Adhesive tape for semiconductor manufacturing processes

Abstract

The present invention provides an adhesive tape for semiconductor manufacturing processes that offers excellent pickup and release properties for semiconductor chips, even when the semiconductor chip size is small. [Solution] A double-sided adhesive tape having a first adhesive layer, a base layer, and a second adhesive layer in this order, wherein the first adhesive layer contains a base polymer and an ultraviolet absorber, and the probe tack value 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 release speed of 0.1 mm / sec is 10 N / 5 mmφ or more and 30 N / 5 mmφ or less, and the probe tack value 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 release speed of 15 mm / sec is 1 N / 5 mmφ or more and 20 N / 5 mmφ or less, an adhesive tape for semiconductor manufacturing processes.

Description

[Technical Field]

[0001] This invention relates to adhesive tape for semiconductor manufacturing processes. [Background technology]

[0002] In the manufacturing process of semiconductor devices, a large number of chip components placed on an adhesive layer are sometimes transferred onto a drive circuit board. For example, a microLED display is a display device in which 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 the 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. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2019 / 065441 [Overview of the project] [Problems that the invention aims to solve]

[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 an adhesive layer, and this laminate is then placed opposite a drive circuit board. The chip components are then peeled off the transfer laminate and an electrical connection is made with the drive circuit board (transfer process).

[0005] The transfer process may be performed multiple times. That is, before finally transferring the chip components onto the drive circuit board, the chip components are first transferred onto a carrier material for transport and processing, and then the chip components are re-transferred from the carrier material to another carrier material or the drive circuit board. As an example of a carrier material, Patent Document 1 describes a transfer substrate comprising at least a base material and a shock-absorbing layer.

[0006] As the carrier material also needs to have the ability to temporarily hold semiconductor chips, the use of adhesive tape with an adhesive layer is also being considered. However, when conventional adhesive tapes are used as carrier materials, especially when transferring small semiconductor chips such as micro-LED chips, conventional tapes do not have sufficient pickup properties for the semiconductor chips. When receiving the semiconductor chip, it may not adhere to the adhesive tape, resulting in poor transfer. Furthermore, conventional tapes do not have sufficient release properties for the semiconductor chips. When re-transferring the semiconductor chip to another carrier material or drive circuit board after receiving it, poor detachment of the semiconductor chip occurs, leading to a deterioration in the positional accuracy of the transfer. Even if the semiconductor chip can be detached, there is a problem of adhesive residue adhering to the semiconductor chip.

[0007] The present invention aims to provide an adhesive tape for semiconductor manufacturing processes that exhibits excellent pick-up and release properties for semiconductor chips, even when the size of the semiconductor chip is small. [Means for solving the problem]

