Adhesive tape for semiconductor manufacturing process, and method for manufacturing semiconductor chip

Abstract

The purpose of the present invention is to provide an adhesive tape for a semiconductor manufacturing process, which enables satisfactory transferring of a large number of semiconductor chips even when the size of the semiconductor chips is small. Further, the purpose of the present invention is to provide a semiconductor chip using said adhesive tape for a semiconductor manufacturing process. The present invention is an adhesive tape for a semiconductor manufacturing process, which has a first adhesive layer and a base material layer and in which at least one layer constituting the adhesive tape for a semiconductor manufacturing process contains an antistatic agent. The adhesive tape for a semiconductor manufacturing process is used in a method for manufacturing a semiconductor chip, the method including a transfer step for continuously placing semiconductor chips on the first adhesive layer, removing the semiconductor chips from the first adhesive layer, and then bringing the removed semiconductor chips into contact with a carrier material. In said transfer step, removing of the semiconductor chips from the first adhesive layer and contact of the removed semiconductor chips with the carrier material are continuously performed.

Description

Adhesive tape for semiconductor manufacturing processes, and method for manufacturing semiconductor chips

[0001] This invention relates to an adhesive tape for semiconductor manufacturing processes. Furthermore, this invention relates to a method for manufacturing a semiconductor chip using the adhesive tape for semiconductor manufacturing processes.

[0002] In the manufacturing process of semiconductor devices, numerous chip components placed on an adhesive layer are sometimes transferred onto a drive circuit board. For example, in a microLED display, each of the chips that make up the pixels is a tiny light-emitting diode (LED) chip, and these microLED chips emit light themselves to display an image. MicroLED displays are attracting attention as next-generation display devices because they have high contrast, fast response speed, and can be made thinner by not requiring color filters used in liquid crystal displays, organic EL displays, etc. In a microLED display, a large number of microLED chips are densely arranged on a plane.

[0003] Japanese Patent Publication No. 2019-138949, Japanese Patent Publication No. 2019-15899, Japanese Patent Publication No. 2003-7986

[0004] In the manufacturing process of semiconductor devices such as micro-LED displays, for example, a transfer laminate is created by attaching numerous chip components to the adhesive layer of an adhesive tape, and this laminate is then placed opposite a drive circuit board. The chip components are then peeled off the transfer laminate to make an electrical connection with the drive circuit board (transfer process).

[0005] One known method for detaching chip components from a transfer laminate is to irradiate the adhesive layer with laser light focused on it from the back surface of the support of the transfer laminate (for example, Patent Document 1). This method is also called laser ablation. Another known method involves incorporating thermally expandable particles, thermally expandable microcapsules, etc., into the adhesive layer, and then thermally expanding the thermally expandable particles, thermally expandable microcapsules, etc., by thermocompression bonding the transfer laminate and the drive circuit board. This deformation of the adhesive layer reduces the bonding area, thereby detaching the chip components (for example, Patent Documents 2 and 3).

[0006] However, with conventional methods for removing chip components, when transferring a large number of small semiconductor chips (such as micro-LED chips and mini-LED chips), transfer failures occur, leading to a deterioration in the positional accuracy of the transfer. Furthermore, even if the semiconductor chip can be removed, adhesive residue may adhere to the semiconductor chip.

[0007] The present invention aims to provide an adhesive tape for semiconductor manufacturing processes that can transfer a large number of semiconductor chips well, even when the size of the semiconductor chips is small. Furthermore, the present invention aims to provide a semiconductor chip using the adhesive tape for semiconductor manufacturing processes.

[0008] Disclosure 1 is an adhesive tape for semiconductor manufacturing processes having a first adhesive layer and a base layer, wherein at least one layer constituting the adhesive tape for semiconductor manufacturing processes contains an antistatic agent, and the adhesive tape is used in a method for manufacturing semiconductor chips, comprising a transfer step in which semiconductor chips are continuously arranged on the first adhesive layer, the semiconductor chips are peeled off the first adhesive layer, and the peeled semiconductor chips are brought into contact with a carrier material, wherein the peeling of the semiconductor chips from the first adhesive layer and the contact of the peeled semiconductor chips with the carrier material are performed continuously in the transfer step. Disclosure 2 is the adhesive tape for semiconductor manufacturing processes of Disclosure 1, wherein the antistatic agent contains at least one compound selected from the group consisting of compounds having a polythiophene skeleton and lithium compounds. Disclosure 3 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 1 or 2, wherein the antistatic agent comprises an ionic compound, and the ionic compound is composed of at least one anion species selected from the group consisting of bis(fluorosulfonyl)imide anion, hexafluorophosphate anion, and carboxy anion. Disclosure 4 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 1, 2, or 3, wherein the first adhesive layer contains a base polymer and the antistatic agent, and the content of the antistatic agent is 0.1 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the base polymer. Disclosure 5 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 4, wherein the base polymer comprises a (meth)acrylic copolymer. Disclosure 6 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 5, wherein the (meth)acrylic copolymer has constituent units derived from alkyl (meth)acrylates with an alkyl group having 1 to 4 carbon atoms at the ester terminal, and the content of the constituent units derived from alkyl (meth)acrylates in the (meth)acrylic copolymer is 50% by mass or more and 99% by mass or less. Disclosure 7 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 5 or 6, wherein the (meth)acrylic copolymer has a weight-average molecular weight of 200,000 to 2,000,000. Disclosure 8 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 1, 2, 3, 4, 5, 6 or 7, wherein the first adhesive layer contains a tackifying resin.Disclosure 9 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 8, wherein the tackifying resin contains a phenolic resin, and the content of the tackifying resin is 5 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the base polymer. Disclosure 10 is an adhesive tape for semiconductor manufacturing processes according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, or 9, wherein the first adhesive layer contains an ultraviolet absorber. Disclosure 11 is an adhesive tape for semiconductor manufacturing processes according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein the first adhesive layer has a gel fraction of 50% by mass or more. Disclosure 12 is an adhesive tape for semiconductor manufacturing processes according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein the first adhesive layer has a shear storage modulus of 5 × 10 at 23°C and a measurement frequency of 10 Hz. ４ The above 1 x 10 ６The adhesive tape for semiconductor manufacturing processes according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11 has a pressure of Pa or less. Disclosure 13 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12, wherein the first adhesive layer has a probe tack value of 10 N / 5 mmφ or more and 30 N / 5 mmφ or less, measured under the conditions of 23°C, pressurized pressure of 0.05 MPa, pressurized speed of 10 mm / sec, pressurized time of 10 seconds, and peeling speed of 0.1 mm / sec. Disclosure 14 is an adhesive tape for semiconductor manufacturing processes according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13, wherein the first adhesive layer has a probe tack value of 1 N / 5 mmφ or more and 20 N / 5 mmφ or less, measured under the conditions of 23°C, a pressurizing pressure of 0.05 MPa, a pressurizing speed of 10 mm / sec, a pressurizing time of 10 seconds, and a release speed of 15 mm / sec. Disclosure 15 is an adhesive tape for semiconductor manufacturing processes according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14, further comprising an intermediate layer between the first adhesive layer and the substrate layer. Disclosure 16 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 15, wherein the intermediate layer comprises an intermediate adhesive layer. Disclosure 17 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 16, wherein the intermediate layer further comprises an intermediate substrate layer. Disclosure 18 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 17, comprising the above-mentioned base layer, the above-mentioned intermediate adhesive layer, the above-mentioned intermediate base layer, and the above-mentioned first adhesive layer in this order. Disclosure 19 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 16, 17, or 18, wherein the intermediate adhesive layer contains an A-B-A type block copolymer having a structure in which block A is derived from an aromatic vinyl monomer and block B is derived from at least one selected from the group consisting of (meth)acrylate, conjugated diene monomer, and hydrogenated conjugated diene monomer. Disclosure 20 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 15, 16, 17, 18, or 19, wherein at least one layer between the first adhesive layer and the intermediate adhesive layer contains an ultraviolet absorber. Disclosure 21 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 20, wherein the intermediate adhesive layer contains an ultraviolet absorber.Disclosure 22 is an adhesive tape for semiconductor manufacturing processes according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or 21, having a second adhesive layer on the side of the base layer opposite to the first adhesive layer. Disclosure 23 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 22, wherein at least one layer of the base layer and the second adhesive layer contains the antistatic agent. Disclosure 24 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 22 or 23, wherein the second adhesive layer has a 180° peel force to a glass plate at 23°C of 2.0 N / 25 mm or more and 10.0 N / 25 mm or less. Disclosure 25 is an adhesive tape for semiconductor manufacturing processes according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24, wherein the ultraviolet absorption rate at a wavelength of 355 nm is 80% or more. Disclosure 26 is an adhesive tape for semiconductor manufacturing processes according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25, wherein the common logarithm of the surface resistance of the adhesive tape for semiconductor manufacturing processes measured from the first adhesive layer side is 15.0 [log(Ω / sq)] or less. Disclosure 27 provides the above-mentioned adhesive tape for semiconductor manufacturing processes, measured with the first adhesive layer side attached to a glass plate, at a wavelength of 355 nm and an irradiation intensity of 7.8 mW / cm. ２ The cumulative amount of ultraviolet light is 190 mJ / cm². ２The adhesive tape for semiconductor manufacturing processes described in 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or 26 of this disclosure is irradiated in such a manner that the rate of decrease in 180° peel strength to glass at 23°C is 60% or less. Disclosure 28 is a semiconductor manufacturing process adhesive tape according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, or 27, wherein, when the semiconductor manufacturing process adhesive tape is left undisturbed in a 40°C environment for one week, the 180° peel force of the semiconductor manufacturing process adhesive tape to glass at 23°C after the long-term storage test is 0.050 N / 20 mm or more and 1.000 N / 20 mm or less. Disclosure 29 is a semiconductor manufacturing process adhesive tape according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, or 28, wherein when the semiconductor manufacturing process adhesive tape is subjected to a long-term storage test in which it is left standing in a 40°C environment for one week, the ratio of the 180° peel force of the semiconductor manufacturing process adhesive tape after the long-term storage test to the 180° peel force of the semiconductor manufacturing process adhesive tape at 23°C at 23°C before the long-term storage test is 0.50 or more and 1.50 or less. Disclosure 30 is an adhesive tape for semiconductor manufacturing processes of Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, or 29, used in a method for manufacturing a semiconductor chip having a rectangular shape with at least one side length of 1000 μm or less. Disclosure 31 is a method for manufacturing a semiconductor chip using an adhesive tape for semiconductor manufacturing processes of Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30. The present invention will be described in detail below. Hereinafter, embodiments of the present invention or one thereof will be described as "this embodiment".

[0009] The inventors of the present invention have found that when transferring a large number of small semiconductor chips, more static electricity accumulates on the adhesive tape on which the large number of semiconductor chips are placed compared to when manufacturing a small number of semiconductor chips, and that this accumulation of static electricity on the adhesive tape on which the semiconductor chips are placed causes poor transfer of the chips. Therefore, the inventors of the present invention have investigated the possibility of including an antistatic agent in at least one layer constituting the adhesive tape having a base layer and an adhesive layer. As a result, they have found that it is possible to obtain an adhesive tape for semiconductor manufacturing processes that can transfer a large number of semiconductor chips well even when the size of the semiconductor chips is small, and have completed the present invention.

[0010] The adhesive tape for semiconductor manufacturing processes of this embodiment has a first adhesive layer and a base layer. The adhesive tape for semiconductor manufacturing processes of this embodiment is used in a semiconductor chip manufacturing method in which semiconductor chips are continuously arranged on the first adhesive layer of the adhesive tape for semiconductor manufacturing processes, the semiconductor chips are peeled off the adhesive tape for semiconductor manufacturing processes, and the peeled semiconductor chips are brought into contact with a carrier material, wherein the peeling of the semiconductor chips from the adhesive tape and the contact of the peeled semiconductor chips with the carrier material are performed continuously in the transfer step. In this semiconductor chip manufacturing method, "continuously arranged semiconductor chips" means that a large number of chips are laid out in a planar manner at high density (for example, at intervals of 10 μm to 1000 μm). In this semiconductor chip manufacturing method, the peeling of the semiconductor chips and contact with the carrier material are performed continuously. That is, since the peeling of the semiconductor chips and contact with the carrier material are not performed simultaneously, there is no need to mechanically move the adhesive tape for semiconductor manufacturing processes or the carrier material, and high-speed manufacturing of semiconductor chips becomes possible. Therefore, it is superior in terms of semiconductor chip manufacturing speed and production efficiency.

[0011] At least one layer constituting the adhesive tape for semiconductor manufacturing processes of this embodiment contains an antistatic agent. By including an antistatic agent in at least one layer constituting the adhesive tape for semiconductor manufacturing processes of this embodiment, the accumulation of static electricity in the resulting adhesive tape for semiconductor manufacturing processes can be suppressed. This improves the release properties of the resulting adhesive tape from semiconductor chips, suppresses transfer defects of semiconductor chips (i.e., improves positional accuracy in semiconductor chip transfer), and suppresses the adhesion of adhesive layer residue to semiconductor chips. Therefore, even when manufacturing a large number of semiconductor chips, semiconductor chips can be transferred well, and the yield of semiconductor chips during semiconductor chip manufacturing can be further improved. In this specification, when each layer constituting the adhesive tape for semiconductor manufacturing processes of this embodiment is described as "containing an antistatic agent," it includes not only cases where the layer contains an antistatic agent as a component, but also cases where the layer is coated with an antistatic agent.

[0012] Examples of the above-mentioned antistatic agents include ionic compounds, conductive polymers, ion-conducting polymers, and ion-conducting fillers. Examples of the above-mentioned ionic compounds include organic ionic compounds containing organic cations and alkali metal salts such as lithium compounds, and examples of the above-mentioned conductive polymers include compounds having a polythiophene skeleton. In particular, it is preferable that the above-mentioned antistatic agent contains at least one compound selected from the group consisting of compounds having a polythiophene skeleton and lithium compounds. By including at least one compound selected from the group consisting of compounds having a polythiophene skeleton and lithium compounds in the above-mentioned antistatic agent, high antistatic performance can be imparted to the adhesive tape for semiconductor manufacturing processes of this embodiment.

[0013] On the other hand, from the viewpoint of making the adhesive tape for semiconductor manufacturing processes of this embodiment more release-friendly even after long-term storage, it is preferable that the antistatic agent contains an ionic compound. By making the adhesive tape for semiconductor manufacturing processes of this embodiment more release-friendly even after long-term storage, it becomes easier to transfer semiconductor chips (including small semiconductor chips) more effectively even when using tape that has been stored for a long time. Long-term storage of the adhesive tape for semiconductor manufacturing processes can be, for example, left undisturbed for several days to several months in an environment of room temperature to 40°C, and more specifically, for example, left undisturbed for one week in an environment of 40°C.

[0014] The above-mentioned ionic compound may be an ionic liquid that is liquid at room temperature, or an ionic solid that is solid at room temperature.

[0015] The above ionic compound is preferably composed of an onium cation as the organic cation. By the above organic ionic compound being composed of an onium cation, the antistatic agent will have higher ionic conductivity, and the accumulation of static electricity on the adhesive tape for semiconductor manufacturing processes in this embodiment will be further suppressed. Examples of the above onium cation include nitrogen-containing onium cation, sulfur-containing onium cation (e.g., trialkylsulfonium cation), phosphorus-containing onium cation (e.g., tetraalkylphosphonium cation), etc. Among these, nitrogen-containing onium cation is preferred from the viewpoint of appropriately adjusting the molecular size and electronegativity of the antistatic agent.

[0016] Examples of the nitrogen-containing onium cations mentioned above include pyridinium cations, pyrrolidinium cations, piperidinium cations, cations having a pyrroline skeleton, cations having a pyrrole skeleton, imidazolium cations, tetrahydropyrimidinium cations, dihydropyrimidinium cations, pyrazolium cations, pyrazolinium cations, and tetraalkylammonium cations.

[0017] Examples of anions constituting the above-mentioned ionic compound include fluoroorganic anions, fluoroinorganic anions, carboxy anions, and sulfonyl anions. Among these, fluoroorganic anions and fluoroinorganic anions are preferred from the viewpoint of further improving the antistatic effect of the adhesive tape for semiconductor manufacturing processes in this embodiment.

[0018] The fluoroorganic anions constituting the ionic compound containing the above-mentioned organic cation may be fully fluorinated (perfluorinated) or partially fluorinated. Examples of the above-mentioned fluoroorganic anions include perfluoroalkyl sulfonates, bis(fluorosulfonyl)imides, bis(perfluoroalkanesulfonyl)imides, and more specifically, trifluoromethanesulfonates, pentafluoroethanesulfonates, heptafluoropropanesulfonates, nonafluorobutanesulfonates, bis(fluorosulfonyl)imides, bis(trifluoromethanesulfonyl)imides, and so on. Examples of fluoroinorganic anions constituting the ionic compound containing the above-mentioned organic cation include hexafluorophosphate and tetrafluoroboric acid.

[0019] On the other hand, from the perspective of more easily suppressing the decrease in peel strength after long-term storage of the adhesive tape for semiconductor manufacturing processes, it is preferable that the ionic compound contains a compound composed of anions having no C-F bond. By the ionic compound containing a compound composed of anions having no C-F bond, it becomes easier to suppress the bleed-out of the antistatic agent during storage of the adhesive tape for semiconductor manufacturing processes. Therefore, it becomes easier to make the adhesive tape for semiconductor manufacturing processes have more excellent pick-up properties with respect to semiconductor chips after long-term storage. Among them, as the compound composed of anions having no C-F bond, the ionic compound preferably contains a compound composed of at least one anion species selected from the group consisting of bis(fluorosulfonyl)imide anion, hexafluorophosphate anion, and carboxy anion, and more preferably contains a compound composed of bis(fluorosulfonyl)imide anion. By the ionic compound containing such a compound as the compound composed of anions having no C-F bond, the molecular size of the antistatic agent does not become too large, the releasability of the obtained adhesive tape for semiconductor manufacturing processes with respect to semiconductor chips is further improved, and it becomes easier to more suppress transfer defects of semiconductor chips. Among them, from the perspective of more easily adjusting the viscosity of the first adhesive layer appropriately, it is preferable that the ionic compound contains such a compound as the compound composed of anions having no C-F bond in the first adhesive layer described later.

[0020] Examples of the compound composed of the above-mentioned bis(fluorosulfonyl)imide anion include, specifically, 1-butyl-3-methylpyridinium bis(fluorosulfonyl)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, lithium bis(fluorosulfonyl)imide, 1-methyl-3-nor maloctylimidazolium bis(fluorosulfonyl)imide, and the like. Examples of the compound composed of the above-mentioned hexafluorophosphate anion include, specifically, 1-butyl-3-methylimidazolium hexafluorophosphate, lithium hexafluorophosphate, 1-hexyl-3-methylpyridinium hexafluorophosphate, and the like. Examples of the compound composed of the above-mentioned carboxylate anion include, specifically, 1-butyl-3-methylpyridinium acetate, and the like.

[0021] The above-mentioned alkali metal salt is a compound composed of an alkali metal cation and an anion constituting the above-mentioned ionic compound. Examples of the above-mentioned alkali metal cation include, for example, lithium cation (Li ＋ ), sodium cation (Na ＋ ), or potassium cation (K ＋ ), and among them, lithium cation (Li ＋ ) is preferred. When the above-mentioned alkali metal cation is lithium cation (Li ＋ ), the molecular size of the above-mentioned antistatic agent does not become too large, and it becomes easier to appropriately adjust the viscosity of the above-mentioned first adhesive layer. Therefore, the releasability of the adhesive tape for semiconductor manufacturing process of the present embodiment with respect to the semiconductor chip is further improved, and it is easier to suppress transfer defects of the semiconductor chip.

[0022] Examples of the above-mentioned lithium compound include alkali metal salts composed of lithium cations such as lithium bistrifluoromethanesulfonylimide and lithium perchlorate, and the like.

[0023] Examples of the compound having the above-mentioned polythiophene skeleton include, for example, a mixture of poly(3,4-ethylenedioxythiophene)·polystyrenesulfonic acid (PEDOT / PSS), and the like.

