Adhesive tape

Abstract

The present invention provides an adhesive tape that has good resistance to a cleaning liquid and is capable of maintaining good peelability realized through irradiation with an energy ray, even after making contact with the cleaning liquid. An adhesive tape according to the present invention is provided with a base material and an adhesive layer laminated on one surface of the base material. The adhesive tape is characterized in that: the adhesive tape is for use in temporarily fixing a substrate; the adhesive layer contains a double bond introduction type acrylic resin having an unsaturated double bond in a side chain, and a curable resin that becomes cured through irradiation with an energy ray; and the blended ratio of the curable resin with respect to 100 parts by mass of the double bond introduction type acrylic resin is more than 0 parts by mass but not more than 180 parts by mass.

Description

adhesive tape

[0001] The present invention relates to an adhesive tape used for temporarily fixing substrates.

[0002] In the manufacturing process of a semiconductor device, an adhesive tape (dicing tape) is used to temporarily fix a semiconductor substrate.

[0003] For example, Patent Document 1 discloses a semiconductor processing sheet (adhesive tape) including a substrate and an adhesive layer laminated on the substrate. This semiconductor processing sheet is used so that the adhesive layer adheres to a TSV wafer or a TSV chip. This allows the TSV wafer or the like to be temporarily fixed.

[0004] The pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive formed from a pressure-sensitive adhesive composition containing a (meth)acrylic acid ester copolymer (A) having an energy ray-curable group introduced into its side chain. The (meth)acrylic acid ester copolymer (A) is obtained by reacting an acrylic copolymer (AP) obtained by copolymerizing methyl (meth)acrylate (A1) and a functional group-containing monomer (A2) having a reactive functional group with a curable group-containing compound (A3) having a substituent reactive with the functional group of the functional group-containing monomer (A2) and an energy ray-curable carbon-carbon double bond.

[0005] Patent Literature 1 also discloses that parameters P1 and P2 related to component AP each satisfy a predetermined condition. Parameter P1 is the mass ratio of the structure derived from component A1 in component AP, and when this parameter satisfies a predetermined condition, a pressure-sensitive adhesive layer having resistance to polar solvents is obtained. Parameter P2 is the product of the mass ratio of the structure derived from component A1 in component AP and the gel fraction of the pressure-sensitive adhesive, and when this parameter satisfies a predetermined condition, a pressure-sensitive adhesive layer having embeddability for minute protrusions is obtained.

[0006] However, the semiconductor processing sheet described in Patent Document 1 has the following problem. During the manufacturing process of a semiconductor device, the outer periphery of the adhesive layer of the semiconductor processing sheet is fixed with a ring frame, and then the backside of a semiconductor substrate such as a TSV wafer is attached to the adhesive layer. At this time, the front side of the semiconductor substrate may be covered with protective tape. In this case, the protective tape is peeled off before proceeding to the next process. However, in case the adhesive of the protective tape remains on the surface of the semiconductor substrate, the semiconductor substrate is cleaned with a cleaning solution. This cleaning solution affects not only the remaining adhesive of the protective tape, but also the semiconductor processing sheet attached to the backside of the semiconductor substrate.

[0007] Conventional semiconductor processing sheets have the problem of low resistance of the adhesive layer to the cleaning solution. This allows the cleaning solution to easily penetrate between the semiconductor processing sheet and the semiconductor substrate, causing the adhesive layer to swell and undergo other changes. As a result, when the semiconductor element is picked up from the semiconductor processing sheet in subsequent processes, the components of the adhesive layer adhere to the backside of the semiconductor element. Another problem is maintaining good releasability when irradiated with energy rays after contact with the cleaning solution.

[0008] JP 2015-073056 A

[0009] An object of the present invention is to provide a pressure-sensitive adhesive tape that has good resistance to cleaning solutions and that can maintain good releasability when irradiated with energy rays even after contact with the cleaning solution.

[0010] These objects are achieved by the present invention as set forth in (1) to (5) below: (1) An adhesive tape used for temporarily fixing a substrate, comprising a substrate and an adhesive layer laminated on one surface of the substrate, wherein the adhesive layer contains a double-bond-introduced acrylic resin having an unsaturated double bond in a side chain, and a curable resin that is cured by irradiation with energy rays, and wherein the blending ratio of the curable resin to 100 parts by mass of the double-bond-introduced acrylic resin is more than 0 parts by mass and not more than 180 parts by mass.

[0011] (2) The pressure-sensitive adhesive tape according to (1), wherein the curable resin has a polymerizable carbon-carbon double bond that can be three-dimensionally crosslinked by irradiation with energy rays, and the number of functional groups per molecule of the curable resin is 2 or more.

[0012] (3) The pressure-sensitive adhesive tape according to (1) or (2), wherein the curable resin contains at least one of an ester of (meth)acrylic acid and a polyhydric alcohol, a urethane acrylate, and an epoxy acrylate.

[0013] (4) The pressure-sensitive adhesive tape according to (3), wherein the curable resin contains bisphenol A epoxy acrylate.

[0014] (5) The pressure-sensitive adhesive tape according to any one of (1) to (4), wherein the double bond-introduced acrylic resin has a polymerizable carbon-carbon double bond in a side chain that can be three-dimensionally crosslinked by irradiation with energy rays.

[0015] According to the present invention, a pressure-sensitive adhesive tape can be obtained which has good resistance to cleaning solutions and maintains good releasability after irradiation with energy rays.

[0016] Fig. 1 is a longitudinal sectional view showing an example of a semiconductor device manufactured using the adhesive tape according to the embodiment. Fig. 2 is a longitudinal sectional view for explaining a method for manufacturing a semiconductor device using the adhesive tape according to the embodiment. Fig. 3 is a longitudinal sectional view for explaining a method for manufacturing a semiconductor device using the adhesive tape according to the embodiment. Fig. 4 is a longitudinal sectional view showing the adhesive tape according to the embodiment.

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The pressure-sensitive adhesive tape according to the present invention will be described in detail below with reference to preferred embodiments shown in the accompanying drawings.

[0018] 1. Semiconductor Device First, prior to describing the adhesive tape according to the embodiment, an example of a semiconductor device manufactured using the adhesive tape will be described.

[0019] 1 is a longitudinal cross-sectional view showing an example of a semiconductor device manufactured using an adhesive tape according to an embodiment. In the following description, the upper side in FIG. 1 is referred to as "top" and the lower side is referred to as "bottom." In addition, in each drawing of the present application, the dimensional ratios in the left-right direction and the thickness direction may differ from the actual ratios.

[0020] The semiconductor device 10 shown in FIG. 1 includes a semiconductor chip 20 (semiconductor element), an interposer 30 (substrate) that supports the semiconductor chip 20, a plurality of conductive bumps 70 (terminals), and a molded portion 17 (sealing portion) that seals the semiconductor chip 20.

[0021] The interposer 30 is an insulating substrate and is made of various resin materials such as polyimide, epoxy resin, cyanate resin, bismaleimide triazine resin (BT resin), etc. The planar shape of the interposer 30 can be, for example, a quadrilateral such as a square or a rectangle.

[0022] Terminals 41 made of a conductive metal material such as copper are provided in a predetermined shape on the upper surface of the interposer 30 .

[0023] Furthermore, a plurality of vias (through holes) and through-wirings (not shown) are formed in the interposer 30 so as to penetrate the interposer 30 in the thickness direction.

[0024] Each bump 70 protrudes from the lower surface of the interposer 30. Each bump 70 is electrically connected to a terminal 41 via a through-wiring. Such a bump 70 is mainly made of a brazing material such as solder, silver brazing, copper brazing, or phosphorus copper brazing.

