agent into the base layer described in Patent Document 3 also raises concerns about the antistatic agent contaminating devices 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, which solves the problem of contamination of the adherend, equipment, etc. by the antistatic agent. However, according to the studies of the present inventors, when the adhesive layer is made thick (for example, when it exceeds 100 μm) in order to achieve high conformability to the surface of an adherend with large surface unevenness, it has been found that it is difficult for the antistatic layer disposed as an intermediate layer to exhibit the desired antistatic performance (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). [Means for solving the problem]

[0008] The above-mentioned problems of the present invention have been solved by the following means. <1> a resin layer A, a primer layer, a resin layer B, and a pressure-sensitive adhesive layer in this order; A tape for processing electronic components, wherein the primer layer contains an antistatic agent. <2> The antistatic agent is an ionic liquid. <1> The tape for processing electronic components according to claim 1. <3> The adhesive constituting the primer layer is an acrylic adhesive or a polyester adhesive. <1> or <2> The tape for processing electronic components according to claim 1. <4> The adhesive layer is characterized in that the adhesive is an acrylic adhesive. <1> ~ <3> 10. The tape for processing electronic components according to claim 9. <5> The thickness of the primer layer is 1 to 55 μm. <1> ~ <4> 10. The tape for processing electronic components according to claim 9. <6> The melting point Tm of the resin layer A A and the melting point Tm of the resin layer B B Toga, Tm A ≧Tm B characterized in that <1> ~ <5> 10. The tape for processing electronic components according to claim 9. <7> The melting point Tm of the resin layer A A is 80°C or higher, <1> ~ <6> 10. The tape for processing electronic components according to claim 9. <8> The storage modulus of the resin layer B at 70°C is 3.0 × 10 6 Pa or less, <1> ~ <7> 10. The tape for processing electronic components according to claim 9. [Effects of the Invention]

[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. [Brief explanation of the drawings]

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

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

[0012] [Tape for processing electronic components] The tape for processing electronic parts 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, and the primer layer contains an antistatic agent. The tape for processing electronic components of the present invention has a pressure-sensitive adhesive layer that is attached to electronic components, and is configured by laminating a resin layer A, a primer layer containing an antistatic agent, a resin layer B, and a pressure-sensitive adhesive layer in that order, and can exhibit excellent antistatic performance regardless of the thickness of the pressure-sensitive adhesive layer. A preferred embodiment of the tape for processing electronic parts of the present invention will be described below.

[0013] As shown in Fig. 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 Fig. 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. that are commonly used as materials for constituting base films in the technical field to which the present invention belongs can be used. Examples of resins that can be used to form the resin layer A(2) include polyolefin resins made of homopolymers or copolymers of monomers containing ethylenically unsaturated groups, such as polyethylenes such as low-density polyethylene, polypropylene, ethylene-propylene copolymers, polybutene-1, poly-4-methylpentene-1, ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, ethylene-methyl acrylate copolymers, ethylene-acrylic acid copolymers, and ionomers; engineering plastics such as polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polycarbonate resins, polyurethane resins, and polymethyl methacrylate resins; synthetic rubbers such as styrene-ethylene-butene copolymers or styrene-ethylene-pentene copolymers; and thermoplastic elastomers such as polyamide-polyol copolymers. 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 resin, 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 heating temperature 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. Melting point Tm of resin layer A(2) A When the temperature is 80°C or higher, the resin layer A (2) can be prevented from melting and fusing to devices, etc., due to the temperature environment when the tape for processing electronic components (1) of the present invention is attached to electronic components or when the electronic components are processed in the attached 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 as a dicing-die bonding integrated film (DDF), it can prevent adhesion to a lamination roller or chuck table when heated and laminated at temperatures of approximately 40°C to 70°C. In addition, when the resin layer A(2) is a multi-layer, the above-mentioned "melting point Tm A " means the melting point of the layer that constitutes the outermost layer opposite to the primer layer (3) among the layers that constitute the resin layer A (2). Melting point Tm A is a value measured at a heating rate of 10°C / min by DSC (differential scanning calorimetry) 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 preferably, for example, 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 "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 tape (1) for processing electronic parts of the present invention has a primer layer (3) containing an antistatic agent. The primer layer (3) used in the tape (1) for electronic component processing of the present invention functions as an adhesive layer that bonds the resin layer A and the resin layer B, and as a relaxation layer that suppresses warping after back grinding (thin film grinding) of the semiconductor wafer, and the antistatic agent contained in the layer enables the tape (1) for electronic component processing 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 acrylic pressure-sensitive adhesive has the same definition as the acrylic pressure-sensitive adhesive in the pressure-sensitive adhesive layer described below.