[0024] Examples of the ion-conducting polymers mentioned above include poly-3,4-ethylenedioxythiophene / poly-4-styrene sulfonate.

[0025] Examples of the ion-conducting fillers mentioned above include carbon nanotubes.

[0026] The adhesive tape for semiconductor manufacturing processes of this embodiment has a first adhesive layer. The first adhesive layer preferably contains a base polymer (hereinafter, the base polymer contained in the first adhesive layer may simply be referred to as "base polymer (P1)"). Examples of the base polymer (P1) include (meth)acrylic copolymers, styrene elastomers, urethane copolymers, silicone polymers, etc. In particular, it is preferable that the base polymer (P1) contains a (meth)acrylic copolymer because it can further improve the release properties of the resulting adhesive tape for semiconductor manufacturing processes and further reduce adhesive residue on semiconductor chips. In this specification, "(meth)acrylic" means acrylic or methacrylic.

[0027] The above (meth)acrylic copolymer is a copolymer having structural units derived from alkyl (meth)acrylate. The structural units derived from alkyl (meth)acrylate preferably include structural units derived from alkyl (meth)acrylate having an alkyl group with 4 or fewer carbon atoms at the ester terminus (hereinafter sometimes simply referred to as "alkyl (meth)acrylate (a)"). That is, the above (meth)acrylic copolymer preferably has structural units derived from alkyl (meth)acrylate (a). By making the above (meth)acrylic copolymer have structural units derived from alkyl (meth)acrylate (a), the resulting adhesive tape for semiconductor manufacturing processes can be used to better adhere semiconductor chips when receiving them, and transfer can be performed more effectively (i.e., the pick-up ability of the adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved). In addition, the resulting adhesive tape for semiconductor manufacturing processes can be made to have superior release properties. Note that the lower limit of the number of carbon atoms of the alkyl group with 4 or fewer carbon atoms present at the ester terminus in alkyl (meth)acrylate (a) may be 1, and the preferred lower limit is 2. Furthermore, the number of carbon atoms in the alkyl group having 4 or fewer carbon atoms at the ester end of the alkyl (meth)acrylate (a) may be 1 to 4 or 2 to 4. Also, in this specification, "(meth)acrylate" means acrylate or methacrylate.

[0028] Examples of the alkyl (meth)acrylate (a) mentioned above include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, and the like. These alkyl (meth)acrylates may be used individually or in combination of two or more.

[0029] The glass transition temperature (Tg) of the alkyl (meth)acrylate homopolymer described above has a preferred lower limit of 0°C. That is, the (meth)acrylic copolymer preferably has constituent units derived from alkyl (meth)acrylate (hereinafter sometimes simply referred to as "alkyl (meth)acrylate (b)") whose homopolymer has a glass transition temperature (Tg) of 0°C or higher. By making the (meth)acrylic copolymer have constituent units derived from alkyl (meth)acrylate (b), the peeling performance when re-transferring semiconductor chips can be further improved, and the release properties of the resulting adhesive tape for semiconductor manufacturing processes can be further enhanced. A more preferred lower limit for the glass transition temperature (Tg) of the alkyl (meth)acrylate (b) homopolymer is 4°C, and an even more preferred lower limit is 8°C. Furthermore, a preferred upper limit for the glass transition temperature (Tg) of the alkyl (meth)acrylate (b) homopolymer is 30°C. By setting the glass transition temperature (Tg) of the alkyl (meth)acrylate (b) homopolymer to 30°C or lower, the peeling performance when transferring semiconductor chips can be further improved, and the release properties of the resulting adhesive tape for semiconductor manufacturing processes can be further enhanced. A more preferable upper limit for the glass transition temperature (Tg) of the alkyl (meth)acrylate (b) homopolymer is 25°C, and an even more preferable upper limit is 20°C. The glass transition temperature (Tg) of the alkyl (meth)acrylate (b) homopolymer may be 0 to 30°C, 4 to 25°C, or 8 to 20°C. In this specification, the glass transition temperature (Tg) of the homopolymer can be measured by differential scanning calorimetry for homopolymers with a weight-average molecular weight (Mw) of about 5,000 to 1,000,000 or a degree of polymerization of about 500,000 to 10,000. Examples of differential scanning calorimeters include differential scanning calorimeters manufactured by T.A. Instruments, Inc.

[0030] The alkyl (meth)acrylate (b) described above is not particularly limited, and examples of alkyl (meth)acrylates mentioned above include methyl acrylate (glass transition temperature (Tg) of the homopolymer: 8°C), methyl methacrylate (glass transition temperature (Tg) of the homopolymer: 105°C), ethyl methacrylate (glass transition temperature (Tg) of the homopolymer: 65°C), n-butyl methacrylate (glass transition temperature (Tg) of the homopolymer: 20°C), t-butyl acrylate (glass transition temperature (Tg) of the homopolymer: 14°C), and the like. In particular, from the viewpoint of further improving the peeling performance when transferring semiconductor chips and further improving the release properties of the resulting adhesive tape for semiconductor manufacturing processes, it is preferable that the alkyl (meth)acrylate (b) described above includes at least one selected from the group consisting of methyl acrylate and t-butyl acrylate. That is, it is preferable that the (meth)acrylic copolymer has at least one selected from the group consisting of constituent units derived from methyl acrylate and constituent units derived from t-butyl acrylate.

[0031] When the above (meth)acrylic copolymer has constituent units derived from the above alkyl (meth)acrylate (a), the preferred lower limit of the content of the constituent units derived from the above alkyl (meth)acrylate (a) in the above (meth)acrylic copolymer is 20% by mass. By setting the content of the constituent units derived from the above alkyl (meth)acrylate (a) to 20% by mass or more, the pick-up and release properties of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips can be improved. A more preferred lower limit for the content of the constituent units derived from the above alkyl (meth)acrylate (a) is 30% by mass, an even more preferred lower limit is 50% by mass, an even more preferred lower limit is 60% by mass, a particularly preferred lower limit is 70% by mass, and a particularly preferred lower limit is 80% by mass. For example, a content of the constituent units derived from the above alkyl (meth)acrylate (a) that is above the particularly preferred lower limit is 90% by mass. Furthermore, there is no particular upper limit to the content of the constituent units derived from the alkyl (meth)acrylate (a) above. However, from the viewpoint of making it possible to copolymerize a crosslinkable functional group-containing monomer as the constituent unit monomer of the (meth)acrylic copolymer, and making it easier to improve the pick-up and release properties of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips, a preferred upper limit is 99% by mass, and a more preferred upper limit is 97% by mass. The content of the constituent units derived from the alkyl (meth)acrylate (a) above may be 20 to 99% by mass, 30 to 99% by mass, 50 to 97% by mass, 60 to 97% by mass, 70 to 97% by mass, 80 to 97% by mass, or 90 to 97% by mass.

[0032] Furthermore, if the (meth)acrylic copolymer has constituent units derived from the alkyl (meth)acrylate (b), the preferred lower limit of the content of the constituent units derived from the alkyl (meth)acrylate (b) in the (meth)acrylic copolymer is 20% by mass. By setting the content of the constituent units derived from the alkyl (meth)acrylate (b) to 20% by mass or more, the peeling performance when transferring semiconductor chips can be further improved, and the release properties of the resulting adhesive tape for semiconductor manufacturing processes can be further enhanced. A more preferred lower limit for the content of the constituent units derived from the alkyl (meth)acrylate (b) is 25% by mass. In order for the first adhesive layer to maintain its adhesiveness at room temperature, from the viewpoint of adjusting the glass transition temperature (Tg) of the (meth)acrylic copolymer to a certain range, the preferred upper limit for the content of the constituent units derived from the alkyl (meth)acrylate (b) is 80% by mass, and a more preferred upper limit is 70% by mass. The content of the constituent units derived from the alkyl (meth)acrylate (b) may be 20 to 80% by mass or 25 to 70% by mass.

[0033] The above-mentioned structural units derived from alkyl (meth)acrylate may include structural units derived from alkyl (meth)acrylate having an alkyl group with 5 or more carbon atoms at its ester terminus (hereinafter sometimes simply referred to as "alkyl (meth)acrylate (c)").

[0034] Examples of the alkyl (meth)acrylate (c) mentioned above include pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, isobornyl (meth)acrylate, etc. These alkyl (meth)acrylates may be used individually or in combination of two or more.

[0035] Preferably, the (meth)acrylic copolymer further has constituent units derived from a crosslinkable functional group-containing monomer. By making the (meth)acrylic copolymer have constituent units derived from a crosslinkable functional group-containing monomer, the cohesive force of the first adhesive layer can be increased, and the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved, thereby reducing adhesive residue on semiconductor chips. Furthermore, if the first adhesive layer contains a crosslinking agent described later, the crosslinkable functional groups derived from the crosslinkable functional group-containing monomer and the crosslinking agent can be reacted to form a crosslinked structure in the (meth)acrylic copolymer, thereby further improving the release properties of the resulting adhesive tape for semiconductor manufacturing processes and reducing adhesive residue on semiconductor chips.

[0036] The above-mentioned crosslinkable functional group-containing monomers are not particularly limited, and examples include carboxyl group-containing monomers, hydroxyl group-containing monomers, epoxy group-containing monomers, carbon-carbon double bond-containing monomers, carbon-carbon triple bond-containing monomers, amino group-containing monomers, amide group-containing monomers, and nitrile group-containing monomers. In particular, it is preferable to include at least one selected from the group consisting of carboxyl group-containing monomers, hydroxyl group-containing monomers, epoxy group-containing monomers, carbon-carbon double bond-containing monomers, carbon-carbon triple bond-containing monomers, and amide group-containing monomers, in order to further improve the release properties of adhesive tapes for semiconductor manufacturing processes from semiconductor chips and to further reduce adhesive residue on semiconductor chips. Among these, it is more preferable to include at least one selected from the group consisting of carboxyl group-containing monomers and hydroxyl group-containing monomers, and even more preferable to include a hydroxyl group-containing monomer. These crosslinkable functional group-containing monomers may be used individually or in combination of two or more.

[0037] Examples of monomers containing a carboxyl group include (meth)acrylic acid. Examples of monomers containing a hydroxyl group include hydroxyalkyl (meth)acrylates such as 4-hydroxybutyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate. Examples of monomers containing an epoxy group include glycidyl (meth)acrylate. Examples of monomers containing a carbon-carbon double bond include allyl (meth)acrylate and hexanediol di(meth)acrylate. Examples of monomers containing a carbon-carbon triple bond include propargyl (meth)acrylate. Examples of monomers containing an amide group include (meth)acrylamide.

[0038] The preferred lower limit for the content of constituent units derived from the hydroxyl group-containing monomer in the above (meth)acrylic copolymer is 2% by mass. By setting the content of constituent units derived from the hydroxyl group-containing monomer to 2% by mass or more, the cohesive force of the first adhesive layer can be further increased, and the release properties of the adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved, thereby further reducing adhesive residue on semiconductor chips. A more preferred lower limit for the content of constituent units derived from the hydroxyl group-containing monomer is 3% by mass, and an even more preferred lower limit is 5% by mass. Furthermore, the preferred upper limit for the content of constituent units derived from the hydroxyl group-containing monomer is 10% by mass. By setting the content of constituent units derived from the hydroxyl group-containing monomer to 10% by mass or less, the first adhesive layer does not become too hard, and the semiconductor chips placed on the first adhesive layer can be held more firmly in the same position, thereby further improving the pick-up properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips. A more preferred upper limit for the resulting adhesive tape for semiconductor manufacturing processes is 8% by mass, and an even more preferred upper limit is 7% by mass. The content of the constituent units derived from the above-mentioned hydroxyl group-containing monomer may be 2 to 10% by mass, 3 to 8% by mass, or 5 to 7% by mass.

[0039] In the above (meth)acrylic copolymer, the preferred lower limit of the total content of constituent units derived from the above crosslinkable functional group-containing monomer is 0.1% by mass, and the preferred upper limit is 30% by mass. By keeping the total content of constituent units derived from the above crosslinkable functional group-containing monomer within the above range, the cohesive force of the first adhesive layer is further increased, and the release properties of the adhesive tape for semiconductor manufacturing processes from semiconductor chips are further improved, thereby further reducing adhesive residue on semiconductor chips. A more preferred lower limit of the total content of constituent units derived from the above crosslinkable functional group-containing monomer is 0.5% by mass, a more preferred upper limit is 25% by mass, an even more preferred lower limit is 1.0% by mass, and an even more preferred upper limit is 20% by mass. The total content of constituent units derived from the above crosslinkable functional group-containing monomer may be 0.1 to 30% by mass, 0.5 to 25% by mass, or 1.0 to 20% by mass. Furthermore, if only one type of structural unit derived from the above-mentioned crosslinkable functional group-containing monomer is present in the above-mentioned (meth)acrylic copolymer, the total content ratio of structural units derived from the above-mentioned crosslinkable functional group-containing monomer represents the content ratio of the structural unit derived from the above-mentioned crosslinkable functional group-containing monomer, of which only one type exists.

[0040] The above (meth)acrylic copolymer may further contain structural units derived from monomers other than the alkyl (meth)acrylate and the crosslinkable functional group-containing monomer.

[0041] Examples of other monomers mentioned above include 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, which has ultraviolet absorption properties.

[0042] The preferred lower limit of the weight-average molecular weight (Mw) of the above (meth)acrylic copolymer is 200,000, and the preferred upper limit is 2,000,000. By setting the weight-average molecular weight of the above (meth)acrylic copolymer within the above range, the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved, transfer defects of semiconductor chips can be further suppressed, and adhesive residue on semiconductor chips can be further reduced. The more preferred lower limit of the weight-average molecular weight of the above (meth)acrylic copolymer is 1,000,000, and the more preferred upper limit is 1,800,000. The weight-average molecular weight (Mw) of the above (meth)acrylic copolymer may be between 200,000 and 2,000,000, or between 1,000,000 and 1,800,000. In this specification, weight-average molecular weight (Mw) means the weight-average molecular weight on a standard polystyrene basis measured by GPC (Gel Permeation Chromatography).

[0043] The preferred lower limit of the polydispersity (Mw / Mn) of the above (meth)acrylic copolymer is 2, and the preferred upper limit is 8. By setting the polydispersity of the above (meth)acrylic copolymer within the above range, the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved, and adhesive residue on semiconductor chips can be further reduced. The more preferred lower limit of the polydispersity of the above (meth)acrylic copolymer is 3, and the more preferred upper limit is 5. The polydispersity (Mw / Mn) of the above (meth)acrylic copolymer may be 2 to 8 or 3 to 5. In this specification, the number average molecular weight (Mn) refers to the number average molecular weight on a standard polystyrene basis as measured by GPC.

[0044] The weight-average molecular weight (Mw), number-average molecular weight (Mn), and polydispersity (Mw / Mn) of the above (meth)acrylic copolymer are measured by the following method. Specifically, the (meth)acrylic copolymer is diluted 50-fold with tetrahydrofuran (THF), and the resulting dilution is filtered through a filter (material: polytetrafluoroethylene, pore diameter: 0.2 μm) to prepare a measurement sample. Next, this measurement sample is supplied to a gel permeation chromatograph (e.g., Waters, "2690 Separations Module"), and GPC measurement is performed under conditions of sample flow rate of 1 mL / min and column temperature of 40°C. The polystyrene-equivalent molecular weight of the (meth)acrylic copolymer is measured to obtain the weight-average molecular weight and number-average molecular weight of the (meth)acrylic copolymer. Then, the polydispersity is calculated using the obtained weight-average molecular weight and number-average molecular weight of the (meth)acrylic copolymer. A GPC KF-806L column (manufactured by Showa Denko Corporation) is used, and a differential refractometer is used as the detector.

[0045] The above (meth)acrylic copolymer can be obtained, for example, by polymerizing a mixture of constituent monomer units in the presence of a polymerization initiator through a radical reaction. Examples of radical reaction methods include living radical polymerization and free radical polymerization. Living radical polymerization yields a copolymer with a more uniform molecular weight and composition compared to free radical polymerization, and suppresses the generation of low molecular weight components. As a result, the cohesive force of the first adhesive layer is increased, the release properties of the resulting adhesive tape for semiconductor manufacturing processes are improved, and adhesive residue on semiconductor chips is reduced. Conventional known methods can be used to polymerize the monomer mixture, such as solution polymerization (boiling point polymerization or constant temperature polymerization), UV polymerization, emulsion polymerization, suspension polymerization, and bulk polymerization. Among these, solution polymerization and UV polymerization are preferred because they can increase the adhesive strength of the resulting adhesive tape. When solution polymerization is used as the method for polymerizing the monomer mixture, examples of reaction solvents include ethyl acetate, toluene, methyl ethyl ketone, dimethyl sulfoxide, ethanol, acetone, and diethyl ether. These reaction solvents may be used individually or in combination of two or more.

[0046] Examples of polymerization initiators include organic peroxides and azo compounds. Examples of organic peroxides include 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxy-3,5,5-trimethylhexanoate, and t-butylperoxylaurate. Examples of azo compounds include azobisisobutyronitrile and azobiscyclohexanecarbonilonitrile. These polymerization initiators may be used individually or in combination of two or more. Furthermore, if the radical reaction method is the living radical polymerization described above, examples of the polymerization initiator include organic tellurium polymerization initiators. The organic tellurium polymerization initiator is not particularly limited as long as it is commonly used in living radical polymerization, and examples include organic tellurium compounds and organic telluride compounds. In addition to the organic tellurium polymerization initiator, an azo compound may also be used as a polymerization initiator in living radical polymerization to accelerate the polymerization rate.

[0047] The first adhesive layer preferably contains a tackifying resin. By including a tackifying resin in the first adhesive layer, the adhesive strength of the first adhesive layer can be further improved, and the pickability of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved.

[0048] The tackifying resin mentioned above is not particularly limited and may be a solid tackifying resin at 23°C or a liquid tackifying resin at 23°C. Specifically, examples include rosin-based resins, terpene resins, phenol resins, coumarone resins, xylene resins, etc. Among these, from the viewpoint of compatibility with the (meth)acrylic copolymer mentioned above, it is preferable that the tackifying resin includes at least one selected from the group consisting of rosin-based resins, phenol resins, and xylene resins. Furthermore, from the viewpoint of further improving the pick-up and release properties of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips, it is even more preferable to include a phenol resin. The phenol resin mentioned above is a resin having a phenol structure, and examples include terpene phenol resins and alkyl phenol resins.

[0049] The tackifying resin preferably includes a tackifying resin in which at least one of the acid value and hydroxyl value is 20 mg KOH / g or more and 200 mg KOH / g or less. By including a tackifying resin in which at least one of the acid value and hydroxyl value is 20 mg KOH / g or more, the adhesive strength can be further improved, and the pickability of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved. By setting at least one of the acid value and hydroxyl value of the tackifying resin to 200 mg KOH / g or less, the compatibility with the (meth)acrylic copolymer can be further improved, and defects in the appearance of the first adhesive layer, such as whitening, can be suppressed. In particular, it is more preferable that the tackifying resin includes a tackifying resin in which the hydroxyl value is 20 mg KOH / g or more and 200 mg KOH / g or less.

[0050] The more preferable lower limit for the hydroxyl value of the above tackifying resin is 40 mg KOH / g, the more preferable upper limit is 160 mg KOH / g, the even more preferable lower limit is 50 mg KOH / g, and the even more preferable upper limit is 150 mg KOH / g. The hydroxyl value of the above tackifying resin may be 20 to 200 mg KOH / g, 40 to 160 mg KOH / g, or 50 to 150 mg KOH / g.

[0051] The more preferable lower limit for the acid value of the above tackifying resin is 25 mg KOH / g, the more preferable upper limit is 160 mg KOH / g, the even more preferable lower limit is 30 mg KOH / g, and the even more preferable upper limit is 120 mg KOH / g. The acid value of the above tackifying resin may be 20 to 200 mg KOH / g, 25 to 160 mg KOH / g, or 30 to 120 mg KOH / g.