[0025] Terminals 41 provided on the interposer 30 are electrically connected to terminals 21 of the semiconductor chip 20 via connecting portions 81 .

[0026] An underfill material is filled in the gap between the semiconductor chip 20 and the interposer 30. The hardened underfill material forms a sealing layer 80. This sealing layer 80 improves the bonding strength between the semiconductor chip 20 and the interposer 30 and prevents the intrusion of foreign matter, moisture, and the like into the gap.

[0027] A molded portion 17 is provided on the upper side of the interposer 30 so as to cover the semiconductor chip 20 and the interposer 30. The molded portion 17 is made of a hardened semiconductor sealing material (sealant). By providing the molded portion 17, the semiconductor chip 20 is sealed, and the intrusion of foreign matter, moisture, etc. into the semiconductor chip 20 is prevented.

[0028] 1, the semiconductor chip 20 (semiconductor element) has a semiconductor chip body 23 (semiconductor element body) and terminals 21 provided on the underside of the semiconductor chip body 23. A circuit (not shown) is formed on the upper surface of the semiconductor chip body 23. Examples of materials that can be used for the semiconductor chip body 23 include Si, SiC, GaN, and Ga. ２ O ３ Examples of semiconductor materials include:

[0029] 2. Method for Manufacturing Semiconductor Device Next, an example of a method for manufacturing the semiconductor device 10 using the adhesive tape according to the embodiment will be described.

[0030] 2 and 3 are vertical cross-sectional views for explaining a method for manufacturing a semiconductor device 10 using the adhesive tape 100 according to the embodiment. In the following description, the upper side in each figure will be referred to as "upper" and the lower side will be referred to as "lower."

[0031] [1A] First, a semiconductor substrate 7 (semiconductor wafer) with a protective tape 500 attached thereto is prepared, as shown in Figure 2(a). The protective tape 500 is attached to a surface 71 of the semiconductor substrate 7, and protects a circuit formation region (not shown) included in the surface 71 from each of the processes described below. The circuit formation region (not shown) includes multiple individual circuits, and is divided into multiple regions in the processes described below.

[0032] [2A] Next, the upper surface of the protective tape 500 is fixed to a chuck table 600 of a back grinding device (back grinder). Then, the back surface 72 of the semiconductor substrate 7 shown in FIG. 2B is ground (back-grinded). This makes it possible to thin the semiconductor substrate 7. The thickness of the semiconductor substrate 7 after back-grinding is not particularly limited, but is, for example, about 40 to 600 μm.

[0033] [3A] Next, an adhesive tape 100 is prepared. The adhesive tape 100 shown in Fig. 2(c) has a base material 4 and an adhesive layer 2 laminated on the base material 4. Next, as shown in Fig. 2(c), an outer periphery 121 of the adhesive layer 2 of the adhesive tape 100 is fixed with a wafer ring 9. Then, the back surface 72 of the semiconductor substrate 7 (semiconductor wafer) is attached to the central portion 122 of the adhesive layer 2.

[0034] [4A] Next, the protective tape 500 is peeled off. By peeling off the protective tape 500, the surface 71 of the semiconductor substrate 7 is exposed, as shown in FIG.

[0035] [5A] Next, as shown in FIG. 2( e), the surface 71 of the semiconductor substrate 7 is cleaned with a cleaning solution CS (surface cleaning process). The cleaning solution CS supplied to the surface 71 acts on the adhesive remaining on the surface 71, removing the adhesive and cleaning the surface. The cleaning solution CS also acts on the adhesive tape 100. Specifically, when the cleaning solution CS acts on the adhesive layer 2 of the adhesive tape 100, the adhesive layer 2 may be deformed, for example, by swelling. In this case, after the semiconductor substrate 7 is singulated in a process described below, the adhesive tape 100 is irradiated with energy rays such as ultraviolet rays to peel off (pick up) the singulated semiconductor chips 20. However, the adhesive strength of the adhesive layer 2 may not be sufficiently reduced even when the energy rays are irradiated, and the adhesive may adhere to the semiconductor chips 20.

[0036] Therefore, the adhesive tape 100 (the adhesive tape according to the embodiment) is required to have good resistance to the cleaning liquid CS.

[0037] Examples of the cleaning solution CS include hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents, and one or a mixture of two or more of these solvents can be used. Examples of the cleaning solution CS include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide (DMSO), N,N-dimethylformamide, hexamethylphosphoric triamide, and 1,3-dimethyl-2-imidazolidinone.

[0038] After cleaning with the cleaning solution CS, the cleaning solution CS may be rinsed away with a rinse solution. As the rinse solution, a solvent with a lower boiling point than the cleaning solution CS is preferably used, for example, alcohols such as methanol, ethanol, and propanol, or ketones such as acetone, diethyl ketone, and methyl ethyl ketone.

[0039] [6A] Next, as shown in FIG. 3( a ), the adhesive tape 100 to which the semiconductor substrate 7 is attached is placed on a dicer table 200 .

[0040] [7A] Next, the semiconductor substrate 7 is cut into individual pieces using a dicing saw (blade) not shown (dicing process). As a result, multiple semiconductor chips 20 are obtained on the adhesive tape 100, as shown in FIG. 3(b). At this time, the adhesive tape 100 holds the semiconductor substrate 7 with strong adhesive force and has the function of preventing the semiconductor substrate 7 from shaking, thereby preventing cracks, chips, etc. from occurring in the semiconductor substrate 7. Furthermore, it is preferable that the cutting marks made by the dicing saw reach the base material 4, as shown in FIG. 3(b). This allows the semiconductor substrate 7 to be reliably cut into individual pieces.

[0041] If necessary, cutting may be performed while supplying water to the semiconductor substrate 7. This can prevent the scattering of dust and overheating of the semiconductor substrate 7 that occur when cutting the semiconductor substrate 7.

[0042] [8A] Next, as shown in Fig. 3(c), the adhesive tape 100 is irradiated with energy rays E such as ultraviolet rays (energy ray irradiation process). In the adhesive tape 100 irradiated with the energy rays E, the adhesive strength of the adhesive layer 2 is reduced. This allows the semiconductor chip 20 to be easily picked up in the pick-up process described below.

[0043] [9A] Next, the adhesive tape 100 with the semiconductor substrate 7 attached thereto is placed on an expanding table 300. The expanding table 300 includes an expanding stage 310 corresponding to the center of the semiconductor substrate 7 and a holding base 320 corresponding to the outer periphery of the semiconductor substrate 7. In the pick-up process, as shown in FIG. 3( d ), the expanding stage 310 is pushed upward against the holding base 320 of the expanding table 300. This causes the adhesive tape 100 to be stretched radially, and gaps are formed between the semiconductor chips 20 obtained by singulation (expanding process).

[0044] [10A] Next, the adhesive tape 100 to which the expanding semiconductor substrate 7 has been attached is placed on a pickup table 400. Then, the semiconductor chip 20 is picked up by a suction tool (not shown) such as a vacuum collet or air tweezers (pickup process), as shown in Fig. 3(e). In the pick-up process, the semiconductor chip 20 may be pushed up from below by a needle (not shown).

[0045] By going through the above-described steps [1A] to [10A], individual semiconductor chips 20 are obtained. The individual semiconductor chips 20 are placed on, for example, the interposer 30 shown in FIG. 1. Then, the sealing layer 80 and the molded portion 17 are provided. In this way, the semiconductor device 10 shown in FIG. 1 is obtained.

[0046] 3. Adhesive Tape Fig. 4 is a vertical cross-sectional view showing an adhesive tape 100 according to an embodiment. In the following description, the upper side in Fig. 4 will be referred to as "top" and the lower side will be referred to as "bottom".