[0008] Disclosure 1 is a double-sided adhesive tape having a first adhesive layer, a base layer, and a second adhesive layer in that order, wherein the first adhesive layer contains a base polymer and an ultraviolet absorber, and the probe tack value 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 release speed of 0.1 mm / sec is 10 N / 5 mmφ or more and 30 N / 5 mmφ or less, and the probe tack value 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 release speed of 15 mm / sec is 1 N / 5 mmφ or more and 20 N / 5 mmφ or less, and is an adhesive tape for semiconductor manufacturing processes. Disclosure 2 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 1, wherein the base polymer comprises a (meth)acrylic copolymer. Disclosure 3 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 2, wherein the (meth)acrylic copolymer contains 20% by mass to 99% by mass of constituent units derived from alkyl (meth)acrylate having an alkyl group with 4 or fewer carbon atoms at its ester terminus. Disclosure 4 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 2 or 3, wherein the (meth)acrylic copolymer contains 20% by mass to 80% by mass of constituent units derived from alkyl (meth)acrylates whose homopolymer has a glass transition temperature of 0°C or higher. Disclosure 5 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 2, 3, or 4, wherein the (meth)acrylic copolymer has constituent units derived from t-butyl acrylate. Disclosure 6 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 2, 3, 4, or 5, wherein the (meth)acrylic copolymer has constituent units derived from methyl acrylate. Disclosure 7 is an adhesive tape for semiconductor manufacturing processes according to Disclosures 2, 3, 4, 5, or 6, wherein the (meth)acrylic copolymer has constituent units derived from hydroxyl group-containing (meth)acrylate. Disclosure 8 is an adhesive tape for semiconductor manufacturing processes according to Disclosures 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 1, 2, 3, 4, 5, 6, 7, or 8, wherein the first adhesive layer comprises an antistatic agent. Disclosure 10 is an adhesive tape for semiconductor manufacturing processes according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, or 9, wherein the first adhesive layer has a gel fraction of 50% by mass or more. Disclosure 11 states that the first adhesive layer has a shear storage modulus of 5 × 10 at 23°C and 10 Hz. 4 Pa or more 1×10 6 Adhesive tapes for semiconductor manufacturing processes according to disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein the Pa is less than or equal to Pa. Disclosure 12 is an adhesive tape for semiconductor manufacturing processes according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11, wherein the first adhesive layer has a 180° peel force to a glass plate at 23°C of 0.2 N / 25 mm or more and 2.0 N / 25 mm or less. Disclosure 13 states that the first adhesive layer is irradiated 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 This is an adhesive tape for semiconductor manufacturing processes according to disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12, wherein the rate of decrease in 180° peel strength against SUS at 23°C after irradiation is 60% or less. 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 second adhesive layer has a 180° peel force to a glass plate at 23°C of 2N / 25mm or more. Disclosure 15 is an adhesive tape for semiconductor manufacturing processes, having an ultraviolet absorption rate of 80% or more at a wavelength of 355 nm, as described in Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14. Disclosure 16 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, or 15, wherein the surface resistance value measured from the first adhesive layer side is 15 (logΩ / sq) or less. The present disclosure 17 includes a transfer process in which semiconductor chips are continuously arranged on the first adhesive layer of the adhesive tape for the semiconductor manufacturing process, the semiconductor chips are peeled off from the adhesive tape for the semiconductor manufacturing process, and then the peeled semiconductor chips are brought into contact with a carrier material. In the transfer process, the peeling of the semiconductor chips from the adhesive tape for the semiconductor manufacturing process and the contact of the peeled semiconductor chips with the carrier material are continuously performed. It is the adhesive tape for the semiconductor manufacturing process of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16 used in the manufacturing method of semiconductor chips. The present disclosure 18 is the adhesive tape for the semiconductor manufacturing process of the present disclosure 17 used in the manufacturing method of semiconductor chips having a square shape with a side length of 500 μm or less. Hereinafter, the present invention will be described in detail.

[0009] The inventors of the present invention considered an adhesive tape having adhesive layers on both sides of a base material, containing an ultraviolet absorber in the adhesive layer for attaching semiconductor chips, and the probe tack value measured under specific conditions in the adhesive layer satisfying a specific range. As a result, it was found that an adhesive tape for semiconductor manufacturing processes excellent in pickup properties and release properties with respect to semiconductor chips can be obtained even when the size of the semiconductor chips is small, and the present invention was completed.

[0010] The adhesive tape for semiconductor manufacturing processes of the present invention has a first adhesive layer, a base material layer, and a second adhesive layer in this order. In the adhesive tape for semiconductor manufacturing processes of the present invention, the first adhesive layer is an adhesive layer for attaching semiconductor chips, and the second adhesive layer is an adhesive layer for bonding to a support such as a glass substrate.

[0011] The adhesive tape for semiconductor manufacturing processes of the present invention has a first adhesive layer. 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 lower limit of 10 N / 5 mmφ and an 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 adhesive tape for semiconductor manufacturing processes of the present invention can be 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 adhesive tape for semiconductor manufacturing processes of the present invention is released can be reduced. The preferred lower limit of the probe tack value (V1) of the first adhesive layer described above is 12 N / 5 mmφ, the preferred upper limit is 27 N / 5 mmφ, the more preferred lower limit is 14 N / 5 mmφ, and the more preferred upper limit is 24 N / 5 mmφ.