[0052] In this specification, "hydroxyl value" refers to an index representing the content of hydroxyl groups in a certain amount of sample. The hydroxyl value of the tackifying resin is the number of mg of potassium hydroxide required to neutralize the acetic acid bound to the hydroxyl groups by neutralization titration after acetylating 1 g of the tackifying resin, and can be calculated by measurement based on the potentiometric titration method specified in JIS K 0070:1992. In this specification, "acid value" refers to an index representing the content of carboxyl groups in a certain amount of sample. The acid value of the tackifying resin is the number of mg of potassium hydroxide required to neutralize the acid contained in 1 g of the tackifying resin, and can be calculated by measurement based on the potentiometric titration method specified in JIS K 0070:1992.

[0053] The tackifying resin described above preferably includes a tackifying resin having a softening point of 95°C to 160°C. By including a tackifying resin with a softening point within the above range, the adhesive strength of the first adhesive layer can be further improved, and the pick-up and release properties of the resulting adhesive tape for semiconductor manufacturing processes can be further improved for semiconductor chips. A more preferable lower limit for the softening point of the tackifying resin is 110°C, and a more preferable upper limit is 155°C. The softening point of the tackifying resin may be between 95°C and 160°C, or between 110°C and 155°C. In this specification, the "softening point" can be measured by the ring-and-ball method specified in JIS K2207.

[0054] When the above-mentioned tackifying resin is included, the preferred lower limit of the content of the tackifying resin is 10 parts by mass and the preferred upper limit is 50 parts by mass per 100 parts by mass of the base polymer (P1). By setting the content of the tackifying resin to 10 parts by mass or more, the tackiness of the first adhesive layer can be further improved, and the pickability of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved. By setting the content of the tackifying resin to 50 parts by mass or less, the release properties of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved. A more preferred lower limit of the content of the tackifying resin is 15 parts by mass, a more preferred upper limit is 47 parts by mass, an even more preferred lower limit is 20 parts by mass, an even more preferred upper limit is 43 parts by mass, an even more preferred lower limit is 25 parts by mass, and an even more preferred upper limit is 40 parts by mass. The content of the tackifying resin may be 10 to 50 parts by mass, 15 to 47 parts by mass, 20 to 43 parts by mass, or 25 to 40 parts by mass.

[0055] Preferably, the first adhesive layer contains an ultraviolet absorber. By including an ultraviolet absorber in the first adhesive layer, heat or vibration is efficiently generated by laser irradiation, making deformation by ablation more likely, and thus the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved. In addition, since the first adhesive layer can absorb laser light to a moderate degree, the absorption of light by the semiconductor chip adhered to the first adhesive layer can be further suppressed, and the manufacturing quality of semiconductor chips manufactured using the resulting adhesive tape for semiconductor manufacturing processes can be improved.

[0056] In the case where the adhesive tape for semiconductor manufacturing processes of this embodiment has an intermediate layer described later, and the intermediate layer has an intermediate adhesive layer described later, it is preferable that at least one layer of the first adhesive layer and the intermediate adhesive layer described later contains an ultraviolet absorber. By including an ultraviolet absorber in at least one layer of the first adhesive layer and the intermediate adhesive layer described later, deformation due to ablation caused by laser light irradiation becomes more likely, and the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved.

[0057] The above-mentioned ultraviolet absorber may be a solid ultraviolet absorber at 23°C or a liquid ultraviolet absorber at 23°C, but a liquid ultraviolet absorber at 23°C is preferred. By incorporating the above-mentioned liquid ultraviolet absorber at 23°C into the first adhesive layer, the release properties of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved. Furthermore, if the ultraviolet absorber is liquid at 23°C, it is less likely to precipitate on the surface of the first adhesive layer, and the pick-up properties of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved.

[0058] Examples of the above-mentioned ultraviolet absorbers include benzotriazole-based ultraviolet absorbers and hydroxylphenyltriazine-based ultraviolet absorbers. Other examples include ethylhexyl methoxycinnamate, octyl methoxycinnamate, ethylhexyl paramethoxycinnamate, diethylamino hydroxybenzoyl hexyl benzoate, bisethylhexyloxyphenol methoxyphenyltriazine, and t-butyl methoxydibenzoylmethane. Among these, benzotriazole-based ultraviolet absorbers and hydroxylphenyltriazine-based ultraviolet absorbers are preferred from the viewpoint of excellent compatibility with other components in the first adhesive layer. These ultraviolet absorbers may be used individually or in combination of two or more.

[0059] A preferred upper limit for the amount of the ultraviolet absorber per 100 parts by mass of the base polymer (P1) is 15 parts by mass. By limiting the amount of the ultraviolet absorber to 15 parts by mass or less, the ultraviolet absorber is less likely to precipitate on the surface of the first adhesive layer, and the pickability of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved. A more preferred upper limit for the amount of the ultraviolet absorber is 12 parts by mass, an even more preferred upper limit is 10 parts by mass, and an even more preferred upper limit is 8 parts by mass. Furthermore, a preferred lower limit for the amount of the ultraviolet absorber is 1 part by mass. By limiting the amount of the ultraviolet absorber to 1 part by mass or more, heat or vibration is generated more efficiently in the first adhesive layer by laser irradiation, and deformation by ablation is more likely to occur, thus further improving the release properties of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips. Furthermore, because the first adhesive layer moderately absorbs laser light, the absorption of light by the semiconductor chip adhered to the first adhesive layer can be further suppressed, thereby improving the manufacturing quality of semiconductor chips manufactured using the resulting adhesive tape for semiconductor manufacturing processes. The more preferable lower limit for the content of the ultraviolet absorber is 2 parts by mass, an even more preferable lower limit is 4 parts by mass, and an even more preferable lower limit is 6 parts by mass. The content of the ultraviolet absorber may be 1 to 15 parts by mass, 2 to 12 parts by mass, 4 to 10 parts by mass, or 6 to 8 parts by mass.

[0060] Preferably, the first adhesive layer contains an antistatic agent. By including an antistatic agent in the first adhesive layer, the accumulation of static electricity in the resulting adhesive tape for semiconductor manufacturing processes can be further suppressed. As a result, using the resulting adhesive tape for semiconductor manufacturing processes can prevent transfer defects of semiconductor chips, thereby improving the yield of semiconductor chips during semiconductor chip manufacturing.

[0061] In the first adhesive layer described above, the antistatic agent is preferably the ionic compound described above, from the viewpoint of excellent compatibility with the (meth)acrylic copolymer.

[0062] Furthermore, the ionic compound in the first adhesive layer preferably includes a compound composed of at least one anion selected from the group consisting of bis(fluorosulfonyl)imide anion, hexafluorophosphate anion, and carboxyl anion, and more preferably includes a compound composed of bis(fluorosulfonyl)imide anion. By including a compound composed of at least one anion selected from the group consisting of bis(fluorosulfonyl)imide anion, hexafluorophosphate anion, and carboxyl anion in the ionic compound in the first adhesive layer, the bleed-out of the antistatic agent to the surface of the first adhesive layer during storage of the tape is more easily suppressed. As a result, the decrease in peel strength of the adhesive tape for semiconductor manufacturing processes after long-term storage is more easily suppressed, and the adhesive tape for semiconductor manufacturing processes is more easily made to have better pickability to semiconductor chips after long-term storage.

[0063] When the above-mentioned antistatic agent is included, the preferred lower limit of the content of the antistatic agent per 100 parts by mass of the base polymer (P1) is 0.01 parts by mass, and the preferred upper limit is 20 parts by mass. By setting the content of the antistatic agent to 0.01 parts by mass or more, the accumulation of static electricity in the resulting adhesive tape for semiconductor manufacturing processes can be further suppressed. By setting the content of the antistatic agent to 20 parts by mass or less, the release properties of the resulting adhesive tape for semiconductor manufacturing processes can be further improved, and adhesive residue on semiconductor chips can be further reduced. In addition, bleed-out of the antistatic agent to the surface of the first adhesive layer can be suppressed, preventing contamination of the adherend and a decrease in the adhesive strength of the adhesive tape for semiconductor manufacturing processes. The more preferred lower limit for the content of the above-mentioned antistatic agent is 0.1 parts by mass, the more preferred upper limit is 10 parts by mass, the even more preferred lower limit is 0.2 parts by mass, the even more preferred upper limit is 5.0 parts by mass, the even more preferred lower limit is 0.3 parts by mass, the even more preferred upper limit is 3.0 parts by mass, the particularly preferred lower limit is 0.5 parts by mass, and the particularly preferred upper limit is 2.0 parts by mass. The content of the above-mentioned antistatic agent per 100 parts by mass of the above-mentioned base polymer (P1) may be 0.01 to 20 parts by mass, 0.1 to 10 parts by mass, 0.2 to 5.0 parts by mass, 0.3 to 3.0 parts by mass, or 0.5 to 2.0 parts by mass.

[0064] The first adhesive layer described above preferably further contains a crosslinking agent. The crosslinking agent is not particularly limited and is selected according to the type of crosslinkable functional group contained in the (meth)acrylic copolymer, and examples include isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, metal chelate crosslinking agents, etc. Among these, isocyanate crosslinking agents are preferred because they make it easier to adjust the gel fraction of the first adhesive layer to the range described later.

[0065] Examples of the above-mentioned isocyanate-based crosslinking agents include toluene diisocyanate (TDI)-based crosslinking agents and hexamethylene diisocyanate (HDI)-based crosslinking agents. Examples of the above-mentioned epoxy-based crosslinking agents include N,N'-(cyclohexane-1,3-diylbismethylene)bis(diglycidylamine) and N,N,N',N'-tetraglycidyl-1,3-benzenedi(methaneamine).

[0066] The content of the crosslinking agent is not particularly limited, and the degree of crosslinking (gel fraction) of the first adhesive layer can be adjusted by adjusting the amount of crosslinkable functional groups in the base polymer contained in the first adhesive layer and the content of the crosslinking agent. The preferred lower limit of the content of the crosslinking agent per 100 parts by mass of the base polymer (P1) is 0.01 parts by mass, and the preferred upper limit is 15 parts by mass. By setting the content of the crosslinking agent within the above range, the base polymer (P1) can be crosslinked appropriately, and the cohesive force of the first adhesive layer can be further increased. As a result, the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved, transfer defects of semiconductor chips can be further suppressed, and adhesive residue on semiconductor chips can be further reduced. The more preferable lower limit for the content of the above-mentioned crosslinking agent is 0.10 parts by mass, the more preferable upper limit is 12 parts by mass, the even more preferable lower limit is 0.15 parts by mass, the even more preferable upper limit is 8 parts by mass, the even more preferable lower limit is 0.50 parts by mass, the even more preferable upper limit is 5 parts by mass, the particularly preferable lower limit is 1 part by mass, and the particularly preferable upper limit is 3 parts by mass. The content of the above-mentioned crosslinking agent may be 0.01 to 15 parts by mass, 0.10 to 12 parts by mass, 0.15 to 8 parts by mass, 0.50 to 5 parts by mass, or 1 to 3 parts by mass.

[0067] The first adhesive layer may further contain an inorganic filler such as fumed silica. By including an inorganic filler in the first adhesive layer, the cohesive force of the first adhesive layer can be further increased, the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved, and adhesive residue on semiconductor chips can be further reduced.

[0068] The first adhesive layer described above may further contain known additives such as plasticizers, resins, surfactants, waxes, and particulate fillers. These additives may be used individually or in combination of two or more.

[0069] The first adhesive layer described above has a preferred lower limit of gel fraction of 50% by mass. By setting the gel fraction of the first adhesive layer to 50% by mass or more, the cohesive force of the first adhesive layer can be further increased, and the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved. A more preferred lower limit for the gel fraction of the first adhesive layer is 55% by mass, an even more preferred lower limit is 60% by mass, an even more preferred lower limit is 70% by mass, and a particularly preferred lower limit is 80% by mass. Furthermore, the first adhesive layer has a preferred upper limit of gel fraction of 99% by mass. By setting the gel fraction of the first adhesive layer to 99% by mass or less, the adhesive strength of the first adhesive layer can be further increased, and as a result, the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved, thereby reducing adhesive residue on semiconductor chips. A more preferred upper limit for the gel fraction of the first adhesive layer is 97% by mass, and an even more preferred upper limit is 95% by mass. Furthermore, the gel fraction of the upper adhesive layer may be 50 to 99% by mass, 55 to 97% by mass, 60 to 97% by mass, 70 to 95% by mass, or 80 to 95% by mass.

[0070] The gel fraction of the first adhesive layer described above can be measured by the following method: Only the first adhesive layer is extracted from the adhesive tape used in semiconductor manufacturing processes. ０ (g) Remove and immerse in 50 mL of ethyl acetate, and shake in a shaker at a temperature of 23°C and 200 rpm for 24 hours. After shaking, use a metal mesh (mesh size #200, W １ (g)) is used to separate the ethyl acetate and the first adhesive layer that has absorbed and swollen with ethyl acetate. The separated first adhesive layer is dried at 110°C for 1 hour. The mass W of the first adhesive layer containing the metal mesh after drying. ２(g) is measured, and the gel fraction of the first adhesive layer is calculated using the following formula: Gel fraction (mass%) = 100 × (W ２ -W １ ) / W ０ (W ０ : Mass of the initial first adhesive layer, W １ Initial mass of the metal mesh, W ２ : Mass of the first adhesive layer containing the metal mesh after drying) However, if the first adhesive layer does not dissolve completely in ethyl acetate, a solvent such as toluene, hexane, or water may be used instead of ethyl acetate. Specifically, if the first adhesive layer contains, for example, a styrene-based elastomer as the base polymer (P1), toluene or hexane may be used, and if it contains polyvinyl alcohol, hot water at 90°C may be used.

[0071] Methods for adjusting the gel fraction of the first adhesive layer to the above range include, for example, adjusting the composition and weight-average molecular weight (Mw) of the base polymer (P1), adjusting the type and content of the crosslinking agent contained in the first adhesive layer, and adjusting the type and content of the tackifying resin, ultraviolet absorber, antistatic agent, etc., contained in the first adhesive layer.

[0072] The first adhesive layer described above has a preferred lower limit of 5 × 10⁻¹⁰ shear storage modulus (G') at 23°C and a measurement frequency of 10 Hz. ４ Pa is the preferred upper limit, and the preferred upper limit is 1 × 10⁻⁶ ６ The value is Pa. The shear storage modulus (G') of the first adhesive layer at 23°C and a measurement frequency of 10 Hz is 5 × 10⁻⁶. ４ By setting the pressure to Pa or higher, the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved. The shear storage modulus (G') of the first adhesive layer at 23°C and a measurement frequency of 10 Hz is set to 1 × 10⁻⁶. ６ By setting it to Pa or less, the pickability of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved. A more preferable lower limit for the shear storage modulus (G') of the first adhesive layer at 23°C and a measurement frequency of 10 Hz is 8 × 10 ４ Pa, a more preferable upper limit is 8 × 10５ Pa, a more preferable lower limit is 1 × 10⁻⁶ ５ Pa, a more preferable upper limit is 6 × 10 ５ It is Pa. The shear storage modulus (G') of the first adhesive layer at 23°C and a measurement frequency of 10 Hz is 5 × 10 ４ ~1 x 10 ６ It may also be Pa, 8 x 10 ４ ~8 x 10 ５ It may also be Pa, 1 × 10 ５ ~6 x 10 ５ Pa is also acceptable.

[0073] The shear storage modulus (G') of the first adhesive layer at 23°C and a measurement frequency of 10 Hz can be measured by dynamic viscoelasticity measurement. Specifically, for the first adhesive layer, a dynamic viscoelasticity measuring device (for example, Rheometrics Dynamic Analyze RDA-700, manufactured by Rheometrics Inc.) is used to measure the dynamic viscoelastic spectrum under the conditions of a measurement temperature of -40 to 150°C, a heating rate of 5°C / min, and a measurement frequency of 10 Hz, from which the storage modulus at each temperature can be obtained. If the thickness of the first adhesive layer is less than 500 μm, the first adhesive layer is stacked to create a sample of only the first adhesive layer with a thickness of approximately 500 μm, and the measurement is performed. In this case, a sample of only the first adhesive layer can be prepared by removing the substrate layer from a semiconductor manufacturing process adhesive tape, separating only the first adhesive layer to prepare multiple sheets of only the first adhesive layer, and then stacking the separated first adhesive layers. The method for removing the substrate layer is not particularly limited, as long as it avoids solvent treatment, chemical reaction treatment, high-temperature treatment, etc., in order to avoid deformation of the adhesive layer. As a specific method, one can choose to remove the substrate layer by bonding the first adhesive layers together, selecting an appropriate temperature and peeling speed, and peeling the substrate layer from the first adhesive layer, or by physically grinding the substrate layer. Alternatively, a sample of only the first adhesive layer can be prepared using a sheet consisting only of the first adhesive layer that has been prepared separately.

[0074] Methods for adjusting the shear storage modulus (G') of the first adhesive layer at 23°C and a measurement frequency of 10 Hz to within the above range include, for example, changing the composition of the base polymer (P1) contained in the first adhesive layer, adjusting the weight-average molecular weight (Mw) and polydispersity (Mw / Mn) of the base polymer (P1) contained in the first adhesive layer, and adjusting the type and content of the crosslinking agent, tackifying resin, ultraviolet absorber, and antistatic agent contained in the first adhesive layer.

[0075] The probe tack value (hereinafter sometimes simply referred to as "probe tack value (V1) of the first adhesive layer") of the first adhesive layer described above, measured under the conditions of 23°C, pressurized pressure of 0.05 MPa, pressurizing speed of 10 mm / sec, pressurizing time of 10 seconds, and release speed of 0.1 mm / sec, has a preferred lower limit of 10 N / 5 mmφ and a preferred upper limit of 30 N / 5 mmφ. By setting the probe tack value (V1) of the first adhesive layer to 10 N / 5 mmφ or higher, the pickability of the resulting adhesive tape for semiconductor manufacturing processes can be further improved. By setting the probe tack value (V1) of the first adhesive layer to 30 N / 5 mmφ or lower, the residue generated when the resulting adhesive tape for semiconductor manufacturing processes is released can be further reduced. A more preferred lower limit for the probe tack value (V1) of the first adhesive layer described above is 12 N / 5 mmφ, a more preferred upper limit is 27 N / 5 mmφ, an even more preferred lower limit is 14 N / 5 mmφ, and an even more preferred upper limit is 24 N / 5 mmφ. The probe tack value (V1) of the first adhesive layer described above may be 10 to 30 N / 5 mmφ, 12 to 27 N / 5 mmφ, or 14 to 24 N / 5 mmφ.

[0076] The probe tack value (V2) of the first adhesive layer, measured under the conditions of 23°C, pressurized pressure of 0.05 MPa, pressurizing speed of 10 mm / sec, pressurizing time of 10 seconds, and release speed of 15 mm / sec, has a preferred lower limit of 1 N / 5 mmφ and a preferred upper limit of 20 N / 5 mmφ. By setting the probe tack value (V2) of the first adhesive layer to be between 1 N / 5 mmφ and 20 N / 5 mmφ, the release properties of the resulting adhesive tape for semiconductor manufacturing processes can be further improved. A more preferred lower limit for the probe tack value (V2) of the first adhesive layer is 3 N / 5 mmφ, a more preferred upper limit is 15 N / 5 mmφ, an even more preferred lower limit is 5 N / 5 mmφ, and an even more preferred upper limit is 10 N / 5 mmφ. The probe tack value (V2) of the first adhesive layer described above may be 1 to 20 N / 5 mmφ, 3 to 15 N / 5 mmφ, or 5 to 10 N / 5 mmφ.

[0077] In this specification, "probe tack value" means the maximum load applied to the probe when it is brought into contact with the adhesive layer using a probe tack measuring device and then lifted. Specifically, it can be obtained by performing a measurement using a probe tack measuring device (such as the "TAC-2 tacking tester" manufactured by RHESCA).