[0047] The adhesive tape 100 is an adhesive tape used to temporarily fix a semiconductor substrate 7, and as shown in FIG. 4, includes a substrate 4 and an adhesive layer 2. The adhesive layer 2 is laminated on the upper surface (one surface) of the substrate 4. The adhesive layer 2 contains a double-bond-introduced acrylic resin (A) and a curable resin (B). The double-bond-introduced acrylic resin (A) is an acrylic resin having an unsaturated double bond in its side chain. Both the double-bond-introduced acrylic resin (A) and the curable resin (B) provide adhesiveness. They are cured by irradiation with energy rays. The blending ratio of the curable resin (B) is more than 0 parts by mass and not more than 180 parts by mass per 100 parts by mass of the double-bond-introduced acrylic resin (A).

[0048] With this configuration, even if the cleaning solution CS comes into contact with the adhesive layer 2, the double-bond-introduced acrylic resin (A) in the peripheral portion of the semiconductor substrate 7 swells, and the low-molecular-weight curable resin (B) dissolves into the cleaning solution CS, the double-bond-introduced acrylic resin (A) itself can be cured with energy rays, so the peelability is not lost (can trigger peeling). Furthermore, since the curable resin (B) does not dissolve from the adhesive layer 2 in contact with the semiconductor substrate 7, the peelability is improved by the curable resin (B). The reason for this effect is thought to be the combined use of the double-bond-introduced acrylic resin (A) and the curable resin (B). As a result, the curable resin (B) maintains high adhesive strength before the energy ray irradiation process, ensuring reliable fixation of the semiconductor substrate 7. Even after the energy ray irradiation process, the peelability is not lost and low adhesive strength is obtained. This reduces the occurrence of defects during the dicing and pick-up processes. Each component of the adhesive tape 100 is described in detail below.

[0049] 3.1. Substrate Examples of materials that can be used for the substrate 4 include resin materials. Examples of resin materials that can be used for the substrate 4 include thermoplastic resins such as olefin resins, polyester resins (ester polymers) such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate, polyvinyl chloride resins, polyurethanes, polyimides, polyamides, polyether ketones such as polyether ether ketone, polyethersulfones, polystyrenes, fluororesins, silicone resins, cellulose resins, styrene-based thermoplastic elastomers (styrene-based polymers), acrylic resins, polyester-based thermoplastic elastomers, polyvinyl isoprene, and polycarbonates (carbonate-based polymers), as well as mixtures containing these thermoplastic resins.

[0050] These resin materials are materials that can transmit energy rays such as visible light, near-infrared rays, ultraviolet rays, X-rays, and electron beams, and therefore, in the energy ray irradiation treatment described above, the irradiated energy rays penetrate the substrate 4 and are irradiated onto the adhesive layer 2. Therefore, the adhesive strength of the adhesive layer 2 can be more reliably reduced.

[0051] The substrate 4 may contain a softener such as mineral oil, a filler such as calcium carbonate, silica, talc, mica, or clay, an antioxidant, a light stabilizer, a lubricant, a dispersant, a neutralizer, a colorant, or the like.

[0052] The content of the resin material in the substrate 4 is preferably 50% by mass or more, and more preferably 80% by mass or more, which ensures good flexibility of the substrate 4 and good adhesion of the substrate 4 to the adhesive layer 2.

[0053] The thickness of the substrate 4 is not particularly limited, but is preferably 30 μm or more and 200 μm or less, and more preferably 40 μm or more and 150 μm or less. When the thickness of the substrate 4 is within this range, the mechanical properties of the substrate 4 are optimized, and the substrate 4 can more reliably perform its functions. This makes it possible to prevent breakage of the substrate 4 during dicing, expanding, picking up, and the like.

[0054] The surface roughness Ra of the substrate 4 is, for example, preferably 0.2 μm or more and 2.0 μm or less, and more preferably 0.5 μm or more and 1.5 μm or less. When the surface roughness Ra of the substrate 4 is within this range, the adhesion between the substrate 4 and the adhesive layer 2 is improved. This makes it possible to prevent peeling between the substrate 4 and the adhesive layer 2 during the pick-up process.

[0055] 3.2 Adhesive Layer The adhesive layer 2 has enough adhesiveness to support the semiconductor substrate 7 during the dicing process and to allow the semiconductor chip 20 to be picked up properly during the pick-up process.

[0056] The adhesive layer 2 contains a double bond-introduced acrylic resin (A) as a base resin that is cured by irradiation with energy rays, and a curable resin (B).

[0057] 3.2.1. Double Bond-Introduced Acrylic Resin (A) The double bond-introduced acrylic resin (A) is an adhesive that imparts adhesiveness to the semiconductor substrate 7 to the adhesive layer 2. The double bond-introduced acrylic resin (A) is an acrylic resin having an unsaturated double bond in its side chain. The unsaturated double bond is not particularly limited as long as it is an unsaturated double bond, but is preferably a polymerizable carbon-carbon double bond (ethylenically unsaturated double bond) that can be three-dimensionally crosslinked by irradiation with energy rays. Having a group containing such a polymerizable carbon-carbon double bond in its side chain more reliably forms three-dimensional crosslinks within the polymer main chain of the double bond-introduced acrylic resin (A) or between polymer main chains.

[0058] Specific examples of the group containing a polymerizable carbon-carbon double bond include a (meth)acryloyl group, a (meth)acryloyloxy group, a (meth)acryloylamino group, an allyl group, a 1-propenyl group, and a vinyl group.

[0059] In this specification, the term "acrylic resin" refers to a polymer (homopolymer or copolymer) containing a (meth)acrylic acid ester as a monomer component. Furthermore, in this specification, "(meth)acrylic acid" includes both acrylic acid and methacrylic acid. Therefore, for example, "(meth)acrylic acid ester" includes both acrylic acid ester and methacrylic acid ester.

[0060] The double bond-introduced acrylic resin (A) is a polymer containing a structure derived from a (meth)acrylic acid ester as a main structural unit, and is an acrylic resin having a polymer main chain and a side chain bonded to the polymer main chain and containing an unsaturated double bond.

[0061] The double bond-introduced acrylic resin (A) is synthesized, for example, by a method including the steps of: obtaining an acrylic resin having a reactive functional group by copolymerizing one or more (meth)acrylic acid esters (A1-1) with one or more polymerizable compounds (A1-2) having a reactive functional group in the side chain; and reacting the acrylic resin with one or more compounds (A1-3) having a functional group reactive with the reactive functional group and an unsaturated double bond.

[0062] Such double bond-introduced acrylic resin (A) has unsaturated double bonds in its side chains, and thus three-dimensionally crosslinks within and between polymer main chains. Therefore, even when the double bond-introduced acrylic resin (A) is used alone, it can be cured by irradiation with energy rays. This allows the adhesive layer 2 to have good resistance to the cleaning solution CS. Furthermore, the adhesive layer 2 containing the double bond-introduced acrylic resin (A) and the curable resin (B) can maintain good releasability after energy ray irradiation even after contact with the cleaning solution.

[0063] Examples of the (meth)acrylic acid ester (a1) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, and decyl (meth)acrylate. (meth)acrylic acid alkyl esters such as isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, and octadecyl (meth)acrylate; (meth)acrylic acid cycloalkyl esters such as cyclohexyl (meth)acrylate; and (meth)acrylic acid aryl esters such as phenyl (meth)acrylate, and these may be used alone or in combination of two or more.

[0064] Among these, alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and octyl (meth)acrylate are preferably used as the (meth)acrylic acid ester (a1). Alkyl (meth)acrylates have excellent heat resistance and are relatively easily and inexpensively available.