[0012] The probe tack value (hereinafter sometimes simply referred to as "probe tack value (V2) 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 15 mm / sec, has a lower limit of 1 N / 5 mmφ and an 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 semiconductor manufacturing process adhesive tape of the present invention can be improved. The preferred lower limit of the probe tack value (V2) of the first adhesive layer is 3 N / 5 mmφ, the preferred upper limit is 15 N / 5 mmφ, the more preferred lower limit is 5 N / 5 mmφ, and the more preferred upper limit is 10 N / 5 mmφ.

[0013] 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).

[0014] Examples of the probe tack value (V1) of the first adhesive layer described above include adjusting the type and content ratio of monomers constituting the base polymer, as described later, and adjusting it by changing the shear storage modulus at 23°C and 10Hz, as described later. 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. Alternatively, the probe tack value (V1) of the first adhesive layer can be decreased by increasing the shear storage modulus at 23°C and 10Hz.

[0015] Methods for adjusting the probe tack value (V2) of the first adhesive layer described above include, for example, adjusting the type and content ratio of monomers constituting the base polymer described later, and changing the shear storage modulus at 60°C and 10Hz described later. 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. Another example is reducing the probe tack value (V2) of the first adhesive layer by reducing the shear storage modulus at 60°C and 10Hz.

[0016] The first adhesive layer described above contains a base polymer (P1). Examples of the base polymer (P1) include (meth)acrylic copolymers, styrene elastomers, urethane copolymers, and silicone polymers. In particular, it is preferable that the base polymer (P1) includes a (meth)acrylic copolymer, as this can further improve the release properties of the adhesive tape for semiconductor manufacturing processes of the present invention and further reduce adhesive residue on semiconductor chips. In this specification, "(meth)acrylic" means acrylic or methacrylic.

[0017] The above (meth)acrylic copolymer is a copolymer having constituent units derived from alkyl (meth)acrylate. The constituent units derived from the alkyl (meth)acrylate described above preferably include constituent units derived from alkyl (meth)acrylate having an alkyl group with 4 or fewer carbon atoms at its ester terminus (hereinafter sometimes simply referred to as "alkyl (meth)acrylate (a)"). That is, the (meth)acrylic copolymer described above preferably has constituent units derived from alkyl (meth)acrylate (a) described above. By making the above (meth)acrylic copolymer have constituent units derived from the above alkyl (meth)acrylate (a), it becomes easier to adjust the probe tack value (V1) and the probe tack value (V2) of the first adhesive layer to within the above range, and the adhesive tape for semiconductor manufacturing processes of the present invention can be made to have superior pickup and release properties for semiconductor chips. The lower limit of the number of carbon atoms of the alkyl group having 4 or fewer carbon atoms present at the ester end of alkyl (meth)acrylate (a) may be 1, but the preferred lower limit is 2. In this specification, "(meth)acrylate" means acrylate or methacrylate.

[0018] 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.

[0019] The glass transition temperature (Tg) of the above alkyl (meth)acrylate homopolymer preferably has a lower limit of 0°C. That is, the above (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 above (meth)acrylic copolymer have constituent units derived from alkyl (meth)acrylate (b), the peeling performance when retransferring semiconductor chips can be further improved, and the release properties of the adhesive tape for semiconductor manufacturing processes of the present invention can be further improved. 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 re-transferring semiconductor chips can be further improved, and the release properties of the adhesive tape for semiconductor manufacturing processes of the present invention can be further enhanced. A more preferred upper limit for the glass transition temperature (Tg) of the alkyl (meth)acrylate (b) homopolymer is 25°C, and an even more preferred upper limit is 20°C. The glass transition temperature (Tg) of a homopolymer can be measured for homopolymers with a weight-average molecular weight (Mw) of approximately 5,000 to 1,000,000 or a degree of polymerization of approximately 500,000 to 10,000, for example, using differential scanning calorimetry (manufactured by T.A. Instruments).