[0019] Examples of the (meth)acrylic acid ester copolymer that constitutes the acrylic pressure-sensitive adhesive include a (meth)acrylic acid ester copolymer that is 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 (meth)acrylic acid cycloalkyl ester, (meth)acrylic acid benzyl ester, and (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). Furthermore, examples of the (meth)acrylic acid ester monomer substituted with a functional group such as a hydroxy group include (meth)acrylic acid ester monomers in which a cycloalkyl group, a benzyl group, or an alkyl group constituting the ester in the above-mentioned (meth)acrylic acid ester is substituted with a hydroxy group, and 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, chelating compounds, etc., and more preferably a polyisocyanate compound. The polyvalent isocyanate compound is not particularly limited, and examples thereof include aromatic isocyanates such as 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, 4,4'-diphenylether diisocyanate, 4,4'-[2,2-bis(4-phenoxyphenyl)propane]diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethyl-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, lysine diisocyanate, lysine triisocyanate, etc. Commercially available crosslinking agents can also be used, such as Coronate L (manufactured by Tosoh Corporation). Examples of polyepoxy 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. An example of the anilines is 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, hexa[1-(2-methyl)-aziridinyl]triphosphatriazine, etc. Examples of chelate compounds include ethyl acetoacetate aluminum diisopropylate, aluminum tris(ethyl acetoacetate), etc.

[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 trivalent or higher polycarboxylic acids. Examples of the polyol component include dihydric alcohols and trivalent or higher polyhydric alcohols. 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 adhesive, the primer layer (3) may contain additives such as colorants and antioxidants as needed, provided that the physical properties are not affected.

[0024] The antistatic agent contained in the primer layer (3) is not particularly limited, and any antistatic agent commonly used in electronic component processing tapes can be used, as long as the tape (1) of the present invention can exhibit antistatic properties. In particular, when the antistatic agent is an ionic liquid, excellent antistatic performance can be exhibited on both the resin layer A (2) and the pressure-sensitive adhesive layer (5) in the tape for processing electronic components (1) of the present invention, which is preferable. In the present invention, the term "ionic liquid" refers to a compound that is 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 the 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 the anions constituting the ionic liquid include hexafluorophosphate ion (PF6 - ), thiocyanate ion (SCN - ), alkylbenzenesulfonate ion (RC6H4SO3 - ), perchlorate ion (ClO4 - ), tetrafluoroborate ion (BF4 - ), F-containing imide ions (R F 2N - (Details will be described later.) and other inorganic or organic anions. Preferred examples of the ionic liquid include compounds having at least one of the above-mentioned cations and anions, and more preferred are compounds having the above-mentioned cations and anions. 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 the substituents, etc., it is possible to obtain an ionic liquid with 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 [RN + -C n H 2n -OC(=O)CQ=CH2, where Q=H or CH3, R=alkyl], and the anion constituting the ionic liquid is a hexafluorophosphate ion (PF6 - ), thiocyanate ion (SCN - ), organic sulfonate ions (RSO3 - ), perchlorate ion (ClO4 - ), tetrafluoroborate ion (BF4 - ), F-containing imide ions (R F 2N - ) and other inorganic or organic anions. F-containing imide ions (R F 2N - ) in R F Examples of the fluorine-containing imide ion include perfluoroalkanesulfonyl groups such as trifluoromethanesulfonyl and pentafluoroethanesulfonyl groups, and fluorosulfonyl groups. Examples of the fluorine-containing imide ion include bis(fluorosulfonyl)imide ion [(FSO2)2N - ], bis(trifluoromethanesulfonyl)imide ion [(CF3SO2)2N - ], bis(pentafluoroethanesulfonyl)imide ion [(C2F5SO2)2N- ] and the like.