[0065] The ratio of the (meth)acrylic acid ester (A1-1) in the double bond-introduced acrylic resin (A) is preferably 50% by mass or more and 99% by mass or less, and more preferably 70% by mass or more and 95% by mass or less, based on the total mass of the monomer components constituting the double bond-introduced acrylic resin (A).

[0066] The polymerizable compound (A1-2) is a polymerizable compound having a reactive functional group. Examples of the reactive functional group include a carboxy group, a hydroxyl group, an amino group, a mercapto group, a cyclic acid anhydride group, and an epoxy group. Among these, when the reactive functional group is a carboxy group, a hydroxyl group, an amino group, a mercapto group, or a cyclic acid anhydride group, the reactivity with, for example, a compound (A1-3) having an epoxy group, an isocyanate group, or the like as a functional group is good. Furthermore, when the reactive functional group is a cyclic acid anhydride group, the reactivity with, for example, a compound (A1-3) having a carboxy group, a hydroxyl group, an amino group, a mercapto group, or the like as a functional group is good.

[0067] Examples of the polymerizable compound (A1-2) having an epoxy group as a reactive functional group include glycidyl (meth)acrylate and 3,4-epoxycyclohexyl (meth)acrylate.

[0068] Examples of the polymerizable compound (A1-2) having a hydroxyl group as a reactive functional group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and glycerin mono(meth)acrylate.

[0069] Examples of the polymerizable compound (A1-2) having a carboxyl group as a reactive functional group include (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid.

[0070] The acrylic resin may contain, in addition to the (meth)acrylic acid ester (A1-1) and the polymerizable compound (A1-2), other polymerizable compounds as monomer units, such as aromatic vinyl compounds such as styrene and vinyltoluene.

[0071] The compound (A1-3) is a compound having a functional group that reacts with the reactive functional group of the polymerizable compound (A1-2) and an unsaturated double bond.

[0072] Examples of the compound (A1-3) having a carboxyl group include (meth)acrylic acid, a dimer of (meth)acrylic acid, caprolactone-modified (meth)acrylic acid, a compound obtained by a ring-opening reaction between a (meth)acrylate having a hydroxyl group and a carboxylic acid anhydride, and β-acryloyloxyethyl hydrogen succinate.

[0073] Examples of the compound (A1-3) having an isocyanate group include methacryloyloxyethyl isocyanate.

[0074] Examples of the compound (A1-3) having an epoxy group include glycidyl (meth)acrylate and allyl glycidyl ether.

[0075] The double bond-introduced acrylic resin (A) can be produced by polymerizing a single monomer component or a mixture of two or more monomer components, and the polymerization of these monomer components can be carried out using a polymerization method such as solution polymerization, emulsion polymerization, bulk polymerization, or suspension polymerization.

[0076] From the viewpoint of preventing contamination of the semiconductor substrate 7 and the like during the dicing process, the double bond-introduced acrylic resin (A) preferably has a low content of low-molecular-weight substances. From this viewpoint, the weight-average molecular weight of the double bond-introduced acrylic resin (A) is preferably 300,000 to 2,000,000, more preferably 400,000 to 1,800,000, and even more preferably 500,000 to 1,500,000. If the weight-average molecular weight of the double bond-introduced acrylic resin (A) is below the lower limit, depending on the type of monomer component, the contamination prevention properties against the semiconductor substrate 7 and the like may be reduced, resulting in the risk of adhesives and the like adhering to the semiconductor chip 20. On the other hand, if the weight-average molecular weight of the double bond-introduced acrylic resin (A) is above the upper limit, the viscosity of the composition for forming the adhesive layer 2 may increase, potentially increasing the difficulty of manufacturing the adhesive tape 100. The weight-average molecular weight is calculated as a standard polystyrene equivalent by gel permeation chromatography (GPC).

[0077] The glass transition temperature Tg of the double bond-introduced acrylic resin (A) is preferably -80°C or higher and -10°C or lower, more preferably -70°C or higher and -15°C or lower, and even more preferably -60°C or higher and -20°C or lower. This allows the adhesive strength of the adhesive layer 2 to be optimized. Note that if the glass transition temperature Tg is below the lower limit, the double bond-introduced acrylic resin (A) becomes less likely to aggregate, which may result in the adhesive or the like adhering to the picked-up semiconductor chip 20. On the other hand, if the glass transition temperature Tg is above the upper limit, the adhesive strength of the adhesive layer 2 may be insufficient, which may result in defects during the dicing process.

[0078] The glass transition temperature Tg is appropriately adjusted depending on the monomer components constituting the double bond-introduced acrylic resin (A), the molecular weight, etc. The glass transition temperature Tg is measured using a differential scanning calorimeter (DSC) at a temperature rise rate of 0.1°C / min.

[0079] The acid value of the double bond-introduced acrylic resin (A) is preferably greater than 0 mgKOH / g and less than 30 mgKOH / g, more preferably from 0.2 mgKOH / g to 25 mgKOH / g, and even more preferably from 0.5 mgKOH / g to 20 mgKOH / g. The acid value of the double bond-introduced acrylic resin (A) tends to reflect storage stability and reactivity. Therefore, if the acid value is within the above range, the storage stability and curability of the adhesive layer 2 can be achieved. Note that if the acid value is below the lower limit, the reactivity of the double bond-introduced acrylic resin (A) may decrease, and the peelability of the adhesive layer 2 may decrease after energy ray irradiation. On the other hand, if the acid value is above the upper limit, the storage stability of the double bond-introduced acrylic resin (A) may decrease, and the adhesive layer 2 may be more susceptible to denaturation, such as swelling, upon contact with a cleaning solution.

[0080] The acid value of the double bond-introduced acrylic resin (A) is the acid value of the solid content (the number of mg of potassium hydroxide required to neutralize the free fatty acids present in 1 g of the solid content of the double bond-introduced acrylic resin (A)), and is measured in accordance with the method specified in JIS K 0070:1992.

[0081] The hydroxyl value of the double bond-introduced acrylic resin (A) is preferably greater than 0 mgKOH / g and less than 50 mgKOH / g, more preferably from 3 mgKOH / g to 45 mgKOH / g, and even more preferably from 5 mgKOH / g to 40 mgKOH / g. The hydroxyl value of the double bond-introduced acrylic resin (A) tends to reflect adhesion and curability. Therefore, if the hydroxyl value is within the above range, an adhesive layer 2 can be obtained that maintains adhesion and curability even after contact with a cleaning solution. If the hydroxyl value is below the lower limit, the peelability of the adhesive layer 2 may be reduced after energy ray irradiation. On the other hand, if the hydroxyl value is above the upper limit, the adhesive strength of the adhesive layer 2 may be insufficient.

[0082] The hydroxyl value of the double bond-introduced acrylic resin (A) is a solid content hydroxyl value (the number of mg of potassium hydroxide required to neutralize acetic acid bonded to a hydroxyl group when 1 g of the solid content of the double bond-introduced acrylic resin (A) is acetylated), and is measured in accordance with the method specified in JIS K 0070:1992.

[0083] The acid value and hydroxyl value can be controlled by adjusting the amount of compound (A1-3) added during the preparation of the double bond-introduced acrylic resin (A).

[0084] The unsaturated double bond equivalent of the double bond-introduced acrylic resin (A) is preferably 200 or more and 4000 or less, more preferably 250 or more and 3000 or less. The unsaturated double bond equivalent of the double bond-introduced acrylic resin (A) tends to reflect the adhesiveness, curability, and retention of the curable resin (B). Therefore, if the unsaturated double bond equivalent is within the above range, an adhesive layer 2 having excellent resistance to cleaning solutions and good adhesiveness and curability even after contact with cleaning solutions can be obtained. Note that if the unsaturated double bond equivalent is below the lower limit, the peelability of the adhesive layer 2 may be reduced after energy ray irradiation treatment. On the other hand, if the unsaturated double bond equivalent is above the upper limit, the adhesiveness of the adhesive layer 2 may be insufficient.