[0020] 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), and t-butyl acrylate (glass transition temperature (Tg) of the homopolymer: 14°C). In particular, from the viewpoint of further improving the peeling performance when re-transferring semiconductor chips and further improving the release properties of the adhesive tape for semiconductor manufacturing processes of the present invention, it is preferable that the alkyl (meth)acrylate (a-1) described above includes at least one selected from the group consisting of methyl acrylate and t-butyl acrylate. In other words, 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.

[0021] 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 above constituent units to 20% by mass or more, it becomes easier to adjust the probe tack value (V1) and the probe tack value (V2) of the first adhesive layer to within the above range, and the adhesive tape for semiconductor manufacturing processes of the present invention can be made to have superior pickup and release properties for semiconductor chips. 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 ratio of the constituent units derived from the alkyl (meth)acrylate (a) mentioned above, but a preferred upper limit is 99% by mass, and a more preferred upper limit is 97% by mass.

[0022] Furthermore, if the (meth)acrylic copolymer contains structural units derived from the alkyl (meth)acrylate (b), the preferred lower limit of the content of structural units derived from the alkyl (meth)acrylate (b) in the (meth)acrylic copolymer is 20% by mass. By having a content of structural units derived from the alkyl (meth)acrylate (b) of 20% by mass or more, the peeling performance when re-transferring semiconductor chips can be further improved, and the release properties of the adhesive tape for semiconductor manufacturing processes of the present invention can be further enhanced. A more preferred lower limit for the content of structural units derived from the alkyl (meth)acrylate (a-1) is 25% by mass. From the viewpoint of adjusting the Tg to a certain range in order to maintain tackiness at room temperature, the upper limit of the content of the constituent units derived from the alkyl (meth)acrylate (b) is preferably 80% by mass and more preferably 70% by mass.

[0023] 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)").

[0024] 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, and the like. These alkyl(meth)acrylates may be used alone or in combination of two or more.

[0025] The above (meth)acrylic copolymer preferably further contains constituent units derived from a monomer containing a crosslinkable functional group. By making the (meth)acrylic copolymer contain structural units derived from the above-mentioned crosslinkable functional group-containing monomer, the cohesive force of the first adhesive layer can be increased, thereby improving the release properties of the adhesive tape for semiconductor manufacturing processes of the present invention from semiconductor chips, and further reducing adhesive residue on semiconductor chips. Furthermore, when the first adhesive layer contains a crosslinking agent described later, the crosslinkable functional groups derived from the above-mentioned crosslinkable functional group-containing monomer react with the crosslinking agent to form a crosslinked structure in the (meth)acrylic copolymer, thereby further improving the release properties of the adhesive tape for semiconductor manufacturing processes of the present invention and further reducing adhesive residue on semiconductor chips.

[0026] 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, nitrile group-containing monomers, and the like. These crosslinkable functional group-containing monomers may be used alone or in combination of two or more. 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.

[0027] Examples of the above-mentioned carboxyl group-containing monomers include (meth)acrylic acid-based monomers such as (meth)acrylic acid. Examples of the hydroxyl group-containing monomers mentioned above include hydroxyalkyl (meth)acrylates such as 4-hydroxybutyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate. Examples of epoxy group-containing monomers include glycidyl (meth)acrylate. Examples of the above-mentioned carbon-carbon double bond-containing monomers include allyl (meth)acrylate and hexanediol di(meth)acrylate. Examples of the above-mentioned carbon-carbon triple bond-containing monomers include propargyl (meth)acrylate. Examples of the above-mentioned amide group-containing monomers include (meth)acrylamide.

[0028] 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 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 the constituent units derived from the hydroxyl group-containing monomer is 10% by mass. By setting the content of the 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 chip placed on the first adhesive layer can be held more firmly in the same position, thereby further improving the pickability of the semiconductor chip of the adhesive tape for semiconductor manufacturing processes of the present invention. A more preferred upper limit for the adhesive tape for semiconductor manufacturing processes of the present invention is 8% by mass, and an even more preferred upper limit is 7% by mass.

[0029] 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% by mass, and an even more preferred upper limit is 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.