[0027] Specific preferred 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 type ionic liquid containing an acryloyl group include ((meth)acryloyloxymethyl)trimethylammonium hexafluorophosphate [(CH3)3N + CH2OC(=O)CQ=CH2·PF6 - , where Q=H or CH3], ethyl(2-(meth)acryloylethyl)trimethylammonium bis(trifluoromethanesulfonyl)imide salt [(CH3)3N + (CH2)2OC(=O)CQ=CH2·(CF3SO2)2N - , where Q=H or CH3], ((meth)acryloyloxymethyl)trimethylammonium bis(fluorosulfonyl)imide salt [(CH3)3N + CH2OC(=O)CQ=CH2·(FSO2)2N - , where Q=H or CH3).

[0028] The content of the antistatic agent in the primer layer (3) is usually 1 to 20 mass % to exhibit antistatic properties, preferably 1 to 15 mass %, more preferably 3 to 10 mass %, and even more preferably 4 to 10 mass %. 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 exert antistatic performance. Considering the possibility of contamination of the blade 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 multi-layered layer, the "thickness of the primer layer (3)" means 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 improves conformability to the irregularities of electronic components when the tape for processing electronic components (1) of the present invention is bonded to the electronic components. Since the resin layer B(4) is not intended to be adhesive, it is preferably non-adhesive. Non-adhesive means 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, i.e., copolymers of ethylene with at least one comonomer selected from radically polymerizable acid comonomers, acrylic acid ester comonomers, methacrylic acid ester comonomers, and carboxylic acid vinyl ester comonomers; 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 or more of these resins alone or in combination. 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 such as maleic acid, fumaric acid, citraconic acid, and itaconic acid, or anhydrides thereof, and unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, vinylacetic acid, and pentenoic acid, and among these, maleic anhydride, acrylic acid, and methacrylic acid are 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 vinyl carboxylic acid 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. Examples of 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-ethyl methacrylate copolymer, and ethylene-maleic anhydride-vinyl acetate copolymer. Further, quaternary or higher multi-component copolymers obtained by combining the above-mentioned comonomers may also be used. 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] In the total mass of ethylene and comonomer used in the synthesis of the ethylene copolymer, the proportion of the comonomer is preferably from 10% by mass to 50% by mass, more preferably from 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 Tm A ≧Tm B It is preferable that Tm A ≧Tm B If Tm 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 a heat of less than 1000 W, the back surface of the resin layer A (2) can be adhered to the semiconductor wafer with good conformity to the irregularities of the semiconductor wafer while reducing the possibility of the back surface of the resin layer A (2) melting and fusing to a lamination roller, chuck table, or other device. 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 semiconductor wafer or other electronic component, thereby preventing dust from entering. Melting point Tm of resin layer B(4) B Generally, the temperature is sufficient as long as it is 95°C or lower, preferably 40 to 95°C, more preferably 40 to 80°C, and even more preferably 40 to 70°C. In addition, when the resin layer B(4) is a multi-layer, the above-mentioned "melting point Tm B " means the melting point of the layer that constitutes the outermost layer on the side opposite to the pressure-sensitive adhesive layer 5, among the layers that constitute the resin layer B(4). Melting point Tm B is a value measured at a heating rate of 10°C / min by DSC (differential scanning calorimetry) 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, 3.0 x 10 6 Pa or less, and 1.0 × 10 3 ~3.0×10 6 Pa, more preferably 1.0×10 3 ~1.0×10 6 More preferably, it is 1.0×10 Pa. 4 ~5.0×10 5 Pa is particularly preferred. When the storage modulus at 70° C. of the resin layer B(4) is within the above preferred range, conformability to the uneven surface of electrical components such as semiconductor wafers can be reliably ensured. In addition, when the resin layer B(4) is a multi-layered structure, the above-mentioned "storage modulus of the resin layer B at 70°C" means the "storage modulus of the resin layer B at 70°C" for each layer constituting the resin layer B(4). That is, when the storage modulus of the resin layer B(4) at 70°C is 6.0 × 10 6 When the storage modulus is "less 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 pressure is less than or equal to 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 equal to or 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 viewpoints 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, since an error of about 10 μm occurs when manufacturing the bump portion of a bumped semiconductor wafer, 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 tape (1) for processing electronic components of the present invention may be any layer containing an adhesive, and may be formed using, for example, an adhesive composition. When the tape (1) for processing electronic components of the present invention is applied to an electronic component, the adhesive layer (5) is attached to the surface of the electronic component having irregularities. The adhesive that constitutes the adhesive layer (5) is preferably an acrylic adhesive. In the present invention, the term "acrylic pressure-sensitive adhesive" refers to a pressure-sensitive adhesive containing a copolymer having a (meth)acrylic acid ester as a constituent component (hereinafter referred to as "(meth)acrylic acid ester copolymer") as a main component polymer (pressure-sensitive adhesive base polymer). In addition to the (meth)acrylic acid ester copolymer, the pressure-sensitive adhesive may contain a crosslinking agent, which will be described later. Here, "containing a (meth)acrylic acid ester copolymer as a main component" means that the content of the (meth)acrylic acid ester copolymer among the polymers or resins that make up the base resin of the adhesive is at least 50% by mass, and 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 is cured by irradiation with radiation, or a non-radiation-curable adhesive that is not cured by irradiation with radiation. As the radiation-curable adhesive, for example, the radiation-curable adhesives described in