[0085] The equivalent weight of the unsaturated double bond of the double bond-introduced acrylic resin (A) is determined by "molecular weight / number of unsaturated double bonds in the same molecule."

[0086] The content of the double bond-introduced acrylic resin (A) in the resin composition constituting the adhesive layer 2 is preferably 30% by mass or more and 90% by mass or less of the total solid content of the resin composition, and more preferably 40% by mass or more and 80% by mass or less.

[0087] 3.2.2. Curable Resin (B) The curable resin (B) is a resin that has the ability to be cured by irradiation with energy rays. The curable resin (B) may be a resin having a polymerizable functional group that polymerizes by irradiation with energy rays, but is preferably a resin having a group containing a polymerizable carbon-carbon double bond that can be three-dimensionally crosslinked by irradiation with energy rays.

[0088] Specific examples of the group containing a polymerizable carbon-carbon double bond include a (meth)acryloyl group, a (meth)acryloyloxy group, a (meth)acryloylamino group, an allyl group, a 1-propenyl group, and a vinyl group.

[0089] Examples of the curable resin (B) include low molecular weight compounds having in the molecule at least two groups containing polymerizable carbon-carbon double bonds that can be three-dimensionally crosslinked by irradiation with energy rays. Specific examples of the compound include esters of (meth)acrylic acid and polyhydric alcohols such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and glycerin di(meth)acrylate; ester acrylate oligomers; cyanurate compounds having a carbon-carbon double bond-containing group such as 2-propenyl-di-3-butenyl cyanurate; tris(2-acryloxyethyl)isocyanurate; tris(2-methyl)isocyanurate; Examples of the acrylic acid acrylate include isocyanurate compounds having a carbon-carbon double bond-containing group, such as tris(1,3-diacryloxy-2-propyl-oxycarbonylamino-n-hexyl)isocyanurate, 2-hydroxyethylbis(2-acryloxyethyl)isocyanurate, bis(2-acryloxyethyl)2-[(5-acryloxyhexyl)-oxy]ethyl isocyanurate, tris(1,3-diacryloxy-2-propyl-oxycarbonylamino-n-hexyl)isocyanurate, tris(1-acryloxyethyl-3-methacryloxy-2-propyl-oxycarbonylamino-n-hexyl)isocyanurate, and tris(4-acryloxy-n-butyl)isocyanurate; commercially available oligoester acrylates; aromatic and aliphatic urethane acrylates; and epoxy acrylates such as bisphenol A epoxy acrylate, phenol novolac epoxy acrylate, and cresol novolac epoxy acrylate. These may be used alone or in combination of two or more.

[0090] Among these, it is preferable to include at least one of an ester of (meth)acrylic acid and a polyhydric alcohol, a urethane acrylate, and an epoxy acrylate, and it is more preferable to include a bisphenol A-type epoxy acrylate. This allows for good releasability during energy ray irradiation and suppression of defects during pickup processing. In particular, when the curable resin (B) includes a benzene ring structure, the heat resistance and chemical resistance of the adhesive layer 2 are improved. Furthermore, when the curable resin (B) includes multiple benzene ring structures or a bisphenol A-type structure, this tendency can be further enhanced.

[0091] The number of functional groups (the number of groups containing a polymerizable carbon-carbon double bond) per molecule of the curable resin (B) may be 2 or more, preferably 2 or more and 20 or less, and more preferably 2 or more and 15 or less. This can increase the reactivity of the curable resin (B), and in the adhesive layer 2, it is possible to more reliably achieve good releasability by energy ray irradiation treatment and suppression of defects in the pick-up treatment.

[0092] The weight average molecular weight of the curable resin (B) is not particularly limited as long as it is smaller than the weight average molecular weight of the double bond-introduced acrylic resin (A), but is preferably 100 to 1,000, more preferably 200 to 500. The weight average molecular weight is measured by gel permeation chromatography (GPC) in terms of standard polystyrene.

[0093] The blending ratio of the curable resin (B) is more than 0 parts by mass and not more than 180 parts by mass, preferably 3 parts by mass or more and not more than 160 parts by mass, more preferably 5 parts by mass or more and not more than 140 parts by mass, and even more preferably 8 parts by mass or more and not more than 120 parts by mass, per 100 parts by mass of the double bond-introduced acrylic resin (A). This achieves the effect of using the double bond-introduced acrylic resin (A) and the curable resin (B) in combination. That is, a sufficiently high adhesive strength can be ensured before curing of the adhesive layer 2, and the adhesive strength can be sufficiently reduced after curing.

[0094] If the blending ratio of the curable resin (B) is below the lower limit, the adhesive layer 2 before curing will have insufficient adhesive strength, and the adhesive layer 2 will be difficult to cure, resulting in reduced peelability due to energy ray irradiation and defects in the pickup process. Furthermore, due to a shortage of the curable resin (B), the adhesive tape 100 will have poor appearance, such as wrinkles and slack, after the surface cleaning process. On the other hand, if the blending ratio of the curable resin (B) is above the upper limit, the curable resin (B) will be excessive, which will easily cause the curable resin (B) to dissolve in the cleaning solution, potentially leading to contamination of the semiconductor substrate 7 by the curable resin (B).

[0095] 3.2.3 Photopolymerization initiator The adhesive layer 2 preferably contains a photopolymerization initiator, which facilitates initiation of polymerization of the double bond-introduced acrylic resin (A) and the curable resin (B).

[0096] Examples of the photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'- Dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, 1-hydroxycyclohexyl phenyl ketone, Michler's ketone, acetophenone, methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl, benzoin, Dibenzyl, α-hydroxycyclohexyl phenyl ketone, benzil dimethyl ketal, 2-hydroxymethylphenylpropane, 2-naphthalenesulfonyl chloride, 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime, benzophenone, benzoylbenzoic acid, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, 4,4'-dichlorobenzophenone, 3,3'-dimethyl-4-methoxybenzophenone, o-acryloxybenzophenone, p-acryloxybenzophenone Benzophenone-4-carboxylic acid esters of acrylates such as benzophenone, o-methacryloxybenzophenone, p-methacryloxybenzophenone, p-(meth)acryloxyethoxybenzophenone, 1,4-butanediol mono(meth)acrylate, 1,2-ethanediol mono(meth)acrylate, 1,8-octanediol mono(meth)acrylate, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,Examples of the thioxanthone include 4-diethylthioxanthone, 2,4-diisopropylthioxanthone, azobisisobutyronitrile, β-chloroanthraquinone, camphorquinone, halogenated ketones, acylphosphinoxides, acylphosphonates, polyvinylbenzophenone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, 2-ethylanthraquinone, t-butylanthraquinone, and 2,4,5-triarylimidazole dimers, and these can be used alone or in combination of two or more.

[0097] The photopolymerization initiator is preferably blended in an amount of 0.1 to 50 parts by mass, more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the double bond-introduced acrylic resin (A). By adjusting the blending amount of the photopolymerization initiator as described above, the function exhibited by adding the photopolymerization initiator can be reliably exhibited, and excess photopolymerization initiator can be avoided.

[0098] 3.2.4 Crosslinking Agent The resin composition constituting the adhesive layer 2 may contain a crosslinking agent. By containing a crosslinking agent, the adhesive layer 2 can be adjusted to have an appropriate hardness.