[0078] The probe tack value (V1) of the first adhesive layer can be adjusted by, for example, adjusting the type and content ratio of the constituent unit monomers that make up the base polymer (P1), or by changing the shear storage modulus (G') of the first adhesive layer at 23°C and a measurement frequency of 10 Hz. Specifically, for example, the probe tack value (V1) of the first adhesive layer can be increased by using a (meth)acrylic copolymer having constituent units derived from 2-ethylhexyl acrylate as the base polymer (P1). Alternatively, the probe tack value (V1) of the first adhesive layer can be decreased by increasing the shear storage modulus (G') of the first adhesive layer at 23°C and a measurement frequency of 10 Hz.

[0079] Methods for adjusting the probe tack value (V2) of the first adhesive layer include, for example, adjusting the type and content ratio of the constituent unit monomers that make up the base polymer (P1), and changing the shear storage modulus (G') of the first adhesive layer at 23°C and a measurement frequency of 10 Hz. Specifically, for example, the probe tack value (V2) of the first adhesive layer can be reduced by using a (meth)acrylic copolymer having constituent units derived from methyl acrylate or t-butyl acrylate as the base polymer (P1). Alternatively, the probe tack value (V2) of the first adhesive layer can be reduced by lowering the shear storage modulus (G') of the first adhesive layer at 23°C and a measurement frequency of 10 Hz.

[0080] The common logarithm of the surface resistance of the first adhesive layer (hereinafter sometimes simply referred to as "surface resistance of the first adhesive layer") has a preferred upper limit of 15.0 [log(Ω / sq)]. By setting the surface resistance of the first adhesive layer to 15.0 [log(Ω / sq)] or less, the accumulation of static electricity in the resulting adhesive tape for semiconductor manufacturing processes can be suppressed. Therefore, when using the adhesive tape for semiconductor manufacturing processes of this embodiment to transfer semiconductor chips, chip transfer defects can be prevented, and the yield of semiconductor chips in the semiconductor manufacturing process can be further improved. A more preferred upper limit for the surface resistance of the first adhesive layer is 14.7 [log(Ω / sq)], an even more preferred upper limit is 14.0 [log(Ω / sq)], and an even more preferred upper limit is 13.5 [log(Ω / sq)]. There is no particular lower limit to the surface resistance of the first adhesive layer described above, but the practical lower limit is 6.0 [log(Ω / sq)]. The surface resistance of the first adhesive layer may be 6.0 to 15.0 [log(Ω / sq)], 6.0 to 14.7 [log(Ω / sq)], 6.0 to 14.0 [log(Ω / sq)], or 6.0 to 13.5 [log(Ω / sq)]. Furthermore, in this specification, "surface resistance" can be measured by a method conforming to JIS K7194.

[0081] Methods for adjusting the surface resistance of the first adhesive layer include: incorporating an antistatic agent into the first adhesive layer; adjusting the composition of the base polymer (P1) contained in the first adhesive layer; adjusting the type and content of the tackifying resin, crosslinking agent, ultraviolet absorber, and antistatic agent contained in the first adhesive layer; and adjusting the thickness of the first adhesive layer.

[0082] The first adhesive layer described above has a preferred lower limit of 5 μm and a preferred upper limit of 40 μm in thickness. By setting the thickness of the first adhesive layer to 5 μm or more and 40 μm or less, the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved, thereby further suppressing transfer defects of semiconductor chips. In addition, the adhesive strength of the first adhesive layer can be further increased, thereby further improving the pick-up properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips. By setting the thickness of the first adhesive layer to 40 μm or less, the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved, thereby further reducing adhesive residue on semiconductor chips. A more preferred lower limit for the thickness of the first adhesive layer is 10 μm, a more preferred upper limit is 30 μm, and an even more preferred upper limit is 20 μm. Note that the thickness of the first adhesive layer may be 5 to 40 μm, 10 to 30 μm, or 10 to 20 μm.

[0083] The adhesive tape for semiconductor manufacturing processes according to this embodiment has a base layer. By having a base layer in the adhesive tape for semiconductor manufacturing processes according to this embodiment, it is possible to make an adhesive tape that has appropriate stiffness and excellent handling properties.

[0084] The above-mentioned substrate layer is preferably a substrate containing at least one selected from the group consisting of polyolefin resin, cellulose derivative, (meth)acrylic resin, and polyester resin, and more preferably a substrate containing polyester resin. By making the above-mentioned substrate layer a substrate containing at least one selected from the group consisting of polyolefin resin, cellulose derivative, (meth)acrylic resin, and polyester resin, ultraviolet light can be irradiated onto the first adhesive layer without attenuation, thereby further improving the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips.

[0085] Examples of substrates containing the above-mentioned polyolefin resin include OPP film, CPP film, and COP film. Examples of substrates containing the above-mentioned cellulose derivative include triacetylcellulose (TAC) film. Examples of substrates containing the above-mentioned (meth)acrylic resin include polymethyl methacrylate (PMMA) film. Examples of substrates containing the above-mentioned polyester resin include PET film and PEN film.

[0086] Preferably, the above-mentioned substrate layer contains an antistatic agent. By including an antistatic agent in the above-mentioned substrate layer, the accumulation of static electricity in the resulting adhesive tape for semiconductor manufacturing processes can be suppressed, and by using the resulting adhesive tape for semiconductor manufacturing processes, transfer defects of semiconductor chips can be prevented. As a result, semiconductor chips can be transferred smoothly, and the yield of semiconductor chips during semiconductor chip manufacturing can be further improved.

[0087] In the case of the semiconductor manufacturing process adhesive tape of this embodiment, if it has a second adhesive layer as described later, it is preferable that at least one layer of the base layer and the second adhesive layer is contained in an antistatic agent. By containing an antistatic agent in at least one layer of the base layer and the second adhesive layer, it is possible to suppress the accumulation of static electricity in the resulting semiconductor manufacturing process adhesive tape without containing an antistatic agent in the first adhesive layer. As a result, the content ratio of the low molecular weight composition in the first adhesive layer is reduced, and the impact on the release properties of the resulting semiconductor manufacturing process adhesive tape is reduced.

[0088] If the above-mentioned base material layer contains an antistatic agent, it is preferable that the antistatic agent is coated on the surface of the base material layer. By coating the surface of the base material layer with the antistatic agent, the surface resistance value of the adjacent first adhesive layer can be reduced.

[0089] When the above-mentioned antistatic agent is applied to the surface of a substrate layer, it is preferable that the antistatic agent contains a compound having a polythiophene skeleton from the viewpoint of ultraviolet light transmission.

[0090] When the above-mentioned antistatic agent is applied to the surface of the substrate layer, the preferred lower limit of the applied antistatic agent is 0.05 μm, and the preferred upper limit is 3 μm. By making the thickness of the applied antistatic agent 0.05 μm or more, the accumulation of static electricity in the resulting adhesive tape for semiconductor manufacturing processes can be further suppressed. By making the thickness of the applied antistatic agent 3 μm or less, an adhesive tape with appropriate stiffness and better handling properties can be obtained. A more preferred lower limit for the thickness of the applied antistatic agent is 0.1 μm, and a more preferred upper limit is 2 μm. Furthermore, the thickness of the applied antistatic agent may be 0.05 to 3 μm, or 0.1 to 2 μm.

[0091] The common logarithm of the surface resistance of the above-mentioned substrate layer (hereinafter sometimes simply referred to as "surface resistance of the substrate layer") has a preferred upper limit of 12 [log(Ω / sq)]. By setting the surface resistance of the above-mentioned substrate layer to 12 [log(Ω / sq)] or less, it becomes possible to suppress the accumulation of static electricity in the resulting adhesive tape for semiconductor manufacturing processes. Therefore, by using the resulting adhesive tape for semiconductor manufacturing processes, it becomes possible to prevent chip transfer defects when transferring semiconductor chips, and the yield of semiconductor chips in the semiconductor manufacturing process can be further improved. A more preferred upper limit for the surface resistance of the above-mentioned substrate layer is 10 [log(Ω / sq)], and an even more preferred upper limit is 8 [log(Ω / sq)]. Furthermore, there is no particular lower limit for the surface resistance of the above-mentioned substrate layer, but the practical lower limit is 5 [log(Ω / sq)]. The surface resistance of the above-mentioned base material layer may be 5 to 12 [log(Ω / sq)], 5 to 10 [log(Ω / sq)], or 5 to 8 [log(Ω / sq)].

[0092] Methods for adjusting the surface resistance of the above-mentioned substrate layer include adding an antistatic agent to the substrate layer and adjusting the thickness of the substrate layer.

[0093] The preferred lower limit for the thickness of the base material layer is 3 μm, and the preferred upper limit is 100 μm. By setting the thickness of the base material layer within the above range, an adhesive tape with appropriate stiffness and superior handling properties can be obtained. A more preferred lower limit for the thickness of the base material layer is 12 μm, and a more preferred upper limit is 75 μm.

[0094] The adhesive tape for semiconductor manufacturing processes of this embodiment may have a base layer as described above and a first adhesive layer, but may also have other layers as long as the effects of the present invention are not impaired.

[0095] In this embodiment, the adhesive tape for semiconductor manufacturing processes preferably has an intermediate layer between the first adhesive layer and the base material layer. By having an intermediate layer between the first adhesive layer and the base material layer in the adhesive tape for semiconductor manufacturing processes of this embodiment, deformation caused by ablation of the intermediate layer by irradiation with laser light is transmitted to the first adhesive layer, making it easier to peel off the semiconductor chip placed on the first adhesive layer, and thus improving the release properties of the resulting adhesive tape for semiconductor manufacturing processes from the semiconductor chip.

[0096] The above-mentioned intermediate layer preferably has an intermediate adhesive layer. By having the intermediate adhesive layer, the intermediate adhesive layer can be deformed by ablation by irradiation with laser light, and the first adhesive becomes easier to deform through that deformation. As a result, the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved. Furthermore, if the above-mentioned intermediate layer has an intermediate adhesive layer, it is preferable that it also has an intermediate substrate layer. By having the above-mentioned intermediate layer have an intermediate adhesive layer and an intermediate substrate layer, the intermediate adhesive layer can be deformed by ablation by irradiation with laser light, and this deformation is more easily transmitted to the first adhesive through the intermediate substrate layer, making it easier to peel off the semiconductor chip placed on the first adhesive layer. In addition, at this time, the adhesive residue that may be generated by ablation can be reduced by the intermediate substrate layer. Therefore, by making the intermediate layer comprise an intermediate adhesive layer and an intermediate substrate layer, the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved, and the amount of residue of the first adhesive layer adhering to the semiconductor chip components can be reduced as the first adhesive layer tears when the semiconductor chip components are peeled off.

[0097] The adhesive tape for semiconductor manufacturing processes of this embodiment preferably has the above-mentioned base layer, the above-mentioned intermediate adhesive layer, the above-mentioned intermediate base layer, and the above-mentioned first adhesive layer in this order. By having the adhesive tape for semiconductor manufacturing processes of this embodiment have this configuration, the first adhesive layer tears when the semiconductor chip components are peeled off, and the amount of residue of the first adhesive layer adhering to the semiconductor chip components can be reduced.

[0098] The intermediate adhesive layer preferably contains a base polymer. Examples of base polymers to be included in the intermediate adhesive layer include block copolymers, (meth)acrylic copolymers, urethane copolymers, and silicone polymers. Among these, block copolymers and (meth)acrylic copolymers are preferred as the base polymer to be included in the intermediate adhesive layer, from the viewpoint that the intermediate adhesive layer is easily deformed appropriately by ablation and that the release properties of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips are easily improved. Furthermore, block copolymers are more preferred from the viewpoint that the ablation generated at the irradiated area does not become too large and the scattering of the intermediate adhesive layer can be suppressed. In addition, (meth)acrylic copolymers are more preferred from the viewpoint that the adhesion between the intermediate adhesive layer and the substrate layer and the intermediate substrate layer described later can be ensured and defects such as edge lifting can be suppressed.

[0099] The above block copolymer preferably includes an A-B-A type block copolymer in which block A has a structure derived from an aromatic vinyl monomer, and block B has a structure derived from at least one selected from the group consisting of (meth)acrylic monomers, conjugated diene monomers, and hydrogenated conjugated diene monomers.

[0100] The above-described A-B-A type block copolymer is a copolymer containing a rigid block A (hereinafter also referred to as the "hard segment") and a flexible block B (hereinafter also referred to as the "soft segment"). The above-described A-B-A type block copolymer may have a heterogeneous phase separation structure in which the two blocks are poorly miscible, with spherical islands formed by the aggregation of block A scattered within a sea of ​​block B, or a heterogeneous phase separation structure in which cylindrical structures formed by the aggregation of block A scattered within a sea of ​​block B. Such a phase separation structure with scattered spherical islands is also called a sphere-shaped phase separation structure, and a phase separation structure with scattered cylindrical structures is also called a cylindrical phase separation structure. Furthermore, since the islands of the above phase separation structure act as pseudo-crosslinking points, rubber elasticity can be imparted to the above-described A-B-A type block copolymer, thereby improving the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips.

[0101] Examples of the aromatic vinyl monomers in Block A above include styrene, alpha-methylstyrene, para-methylstyrene, and chlorostyrene. Among these, styrene is preferred because it further improves the release properties of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips. These aromatic vinyl monomers may be used individually or in combination of two or more. In this specification, the structure derived from the aromatic vinyl monomer refers to the structure shown in formula (1) or (2) below.

[0102]

[0103] In equations (1) and (2), R １ * represents a substituent having an aromatic ring. A substituent R having an aromatic ring １ Examples include phenyl groups, methylphenyl groups, and chlorophenyl groups.

[0104] In the above A-B-A type block copolymer, the preferred lower limit of the content of the structure derived from the aromatic vinyl monomer is 1% by mass, and the preferred upper limit is 30% by mass. By keeping the content of the structure derived from the aromatic vinyl monomer within the above range, the tensile strength of the intermediate adhesive layer is increased, and adhesive residue on the semiconductor chip can be further reduced. A more preferred lower limit of the content of the structure derived from the aromatic vinyl monomer is 5% by mass, a more preferred upper limit is 28% by mass, an even more preferred lower limit is 8% by mass, an even more preferred upper limit is 25% by mass, a particularly preferred lower limit is 10% by mass, and a particularly preferred upper limit is 20% by mass. The content of the structure derived from the aromatic vinyl monomer in the above A-B-A type block copolymer may be 1 to 30% by mass, 5 to 28% by mass, 8 to 25% by mass, or 10 to 20% by mass.

[0105] Block A described above may, in addition to the structure derived from the aromatic vinyl monomer, also have structures derived from, for example, a compound having a cyclic structure, a compound with short side chain substituents, etc., to the extent that it does not impair the effects of the present invention.

[0106] The content of block A in the above A-B-A type block copolymer is not particularly limited, but a preferred lower limit is 1% by mass and a preferred upper limit is 40% by mass. When the content of block A is within the above range, the tensile strength of the intermediate adhesive layer is increased, and adhesive residue on the semiconductor chip can be further reduced. A more preferred lower limit for the content of block A is 2% by mass, a more preferred upper limit is 35% by mass, an even more preferred lower limit is 5% by mass, an even more preferred upper limit is 30% by mass, and an even more preferred lower limit is 10% by mass. An even more preferred upper limit is 25% by mass, a particularly preferred upper limit is 22% by mass, and an especially preferred upper limit is 20% by mass. Furthermore, the content of block A in the above A-B-A type block copolymer may be 1 to 40% by mass, 2 to 35% by mass, 5 to 30% by mass, 10 to 25% by mass, 10 to 22% by mass, or 10 to 20% by mass.

[0107] Examples of the (meth)acrylic monomers in block B above include those similar to the alkyl (meth)acrylates used in the (meth)acrylic copolymer of the adhesive layer described above. These monomers may be a single monomer or a combination of monomers may be used.

[0108] Examples of the conjugated diene monomers in Block B above include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-octadiene, 1,3-hexadiene, 1,3-cyclohexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, myrcene, chloroprene, and the like. These conjugated diene monomers may be used individually or in combination of two or more. Among these, 1,3-butadiene and isoprene are preferred due to their high polymerization reactivity and ease of industrial availability.

[0109] Examples of structures derived from the hydrogenated conjugated diene monomer in Block B include structures in which the double bond (unsaturated bond) of the structure derived from 1,3-butadiene, which is derived from the conjugated diene monomer, is hydrogenated and converted to an ethylene-butylene structure. The hydrogenation ratio (hydrogenation rate) is not particularly limited and may be partially hydrogenated or mostly hydrogenated. The hydrogenation ratio (hydrogenation rate) is determined using deuterated chloroform as a solvent at 20 Hz. １ It can be calculated by measuring the H-NMR spectrum.

[0110] In the above A-B-A type block copolymer, the content of the structure derived from the conjugated diene monomer is such that the effects of the present invention are achieved, so the lower limit may be 0% by mass, and the substantial upper limit is 99% by mass. From the viewpoint of further improving the release properties of the adhesive tape for semiconductor manufacturing processes to semiconductor chips, the preferred lower limit of the content of the structure derived from the conjugated diene monomer is 30% by mass, the preferred upper limit is 95% by mass, the more preferred lower limit is 40% by mass, the more preferred upper limit is 90% by mass, and the still preferred lower limit is 70% by mass. The content of the structure derived from the conjugated diene monomer in the above A-B-A type block copolymer may be 0 to 99% by mass, 30 to 95% by mass, 40 to 90% by mass, or 70 to 90% by mass.

[0111] Block B described above may have a structure derived from monomers other than the (meth)acrylic monomer, the conjugated diene monomer, and hydrogenated products of the conjugated diene monomer, to the extent that it does not impair the effects of the present invention.

[0112] It is preferable that block B further has a structure derived from a crosslinkable functional group-containing monomer. By making block B have a structure derived from the crosslinkable functional group-containing monomer, the cohesive force of the intermediate adhesive layer is further increased, thereby improving the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips. Furthermore, if the intermediate adhesive layer contains a crosslinking agent described later, the crosslinkable functional group derived from the crosslinkable functional group-containing monomer reacts with the crosslinking agent to form a crosslinked structure, thereby further improving the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips.

[0113] Examples of the crosslinkable functional group-containing monomers in block B include those similar to the crosslinkable functional group-containing monomers used in the first adhesive layer described above. These monomers may be a single monomer or a combination of monomers.

[0114] Furthermore, in addition to block B, it is preferable that block A also has a structure derived from the above-mentioned crosslinkable functional group-containing monomer.

[0115] In the above A-B-A type block copolymer, the preferred lower limit of the content of the structure derived from the crosslinkable functional group-containing monomer (the sum of the content of the structure derived from the crosslinkable functional group-containing monomer in block A and the content of the structure derived from the crosslinkable functional group-containing monomer in block B) is 0.1% by mass, and the preferred upper limit is 30% by mass. By setting the content of the structure derived from the crosslinkable functional group-containing monomer within the above range, the cohesive force of the intermediate adhesive layer is further increased, and the release properties of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved. A more preferred lower limit for the content of the structure derived from the crosslinkable functional group-containing monomer is 0.5% by mass, an even more preferred lower limit is 1% by mass, an even more preferred upper limit is 20% by mass, and an even more preferred upper limit is 10% by mass. Note that the content of the structure derived from the crosslinkable functional group-containing monomer in the above A-B-A type block copolymer may be 0.1 to 30% by mass, 0.5 to 20% by mass, or 1 to 10% by mass.

[0116] The glass transition temperature of block B in the above A-B-A type block copolymer is not particularly limited, but a preferred lower limit is -70°C and a preferred upper limit is 0°C. By setting the glass transition temperature of block B within the above range, the release properties of the adhesive tape from the semiconductor chip are further improved, even when transferring semiconductor chips with protrusions or small-sized semiconductor chips, and adhesive residue on the semiconductor chip can be further reduced. Furthermore, a more preferred lower limit for the glass transition temperature of block B is -50°C, an even more preferred lower limit is -30°C, an even more preferred upper limit is -5°C, and an even more preferred upper limit is -10°C. Note that the glass transition temperature of block B in the above A-B-A type block copolymer may be -70 to 0°C, -50 to -5°C, or -30 to -10°C.