[0030] 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.

[0031] Examples of other monomers mentioned above include 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole, which has ultraviolet absorption properties.

[0032] 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 adhesive tape for semiconductor manufacturing processes of the present invention from semiconductor chips can be further improved, 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. In this specification, weight-average molecular weight (Mw) refers to the weight-average molecular weight on a standard polystyrene basis, measured by GPC (Gel Permeation Chromatography).

[0033] The preferred lower limit for 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 adhesive tape for semiconductor manufacturing processes of the present invention from semiconductor chips can be further improved, and adhesive residue on semiconductor chips can be further reduced. The more preferred lower limit for the polydispersity of the above (meth)acrylic copolymer is 3, and the more preferred upper limit is 5. In this specification, the number-average molecular weight (Mn) refers to the number-average molecular weight converted to standard polystyrene as measured by GPC.

[0034] The weight-average molecular weight (Mw) and polydispersity (Mw / Mn) of the above (meth)acrylic copolymer are measured by the following method. Specifically, a (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 the 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, and the polydispersity is calculated. A GPC KF-806L (Showa Denko Corporation) is used as the column, and a differential refractometer is used as the detector.

[0035] The above (meth)acrylic copolymer can be obtained, for example, by polymerizing a mixture of starting monomers through a radical reaction in the presence of a polymerization initiator. Examples of the radical reaction methods mentioned above include living radical polymerization and free radical polymerization. Living radical polymerization yields copolymers with 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 further enhanced, improving the release properties of the adhesive tape for semiconductor manufacturing processes of the present invention, and reducing adhesive residue on semiconductor chips. Conventional methods can be used to polymerize the above monomer mixture, including, for example, 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 further enhance the adhesive strength of the resulting adhesive tape. When solution polymerization is used as the polymerization method for the above 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.

[0036] Examples of polymerization initiators include organic peroxides and azo compounds. Examples of the above-mentioned 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 the above-mentioned azo compounds include azobisisobutyronitrile and azobiscyclohexanecarbonitride. 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.

[0037] The first adhesive layer described above contains an ultraviolet absorber. By incorporating an ultraviolet absorber into the first adhesive layer described above, heat or vibration is efficiently generated by laser irradiation, making deformation due to ablation more likely, thereby improving the release properties of the semiconductor manufacturing adhesive tape of the present invention from semiconductor chips. Furthermore, because the first adhesive layer absorbs laser light to a moderate degree, it suppresses light absorption by the adhered chip, thereby improving the manufacturing quality of chips produced using the semiconductor manufacturing adhesive tape of the present invention.

[0038] 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 adhesive tape for semiconductor manufacturing processes of the present invention to semiconductor chips can be further improved. Furthermore, if the above-mentioned ultraviolet absorber is liquid at 23°C, the ultraviolet absorber is less likely to precipitate on the surface of the first adhesive layer, and the pick-up properties of the adhesive tape for semiconductor manufacturing processes of the present invention to semiconductor chips can be further improved.

[0039] 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 alone or in combination of two or more.

[0040] 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, thereby further improving the pickup properties of the semiconductor manufacturing process adhesive tape of the present invention for semiconductor chips. A more preferred upper limit for the amount of the ultraviolet absorber is 12 parts by mass, and an even more preferred upper limit is 10 parts by mass. Furthermore, the preferred lower limit for the content of the above-mentioned ultraviolet absorber is 1 part by mass. By setting the content of the above-mentioned ultraviolet absorber to 1 part by mass or more, the first adhesive layer generates heat or vibration more efficiently when irradiated with laser light, and deformation due to ablation becomes more likely, thereby further improving the release properties of the adhesive tape for semiconductor manufacturing processes of the present invention from semiconductor chips. In addition, because the adhesive layer absorbs laser light to an appropriate extent, the absorption of light by the bonded semiconductor chip can be further suppressed, thereby further improving the manufacturing quality of semiconductor chips manufactured using the adhesive tape for semiconductor manufacturing processes of the present invention. The more preferred lower limit for the content of the above-mentioned ultraviolet absorber is 2 parts by mass, and the even more preferred lower limit is 4 parts by mass.