[0099] The crosslinking agent is not particularly limited, but examples thereof include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, urea resin-based crosslinking agents, methylol-based crosslinking agents, chelate-based crosslinking agents, aziridine-based crosslinking agents, melamine-based crosslinking agents, polyvalent metal chelate-based crosslinking agents, acid anhydride-based crosslinking agents, polyamine-based crosslinking agents, carboxyl group-containing polymer-based crosslinking agents, etc. Among these, isocyanate-based crosslinking agents are preferred.

[0100] The isocyanate-based crosslinking agent is not particularly limited, but examples thereof include polyisocyanate compounds of polyvalent isocyanates, trimers of polyisocyanate compounds, trimers of isocyanate-terminated compounds obtained by reacting a polyisocyanate compound with a polyol compound, and blocked polyisocyanate compounds in which isocyanate-terminated urethane prepolymers are blocked with phenol, oximes, or the like.

[0101] Examples of polyisocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, 4,4'-diphenylether diisocyanate, 4,4'-[2,2-bis(4-phenoxyphenyl)propane]diisocyanate, and 2,2,4-trimethyl-hexamethylene diisocyanate. These may be used alone or in combination of two or more. Among these, at least one polyvalent isocyanate selected from the group consisting of 2,4-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, and hexamethylene diisocyanate is preferred.

[0102] The crosslinking agent is preferably blended in an amount of 0.01 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the double bond-introduced acrylic resin (A). By adjusting the blending amount of the crosslinking agent as described above, the crosslinking agent can be made to reliably exhibit the function exhibited by adding the crosslinking agent to the resin composition.

[0103] 3.2.5 Attributes of the Adhesive Tape The thickness of the adhesive layer 2 is not particularly limited, but is preferably 5 μm to 100 μm, more preferably 5 μm to 50 μm. By setting the thickness of the adhesive layer 2 within this range, it is possible to achieve an adhesive layer 2 that exhibits good adhesion to the semiconductor substrate 7 during the dicing process and good releasability during the pick-up process.

[0104] The adhesive layer 2 may be formed as a laminate (multilayer body) in which a plurality of layers made of different resin compositions are laminated.

[0105] Furthermore, when the adhesive tape 100 is immersed in a cleaning solution, the change in haze is suppressed compared to before the immersion. Since haze has a negative effect on the appearance of the adhesive tape 100, it is desirable that the change in haze be small before and after contact with the cleaning solution.

[0106] Specifically, the adhesive tape 100 is immersed in the cleaning solution for 30 minutes with DMSO as the cleaning solution and ethanol as the rinsing solution while the outer periphery of the adhesive layer 2 is fixed to a ring frame, and the haze of the adhesive tape 100 measured after being removed is defined as Ha. The haze measured before being immersed in the cleaning solution is defined as Hb. In this case, the haze difference of the adhesive tape 100, calculated by (Ha - Hb), is preferably 40% or less, more preferably 30% or less, and even more preferably 20% or less.

[0107] According to this configuration, an adhesive tape 100 can be obtained in which changes in appearance before and after contact with a cleaning solution are suppressed. It is also thought that the haze reflects changes in the surface structure of the adhesive layer 2 that occur when the adhesive tape 100 comes into contact with a cleaning solution. An adhesive tape 100 with a small difference in haze can suppress poor appearance caused by contact with a cleaning solution. This is thought to be because swelling of the adhesive layer 2 and elution of low molecular weight components from the adhesive layer 2 can be suppressed.

[0108] The haze can be measured using a haze meter in accordance with the measurement method specified in JIS K 7136:2000.

[0109] 4. Method for Producing the Adhesive Tape Next, an example of a method for producing the adhesive tape 100 will be described.

[0110] [1B] First, prepare the substrate 4. The method for producing the substrate 4 is not particularly limited, but examples thereof include common molding methods such as extrusion molding methods such as a calendar method, an inflation extrusion method, and a T-die extrusion method, and a wet casting method.

[0111] The upper surface of the substrate 4 may be previously subjected to a surface treatment such as corona treatment, chromic acid treatment, matte treatment, ozone exposure treatment, flame exposure treatment, high-voltage shock exposure treatment, ionizing radiation treatment, primer treatment, or anchor coating treatment, which can improve the adhesion between the substrate 4 and the adhesive layer 2.

[0112] [2B] Next, adhesive layer 2 is formed on the upper surface of substrate 4. Adhesive layer 2 is formed by coating or spraying a liquid material, prepared by dissolving a resin composition in a solvent to form a varnish, onto the upper surface of a film such as polyethylene terephthalate, then volatilizing the solvent to form a layer, and then transferring the layer to substrate 4.

[0113] The solvent is not particularly limited, but examples thereof include methyl ethyl ketone, acetone, toluene, ethyl acetate, dimethyl formaldehyde, etc., and one or more of these can be used in combination.

[0114] The liquid material can be applied or sprayed onto the substrate 4 using methods such as die coating, curtain die coating, gravure coating, comma coating, bar coating, and lip coating.

[0115] Thereafter, if necessary, treatments such as removing a portion of the adhesive layer 2 and laminating a separator may be carried out. In this manner, the adhesive tape 100 is obtained.

[0116] 5. Effects of the Embodiments The pressure-sensitive adhesive tape 100 according to the embodiments is a pressure-sensitive adhesive tape that includes a substrate 4 and a pressure-sensitive adhesive layer 2 laminated on one surface of the substrate 4, and is used to temporarily fix a semiconductor substrate 7 (substrate). The pressure-sensitive adhesive layer 2 contains a double-bond-introduced acrylic resin (A) having an unsaturated double bond in a side chain, and a curable resin (B) that is cured by irradiation with energy rays. The blending ratio of the curable resin (B) to 100 parts by mass of the double-bond-introduced acrylic resin (A) is more than 0 parts by mass and not more than 180 parts by mass.

[0117] According to this configuration, it is possible to obtain an adhesive tape 100 that has good resistance to cleaning solutions and maintains good releasability after irradiation with energy rays, thereby making it possible to suppress the occurrence of defects during dicing and pick-up processes.

[0118] The curable resin (B) preferably has a polymerizable carbon-carbon double bond that can be three-dimensionally crosslinked by irradiation with energy rays, and the number of functional groups per molecule of the curable resin (B) is preferably 2 or more.

[0119] According to this configuration, the reactivity of the curable resin (B) can be increased, and the adhesive layer 2 can more reliably achieve good peelability by energy ray irradiation treatment and suppression of defects during pickup treatment.

[0120] The curable resin (B) preferably contains at least one of an ester of (meth)acrylic acid and a polyhydric alcohol, a urethane acrylate, and an epoxy acrylate.

[0121] According to this configuration, the curable resin (B) can be more reliably cured by irradiation with energy rays, thereby realizing good peelability of the adhesive layer 2 by the energy ray irradiation treatment and suppressing the occurrence of defects in the pickup treatment.

[0122] The curable resin (B) preferably contains bisphenol A epoxy acrylate.

[0123] According to this configuration, the curable resin (B) can be more reliably cured by irradiation with energy rays, thereby realizing good peelability of the adhesive layer 2 by the energy ray irradiation treatment and suppressing the occurrence of defects in the pickup treatment.

[0124] The double bond-introduced acrylic resin (A) preferably has a polymerizable carbon-carbon double bond in the side chain that can be three-dimensionally crosslinked by irradiation with energy rays.

[0125] By having such a polymerizable carbon-carbon double bond in the side chain, three-dimensional crosslinking can be more reliably formed within the polymer main chain or between polymer main chains of the double bond-introduced acrylic resin (A).