[0117] The glass transition temperature of block B can be measured using a dynamic viscoelasticity analyzer (for example, Rheometrics Dynamic Analyze RDA-700) under the conditions of a measurement temperature of -40 to 150°C, a heating rate of 5°C / min, and a measurement frequency of 1 Hz. In this specification, "glass transition temperature of block B" refers to the temperature at which a maximum of loss loss tangent (tanδ) obtained by dynamic viscoelasticity measurement occurs, which is attributed to micro-Brownian motion.

[0118] The method for adjusting the glass transition temperature of block B to the above range is not particularly limited, but examples include using an alkyl (meth)acrylate as the (meth)acrylic monomer, the homopolymer having a glass transition temperature of -10°C or lower.

[0119] By including an alkyl (meth)acrylate in the above (meth)acrylic monomer whose homopolymer has a glass transition temperature of -10°C or lower, the intermediate adhesive layer can be adjusted to an appropriate hardness. Examples of alkyl (meth)acrylates in the above (meth)acrylic monomer whose homopolymer has a glass transition temperature of -10°C or lower include butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, lauryl acrylate, and methoxyethyl acrylate. Among these, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, and methoxyethyl acrylate are preferred.

[0120] The content of the structure derived from alkyl (meth)acrylate, which has a glass transition temperature of -10°C or lower, in the above A-B-A type block copolymer is not particularly limited and may be 0% by mass, but a preferred lower limit is 40% by mass. If the content of the structure derived from alkyl (meth)acrylate, which has a glass transition temperature of -10°C or lower, is 40% by mass or more, the release properties of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved. A more preferred lower limit for the content of the structure derived from alkyl (meth)acrylate, which has a glass transition temperature of -10°C or lower, is 50% by mass. Furthermore, there is no particular upper limit for the content of the structure derived from alkyl (meth)acrylate, which has a glass transition temperature of -10°C or lower, but from the viewpoint of improving the pick-up properties of the adhesive tape for semiconductor manufacturing processes to semiconductor chips, a preferred upper limit is 95% by mass and a more preferred upper limit is 90% by mass. Furthermore, the content of structures derived from alkyl (meth)acrylates having a glass transition temperature of -10°C or lower in the above A-B-A type block copolymer may be 40 to 95% by mass or 50 to 90% by mass.

[0121] The weight-average molecular weight (Mw) of the above A-B-A type block copolymer is not particularly limited, but is preferably 50,000 or more and 800,000 or less. By setting the weight-average molecular weight of the above A-B-A type block copolymer within the above range, the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved, and adhesive residue on semiconductor chips can be further reduced. A more preferred lower limit for the weight-average molecular weight of the above A-B-A type block copolymer is 75,000, an even more preferred lower limit is 100,000, and an even more preferred lower limit is 200,000. A more preferred upper limit for the weight-average molecular weight of the above A-B-A type block copolymer is 600,000. The weight-average molecular weight (Mw) of the above A-B-A type block copolymer may be 50,000 to 800,000, 75,000 to 600,000, 100,000 to 600,000, or 200,000 to 600,000.

[0122] The weight-average molecular weight of the above A-B-A type block copolymer can be determined, for example, by GPC (Gel Permeation Chromatography) on a standard polystyrene basis. More specifically, for example, it can be measured using a Waters 2690 Separations Module as the measuring instrument, a Showa Denko GPC KF-806L as the column, and ethyl acetate as the solvent, under conditions of a sample flow rate of 1 mL / min and a column temperature of 40°C.

[0123] To obtain the above A-B-A type block copolymer, the raw material monomers for block A and block B can be subjected to radical reactions in the presence of a polymerization initiator to obtain block A and block B, and then the two can be reacted or copolymerized. Alternatively, after obtaining block A, the raw material monomers for block B may be added and copolymerized. Conventional known methods can be used for the radical reaction, i.e., polymerization methods, such as solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, and bulk polymerization.

[0124] As the (meth)acrylic copolymer in the above-mentioned intermediate adhesive layer, for example, the same type as the (meth)acrylic copolymer in the above-mentioned first adhesive layer can be used.

[0125] Preferably, the intermediate adhesive layer further contains an ultraviolet absorber. By including an ultraviolet absorber in the intermediate adhesive layer, the stimulation of laser light is more efficiently converted into heat or vibration in the intermediate adhesive layer, making deformation due to ablation of the intermediate adhesive layer more likely, and thus improving the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips.

[0126] In the case where the adhesive tape for semiconductor manufacturing processes of this embodiment has the above-mentioned intermediate layer, and the intermediate layer has the above-mentioned intermediate adhesive layer, it is preferable that at least one layer between the first adhesive layer and the intermediate adhesive layer contains an ultraviolet absorber. By including an ultraviolet absorber in at least one layer between the first adhesive layer and the intermediate adhesive layer, deformation due to ablation of the adhesive tape for semiconductor manufacturing processes of this embodiment due to irradiation with laser light becomes more likely, and the release properties of the resulting adhesive tape for semiconductor manufacturing processes from the semiconductor chip can be improved.

[0127] Examples of UV absorbers in the intermediate adhesive layer include those similar to those in the first adhesive layer described above. These UV absorbers may be used individually or in combination of two or more types.

[0128] A preferred upper limit for the amount of ultraviolet absorber contained in the intermediate adhesive layer is 15 parts by mass per 100 parts by mass of the base polymer contained in the intermediate adhesive layer. If the amount of ultraviolet absorber contained in the intermediate adhesive layer is 15 parts by mass or less, the adhesion between the intermediate adhesive layer and other layers and the pickability of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved. A more preferred upper limit for the amount of ultraviolet absorber contained in the intermediate adhesive layer is 12 parts by mass, and an even more preferred upper limit is 10 parts by mass. Furthermore, a preferred lower limit for the amount of ultraviolet absorber contained in the intermediate adhesive layer is 1 part by mass. By having an amount of ultraviolet absorber contained in the intermediate adhesive layer of 1 part by mass or more, the stimulation of laser light in the intermediate adhesive layer is more efficiently converted into heat or vibration, so deformation due to ablation of the intermediate adhesive layer becomes more likely, and the release of the resulting adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved. A more preferred lower limit for the amount of ultraviolet absorber contained in the intermediate adhesive layer is 2 parts by mass, and an even more preferred lower limit is 4 parts by mass. The amount of ultraviolet absorber contained in the above-mentioned intermediate adhesive layer may be 1 to 15 parts by mass, 1 to 12 parts by mass, or 1 to 10 parts by mass.

[0129] The thickness of the intermediate adhesive layer is not particularly limited, but a preferred lower limit is 3 μm and a preferred upper limit is 50 μm. If the thickness of the intermediate adhesive layer is within the above range, when transferring a semiconductor chip from a dicing tape or the like to the adhesive tape for the semiconductor manufacturing process, the intermediate adhesive layer acts as a cushioning layer, making it easier to adhere the semiconductor chip to the adhesive tape for the semiconductor manufacturing process. Therefore, the pickability of the semiconductor chip can be further improved. Also, if the thickness of the intermediate adhesive layer is within the above range, the intermediate adhesive layer can be appropriately deformed by ablation when irradiated with laser light, further improving the release properties of the resulting adhesive tape for the semiconductor manufacturing process from the semiconductor chip. A more preferred lower limit for the thickness of the intermediate adhesive layer is 5 μm, a more preferred upper limit is 30 μm, an even more preferred lower limit is 8 μm, and an even more preferred upper limit is 20 μm. The thickness of the intermediate adhesive layer may be 3 to 50 μm, 5 to 30 μm, or 8 to 20 μm.

[0130] The intermediate substrate layer preferably has a resin film having polar functional groups. By making the intermediate substrate layer a resin film having polar functional groups, the anchoring between the intermediate substrate layer and the first adhesive layer or the intermediate adhesive layer can be increased, thereby improving the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips and further reducing adhesive residue on semiconductor chips.

[0131] The resin film having the above polar functional groups is not particularly limited, but from the viewpoint of superior heat resistance, it is preferable to include a polyester film. Examples of the above polyester film include polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, and polybutylene terephthalate (PBT) film. Among these, polyethylene terephthalate (PET) film is preferred from the viewpoint of a good balance between price and excellent permeability. Furthermore, from the viewpoint of superior ultraviolet transmittance, the above resin film having the above polar functional groups is preferably a (meth)acrylic resin film. Examples of the above (meth)acrylic resin film include polymethyl methcrate film. Furthermore, examples of resin films having the above-mentioned polar functional groups include polyacetal films, polyamide films, polycarbonate films, polyphenylene ether films, ultra-high molecular weight polyethylene films, syndiotactic polystyrene films, polyarylate films, polysulfone films, polyethersulfone films, polyphenylene sulfide films, polyetheretherketone films, polyimide films, polyetherimide films, fluororesin films, and liquid crystal polymer films.

[0132] The thickness of the above-mentioned intermediate substrate layer is not particularly limited, but a preferred lower limit is 0.1 μm and a preferred upper limit is 20 μm. If the thickness of the above-mentioned intermediate substrate layer is within the above range, the release properties of the resulting adhesive tape for semiconductor manufacturing processes from the semiconductor chip can be further improved. A more preferred lower limit for the thickness of the above-mentioned intermediate substrate layer is 3 μm, a more preferred upper limit is 8 μm, and an even more preferred upper limit is 6 μm. The thickness of the above-mentioned intermediate substrate layer may be 0.1 to 20 μm, 3 to 8 μm, or 3 to 6 μm.

[0133] The above-mentioned intermediate substrate layer may, if necessary, contain additives such as plasticizers, emulsifiers, softeners, fillers, pigments, dyes, and other resins.

[0134] In this embodiment, the adhesive tape for semiconductor manufacturing processes preferably has a second adhesive layer on the side of the base layer opposite to the first adhesive layer. Having a second adhesive layer in this embodiment allows the adhesive tape to be attached to a support, thereby improving the handling of the resulting adhesive tape in the semiconductor manufacturing process. The support is not particularly limited and examples include glass, a quartz substrate, a metal plate, etc.

[0135] The second adhesive layer described above may be an adhesive layer similar to the first adhesive layer described above, or it may be a different adhesive layer. If the second adhesive layer is different from the first adhesive layer, the second adhesive layer is not particularly limited, and conventionally known adhesive layers can be used.

[0136] The second adhesive layer preferably contains an antistatic agent. By including an antistatic agent in the second adhesive layer, the accumulation of static electricity in the resulting adhesive tape for semiconductor manufacturing processes can be further suppressed, thereby preventing transfer defects of semiconductor chips when using the resulting adhesive tape for semiconductor manufacturing processes. As a result, semiconductor chips can be transferred more effectively, and the yield of semiconductor chips during semiconductor chip manufacturing can be further improved.

[0137] In this embodiment, it is preferable that at least one layer of the semiconductor manufacturing process adhesive tape, consisting of the base layer and the second adhesive layer, contains an antistatic agent. By including an antistatic agent in at least one layer of the base layer and the second adhesive layer, the accumulation of static electricity in the resulting semiconductor manufacturing process adhesive tape can be further suppressed without including an antistatic agent in the first adhesive layer. This reduces the proportion of low molecular weight composition in the first adhesive layer, thereby further reducing the impact on the release properties of the resulting semiconductor manufacturing process adhesive tape.

[0138] The antistatic agent in the second adhesive layer described above can be the same as the antistatic agent that can be used in the first adhesive layer described above.

[0139] The preferred lower limit of the 180° peel force of the second adhesive layer against a glass plate at 23°C is 2.0 N / 25 mm. By setting the 180° peel force of the second adhesive layer against a glass plate at 23°C to 2.0 N / 25 mm or higher, the adhesive tape for semiconductor manufacturing processes of this embodiment can be firmly attached to the support, thereby further preventing the adhesive tape for semiconductor manufacturing processes of this embodiment from peeling off from the support such as a glass substrate when peeling off a semiconductor chip. A more preferred lower limit of the 180° peel force of the second adhesive layer against a glass plate at 23°C is 4.0 N / 25 mm. Furthermore, a preferred upper limit of the 180° peel force of the second adhesive layer against a glass plate at 23°C is 10.0 N / 25 mm. By setting the 180° peel force of the second adhesive layer to the glass plate at 23°C to 10.0 N / 25 mm or less, the adhesive tape for semiconductor manufacturing processes obtained from the support becomes easier to re-peel, thereby improving the handling of the adhesive tape for semiconductor manufacturing processes in the semiconductor manufacturing process. A more preferable upper limit for the 180° peel force of the second adhesive layer to the glass plate at 23°C is 8.0 N / 25 mm. The 180° peel force of the second adhesive layer to the glass plate at 23°C may be 2.0 to 10.0 N / 25 mm or 4.0 to 8.0 N / 25 mm.

[0140] The 180° peel force of the second adhesive layer on the glass plate at 23°C can be measured by the following method (i.e., the first adhesive layer is backed with a 23 μm thick biaxially oriented PET film (Futamura Chemical Co., Ltd., "FE2002"), and then the second adhesive layer is pressed onto the glass plate to create a sample, except that the method is the same as the method for measuring the rate of decrease in peel force after UV irradiation of adhesive tapes for semiconductor manufacturing processes described later, which measures the 180° peel force (mN / 25 mm) before UV irradiation). Specifically, a semiconductor manufacturing process adhesive tape, in which a first adhesive layer is backed with a 23 μm thick biaxially oriented PET film (Futamura Chemical Co., Ltd., "FE2002"), is cut into a flat rectangular shape with a width of 25 mm and a length of 75 mm. The cut adhesive tape is pressed onto a glass plate (Yutaka Panel Service Co., Ltd., "Glass Plate 2.0 × 50 × 125") by passing it back and forth once at a speed of 300 mm / min using a 2 kg rubber roller, and then left to stand for 20 minutes under conditions of 23°C and 50% RH to prepare a test specimen. The obtained test specimen is then subjected to a 180° peel test using a tensile testing machine (Shimadzu Corporation, "AGS-X", etc.) in accordance with JIS Z0237, at 23°C, 50% RH, and a peel speed of 300 mm / min, thereby measuring the 180° peel force of the second adhesive layer on the glass plate at 23°C.

[0141] Methods for adjusting the 180° peel force of the second adhesive layer to the glass plate at 23°C to within the above range include, for example, adjusting the composition and weight-average molecular weight (Mw) of the base polymer contained in the second adhesive layer, or adjusting the type or content of the crosslinking agent contained in the second adhesive layer.

[0142] The common logarithm of the surface resistance of the second adhesive layer (hereinafter sometimes simply referred to as "surface resistance of the second adhesive layer") has a preferred upper limit of 15 [log(Ω / sq)]. By setting the surface resistance of the second adhesive layer to 15 [log(Ω / sq)] or less, the accumulation of static electricity in the resulting adhesive tape for semiconductor manufacturing processes can be further suppressed. Therefore, by using the resulting adhesive tape for semiconductor manufacturing processes, transfer defects of semiconductor chips can be prevented, and the yield of semiconductor chips in the semiconductor manufacturing process can be further improved. A more preferred upper limit for the surface resistance of the second adhesive layer is 13.5 [log(Ω / sq)], and an even more preferred upper limit is 13 [log(Ω / sq)]. There is no particular lower limit for the surface resistance of the second adhesive layer, but the practical lower limit is 6 [log(Ω / sq)]. The surface resistance of the second adhesive layer may be 6 to 15 [log(Ω / sq)], 6 to 13.5 [log(Ω / sq)], or 6 to 13 [log(Ω / sq)].

[0143] Methods for adjusting the surface resistance of the second adhesive layer include adding an antistatic agent to the second adhesive layer, adjusting the composition of the base polymer contained in the second adhesive layer, adjusting the type and content of the tackifying resin, crosslinking agent, ultraviolet absorber, and antistatic agent contained in the second adhesive layer, and adjusting the thickness of the second adhesive layer.

[0144] The thickness of the second adhesive layer described above has a preferred lower limit of 3 μm and a preferred upper limit of 30 μm. By setting the thickness of the second adhesive layer to 3 μm or more, it is possible to better prevent the tape from peeling off the support such as a glass substrate when peeling off a semiconductor chip. By setting the thickness of the second adhesive layer to 30 μm or less, it is possible to make it easier to re-peel off the resulting adhesive tape for semiconductor manufacturing processes. A more preferred lower limit for the thickness of the second adhesive layer is 5 μm, a more preferred upper limit is 20 μm, an even more preferred lower limit is 8 μm, and an even more preferred upper limit is 12 μm. The thickness of the second adhesive layer may be 3 to 30 μm, 5 to 20 μm, or 8 to 12 μm.

[0145] The method for manufacturing the adhesive tape for semiconductor manufacturing processes according to this embodiment is not particularly limited, but for example, first, the above-mentioned base polymer (P1) and, if necessary, a tackifying resin, an ultraviolet absorber, an antistatic agent, and other additives are added and stirred to obtain an adhesive solution, and then the adhesive solution is applied to a substrate layer and dried to obtain a laminated film (a) having a substrate layer and a first adhesive layer. Next, the prepared adhesive solution is applied to the release treatment surface of a release PET film by the same method and dried to obtain a laminated film (b) having a second adhesive layer. Then, the second adhesive layer of laminated film (b) is bonded to the side of laminated film (a) that does not have the first adhesive layer of the substrate layer to laminate and integrate them, and then cured to obtain the adhesive tape for semiconductor manufacturing processes according to this embodiment.

[0146] Furthermore, the adhesive tape for semiconductor manufacturing processes according to this embodiment can also be obtained by creating a laminated film in which the first adhesive layer and the second adhesive layer are formed on the release treatment surface of a separate release PET film, laminating the respective laminated films to separate surfaces of a base layer, laminating them together, and then curing them.

[0147] The preferred lower limit for the ultraviolet absorption rate at a wavelength of 355 nm of the adhesive tape for semiconductor manufacturing processes in this embodiment is 80%. By setting the ultraviolet absorption rate at a wavelength of 355 nm of the above-mentioned adhesive tape for semiconductor manufacturing processes to 80% or higher, the resulting adhesive tape for semiconductor manufacturing processes generates heat or vibration more efficiently when irradiated with laser light, and deformation due to ablation becomes more likely. Therefore, the release properties of the resulting adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved. In addition, because the adhesive tape for semiconductor manufacturing processes absorbs laser light to an appropriate degree, the absorption of light by the semiconductor chip adhered to the adhesive tape for semiconductor manufacturing processes in this embodiment can be further suppressed, thereby improving the manufacturing quality of semiconductor chips manufactured using the above-mentioned adhesive tape for semiconductor manufacturing processes. The more preferred lower limit for the ultraviolet absorption rate at a wavelength of 355 nm of the adhesive tape for semiconductor manufacturing processes in this embodiment is 90%, and the even more preferred lower limit is 95%. The higher the ultraviolet absorption rate at a wavelength of 355 nm of the above-mentioned adhesive tape for semiconductor manufacturing processes, the better, and it may even be 100%. The ultraviolet absorption rate of the above-mentioned adhesive tape for semiconductor manufacturing processes at a wavelength of 355 nm may be 80-100%, 90-100%, or 95-100%. A method for measuring the ultraviolet absorption rate of the above-mentioned adhesive tape for semiconductor manufacturing processes at a wavelength of 355 nm may be, for example, using a spectrophotometer (such as Shimadzu Corporation's "UV-2600i") to measure the adhesive tape for semiconductor manufacturing processes according to JIS L1925.

[0148] Methods for adjusting the ultraviolet absorption rate of the above-mentioned adhesive tape for semiconductor manufacturing processes at a wavelength of 355 nm to within the above range include, for example, changing the composition of the base polymer (P1), adjusting the type and content of the crosslinking agent, tackifying resin, ultraviolet absorber, and antistatic agent contained in the first adhesive layer, and adjusting the thickness of the layers constituting the adhesive tape for semiconductor manufacturing processes.