[0041] Preferably, the first adhesive layer contains a tackifying resin. By including a tackifying resin in the first adhesive layer, the adhesive strength of the first adhesive layer is further improved, and the pickability of the semiconductor manufacturing process adhesive tape of the present invention on semiconductor chips can be further improved. The tackifying resin described above may be a solid tackifying resin at 23°C, or a liquid tackifying resin at 23°C.

[0042] The tackifying resin is not particularly limited, and examples include rosin resins, terpene phenol resins, terpene resins, phenol resins, coumarone resins, xylene resins, etc. Among these, from the viewpoint of compatibility with the (meth)acrylic copolymer, it is preferable that the tackifying resin includes at least one selected from the group consisting of rosin resins, terpene phenol resins, phenol resins, and xylene resins.

[0043] The tackifying resin described above 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 setting at least one of the acid value and hydroxyl value of the tackifying resin to 20 mg KOH / g or more, the adhesive strength is further improved, and the pickability of the adhesive tape for semiconductor manufacturing processes of the present invention 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 is further improved, and appearance defects such as whitening can be suppressed. In particular, the tackifying resin described above is more preferably a tackifying resin in which the hydroxyl value is 20 mg KOH / g or more and 200 mg KOH / g or less. The more preferred lower limit for the hydroxyl value of the above-mentioned tackifying resin is 40 mg KOH / g, the more preferred upper limit is 160 mg KOH / g, the even more preferred lower limit is 50 mg KOH / g, and the even more preferred upper limit is 150 mg KOH / g. The more preferable lower limit for the acid value of the above-mentioned 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. 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 measuring it based on the potentiometric titration method specified in JIS K 0070:1992. Furthermore, 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.

[0044] The tackifying resin described above preferably includes a tackifying resin having a softening point of 95°C or higher and 160°C or lower. By setting the softening point of the tackifying resin within the above range, the adhesive strength of the first adhesive layer is further improved, and the pickup and release properties of the semiconductor manufacturing process adhesive tape of the present invention to the semiconductor chip can be further improved. 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. In this specification, the "softening point" can be measured by the ring-and-ball method specified in JIS K2207.

[0045] 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 adhesive strength of the first adhesive layer is further improved, and the pickability of the semiconductor manufacturing process adhesive tape of the present invention on 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 semiconductor manufacturing process adhesive tape of the present invention on 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.

[0046] The first adhesive layer described above preferably contains an antistatic agent. By including an antistatic agent in the first adhesive layer, the accumulation of static electricity in the semiconductor manufacturing process adhesive tape of the present invention can be suppressed. Therefore, by using the semiconductor manufacturing process adhesive tape of the present invention, chip transfer defects can be suppressed when transferring chips, and the chip yield during chip manufacturing can be further improved. In this specification, when a layer constituting the adhesive tape for semiconductor manufacturing processes of the present invention 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 an antistatic agent is coated onto the layer.

[0047] Examples of the antistatic agent to be included in the first adhesive layer include conductive polymers such as ionic compounds containing organic cations, alkali metal salts, and compounds having a polythiophene skeleton, as well as ion-conducting polymers and ion-conducting fillers. In particular, from the viewpoint of excellent compatibility with the (meth)acrylic copolymer, the first adhesive layer preferably contains an ionic compound containing organic cations and an alkali metal salt.

[0048] The ionic compound containing the above-mentioned organic cation may be an ionic liquid that is liquid at room temperature, or an ionic solid that is solid at room temperature. Preferably, the ionic compound containing the organic cation is composed of a fluoroorganic anion or a fluoroinorganic anion and an onium cation.

[0049] Examples of the above-mentioned onium cations include nitrogen-containing onium cations, sulfur-containing onium cations (e.g., trialkylsulfonium cations), and phosphorus-containing onium cations (e.g., tetraalkylphosphonium cations). Among these, nitrogen-containing onium cations are preferred.

[0050] 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.