[0126] Although the pressure-sensitive adhesive tape of the present invention has been described above, the present invention is not limited to the above-described embodiment.

[0127] For example, each layer of the pressure-sensitive adhesive tape of the present invention may contain a component other than the components described in the above embodiment. Furthermore, the pressure-sensitive adhesive tape of the present invention may have an optional layer added to the layer configuration described in the above embodiment. In this case, the location of the additional layer is not particularly limited, and may be on the upper surface of the pressure-sensitive adhesive layer, on the lower surface of the substrate, or between the pressure-sensitive adhesive layer and the substrate. Furthermore, the substrate may be composed of multiple layers.

[0128] Furthermore, the substrate to be temporarily fixed by the pressure-sensitive adhesive tape of the present invention is not limited to the above-mentioned semiconductor substrate (semiconductor wafer), and may be, for example, a glass substrate such as soda-lime glass, borosilicate glass, or quartz glass, a ceramic substrate such as alumina, silicon nitride, or titanium oxide, a resin substrate such as acrylic, polycarbonate, or rubber, a single crystal substrate such as quartz or sapphire, or a metal plate, etc. Furthermore, members such as chips obtained by dividing semiconductor wafers or other substrates are also included in the substrates to be temporarily fixed by the pressure-sensitive adhesive tape.

[0129] Next, specific examples of the present invention will be described. However, the present invention is not limited to the descriptions of these examples. 6. Preparation of Adhesive Tape An adhesive tape was prepared using the following materials.

[0130] 6.1 Preparation of Raw Materials Table 1 shows the base resin, curable resin, photopolymerization initiator, and crosslinking agent used to prepare the adhesive layer.

[0131] Each base resin was synthesized as follows. 6.1.1. Synthesis of Base Resin a1-1 An acrylic copolymer was obtained by copolymerizing 48.3 parts by mass of butyl acrylate (solids equivalent value: hereinafter the same), 14.0 parts by mass of methyl methacrylate, 30.0 parts by mass of hydroxyethyl acrylate, 0.64 parts by mass of acrylic acid, and 7.06 parts by mass of dimethylacrylamide. The obtained acrylic copolymer was then reacted with 2-methacryloyloxyethyl isocyanate (MOI) to obtain a (meth)acrylic acid ester copolymer (base resin a1-1) having an energy ray-curable group (methacryloyl group) introduced into its side chain. The two were reacted so that the MOI was 38.7 g per 100 g of the acrylic copolymer.

[0132] The weight average molecular weight (Mw) of the obtained (meth)acrylic acid ester copolymer was 600,000. In all of the following examples and comparative examples, the weight average molecular weight (Mw) of the (meth)acrylic acid ester copolymer was also 600,000.

[0133] 6.1.2. Synthesis of Base Resin a1-2 65.86 parts by mass of butyl acrylate, 3.5 parts by mass of methyl methacrylate, 30.0 parts by mass of hydroxyethyl acrylate, and 0.64 parts by mass of acrylic acid were copolymerized to obtain an acrylic copolymer. The resulting acrylic copolymer was then reacted with 2-methacryloyloxyethyl isocyanate (MOI) to obtain a (meth)acrylic acid ester copolymer (base resin a1-2) having an energy ray-curable group (methacryloyl group) introduced into the side chain. The two were reacted so that the MOI was 38.7 g per 100 g of the acrylic copolymer.

[0134] 6.1.3. Synthesis of Base Resin a1-3 An acrylic copolymer was obtained by copolymerizing 66.43 parts by mass of butyl acrylate, 1.0 part by mass of methyl methacrylate, 30.0 parts by mass of hydroxyethyl acrylate, and 2.57 parts by mass of acrylic acid. The obtained acrylic copolymer was then reacted with 2-methacryloyloxyethyl isocyanate (MOI) to obtain a (meth)acrylic acid ester copolymer (base resin a1-3) having an energy ray-curable group (methacryloyl group) introduced into the side chain. The two were reacted so that the MOI was 31.8 g per 100 g of the acrylic copolymer.

[0135] 6.1.4. Synthesis of Base Resin a1-4 69.36 parts by mass of 2-ethylhexyl acrylate, 10.00 parts by mass of methyl methacrylate, 20.00 parts by mass of hydroxyethyl acrylate, and 0.64 parts by mass of acrylic acid were copolymerized to obtain an acrylic copolymer. The resulting acrylic copolymer was then reacted with 2-methacryloyloxyethyl isocyanate (MOI) to obtain a (meth)acrylic acid ester copolymer (base resin a1-4) having an energy ray-curable group (methacryloyl group) introduced into its side chain. The two were reacted such that the MOI was 25.4 g per 100 g of the acrylic copolymer.

[0136] 6.1.5. Synthesis of Base Resin a2 An acrylic copolymer (base resin a2) was obtained by copolymerizing 85.0 parts by mass of butyl acrylate, 13.33 parts by mass of methyl methacrylate, 1.03 parts by mass of hydroxyethyl acrylate, and 0.64 parts by mass of acrylic acid.

[0137] 6.1.6. Synthesis of Base Resin a3 An acrylic copolymer (base resin a3) was obtained by copolymerizing 66.2 parts by mass of butyl acrylate, 23.0 parts by mass of methyl methacrylate, 3.1 parts by mass of hydroxyethyl acrylate, 7.06 parts by mass of dimethylacrylamide, and 0.64 parts by mass of acrylic acid.

[0138] In addition, when each base resin is a double bond-introduced acrylic resin having an unsaturated double bond in the side chain, it is marked with a circle in Table 1, and when an unsaturated double bond is not introduced in the side chain, it is marked with an x ​​in Table 1.

[0139] Table 1 also shows the main monomer component, acid value, hydroxyl value, glass transition temperature Tg (theoretical Tg before introduction of side chain double bonds) of the backbone polymer, and weight average molecular weight Mw of each base resin. The main monomer component refers to the component with the highest content by mass among all monomer components. Each base resin was synthesized by changing the blend of monomer components so that these physical properties would achieve the values ​​shown in Table 1. The double bond equivalent of the double bond-introduced acrylic resin was in the range of 200 to 4,000. Among the symbols representing the main monomer components, BA represents butyl acrylate, and 2-EHA represents 2-ethylhexyl acrylate.

[0140] The number of functional groups of the curable resins b1, b2, and b3 is shown in Table 1. Details of each curable resin shown in Table 1 are as follows.

[0141] 6.1.7. Curable Resin b1 Bisphenol A type epoxy acrylate (manufactured by Daicel Allnex Corporation, product number: EBECRYL600) was prepared as the curable resin b1.

[0142] 6.1.8. Curable Resin b2 Urethane acrylate (manufactured by Miwon Specialty Chemical Co., Ltd., product number: SC2152) was prepared as the curable resin b2.

[0143] 6.1.9. Curable Resin b3 Dipentaerythritol hexaacrylate (manufactured by Daicel Allnex Corporation, product number: DPHA), an ester of (meth)acrylic acid and a polyhydric alcohol, was prepared as the curable resin b3.

[0144]

[0145] 6.2. Preparation of Adhesive Layer First, a liquid material was prepared by blending the raw materials shown in Tables 2 and 3 in a predetermined ratio. Next, this liquid material was bar-coated onto the substrates shown in Tables 2 and 3 so that the thickness after drying was the value shown in Tables 2 and 3. The resulting coating was dried at 80°C for 1 minute to obtain an adhesive layer.

[0146] The thickness of the substrate 1 used to prepare the pressure-sensitive adhesive tape is shown in Tables 2 and 3. The constituent materials of the substrate 1 were FS2011DG-2 (PP) / H1062 (elastomer) = 60 / 40 (mass ratio).