[0035] to

[0076] of WO 2018 / 181240 and the radiation-curable adhesives described in

[0031] to

[0050] of JP 2022 / 109374 A can be preferably used.

[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 structural units 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 (meth)acrylic acid ester monomers substituted with functional groups such as hydroxyl groups.

[0043] The non-radiation curable 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 adhesive after application. The polyisocyanate compound is not particularly limited, and for example, the polyisocyanate compound used in the primer layer (3) described above can be used. Specifically, commercially available products such as Coronate L (trade name, manufactured by Tosoh Corporation) can be used. Furthermore, commercially available products such as Nikalac MX-45 (manufactured by Sanwa Chemical Co., Ltd.) and Melan (trade name, manufactured by Hitachi Chemical Co., Ltd.) can be used as the melamine-formaldehyde resin. Furthermore, the epoxy resin such as TETRAD-X (trade name, manufactured by Mitsubishi Chemical Corporation) can be used.

[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, an adhesion 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 parts (1) of the present invention can exhibit excellent antistatic performance even when the pressure-sensitive adhesive layer (5) is made thicker than 100 μm in order to improve conformability to the irregularities on the surface of the adherend.

[0047] (Release film) In the tape (1) for processing electronic components of the present invention, a release film is provided on the adhesive layer (5) as needed. The release film, also called 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, as needed, to enhance releasability from the adhesive layer (5). Furthermore, as needed, an ultraviolet protection treatment may be applied to prevent the adhesive layer (5) from reacting due to unintended exposure to ultraviolet light, such as ambient ultraviolet light. The thickness of the release film is typically 10 to 100 μm, preferably 25 to 50 μm.

[0048] (Method of manufacturing the tape for processing electronic components of the present invention) The method for producing the tape for processing electronic parts of the present invention is not particularly limited, and it can be produced by a conventional method. The resin layer A(2) and the resin layer B(4) can be produced by conventional methods such as extrusion, inflation, casting, etc. Alternatively, a multi-layer resin layer A(2) and a multi-layer resin layer B(4) can be produced by laminating an independently produced film with another film using an adhesive or the like. 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) onto a release film or a film-like resin layer A (2) or resin layer B (4), followed by drying. The obtained primer layer (3) and pressure-sensitive adhesive layer (5) can be laminated as layers constituting the tape for electronic component processing of the present invention by laminating or transferring them with other layers in accordance with the laminate structure to be incorporated into the tape for electronic component processing of the present invention. The method for producing the tape for processing electronic components of the present invention can be exemplified by the following methods, but the method for producing the tape for processing electronic components of the present invention is not limited to the following methods. A primer composition is applied onto a film-like resin layer A (2) and dried, and then a film-like resin layer B (4) is laminated onto the layer obtained by applying and drying the primer composition, thereby obtaining an adhesive film 1. Separately from the laminating film 1, a pressure-sensitive adhesive composition is applied to the release-treated surface of a release film and dried to prepare a pressure-sensitive adhesive layer (5). Thereafter, the obtained pressure-sensitive adhesive layer (5) is attached to the surface of the resin layer B (4) of the adhesive film 1, and the pressure-sensitive adhesive layer (5) is transferred to obtain a tape for processing electronic components. The release film used to prepare the pressure-sensitive adhesive layer (5) may remain attached to the tape for processing electronic components, but when using the tape for processing electronic components of the present invention, the release film is first peeled off from the pressure-sensitive adhesive layer (5).