[0149] The common logarithm of the surface resistance value of the semiconductor manufacturing process adhesive tape of this embodiment, measured from the first adhesive layer side (hereinafter sometimes simply referred to as "surface resistance value of the semiconductor manufacturing process adhesive tape"), has a preferred upper limit of 15.0 [log(Ω / sq)]. By setting the surface resistance value of the semiconductor manufacturing process adhesive tape to 15.0 [log(Ω / sq)] or less, the accumulation of static electricity in the resulting semiconductor manufacturing process adhesive tape can be suppressed. As a result, transfer defects of semiconductor chips can be prevented using the resulting semiconductor manufacturing process adhesive tape, and the yield of semiconductor chips in the semiconductor manufacturing process can be further improved. The more preferable upper limit for the surface resistance of the adhesive tape for semiconductor manufacturing processes described above is 14.7 [log(Ω / sq)], an even more preferable upper limit is 14.0 [log(Ω / sq)], an even more preferable upper limit is 13.0 [log(Ω / sq)], a particularly preferable upper limit is 12.0 [log(Ω / sq)], and a very preferable upper limit is 11.0 [log(Ω / sq)]. There is no particular lower limit for the surface resistance of the adhesive tape for semiconductor manufacturing processes described above, but the practical lower limit is 6 [log(Ω / sq)]. The surface resistance of the adhesive tape for semiconductor manufacturing processes may be 6 to 15.0 [log(Ω / sq)], 6 to 14.7 [log(Ω / sq)], 6 to 14.0 [log(Ω / sq)], 6 to 13.0 [log(Ω / sq)], 6 to 12.0 [log(Ω / sq)], or 6 to 11.0 [log(Ω / sq)].

[0150] Methods for adjusting the surface resistance of the adhesive tape used in the semiconductor manufacturing process include adjusting the surface resistance of each layer constituting the adhesive tape, and adjusting the thickness of each layer constituting the adhesive tape. Specifically, methods for adjusting the surface resistance of each layer constituting the adhesive tape include adjusting the type and amount of antistatic agent contained in each layer, and adjusting the thickness of each layer.

[0151] The adhesive tape for semiconductor manufacturing processes of this embodiment was measured with the first adhesive layer side attached to a glass plate, at a wavelength of 355 nm and an irradiation intensity of 7.8 mW / cm². ２ The cumulative amount of ultraviolet light is 190 mJ / cm². ２ The preferred upper limit for the rate of decrease in 180° peel strength against glass at 23°C after irradiation (hereinafter sometimes simply referred to as the "rate of decrease in peel strength after UV irradiation") is 60%. By setting the rate of decrease in peel strength after UV irradiation to 60% or less, the resulting adhesive tape for semiconductor manufacturing processes can peel off semiconductor chips without requiring separate UV irradiation before laser ablation, thereby further improving the work efficiency of semiconductor chip manufacturing. A more preferred upper limit for the rate of decrease in adhesive strength after UV irradiation is 30%, an even more preferred upper limit is 20%, an even more preferred upper limit is 10%, and a particularly preferred upper limit is 5%. The lower limit for the rate of decrease in adhesive strength after UV irradiation may be 0%, but a preferred lower limit is 1%. The rate of decrease in peel strength after UV irradiation may be 0-60%, 0-30%, 1-20%, 1-10%, or 1-5%.

[0152] The method for measuring the rate of decrease in peel strength after UV irradiation is as follows. Specifically, if necessary, a semiconductor manufacturing process adhesive tape, in which a second adhesive layer is backed with a biaxially oriented PET film with a thickness of 23 μm, is cut into a flat rectangular shape with a width of 25 mm and a length of 75 mm. The cut adhesive tape is pressed onto a glass plate (Yutaka Panel Service Co., Ltd., "Glass Plate 2.0 × 50 × 125") by passing it back and forth once at a speed of 300 mm / min using a 2 kg rubber roller, and then left to stand for 20 minutes under conditions of 23°C and 50% RH to prepare a test specimen. The obtained test specimen is subjected to a 180° peel test using a tensile testing machine (Shimadzu Corporation, "AGS-X", etc.) in accordance with JIS Z0237, at 23°C, 50% RH, and a peel speed of 300 mm / min, to obtain the 180° peel strength (mN / 25 mm) before UV irradiation. Furthermore, adhesive tape cut in the same manner as above and pressed onto glass was subjected to UV irradiation using a black light (NEC Corporation, "FL20SBL") at a wavelength of 355 nm and an irradiation intensity of 7.8 mW / cm².２ The cumulative amount of ultraviolet light is 190 mJ / cm². ２ After irradiating the glass from the side in such a manner, the 180° peeling force (mN / 25mm) after UV irradiation is obtained by measuring the 180° peeling force in the same manner as described above. Then, the percentage of peeling force reduction after UV irradiation is calculated using the following formula: Percentage of peeling force reduction after UV irradiation (%) = 100 × {(180° peeling force before UV irradiation) - (180° peeling force after UV irradiation)} / (180° peeling force before UV irradiation)

[0153] Methods for adjusting the rate of decrease in peeling force after UV irradiation to within the range described above include, for example, changing the composition of the base polymer (P1), adjusting the type and content of the crosslinking agent, tackifying resin, UV absorber, and antistatic agent contained in the first adhesive layer, specifically reducing the content of the UV absorber.

[0154] The preferred lower limit of the peeling force of the above-mentioned adhesive tape for semiconductor manufacturing processes after long-term storage is 0.050 N / 20 mm, and the preferred upper limit is 1.000 N / 20 mm. When the peeling force of the above-mentioned adhesive tape for semiconductor manufacturing processes after long-term storage is 0.050 N / 20 mm or more, the resulting adhesive tape for semiconductor manufacturing processes is more likely to exhibit excellent pickup properties for semiconductor chips even after long-term storage. When the peeling force of the above-mentioned adhesive tape for semiconductor manufacturing processes after long-term storage is 1.000 N / 20 mm or more, the resulting adhesive tape for semiconductor manufacturing processes is more likely to exhibit excellent release properties for semiconductor chips even after long-term storage. A more preferred lower limit of the peeling force of the above-mentioned adhesive tape for semiconductor manufacturing processes after long-term storage is 0.080 N / 20 mm, a more preferred upper limit is 0.800 N / 20 mm, an even more preferred lower limit is 0.100 N / 20 mm, and an even more preferred upper limit is 0.600 N / 20 mm. Furthermore, the peeling force of the above-mentioned adhesive tape for semiconductor manufacturing processes after long-term storage may be 0.050 to 1.000 N / 20 mm, 0.080 to 0.800 N / 20 mm, or 0.100 to 0.600 N / 20 mm.

[0155] The peel force of the above-mentioned adhesive tape for semiconductor manufacturing processes before long-term storage is preferably such that the ratio of the peel force before and after storage satisfies the above-mentioned range, with a preferred lower limit of 0.050 N / 20 mm and a preferred upper limit of 1.000 N / 20 mm. When the peel force of the above-mentioned adhesive tape for semiconductor manufacturing processes before long-term storage is 0.050 N / 20 mm or more, the resulting adhesive tape for semiconductor manufacturing processes is more likely to exhibit excellent pickup properties for semiconductor chips. When the peel force of the above-mentioned adhesive tape for semiconductor manufacturing processes before long-term storage is 1.000 N / 20 mm or more, the resulting adhesive tape for semiconductor manufacturing processes is more likely to exhibit excellent release properties for semiconductor chips. A more preferred lower limit for the peel force of the above-mentioned adhesive tape for semiconductor manufacturing processes before long-term storage is 0.080 N / 20 mm, a more preferred upper limit is 0.800 N / 20 mm, an even more preferred lower limit is 0.100 N / 20 mm, and an even more preferred upper limit is 0.600 N / 20 mm. Furthermore, the peeling force of the above-mentioned adhesive tape for semiconductor manufacturing processes before long-term storage may be 0.050 to 1.000 N / 20 mm, 0.080 to 0.800 N / 20 mm, or 0.100 to 0.600 N / 20 mm.

[0156] The preferred lower limit for the peel force ratio before and after storage of the above-mentioned adhesive tape for semiconductor manufacturing processes is 0.50, and the preferred upper limit is 1.50. By keeping the peel force ratio before and after storage of the above-mentioned adhesive tape for semiconductor manufacturing processes within the above range, the adhesive tape for semiconductor manufacturing processes of this embodiment is more likely to exhibit excellent release and pick-up properties for semiconductor chips both before and after long-term storage. The more preferred lower limit for the peel force ratio before and after storage of the above-mentioned adhesive tape for semiconductor manufacturing processes is 0.60, the more preferred upper limit is 1.30, the even more preferred lower limit is 0.80, the even more preferred upper limit is 1.20, the even more preferred lower limit is 0.90, and the even more preferred upper limit is 1.10. The peel force ratio before and after storage of the above-mentioned adhesive tape for semiconductor manufacturing processes may be 0.50 to 1.50, 0.60 to 1.30, 0.80 to 1.20, or 0.90 to 1.10.

[0157] The peeling force of the above-mentioned adhesive tape for semiconductor manufacturing processes after long-term storage, the peeling force of the above-mentioned adhesive tape for semiconductor manufacturing processes before long-term storage, and the ratio of the peeling force before and after storage of the above-mentioned adhesive tape for semiconductor manufacturing processes can be measured by the following method. Specifically, first, a test piece is prepared by cutting the adhesive tape for semiconductor manufacturing processes into a flat rectangular shape of 25 mm x 75 mm in length, and a long-term storage test is performed by placing the test piece in a constant temperature oven set to 40°C and leaving it undisturbed for one week. Next, the test piece that has undergone the long-term storage test is removed from the constant temperature oven, air-cooled, and then the first adhesive layer on the test piece is pressed onto a glass plate by using a 2 kg rubber roller to make one back-and-forth motion at a speed of 300 mm / min, and then left undisturbed for 20 minutes under conditions of 23°C and 50% RH to prepare a measurement sample. Then, using a tensile testing machine (such as Shimadzu Corporation's "AGS-X"), a 180° peel test can be performed on the prepared measurement sample at 23°C, 50% RH, and a peeling speed of 300 mm / min, in accordance with JIS Z0237, to measure the peel strength of the semiconductor manufacturing adhesive tape after long-term storage. Alternatively, by preparing a measurement sample using the method described above and performing a 180° peel test on a test piece cut into a flat rectangular shape of 25 mm width x 75 mm length, without performing the long-term storage test described above, the peel strength of the semiconductor manufacturing adhesive tape before long-term storage can be measured. Furthermore, by using the measured peel strength of the semiconductor manufacturing adhesive tape after long-term storage and the peel strength of the semiconductor manufacturing adhesive tape before long-term storage, the peel strength ratio before and after storage (peel strength of the semiconductor manufacturing adhesive tape after long-term storage / peel strength of the semiconductor manufacturing adhesive tape before long-term storage) can be obtained.

[0158] Furthermore, if the adhesive tape for semiconductor manufacturing processes according to this embodiment has a second adhesive layer as described later, the peeling force of the adhesive tape for semiconductor manufacturing processes after long-term storage and the peeling force of the adhesive tape for semiconductor manufacturing processes before long-term storage are measured using a test piece in which the second adhesive layer is backed with a PET film or the like.

[0159] Methods for adjusting the peeling force of the adhesive tape for semiconductor manufacturing processes after long-term storage to within the range described above include, for example, changing the type of base polymer (P1), adjusting the type and content ratio of constituent unit monomers in the (meth)acrylic copolymer of the base polymer (P1), changing the weight-average molecular weight (Mw) of the base polymer (P1), adjusting the type and content of the antistatic agent contained in the first adhesive layer, adjusting the type and content of the tackifying resin contained in the first adhesive layer, adjusting the thickness of the first adhesive layer, and adjusting the thickness of the adhesive tape for semiconductor manufacturing processes.

[0160] Methods for adjusting the peeling force of the adhesive tape for semiconductor manufacturing processes before long-term storage to within the above-mentioned range include, for example, changing the type of base polymer (P1) described later, adjusting the type and content ratio of constituent unit monomers in the (meth)acrylic copolymer in the first adhesive layer, changing the weight-average molecular weight (Mw) of the base polymer (P1) described later, adjusting the type and content of tackifying resin contained in the first adhesive layer, adjusting the thickness of the first adhesive layer, and adjusting the thickness of the adhesive tape for semiconductor manufacturing processes.

[0161] The ratio of peel force before and after storage of the above-mentioned adhesive tape for semiconductor manufacturing processes can be adjusted by adjusting the peel force after long-term storage of the above-mentioned adhesive tape for semiconductor manufacturing processes and the peel force before long-term storage of the above-mentioned adhesive tape for semiconductor manufacturing processes.

[0162] As described above, the adhesive tape for semiconductor manufacturing processes is used in a method for manufacturing semiconductor chips, in which semiconductor chips are continuously arranged on a first adhesive layer of the adhesive tape for semiconductor manufacturing processes, the semiconductor chips are peeled off the adhesive tape for semiconductor manufacturing processes, and the peeled semiconductor chips are brought into contact with a carrier material, wherein the peeling of the semiconductor chips from the adhesive tape and the contact of the peeled semiconductor chips with the carrier material occur continuously in the transfer process.Here, the semiconductor chips are released from the adhesive tape for semiconductor manufacturing processes by ablation when irradiated with laser light and transferred to the carrier material, but the adhesive tape for semiconductor manufacturing processes, the semiconductor chips and the carrier material do not come into contact simultaneously, and the release of the semiconductor chips from the adhesive tape for semiconductor manufacturing processes and the contact of the semiconductor chips with the carrier material occur continuously. As described above, the adhesive tape for semiconductor manufacturing processes of this embodiment has excellent release properties to semiconductor chips. Therefore, even when the size of the semiconductor chip to be manufactured is small, using the adhesive tape for semiconductor manufacturing processes of this embodiment in the semiconductor chip manufacturing method described above allows for accurate positional transfer of the semiconductor chip and suppresses the adhesion of adhesive layer residue to the semiconductor chip, thereby improving the yield of the manufactured chips. Furthermore, since the adhesive tape for semiconductor manufacturing processes of this embodiment contains an antistatic agent in at least one of its constituent layers, static electricity is less likely to accumulate on the adhesive tape for semiconductor manufacturing processes. Therefore, in the transfer process, when semiconductor chips are continuously arranged on the first adhesive layer of the adhesive tape for semiconductor manufacturing processes, the distance between each semiconductor chip is very small, and accurate positional transfer of each semiconductor chip is required. However, by using the adhesive tape for semiconductor manufacturing processes of this embodiment, the transfer process can be performed while suppressing transfer defects. Consequently, it becomes possible to efficiently manufacture a large number of semiconductor chips using the semiconductor chip manufacturing method described above. The semiconductor chip manufacturing method using the adhesive tape for semiconductor manufacturing processes of this embodiment is also one of the embodiments.

[0163] The semiconductor manufacturing process adhesive tape of this embodiment is preferably used in a method for manufacturing small semiconductor chips, and more specifically, in a method for manufacturing a rectangular semiconductor chip with at least one side length of 1000 μm or less. Among these, it is more preferable to use it in a method for manufacturing a rectangular semiconductor chip with all sides lengthing 1000 μm or less. In the semiconductor manufacturing process adhesive tape used above, the more preferable lower limit for the side length of the manufactured rectangular semiconductor chip is 10 μm, the more preferable upper limit is 700 μm, the even more preferable lower limit is 20 μm, and the even more preferable upper limit is 500 μm. In the semiconductor manufacturing process adhesive tape used above, the side length of the manufactured rectangular semiconductor chip may be 10 to 1000 μm, 10 to 700 μm, or 20 to 500 μm.

[0164] As described above, the manufacturing method described above can efficiently produce a large number of semiconductor chips. The number of semiconductor chips produced at one time in this manufacturing method is not particularly limited and can be one or more, but from the viewpoint of improving manufacturing efficiency, a preferred lower limit is 100 chips and a more preferred lower limit is 400 chips. Furthermore, a preferred upper limit for the number of semiconductor chips produced at one time in this manufacturing method is 100,000 chips and a more preferred upper limit is 50,000 chips. In addition, the number of semiconductor chips produced at one time in this manufacturing method may be between 10,000 and 100,000 chips, between 100,000 and 50,000 chips, or between 400 and 50,000 chips.

[0165] Examples of the carrier material in the manufacturing method described above include adhesive tape, liquid polyimide-based adhesive, and liquid silicone-based adhesive.

[0166] According to the present invention, it is possible to provide an adhesive tape for semiconductor manufacturing processes that can transfer a large number of semiconductor chips well, even when the size of the semiconductor chips is small. Furthermore, according to the present invention, it is possible to provide a semiconductor chip using the adhesive tape for semiconductor manufacturing processes.

[0167] The embodiments of the present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0168] (Synthesis of (meth)acrylic copolymers) (Synthesis Examples 1-6) 52 parts by mass of ethyl acetate and a mixture of constituent unit monomers shown in Table 1 were placed in a reactor equipped with a thermometer, stirrer, and condenser. After purging with nitrogen, the reactor was placed in a water bath set to 60°C, and the reactor was heated to start reflux. 30 minutes after the start of reflux, 0.05 parts by mass of azobisisobutyronitrile was added as a polymerization initiator, and the polymerization reaction was carried out for 5 hours. By adding ethyl acetate to the reactor and cooling while diluting, a solution containing a (meth)acrylic copolymer was obtained. For Synthesis Examples 4-6, solutions containing (meth)acrylic copolymers were further obtained by appropriately changing the amount of polymerization initiator added, etc. The weight-average molecular weight of the obtained (meth)acrylic copolymers was measured by the GPC method. The measurement was performed using a Waters 2690 Separations Module as the measuring instrument, a Showa Denko GPC KF-806L column, and ethyl acetate as the solvent, with a sample flow rate of 1 mL / min and a column temperature of 40°C. The results are shown in Table 1.

[0169]

[0170] (Synthesis of A-B-A type block copolymer) (Synthesis Example 7) 0.902 g of 1,6-hexanedithiol, 1.83 g of carbon disulfide, and 11 mL of dimethylformamide were placed in a two-necked flask and stirred at 25°C. 2.49 g of triethylamine was added dropwise over 15 minutes and stirred at 25°C for 3 hours. Next, 2.75 g of methyl-α-bromophenylacetic acid was added dropwise over 15 minutes and stirred at 25°C for 4 hours. Then, 100 mL of extraction solvent (n-hexane:ethyl acetate = 50:50) and 50 mL of water were added to the reaction mixture and liquid-liquid extraction was performed. The organic layers obtained from the first and second liquid-liquid extractions were mixed and washed sequentially with 50 mL of 1 M hydrochloric acid, 50 mL of water, and 50 mL of saturated brine. Sodium sulfate was added to the organic layer after washing and dried. The sodium sulfate was filtered off, and the filtrate was concentrated using an evaporator to remove the organic solvent. The obtained concentrate was purified by silica gel column chromatography to obtain the RAFT agent.

[0171] A mixture of the constituent monomers of Block A shown in Table 2, 1.9 parts by mass of the RAFT agent, and 2,2'-azobis(2-methylbutyronitrile) (ABN-E) were placed in a two-necked flask, and the flask was heated to 85°C while purging it with nitrogen gas. The polymerization reaction was then carried out by stirring at 85°C for 6 hours (first stage reaction). After the first stage reaction was completed, 4000 parts by mass of n-hexane were added to the flask, and the reaction products were stirred to precipitate. Unreacted monomers and the RAFT agent were filtered out, and the reaction product was dried under reduced pressure at 70°C to obtain the copolymer (Block A).

[0172] A mixture of the constituent monomers of block B shown in Table 2, a mixture containing 50 parts by mass of ethyl acetate, and the copolymer obtained above (block A) were placed in a two-necked flask, and the temperature was raised to 85°C while replacing the inside of the flask with nitrogen gas. Then, the polymerization reaction was carried out by stirring at 85°C for 6 hours (second-stage reaction), and a reaction solution containing the block copolymer formed from block A and block B was obtained. A portion of the reaction solution was taken, 4000 parts by mass of n-hexane was added to it, and the reactants were stirred to precipitate the reactants. After that, the unreacted monomers and solvent were filtered out, and the reactants were dried under reduced pressure at 70°C to obtain an A-B-A type block copolymer (synthesis Example 3). The weight-average molecular weight of the obtained A-B-A type block copolymer (synthesis Example 3) was measured by the GPC method. The measurement was performed using a Waters 2690 Separations Module as the measuring instrument, a Showa Denko GPC KF-806L column, and ethyl acetate as the solvent, under conditions of a sample flow rate of 1 mL / min and a column temperature of 40°C. The results are shown in Table 2.