[0147] In Tables 2 and 3, examples corresponding to the present invention are designated as "Examples," and examples not corresponding to the present invention are designated as "Comparative Examples."

[0148] 7. Evaluation of Adhesive Tape Next, the prepared adhesive tapes were evaluated for the following items.

[0149] 7.1. Change in Haze The haze of each adhesive tape of each Example and Comparative Example was measured before and after contact with the cleaning solution, and the haze difference was calculated. After immersion in DMSO as the cleaning solution for 30 minutes, the DMSO was rinsed off with ethanol. The calculated haze difference was then evaluated according to the following evaluation criteria. The evaluation results are shown in Tables 2 and 3.

[0150] A: The haze difference is 20% or less. B: The haze difference is more than 20% and 40% or less. C: The haze difference is more than 40%.

[0151] 7.2. Presence or absence of wrinkles or slack The pressure-sensitive adhesive tapes of each Example and Comparative Example were fixed to a ring frame. Next, the presence or absence of wrinkles or slack was observed while immersed in DMSO as a cleaning solution. The observation results were evaluated in accordance with the following evaluation criteria. The evaluation results are shown in Tables 2 and 3.

[0152] A: Almost no wrinkles or looseness (less than 5% of the area inside the ring frame) B: Little wrinkles or looseness (5% to less than 20% of the area inside the ring frame) C: Much wrinkles or looseness (more than 20% of the area inside the ring frame)

[0153] 7.3. Penetration Width of Cleaning Liquid A 4-inch silicon wafer was attached to the adhesive tape of each Example and Comparative Example. Next, DMSO was supplied as a cleaning liquid onto the silicon wafer and left to stand at room temperature for 30 minutes. DMSO was used as the cleaning liquid. At this time, the cleaning liquid was allowed to overflow from the silicon wafer and spread onto the adhesive tape. Next, the DMSO was rinsed away with ethanol. After drying, the outer periphery of the silicon wafer was observed from the adhesive tape side using an optical microscope, and the state of penetration of the cleaning liquid at the interface between the adhesive tape and the silicon wafer (penetration width from the outer edge) was observed. The observation results were then evaluated in light of the following evaluation criteria. The evaluation results are shown in Tables 2 and 3.

[0154] A: The penetration width of the cleaning liquid is small (penetration width less than 500 μm) B: The penetration width of the cleaning liquid is somewhat large (penetration width 500 μm or more and less than 1 mm) C: The penetration width of the cleaning liquid is large (penetration width 1 mm or more)

[0155] 7.4. Adhesion of residue after cleaning "7.3. Cleaning solution penetration width" After use, the adhesive tape was exposed to ultraviolet light with an intensity of 55 W / cm. ２ , UV irradiation amount: 200mJ / cm ２ The adhesive layer was cured by irradiating ultraviolet light under the conditions of

[0043] . Next, the adhesive tape was peeled off from the silicon wafer, and the presence or absence of residue (components contained in the adhesive layer) on the outer periphery of the silicon wafer was observed. The observation results were evaluated according to the following evaluation criteria. The evaluation results are shown in Tables 2 and 3.

[0156] A: Little residue adhered (less than 5% of the tip circumference) B: Somewhat much residue adhered (5% to less than 20% of the tip circumference) C: Much residue adhered (20% or more of the tip circumference)

[0157] 7.5. Evaluation of Post-UV Adhesion Strength After UV irradiation, the peel strength from the silicon wafer was measured to evaluate the post-UV adhesion strength of the adhesive tape as follows.

[0158] First, adhesive tapes with a width of 25 mm for each of the Examples and Comparative Examples were attached to the surface of a silicon wafer whose surface had been polished with #2000 polishing. Then, the adhesive tapes and the silicon wafer were kept at 23°C for 1 hour. Next, the adhesive tapes attached to the silicon wafer were exposed to ultraviolet light with an illuminance of 55 W / cm. ２ , UV irradiation amount: 200mJ / cm ２ The adhesive layer was cured by irradiating ultraviolet light under the conditions of . Next, in accordance with JIS G 3469, a peel test was conducted in an environment of 23°C, in which one end of the adhesive tape was held and pulled at a speed of 300 mm / min in a direction of 180°. Then, the peel strength A1 (peel strength A1) measured during peeling was measured. Note that a tensile tester (manufactured by A&D Co., Ltd., "TENSILON RTG-1310") was used for the test. The measured values ​​were evaluated in accordance with the following evaluation criteria. The evaluation results are shown in Tables 2 and 3.

[0159] A: The measured value is 500 mN / 25 mm or less. B: The measured value is greater than 500 mN / 25 mm and less than or equal to 800 mN / 25 mm. C: The measured value is greater than 800 mN / 25 mm.

[0160]

[0161]

[0162] From the results shown in Tables 2 and 3, the following was confirmed: By using a double bond-introduced acrylic resin and a curable resin in combination as raw materials for the adhesive layer, it was possible to realize an adhesive tape that has a small penetration width of cleaning liquid and is less prone to wrinkles and slack even when it comes into contact with cleaning liquid, and it was also confirmed that adhesion of residue to the chip after pick-up can be suppressed.

[0163] - It was also found that the change in haze could be reduced by optimizing the blending ratio of the curable resin in particular.

[0164] When either the double bond-introduced acrylic resin or the curable resin was not used, good results were not obtained in the above evaluation items.

[0165] Better evaluation results were obtained by optimizing the acid value, hydroxyl value, glass transition temperature Tg, and weight average molecular weight Mw of the base resin. Better evaluation results were obtained by optimizing the type and number of functional groups of the curable resin.

[0166] According to the present invention, it is possible to provide a pressure-sensitive adhesive tape that has good resistance to cleaning solutions and that can maintain good releasability when irradiated with energy rays even after contact with the cleaning solution. Therefore, the present invention has industrial applicability.

[0167] 2 Adhesive layer 4 Base material 7 Semiconductor substrate 9 Wafer ring 10 Semiconductor device 17 Molded portion 20 Semiconductor chip 21 Terminal 23 Semiconductor chip body portion 30 Interposer 41 Terminal 70 Bump 71 Front surface 72 Back surface 80 Sealing layer 81 Connection portion 100 Adhesive tape 121 Peripheral portion 122 Central portion 200 Dicer table 300 Expand table 310 Expansion stage 320 Holding table 400 Pickup table 500 Protective tape 600 Chuck table CS Cleaning liquid E Energy ray

Claims

1. An adhesive tape used to temporarily fix a substrate, comprising a substrate and an adhesive layer laminated on one side of the substrate, wherein the adhesive layer contains a double bond-introduced acrylic resin having an unsaturated double bond in a side chain, and a curable resin that is cured by irradiation with energy rays, and wherein the blending ratio of the curable resin to 100 parts by mass of the double bond-introduced acrylic resin is more than 0 parts by mass and 180 parts by mass or less.

2. The adhesive tape according to claim 1, wherein the curable resin has a polymerizable carbon-carbon double bond that can be three-dimensionally crosslinked by irradiation with energy rays, and the number of functional groups per molecule of the curable resin is two or more.

3. The adhesive tape according to claim 1 or 2, wherein the curable resin contains at least one of an ester of (meth)acrylic acid and a polyhydric alcohol, a urethane acrylate, and an epoxy acrylate.

4. The adhesive tape according to claim 3, wherein the curable resin contains bisphenol A epoxy acrylate.

5. An adhesive tape according to any one of claims 1 to 4, wherein the double bond-introduced acrylic resin has a polymerizable carbon-carbon double bond in the side chain that can be three-dimensionally crosslinked by irradiation with energy rays.

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