[0049] (Uses of the tape for processing electronic components 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. It exhibits excellent conformability to unevenness and is particularly suitable for electronic components with large unevenness differences. One 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, which is adhered to the uneven surface of a semiconductor wafer in a semiconductor chip manufacturing method in which the semiconductor wafer is diced into chips by backgrinding. It is also suitable as a DDF.

[0050] [Semiconductor wafer processing method] The following describes an example of a method for processing electronic components using the tape for processing electronic components of the present invention, taking a method for processing semiconductor wafers as an example, although the application of the tape for processing electronic components of the present invention is not limited to this application.

[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 semiconductor wafer back grinding step, a dicing step, and a dicing die bonding step.

[0052] The tape (1) for processing electronic components of the present invention can be applied to the surface of a semiconductor wafer having a difference in unevenness of 20 μm or more (height of bumps (electrodes) or depth of scribe lines), and is preferably applied to a semiconductor wafer having a difference in unevenness of 200 μm or more, more preferably 200 to 400 μm. In particular, as described in the examples below, the tape (1) for processing electronic components of the present invention can exhibit good unevenness-following ability even on a semiconductor wafer having a difference in unevenness of more than 100 μm. The types of bumps and electrodes on the semiconductor wafer are not particularly limited. For example, the bumps 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 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, of 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 back grinding is not particularly limited, and may be, for example, 500 to 800 μm. Furthermore, the thickness of the semiconductor wafer after back grinding using the tape for processing electronic components (1) of the present invention can be adjusted to a desired thickness, for example, 20 to 500 μm, preferably 50 to 200 μm, and more preferably 80 to 200 μm.

[0055] The method for processing a semiconductor wafer using the electronic component processing tape (1) of the present invention preferably includes a step of laminating the electronic component processing tape (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 electronic component processing tape.

[0056] For example, the adhesive layer (5) of the electronic component processing tape (1) of the present invention is first attached to the circuit pattern surface (front surface) of a semiconductor wafer. Next, the side of the semiconductor wafer opposite the circuit pattern is ground until the thickness of the semiconductor wafer reaches a predetermined thickness, for example, 10 to 200 μm. Thereafter, the electronic component processing tape is placed on a heating and adsorption stage with the adhesive surface facing downward, and in this state, a dicing die bonding film may be attached to the ground surface of the semiconductor wafer. After the dicing step, a heat seal type (thermal fusion type) or adhesive type 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 peeled off from the semiconductor wafer. When peeling off the electronic component processing tape (1), if the adhesive layer (5) is a radiation curable type, it is preferable that the adhesive layer (5) is cured by irradiation with radiation (preferably ultraviolet light) to reduce its adhesive strength. [Example]

[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 polyethylene terephthalate (PET) film having a thickness of 50 μm and having been subjected to a corona treatment on one side was prepared. (Film A2) As film A2, a polypropylene (PP) film having a thickness of 50 μm and having been subjected to a corona treatment on one side was prepared. (Film A3) Melting point Tm AA low-density polyethylene resin (LDPE) having a melting point of 105° 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 A3. (Film A4) Melting point Tm A Ethylene-vinyl acetate copolymer resin (EVA) having a temperature of 90° 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 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) 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) of 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 a film B2. (Film B3) Melting point Tm B The storage modulus at 70°C is 2.8 × 10 6 The 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 B3. (Film B4) Melting point Tm B at 90°C, and the storage modulus at 70°C is 3.9 × 10 6 The 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) Primer composition 1 was obtained by adding and mixing 1.0 part by mass of Coronate L (trade name, manufactured by Tosoh Corporation) and 5.0 parts by mass of an ionic liquid (trade name: Elexel MP-402A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as an antistatic agent 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. (Preparation of Primer Composition 2) Primer composition 2 was obtained by adding and mixing 100 parts by mass of a polyester-based adhesive (manufactured by Mitsubishi Chemical Corporation, trade name: Nichigo Polyester LP-011S50EO), 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: Elexcel MP-402A) as an antistatic agent. (Preparation of Primer Composition 3) Primer composition 3 was obtained by adding and mixing 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.