[0173]

[0174] (Preparation of adhesives) (Adhesives A-Z, AA-AY) The obtained base polymer was dissolved in ethyl acetate so that the solid content was 20% by mass. Each component shown in Tables 3-6 was added to 100 parts by mass of the base polymer, and the mixture was stirred thoroughly to prepare adhesive solutions of adhesives A-Z and AA-AY.

[0175] The components other than those used in Synthesis Examples 1-7 of the adhesives shown in Tables 3-6 are as follows: • SEBS block copolymer: Kraton Polymers, "Kraton FG1924GT" • Terpene phenol resin: Yasuhara Chemical, "YS Polystar G150" • Petroleum resin: Arakawa Chemical Industries, "Alcon P140" • Rosin ester resin: Arakawa Chemical Industries, "Pine Crystal KE-311" • Isocyanate crosslinking agent: Tosoh Corporation, "Coronate HX" • Epoxy crosslinking agent: Soken Chemical, "E-5C" • Triazole UV absorber: BASF, "Tinuvin 928" • Antistatic agent 1: Lithium bistrifluoromethanesulfonylimide (TGR solution) Antistatic agent 2: Lithium perchlorate Antistatic agent 3: 1-butyl-3-methylpyridinium bis(fluorosulfonyl)imide Antistatic agent 4: 2-propen-1-ammonium,N,N'-dimethyl-N-2-propenyl bis(fluorosulfonyl)imide Antistatic agent 5: 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide Antistatic agent 6: 1-butyl-3-methylimidazolium hexafluorophosphate Antistatic agent 7: Lithium bis(fluorosulfonyl)imide Antistatic agent 8: Lithium hexafluorophosphate Antistatic agent 9: 1-butyl-3-methylimidazolium acetate Antistatic agent 10: Lithium bistrifluoromethanesulfonylimide (MEK solution) Furthermore, for the antistatic agent 1, lithium bistrifluoromethanesulfonylimide (TGR solution), and the antistatic agent 10, lithium bistrifluoromethanesulfonylimide (MEK solution), the amount of solids (lithium bisfluoromethanesulfonylimide) in the solution was added in the parts by mass shown in Tables 3 to 6. Note that the TGR solution is a triethylene glycol dimethyl ether solution, and the MEK solution is a methyl ethyl ketone solution.

[0176]

[0177]

[0178]

[0179]

[0180] (Manufacturing of Adhesive Tape) (Examples 1-8, 11-15, 24-27, 33-56, 58-66, Comparative Examples 1, 3) The adhesive solutions of the adhesives shown in Tables 7-15 were applied to the surface of the substrate layers shown in Tables 7-15 using an applicator, and dried at 110°C for 3 minutes to form a first adhesive layer with the thickness shown in Tables 7-15. Furthermore, a release PET film with a thickness of 75 μm was superimposed so that the release treatment surface faced the first adhesive layer, and then cured at 40°C for 48 hours to obtain an adhesive tape for semiconductor manufacturing processes having a first adhesive layer and a substrate layer. Note that the "biaxially oriented PET film" in the intermediate substrate layer and substrate layer shown in Tables 7-15 is FE2002 (manufactured by Futamura Chemical Co., Ltd.), and the "antistatic coated PET film" is FE2001 (manufactured by Futamura Chemical Co., Ltd.).

[0181] (Measurement of probe tack value (V1) of the first adhesive layer) The obtained adhesive tape for semiconductor manufacturing processes was cut to a size of 30 mm in width and 30 mm in length to prepare test pieces. For the first adhesive layer of the obtained test pieces, the probe tack value was measured using a probe tack measuring device (RHESCA Corporation, "Tacking Tester TAC-2") with a 5 mm diameter SUS probe under the conditions of 23°C, pressurization pressure of 0.05 MPa, pressurization speed of 10 mm / sec, pressurization time of 10 seconds, and release speed of 0.1 mm / sec, and the probe tack value (V1) (N / 5 mmφ) of the first adhesive layer was obtained. The probe tack value (V1) of the first adhesive layer was calculated using the average value obtained from five measured probe tack values. The results are shown in Tables 7 to 15. The probe tack value (V1) was measured by peeling off the release PET film protecting the first adhesive layer of the adhesive tape used in semiconductor manufacturing processes.

[0182] (Measurement of probe tack value (V2) of the first adhesive layer) The obtained adhesive tape for semiconductor manufacturing processes was cut to a size of 30 mm in width and 30 mm in length to prepare test pieces. The probe tack value of the first adhesive layer of the obtained test pieces was measured using a probe tack measuring device (RHESCA Corporation, "Tacking Tester TAC-2") with a 5 mm diameter SUS probe, under the conditions of 23°C, pressurization pressure of 0.05 MPa, pressurization speed of 10 mm / sec, pressurization time of 10 seconds, and release speed of 15 mm / sec, to obtain the probe tack value (V2) (N / 5 mmφ) of the first adhesive layer. The probe tack value (V2) of the first adhesive layer was calculated using the average value obtained from five measured probe tack values. The results are shown in Tables 7 to 15. The probe tack value (V2) was measured by peeling off the release PET film protecting the first adhesive layer of the adhesive tape for semiconductor manufacturing processes.

[0183] (Measurement of gel fraction of the first adhesive layer) Only the first adhesive layer is obtained from the semiconductor manufacturing process adhesive tape. ０ (g) Removed and immersed in 50 mL of ethyl acetate, and shaken in a shaker at a temperature of 23°C and 200 rpm for 24 hours. After shaking, a metal mesh (mesh size #200, W １ (g)) was used to separate the ethyl acetate and the adhesive layer that had absorbed and swollen with ethyl acetate. The separated adhesive layers were dried at 110°C for 1 hour. The mass W of the adhesive layer containing the metal mesh after drying. ２ (g) was measured, and the gel fraction (mass%) of the first adhesive layer was calculated using the following formula. The results are shown in Tables 7 to 15. Gel fraction (mass%) = 100 × (W ２ -W １ ) / W ０ (W ０ : Mass of the initial adhesive layer, W １ Initial mass of the metal mesh, W ２ (Mass of the adhesive layer containing the metal mesh after drying)

[0184] (Measurement of shear storage modulus (G') of the first adhesive layer at 23°C and a measurement frequency of 10 Hz) Multiple first adhesive layers were extracted from the obtained semiconductor manufacturing process adhesive tape using a cutter and spatula, and the extracted first adhesive layers were stacked to prepare a sample with a thickness of 500 μm (width 6 mm × length 10 mm). Dynamic viscoelasticity measurements were performed on the obtained sample using a dynamic viscoelasticity analyzer (Rheometrics Dynamic Analyze RDA-700, manufactured by Rheometrics) under nitrogen atmosphere, measurement temperature -40 to 150°C, heating rate 5°C / min, shear mode, and measurement frequency 10 Hz. The shear storage modulus (G') at 23°C and a measurement frequency of 10 Hz was obtained from the measured dynamic viscoelastic spectrum. The results are shown in Tables 7 to 15 as "Shear Storage Modulus (G') (×10 ５ It was shown in "Pa".

[0185] (Measurement of surface resistance of the first adhesive layer) The adhesive solutions of the adhesives shown in Tables 4 to 6 were applied to the release surface of a 75 μm thick release PET film using an applicator, and dried at 110°C for 3 minutes to form a first adhesive layer of the thickness shown in Tables 4 to 6. Furthermore, a test specimen was prepared by stacking a 75 μm thick release PET film so that its release surface faced the first adhesive layer. For the obtained test specimen, the surface resistance of nine points on the first adhesive layer was measured using a probe with a probe spacing of 5 mm arranged in a straight line at equal intervals (Nitto Seiko Co., Ltd., "Hiresta-UX MCP-HT800") in accordance with JIS K7194, and the average of the common logarithms was taken as the surface resistance of the first adhesive layer (log(Ω / sq)). The results are shown in Tables 7 to 15. The surface resistance values ​​of the first adhesive layer at nine points were measured by peeling off the release PET film protecting the first adhesive layer on both sides of the test specimen.

[0186] (Measurement of surface resistance of the substrate layer) For the substrate used as the substrate layer, the surface resistance of nine points on the substrate layer was measured using a probe with a probe spacing of 5 mm arranged in a straight line at equal intervals (Hiresta-UX MCP-HT800, manufactured by Nitto Seiko Co., Ltd.) in accordance with JIS K7194, and the average of the common logarithms was taken as the surface resistance of the substrate layer (log(Ω / sq)). The results are shown in Tables 7 to 15.

[0187] (Calculation of the rate of decrease in peel strength after UV irradiation of adhesive tape for semiconductor manufacturing processes) The obtained adhesive tape was cut into a flat rectangular shape with a width of 25 mm and a length of 75 mm. The cut adhesive tape was attached to a glass plate (Yutaka Panel Service Co., Ltd., "Glass Plate 2.0 × 50 × 125") by rolling it back and forth once at 23°C, 50% RH, and a speed of 300 mm / min using a 2 kg rubber roller, and the test specimen was prepared by letting it stand for 20 minutes under conditions of 23°C and 50% RH. The obtained test specimen was subjected to a 180° peel test using a tensile testing machine (Shimadzu Corporation, "AGS-X") in accordance with JIS Z0237, at 23°C, 50% RH, and a peel speed of 300 mm / min, to measure the 180° peel strength (mN / 25 mm) before UV irradiation. Similarly, for adhesive tape that has been cut and attached to a glass plate, a UV irradiator using a black light (NEC Corporation, "FL20SBL") was used from the first adhesive layer side (glass plate side) at a wavelength of 355 nm and an irradiation intensity of 7.8 mW / cm². ２ The cumulative amount of ultraviolet light is 190 mJ / cm². ２ The sample was irradiated in such a manner, allowed to stand for 20 minutes under conditions of 23°C and 50% RH, and then bonded to a glass plate in the same manner as described above. The 180° peel force (mN / 25mm) after UV irradiation was measured by measuring the 180° peel force. The percentage decrease in peel force after UV irradiation was then calculated using the following formula. The results are shown in Tables 7 to 15. Percentage decrease in peel force after UV irradiation (%) = 100 × {(180° peel force before UV irradiation) - (180° peel force after UV irradiation)} / (180° peel force before UV irradiation)

[0188] (Measurement of UV absorption rate at 355 nm of adhesive tape for semiconductor manufacturing processes) For the obtained adhesive tape for semiconductor manufacturing processes, the UV absorption rate (%) at a wavelength of 355 nm of the adhesive tape was measured from the first adhesive layer side using a spectrophotometer (Shimadzu Corporation, UV-2600i) in accordance with JIS L1925. The results are shown in Tables 7 to 15. The UV absorption rate was measured after peeling off the release PET film protecting the adhesive layers on both sides of the adhesive tape for semiconductor manufacturing processes.

[0189] (Measurement of Surface Resistance of Adhesive Tape for Semiconductor Manufacturing Processes) For the obtained adhesive tape for semiconductor manufacturing processes, the surface resistance values ​​were measured at nine points on the first adhesive layer side using probes with a probe spacing of 5 mm arranged in a straight line at equal intervals ("Hiresta-UX MCP-HT800" manufactured by Nitto Seiko Co., Ltd.), in accordance with JIS K7194. The average of the common logarithms of these measurements was taken as the surface resistance value of the adhesive tape for semiconductor manufacturing processes (log(Ω / sq)). The results are shown in Tables 7 to 15. The measurement of the nine surface resistance values ​​of the adhesive tape for semiconductor manufacturing processes was performed by peeling off the release PET film protecting the adhesive layers on both sides of the adhesive tape for semiconductor manufacturing processes.

[0190] (Measurement of peel strength of adhesive tape for semiconductor manufacturing process before long-term storage) For Examples 25-27, 33-56, 58-66, and Comparative Examples 1-3, the peel strength was measured before long-term storage. First, test pieces were prepared by cutting the obtained adhesive tape for semiconductor manufacturing process into a flat rectangular shape of 25 mm x 75 mm in length. Next, the release PET film of the test piece was peeled off, and the first adhesive layer on the test piece was pressed onto a glass plate by using a 2 kg rubber roller and moving it back and forth once at a speed of 300 mm / min. The sample was then left to stand for 20 minutes under conditions of 23°C and 50% RH to prepare a measurement sample. Then, using a tensile testing machine (Shimadzu Corporation, "AGS-X"), a 180° peel test was performed on the prepared measurement samples in accordance with JIS Z 0237, at 23°C, 50% RH, and a peeling speed of 300 mm / min, to measure the peel force (N / 20 mm) of adhesive tapes for semiconductor manufacturing processes before long-term storage. The results are shown in Tables 10-15.

[0191] (Measurement of peel strength of adhesive tape for semiconductor manufacturing processes after long-term storage) For Examples 25-27, 33-56, 58-66, and Comparative Examples 1-3, the peel strength after long-term storage was measured. In the above-mentioned "(Measurement of peel strength of adhesive tape for semiconductor manufacturing processes before long-term storage)", a long-term storage test was conducted in which the prepared test pieces were placed in a constant-temperature oven set to 40°C and left to stand for one week. Then, measurement samples were prepared using the same method as described above, and the peel strength (N / 20mm) of the adhesive tape for semiconductor manufacturing processes after long-term storage was measured by measuring the 180° peel strength. The results are shown in Tables 10-15.

[0192] (Calculation of the peel force ratio before and after storage of adhesive tapes for semiconductor manufacturing processes) For Examples 25-27, 33-56, 58-66, and Comparative Examples 1-3, the peel force ratio before and after storage was calculated. Using the peel force before and after long-term storage of the adhesive tapes for semiconductor manufacturing processes, measured in "(Measurement of peel force before long-term storage of adhesive tapes for semiconductor manufacturing processes)" and "(Measurement of peel force after long-term storage of adhesive tapes for semiconductor manufacturing processes)" described above, the peel force ratio before and after storage of the adhesive tapes for semiconductor manufacturing processes (peel force after long-term storage of adhesive tapes for semiconductor manufacturing processes / peel force before long-term storage of adhesive tapes for semiconductor manufacturing processes) was calculated. The results are shown in Tables 10-15.

[0193] (Examples 9-10, 29) Using an applicator, the adhesive solutions of the adhesives shown in Tables 8 and 10 were applied to the surface of the substrate layers shown in Tables 8 and 10, and dried at 110°C for 3 minutes to form a first adhesive layer with the thickness shown in Tables 8 and 10. A 75 μm thick release PET film was then layered on top of the adhesive so that its release surface faced the first adhesive layer to produce a laminated film (a). Next, using an applicator, the adhesive solutions of the adhesives shown in Tables 8 and 10 were applied to the release surface of the 75 μm thick release PET film, and dried at 110°C for 3 minutes to obtain a laminated film (b) having a second adhesive layer. Then, the second adhesive layer of laminated film (b) was bonded to the side of the substrate layer of laminated film (a) that did not have the first adhesive layer, and the two layers were laminated together. After curing at 40°C for 48 hours, an adhesive tape for semiconductor manufacturing processes was obtained having the first adhesive layer, the substrate layer, and the second adhesive layer in that order.

[0194] (Measurement of 180° peel force of the second adhesive layer on a glass plate at 23°C) The 180° peel force of the second adhesive layer on a glass plate at 23°C was measured using the same method as for the 180° peel force (mN / 25mm) before UV irradiation in the above-mentioned "(Calculation of the rate of decrease in peel force of adhesive tape for semiconductor manufacturing processes after UV irradiation)". The results are shown in Tables 8 and 10 under "180° peel force on glass plate (N / 25mm)".

[0195] (Measurement of surface resistance of the second adhesive layer) The adhesive solutions of the adhesives shown in Tables 8 and 10 were applied to the release surface of a 75 μm thick release PET film using an applicator, and dried at 110°C for 3 minutes to form a second adhesive layer of the thickness shown in Tables 8 and 10. Furthermore, a test specimen was prepared by stacking a 75 μm thick release PET film so that its release surface faced the second adhesive layer. For the obtained test specimen, the surface resistance values ​​of nine points on the second adhesive layer were measured using probes with a probe spacing of 5 mm arranged in a straight line at equal intervals (Nitto Seiko Co., Ltd., "Hiresta-UX MCP-HT800") in accordance with JIS K7194, and the average of the common logarithms was taken as the surface resistance value of the second adhesive layer (log(Ω / sq)). The results are shown in Tables 8 and 10. The surface resistance values ​​of the second adhesive layer at nine points were measured after peeling off the release PET film protecting the second adhesive layer on both sides of the test specimen.

[0196] Other measurements were performed in the same manner as in Examples 1-8, 11-15, 24-27, 33-56, 58-66, and Comparative Examples 1 and 3, except that in "(Calculation of the rate of decrease in peel strength of the first adhesive layer after UV irradiation)" described above, the second adhesive layer of the semiconductor manufacturing process adhesive tape obtained was backed with a 23 μm thick biaxially oriented PET film (Futamura Chemical Co., Ltd., "FE2002") and then cut to prepare test pieces. Furthermore, "(Measurement of peel strength of semiconductor manufacturing process adhesive tape before long-term storage)", "(Measurement of peel strength of semiconductor manufacturing process adhesive tape after long-term storage)", and "(Calculation of the peel strength ratio before and after storage of semiconductor manufacturing process adhesive tape)" described above were performed only in Example 29. The results are shown in Tables 8 and 10.

[0197] (Examples 16-17) The adhesive solutions of the adhesives shown in Tables 8-9 were applied to the release treatment surface of a 75 μm thick release PET film using an applicator, and dried at 110°C for 3 minutes to form a first adhesive layer with the thickness shown in Tables 8-9, thereby producing a laminated film (a). Next, the adhesive solutions of the adhesives to be used for the intermediate adhesive layer shown in Tables 8-9 were applied to the surface of the base layer shown in Tables 8-9 using an applicator, and dried at 110°C for 3 minutes to form an intermediate layer on the base layer having an intermediate adhesive layer with the thickness shown in Tables 8-9. Then, the intermediate layer and the first adhesive layer were stacked and laminated together so that they faced each other, and then cured at 40°C for 48 hours to obtain an adhesive tape for semiconductor manufacturing processes having the first adhesive layer, the intermediate adhesive layer, and the base layer in that order. Measurements were carried out in the same manner as in Examples 1-8, 11-15, 24-27, 33-56, 58-66, and Comparative Examples 1 and 3. The results are shown in Tables 8-9. Note that the probe tack value (V1) and probe tack value (V2) of the first adhesive layer were measured only in Examples 1-8, 11-15, 24, and Comparative Examples 1 and 3.

[0198] (Examples 18-20, 28, 57, Comparative Example 2) The adhesive solutions of the adhesives shown in Tables 9-10, 13, and 15 were applied to the release treatment surface of a 75 μm thick release PET film using an applicator, and dried at 110°C for 3 minutes to form a first adhesive layer with the thickness shown in Tables 9-10, 13, and 15, thereby producing a laminated film (a). Next, the adhesive solutions of the adhesives used for the intermediate adhesive layer shown in Tables 9-10, 13, and 15 were applied to the surface of the base layer shown in Tables 9-10, 13, and 15 using an applicator, and dried at 110°C for 3 minutes to form an intermediate layer on the base layer having an intermediate adhesive layer with the thickness shown in Tables 9-10, 13, and 15, thereby forming a laminated film (c). Furthermore, by laminating a first adhesive layer to one side of a biaxially oriented PET film (Futamura Chemical Co., Ltd., "FE2002") of the thickness shown in Tables 9-10, 13, and 15, which was prepared as an intermediate substrate layer, and laminating an intermediate adhesive layer to the other side, laminated and integrated laminated film (a) and laminated film (c), and then curing at 40°C for 48 hours, an adhesive tape for semiconductor manufacturing processes was obtained having the first adhesive layer, intermediate substrate layer, intermediate adhesive layer, and substrate layer in this order. Measurements were performed in the same manner as in Examples 1-8, 11-15, 24-27, 33-56, 58-66, and Comparative Examples 1 and 3. In addition, the above-mentioned "(Measurement of peel force of adhesive tape for semiconductor manufacturing processes before long-term storage)", "(Measurement of peel force of adhesive tape for semiconductor manufacturing processes after long-term storage)", and "(Calculation of peel force ratio before and after storage of adhesive tape for semiconductor manufacturing processes)" were performed only in Examples 28 and 57. Furthermore, the probe tack values ​​(V1) and (V2) of the first adhesive layer were measured only in Examples 18-20 and Comparative Example 2. The results are shown in Tables 9-10, 13, and 15.

[0199] (Examples 21-23, 30-32) The adhesive solutions of the adhesives shown in Tables 9-10 were applied to the release surface of a 75 μm thick release PET film using an applicator and dried at 110°C for 3 minutes to form a first adhesive layer with the thickness shown in Tables 9-10, thereby producing laminated film (a). Next, the adhesive solutions of the adhesives used for the intermediate adhesive layer shown in Tables 9-10 were applied to the surface of the base layer shown in Tables 9-10 using an applicator and dried at 110°C for 3 minutes to form an intermediate layer on the base layer having an intermediate adhesive layer with the thickness shown in Tables 9-10, thereby forming laminated film (c). Furthermore, the adhesive solutions of the adhesives shown in Tables 9-10 were applied to the release surface of a 75 μm thick release PET film using an applicator and dried at 110°C for 3 minutes to obtain laminated film (b) having a second adhesive layer. Then, a laminate was created by laminating a laminated film (a) and a laminated film (c) together by laminating a first adhesive layer onto one side of a biaxially oriented PET film (Futamura Chemical Co., Ltd., "FE2002") of the thickness shown in Tables 9 to 10, which was prepared as an intermediate substrate layer, and laminating an intermediate adhesive layer onto the other side. After that, a laminated film (b) was also laminated and integrated by laminating a second adhesive layer onto the side of the substrate layer of the laminate that did not have the first adhesive layer. Subsequently, by curing at 40°C for 48 hours, an adhesive tape for semiconductor manufacturing processes was obtained having the first adhesive layer, the intermediate substrate layer, the intermediate adhesive layer, the substrate layer, and the second adhesive layer in this order. Measurements were performed in the same manner as in Examples 9 to 10 and 29. Furthermore, the above-mentioned "(Measurement of peel force of adhesive tape for semiconductor manufacturing process before long-term storage)", "(Measurement of peel force of adhesive tape for semiconductor manufacturing process after long-term storage)", and "(Calculation of peel force ratio before and after storage of adhesive tape for semiconductor manufacturing process)" were performed only in Examples 30 to 32. In addition, the probe tack value (V1) and probe tack value (V2) of the first adhesive layer were measured only in Examples 21 to 23. The results are shown in Tables 9 to 10.

[0200] <Evaluation> The adhesive tapes obtained in the examples and comparative examples were evaluated using the following method. The results are shown in Tables 7 to 15.

[0201] (Preparation of single-sided adhesive tape for testing) 52 parts by mass of ethyl acetate was placed in a reactor equipped with a thermometer, stirrer, and condenser, and after purging with nitrogen, the reactor was heated and reflux was started. 30 minutes after the ethyl acetate boiled, 0.08 parts by mass of azobisisobutyronitrile was added as a polymerization initiator. 47.5 parts by mass of butyl acrylate, 47.5 parts by mass of lauryl acrylate, 4.7 parts by mass of 4-hydroxybutyl acrylate, and 0.3 parts by mass of acrylic acid were added dropwise and evenly over 1 hour and 30 minutes to allow the reaction to proceed. 30 minutes after the end of the dropwise addition, 0.1 parts by mass of azobisisobutyronitrile was added, and the polymerization reaction was continued for a further 5 hours. A solution of (meth)acrylic polymer was obtained by cooling while diluting the reactor with ethyl acetate. To the obtained (meth)acrylic polymer solution, Coronate L-45 (manufactured by Tosoh Corporation) was added as an isocyanate crosslinking agent to 100 parts by mass of (meth)acrylic polymer, so that the solid content was 1.7 parts by mass, and the mixture was thoroughly stirred to obtain an adhesive solution. The obtained adhesive solution was applied using an applicator onto a 100 μm thick polyethylene terephthalate (PET) film that had been corona-treated as a base layer, so that the dried film thickness would be 75 μm, and the adhesive layer was formed by drying at 110°C for 3 minutes to obtain a test single-sided adhesive tape.

[0202] (Release properties (transfer accuracy)) (1) No long-term storage A wafer on which one Si chip (500 μm x 500 μm square, 50 μm thick) was arranged was placed with the first adhesive layer of semiconductor manufacturing process adhesive tape facing the Si chip side of the wafer, and the first adhesive layer was bonded to the wafer by pressing for 10 seconds under conditions of 23°C, 50% RH, and 0.1 MPa. After that, the wafer was fixed by vacuum adsorption, and the semiconductor manufacturing process adhesive tape and Si chip were peeled off from the wafer, so that the Si chip was placed on the semiconductor manufacturing process adhesive tape and a measurement sample was obtained. Furthermore, a test single-sided adhesive tape was placed at a distance of 500 μm from the Si chip so that the adhesive layer of the test single-sided adhesive tape faced the measurement sample. For the obtained measurement samples, a 355 nm laser beam with an output of 4 W and 4 kHz was irradiated onto the Si chip from the substrate layer side of the adhesive tape used in semiconductor manufacturing processes using a semiconductor solid-state laser. The Si chip was peeled off the adhesive tape and transferred to the adhesive layer of a single-sided adhesive tape used for testing. The position of a specific side of the Si chip before and after transfer was observed using a digital microscope (Keyence Corporation, "VHX-6000"), and the angle between that side before and after transfer was measured. The following criteria were used for evaluation: Release properties were evaluated as follows: "A" if the angle was 5° or less, "B" if the angle was greater than 5° and 10° or less, and "C" if the angle was greater than 10°. In Examples 9-10 and 21-23, where the obtained semiconductor manufacturing process adhesive tape had a second adhesive layer, the second adhesive layer of the obtained semiconductor manufacturing process adhesive tape was bonded to a glass plate, and then a Si chip was bonded to the first adhesive layer to prepare a measurement sample. The Si chip was then irradiated with laser light from the glass plate side of the measurement sample to perform the evaluation.

[0203] (2) After long-term storage, for Examples 25 to 66 and Comparative Examples 1 to 3, the release properties (transfer accuracy) of the adhesive tapes for semiconductor manufacturing processes were evaluated. The adhesive tapes for semiconductor manufacturing processes obtained by the above-mentioned "(manufacturing of adhesive tapes)" were subjected to a long-term storage test in which they were placed in a constant-temperature oven set to 40°C and left to stand for one week. The adhesive tapes for semiconductor manufacturing processes that underwent the long-term storage test were then evaluated using the same measurements and judgment criteria as described above for "(1) No long-term storage".

[0204] (Release Properties (Residue)) (1) No Long-Term Storage In the above-mentioned "(Release Properties (Transfer Accuracy))", the peeled surface of the Si chip peeled from the adhesive tape used for semiconductor manufacturing processes was observed with a digital microscope (Keyence Corporation, "VHX-6000") to check for the presence or absence of residue. The residue was evaluated as follows: "A" if the area of ​​the residue was 5% or less of the peeled surface of the Si chip, "B" if the area of ​​the residue was greater than 5% but 20% or less of the peeled surface of the Si chip, and "C" if the area of ​​the residue was greater than 20% of the peeled surface of the Si chip.

[0205] (2) For Examples 25 to 66 and Comparative Examples 1 to 3 after long-term storage, the release properties (residue) of the adhesive tapes for semiconductor manufacturing processes after long-term storage were evaluated. Using the same method as in "(1) No long-term storage" in "(Release properties (residue))" described above, the presence or absence of residue on the peeled surface of Si chips peeled off from the adhesive tapes for semiconductor manufacturing processes that underwent the long-term storage test was confirmed, and the residue was evaluated using the same method.

[0206] (Possibility of transferring a large quantity of semiconductor chips) (1) No long-term storage A wafer on which 400 Si chips (500 μm x 500 μm square, 50 μm thick) were arranged at 500 μm intervals was placed, and the first adhesive layer of a semiconductor manufacturing process adhesive tape was placed facing the Si chip side of the wafer. The tape was then pressed together for 10 seconds under conditions of 23°C, 50% RH, and 0.1 MPa, thereby bonding the Si chips to the first adhesive layer of the semiconductor manufacturing process adhesive tape. The wafer was then fixed by vacuum adsorption, and the semiconductor manufacturing process adhesive tape and Si chips were peeled off the wafer, thereby placing the Si chips on the semiconductor manufacturing process adhesive tape to obtain a measurement sample. Furthermore, a test single-sided adhesive tape was placed at a 500 μm interval from the Si chips so that the adhesive layer of the test single-sided adhesive tape faced the measurement sample. For the obtained measurement samples, a 355 nm laser beam with an output of 4 W and 4 kHz was irradiated onto the Si chips from the substrate layer side of the adhesive tape used for semiconductor manufacturing processes using a semiconductor solid-state laser. The Si chips were peeled off the adhesive tape and transferred to the adhesive layer of the single-sided adhesive tape used for testing. The possibility of transferring a large number of semiconductor chips was evaluated as follows: "A" if there were 3 or fewer Si chips remaining on the surface of the single-sided adhesive tape used for testing, "B" if there were more than 3 but 9 or fewer Si chips remaining on the surface of the single-sided adhesive tape used for testing, and "C" if there were more than 9 Si chips remaining on the surface of the single-sided adhesive tape used for testing. In Examples 9-10 and 21-23, where the obtained adhesive tape used for semiconductor manufacturing processes had a second adhesive layer, the second adhesive layer of the obtained adhesive tape used for semiconductor manufacturing processes was bonded to a glass plate, and then the Si chips were bonded to the first adhesive layer to prepare measurement samples. The laser beam was then irradiated onto the Si chips from the glass plate side of the measurement sample for evaluation.

[0207] (2) After long-term storage, for Examples 25 to 66 and Comparative Examples 1 to 3, the transferability of a large number of semiconductor chips to the adhesive tapes for semiconductor manufacturing processes after long-term storage was evaluated. The adhesive tapes for semiconductor manufacturing processes obtained by the above-mentioned "(manufacturing of adhesive tapes)" were subjected to a long-term storage test in which they were left standing for one week in a constant-temperature oven set to 40°C. The adhesive tapes for semiconductor manufacturing processes that underwent the long-term storage test were then subjected to the same measurements and evaluation criteria as described above for "(1) No long-term storage".

[0208] (Pickupability after long-term storage) For Examples 25 to 66 and Comparative Examples 1 to 3, the pickupability of semiconductor manufacturing process adhesive tapes after long-term storage was evaluated. A single-sided test adhesive tape was placed on a wafer with 10 Si chips (500 μm x 500 μm square, 50 μm thick) arranged at 500 μm intervals, facing the Si chip side of the wafer. The test single-sided adhesive tape was bonded by pressing it for 10 seconds under conditions of 23°C, 50% RH, and 0.1 MPa. After that, the wafer was fixed by vacuum adsorption, and the semiconductor manufacturing process adhesive tape and Si chips were peeled off the wafer, thereby placing the Si chips on the single-sided test adhesive tape. A single-sided adhesive tape for testing, on which Si chips were placed, and an adhesive tape for semiconductor manufacturing processes, obtained by the above-described "(manufacturing of adhesive tape)" and then subjected to a long-term storage test by being placed in a constant-temperature oven set to 40°C for one week, were placed opposite each other. Using a semiconductor solid-state laser, a laser beam with an output of 4W, 4kHz, and a wavelength of 355nm was irradiated onto each Si chip from the substrate layer side of the single-sided adhesive tape for testing, causing the Si chips to peel off and transfer onto the first adhesive layer of the adhesive tape for semiconductor manufacturing processes. When the adhesive tape for semiconductor manufacturing processes received the Si chips, the pick-up ability was evaluated as follows: "A" if 9 or more Si chips were attached to the adhesive tape for semiconductor manufacturing processes, "B" if 8 chips were attached, and "C" if 7 or fewer Si chips were attached.

[0209] Furthermore, regarding the evaluation of "(Release properties (transfer accuracy))", "(Release properties (residue))", and "(Possibility of transferring a large number of semiconductor chips)" as described above, and the evaluation of "(Pickup properties after long-term storage)", even if the evaluation is "C", the adhesive tape for semiconductor manufacturing processes of this embodiment can be used without practical problems.

[0210]

[0211]

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[0214]

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[0218]

[0219] According to the present invention, it is possible to provide an adhesive tape for semiconductor manufacturing processes that can transfer a large number of semiconductor chips well, even when the size of the semiconductor chips is small. Furthermore, according to the present invention, it is possible to provide a semiconductor chip using the adhesive tape for semiconductor manufacturing processes.

Claims

An adhesive tape for semiconductor manufacturing processes having a first adhesive layer and a base layer, At least one layer constituting the adhesive tape for the semiconductor manufacturing process contains an antistatic agent, An adhesive tape for semiconductor manufacturing processes, characterized in that it is used in a method for manufacturing semiconductor chips, which includes a transfer step of continuously arranging semiconductor chips on a first adhesive layer, peeling the semiconductor chips from the first adhesive layer, and then bringing the peeled semiconductor chips into contact with a carrier material, wherein in the transfer step, the peeling of the semiconductor chips from the first adhesive layer and the contact of the peeled semiconductor chips with the carrier material are performed continuously. The adhesive tape for semiconductor manufacturing processes according to claim 1, wherein the antistatic agent comprises at least one compound selected from the group consisting of compounds having a polythiophene skeleton and lithium compounds. The antistatic agent comprises an ionic compound, The ionic compound is composed of at least one anion species selected from the group consisting of bis(fluorosulfonyl)imide anions, hexafluorophosphate anions, and carboxyl anions. Adhesive tape for semiconductor manufacturing processes according to claim 1 or 2. The first adhesive layer contains a base polymer and the antistatic agent, The amount of the antistatic agent is 0.1 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the base polymer. Adhesive tape for semiconductor manufacturing processes according to claim 1, 2, or 3. The adhesive tape for semiconductor manufacturing processes according to claim 4, wherein the base polymer comprises a (meth)acrylic copolymer. The (meth)acrylic copolymer has a constituent unit derived from alkyl (meth)acrylate with an alkyl group having 1 to 4 carbon atoms at the ester terminus. The content of the constituent units derived from the alkyl (meth)acrylate in the (meth)acrylic copolymer is 50% by mass or more and 99% by mass or less. The adhesive tape for semiconductor manufacturing processes according to claim 5. The (meth)acrylic copolymer has a weight-average molecular weight of 200,000 or more and 2,000,000 or less, as described in claim 5 or 6, for use in semiconductor manufacturing processes. The first adhesive layer contains a tackifying resin, as described in claim 1, 2, 3, 4, 5, 6, or 7, for use in semiconductor manufacturing processes. The tackifying resin includes a phenolic resin, The content of the tackifying resin relative to 100 parts by mass of the base polymer is 5 parts by mass or more and 20 parts by mass or less. The adhesive tape for semiconductor manufacturing processes according to claim 8. The first adhesive layer contains an ultraviolet absorber, as described in claim 1, 2, 3, 4, 5, 6, 7, 8, or 9, for use in semiconductor manufacturing processes. The first adhesive layer has a gel fraction of 50% by mass or more, as described in claim 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, for use in semiconductor manufacturing processes. The first adhesive layer has a shear storage modulus of 5 × 10 at 23°C and a measurement frequency of 10 Hz. ４ The above 1 x 10 ６ An adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11, wherein the pressure is Pa or less. The first adhesive layer has a probe tack value of 10 N / 5 mmφ or more and 30 N / 5 mmφ or less, measured under the conditions of 23°C, pressurized pressure of 0.05 MPa, pressurizing speed of 10 mm / sec, pressurizing time of 10 seconds, and release speed of 0.1 mm / sec, as described in claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12, wherein the first adhesive layer has a probe tack value of 10 N / 5 mmφ or more and 30 N / 5 mmφ or less. The first adhesive layer has a probe tack value of 1 N / 5 mmφ or more and 20 N / 5 mmφ or less, measured under the conditions of 23°C, pressurized pressure of 0.05 MPa, pressurizing speed of 10 mm / sec, pressurizing time of 10 seconds, and release speed of 15 mm / sec, as described in claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13, wherein the first adhesive layer has a probe tack value of 1 N / 5 mmφ or more and 20 N / 5 mmφ or less. Furthermore, the adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14, further comprising an intermediate layer between the first adhesive layer and the substrate layer. The adhesive tape for semiconductor manufacturing processes according to claim 15, wherein the intermediate layer has an intermediate adhesive layer. The adhesive tape for semiconductor manufacturing processes according to claim 16, wherein the intermediate layer further comprises an intermediate substrate layer. The adhesive tape for semiconductor manufacturing processes according to claim 17, comprising the base material layer, the intermediate adhesive layer, the intermediate base material layer, and the first adhesive layer in this order. The adhesive tape for semiconductor manufacturing processes according to claim 16, 17, or 18, wherein the intermediate adhesive layer contains an A-B-A type block copolymer having a structure in which block A is derived from an aromatic vinyl monomer and block B is derived from at least one selected from the group consisting of (meth)acrylate, conjugated diene monomer, and hydrogenated conjugated diene monomer. The adhesive tape for semiconductor manufacturing processes according to claim 15, 16, 17, 18, or 19, wherein at least one layer of the first adhesive layer and the intermediate adhesive layer contains an ultraviolet absorber. The adhesive tape for semiconductor manufacturing processes according to claim 20, wherein the intermediate adhesive layer contains an ultraviolet absorber. The adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or 21, wherein the substrate layer has a second adhesive layer on the side opposite to the first adhesive layer. The adhesive tape for semiconductor manufacturing processes according to claim 22, wherein at least one layer of the base material layer and the second adhesive layer contains the antistatic agent. The adhesive tape for semiconductor manufacturing processes according to claim 22 or 23, wherein the second adhesive layer has a 180° peel force to a glass plate at 23°C of 2.0 N / 25 mm or more and 10.0 N / 25 mm or less. An adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24, wherein the ultraviolet absorption rate at a wavelength of 355 nm is 80% or more. The adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25, wherein the common logarithm of the surface resistance of the adhesive tape for semiconductor manufacturing processes, measured from the first adhesive layer side, is 15.0 [log(Ω / sq)] or less. The semiconductor manufacturing process adhesive tape was measured with the first adhesive layer attached to a glass plate, at a wavelength of 355 nm and an irradiation intensity of 7.8 mW / cm². ２ The cumulative amount of ultraviolet light is 190 mJ / cm². ２ Adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, or 26, wherein, after irradiation to such a state, the rate of decrease in 180° peel strength to glass at 23°C is 60% or less. The semiconductor manufacturing process adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, or 27, wherein, when the semiconductor manufacturing process adhesive tape is subjected to a long-term storage test in which it is left undisturbed in an environment of 40°C for one week, the 180° peel force of the semiconductor manufacturing process adhesive tape to glass at 23°C after the long-term storage test is 0.050 N / 20 mm or more and 1.000 N / 20 mm or less. The semiconductor manufacturing process adhesive tape according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, or 28, wherein when the semiconductor manufacturing process adhesive tape is subjected to a long-term storage test in which it is left standing in a 40°C environment for one week, the ratio of the 180° peel force of the semiconductor manufacturing process adhesive tape after the long-term storage test to the 180° peel force of the semiconductor manufacturing process adhesive tape at 23°C at 23°C before the long-term storage test is 0.50 or more and 1.50 or less. Adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, or 29, used in a method for manufacturing a semiconductor chip having a rectangular shape with at least one side length of 1000 μm or less. A method for manufacturing a semiconductor chip using the adhesive tape for semiconductor manufacturing processes described in claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30.

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