[0061] <Adhesive composition> (Preparation of Adhesive Composition 1) Pressure-sensitive adhesive composition 1 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 70 parts by mass of butyl acrylate, 28 parts by mass of 2-hydroxyethyl acrylate, and 2 parts by mass of methacrylic acid and mixing them. (Preparation of adhesive composition 2) Pressure-sensitive adhesive composition 2 was obtained by adding 1.0 part by mass of Coronate L (trade name, manufactured by Tosoh Corporation) and 0.5 part by mass of tetradecyldimethylbenzylammonium chloride (trade name: NissanCation M2-100, manufactured by NOF Corporation) as an ion-conductive additive 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 mixing them.

[0062] <Production of tape for processing electronic components> 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 bonded to the coated, dried layer side of primer composition 1, thereby obtaining laminated film 1. Separately from the above-mentioned adhesive film 1, a 40 μm thick polypropylene (PP) separator (also referred to as a release film) with one side subjected to release treatment was coated with adhesive composition 1 so that the film thickness after drying would be 10 μm, and dried to obtain an adhesive layer. Thereafter, the adhesive layer was transferred by bonding it to the surface side of resin layer B of the above-mentioned adhesive film 1, and the tape for processing electronic components of Example 1 was obtained. The tape (1) for processing electronic components 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 an adhesive layer (5) are laminated in this order, as shown in FIG. 1, and a release film (not shown in FIG. 1) is further laminated on the adhesive layer (5).

[0063] (Examples 2 to 12, Comparative Example 1) In the preparation of the tape for processing electronic components of Example 1 above, the tapes for processing electronic components of Examples 2 to 12 and Comparative Example 1 were prepared in the same manner, except that the configuration of at least one of the resin layer A (2), the primer layer (3), the resin layer B (4) and the adhesive layer (5) was changed to the configuration described in Tables 1-1 and 1-2 below. The tapes (1) for electronic component processing of Examples 2 to 12 obtained in this manner have 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, and a release film (not shown in FIG. 1) is further laminated on the pressure-sensitive adhesive layer (5), as shown in Fig. 1. The tape for electronic component processing of Comparative Example 1 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, and a release film is further laminated on the pressure-sensitive adhesive layer (5).

[0064] (Comparative Example 2) The ethylene-vinyl acetate copolymer (EVA) used to produce 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 the surface on the resin layer B side was subjected to corona treatment to obtain laminated film 2. Separately from the above-mentioned adhesive film 2, a conductive material containing polyethylenedioxythiophene / polystyrene sulfonic acid (PEDOT / PSS) (manufactured by Nagase ChemteX Corporation, product name: Denatron P-504CT) was applied as an intermediate layer forming material to the release-treated surface of a 25 μm thick polyethylene terephthalate (PET) separator (also called a release film) that had been subjected to a release treatment on one side, so that the film thickness after drying would be 0.1 μm.Then, the adhesive film was attached to the surface of resin layer B of the above-mentioned adhesive film 2, and the PET separator was peeled off to transfer the intermediate layer, thereby obtaining adhesive film 3. Furthermore, separately from the above-mentioned adhesive film 3, the 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 an adhesive layer. Thereafter, the adhesive layer was transferred by bonding it to the surface of the intermediate layer of the above-mentioned adhesive film 3, and a tape for processing electronic components of Comparative Example 2 was obtained. 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 an adhesive layer (5) are laminated in this order, and a release film is further laminated on top of the adhesive layer (5).

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

[0066] The obtained tape for processing electronic parts was evaluated as follows. In addition, 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 thicknesses 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 for antistatic performance] A control tape containing no antistatic agent was prepared in the same manner as in the preparation of the above-mentioned tape for processing electronic components, except that no antistatic agent was added. The surface resistivity of the resin layer A side of each of the tape for processing electronic components and the control tape, as well as the pressure-sensitive adhesive layer side after the release film was peeled off from the tape for processing electronic components and the control tape, was measured as follows. (surface resistivity) Test pieces measuring 10 x 10 cm cut from the tape for electronic component processing and the control tape were stored for 24 hours at a temperature of 23°C and a relative humidity of 50%.The surface resistivity was then measured using an Advantest digital ultra-high resistance / microcurrent meter (model number: 8340A) and a resistivity chamber (model number: R12704) at an applied voltage of 0.10 V, a temperature of 23°C, and a relative humidity of 50%. Using the surface resistivity values ​​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 = [surface resistivity of the adhesive layer surface of the control tape] / [surface resistivity 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. - Anti-static performance - ◎:X 樹脂層A面 and X 粘着剤層面 are 10 or more, and have sufficient antistatic effect on both sides. 〇:X 樹脂層A面 and X 粘着剤層面 When one of these is 10 or more, a sufficient antistatic effect is obtained, and when the other is less than 10, a sufficient antistatic effect is not obtained. ×:X 樹脂層A面 and X 粘着剤層面 are all less than 10, and neither side has a sufficient antistatic effect.

[0068] [2. Evaluation method for unevenness tracking] The electronic component processing tape prepared above was laminated to the bump-bearing side of an 8-inch diameter semiconductor wafer having solder ball-shaped bumps with a ball width of approximately 230 μm, with 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 then circle-cut. The thickness of the semiconductor wafer to which the tape for electronic component processing was attached was measured using a spindle-type dial gauge (manufactured by Mitutoyo Corporation) from the surface of the semiconductor wafer that did not have bumps (starting point) to the surface of the resin layer A (2) of the tape for electronic component processing that was not in contact with the primer layer (3) (ending point), with the measuring probe of the dial gauge facing the tape for electronic component processing. 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, where there were no bumps, was measured as β. If conformability is insufficient, a gap will form between the electronic component processing tape and the semiconductor wafer, resulting in a larger α. Those that satisfied α-β≦60μm were evaluated as having good conformability and given a rating of "Good," those that satisfied 60μm<α-β≦85μm were evaluated as having good conformability and given a rating of "△," and those that satisfied 85μm<α-β were evaluated as "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 The measurements were carried out 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 temperatures of plastics.

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

[0073] [Table 1-2]

[0074] The films, primer compositions, and pressure-sensitive adhesive compositions listed in the columns for resin layers A and B are as described at the beginning of the examples. (Resin layer A) PET: Polyethylene terephthalate PP: Polypropylene LDPE: Low-density polyethylene EVA: Ethylene-vinyl acetate copolymer (Primer layer) Ionic liquid: Elexcel MP-402A (trade name) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. (Resin layer B) EVA: Ethylene-vinyl acetate copolymer TPO: Thermoplastic olefin elastomer (middle class) P-504CT: Conductive material containing polyethylenedioxythiophene / polystyrene sulfonate (PEDOT / PSS) (Nagase ChemteX Corporation, product name: Denatron P-504CT) "-": indicates that the component and / or layer is not present. Content: For the primer layer, it means the content of the antistatic agent in the layer, and for the pressure-sensitive adhesive layer, it means 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 a pressure-sensitive adhesive layer, in that order. Thus, in an electronic component processing tape in which the layer adjacent to the pressure-sensitive adhesive layer is an intermediate layer made of a conductive material, as shown in Reference Example 1, when the pressure-sensitive adhesive layer is as thin as 40 μm, antistatic properties are exhibited on either the front or back side of the tape. However, when the pressure-sensitive adhesive layer is as thick as 120 μm, antistatic properties are not exhibited on either the front or back side of the tape. 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 the range of 10 to 120 μm. [Explanation of symbols]

[0076] 1. Tape for processing electronic components 2 Resin layer A 3 Primer layer 4 Resin layer B 5. Adhesive layer

Claims

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

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

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

4. 2. The tape for processing electronic parts according to claim 1, wherein the adhesive constituting the adhesive layer is an acrylic adhesive.

5. 2. The tape for processing electronic parts according to claim 1, 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 2. The tape for processing electronic components according to claim 1, wherein the above formula (1) is satisfied.

7. Melting point Tm of the resin layer A Ａ 2. The tape for processing electronic parts according to claim 1, wherein the temperature is 80° C. or higher.

8. The storage modulus of the resin layer B at 70°C is 3.0 × 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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