[0051] The fluoroorganic anions constituting the ionic compounds containing the above-mentioned organic cations may be fully fluorinated (perfluorinated) or partially fluorinated. Examples of 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 that constitute the ionic compound containing the above-mentioned organic cation include hexafluorophosphate and tetrafluoroboric acid.

[0052] The alkali metal salt is preferably composed of the above-mentioned fluoroorganic anion or fluoroinorganic anion and an alkali metal cation. The alkali metal cations mentioned above are Li + na + , or K + Among them, Li + It is preferable.

[0053] Examples of the lithium compounds mentioned above include lithium bistrifluoromethanesulfonylimide and lithium perchlorate.

[0054] Examples of compounds having the polythiophene skeleton mentioned above include poly(3,4-ethylenedioxythiophene)·polystyrene sulfonic acid mixture (PEDOT / PSS).

[0055] 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 5 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 adhesive tape for semiconductor manufacturing processes of the present invention can be further suppressed. By setting the content of the antistatic agent to 5 parts by mass or less, bleed-out to the surface of the adhesive layer can be suppressed, preventing contamination of the adherend and a decrease in the adhesive strength of the adhesive tape. A more preferred lower limit of the content of the antistatic agent is 0.1 parts by mass, a more preferred upper limit is 3 parts by mass, an even more preferred lower limit is 0.2 parts by mass, and an even more preferred upper limit is 2 parts by mass.

[0056] Preferably, the first adhesive layer described above further contains a crosslinking agent. The above crosslinking agent is not particularly limited and is selected according to the type of crosslinkable functional group contained in the (meth)acrylic copolymer. Examples include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, and metal chelate-based crosslinking agents. Among these, isocyanate-based crosslinking agents are preferred because they make it easier to adjust the gel fraction of the first adhesive layer to the range described later.

[0057] 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 epoxy crosslinking agents mentioned above include N,N'-(cyclohexane-1,3-diylbismethylene)bis(diglycidylamine) and N,N,N',N'-tetraglycidyl-1,3-benzenedi(methaneamine).

[0058] The amount 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 amount of the crosslinking agent. The preferred lower limit for 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 appropriately crosslinked to increase the cohesive force of the first adhesive layer. As a result, the release properties of the adhesive tape for semiconductor manufacturing processes of the present invention from semiconductor chips can be further improved, thereby reducing adhesive residue on semiconductor chips. The more preferred lower limit for the content of the crosslinking agent is 0.1 parts by mass, the more preferred upper limit is 12 parts by mass, the still more preferred lower limit is 0.15 parts by mass, and the still more preferred upper limit is 8 parts by mass.

[0059] The first adhesive layer described above may further contain an inorganic filler such as fumed silica. By incorporating an inorganic filler into the first adhesive layer, the cohesive force of the first adhesive layer can be further enhanced, thereby improving the release properties of the semiconductor manufacturing process adhesive tape of the present invention from semiconductor chips, and thus reducing adhesive residue on semiconductor chips.

[0060] 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.

[0061] The gel fraction of the first adhesive layer described above has a preferred lower limit 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 adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved. The lower limit of the gel fraction of the first adhesive layer described above is more preferably 55% by mass, even more preferably 60% by mass, even more preferably 70% by mass, and particularly preferably 80% by mass. Furthermore, the preferred upper limit of the gel fraction of the first adhesive layer is 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 the pickability of the adhesive tape for semiconductor manufacturing processes to semiconductor chips can be further improved. The upper limit of the gel fraction of the first adhesive layer is more preferably 97%, and even more preferably 95% by mass. The gel fraction of the first adhesive layer described above can be measured by the following methods, etc. Only the first adhesive layer, W0 (g), is extracted from the adhesive tape used in semiconductor manufacturing processes, immersed in 50 mL of ethyl acetate, and shaken for 24 hours at a temperature of 23°C and 200 rpm using a shaker. After shaking, the ethyl acetate and the first adhesive layer that has absorbed and swollen with ethyl acetate are separated using a metal mesh (mesh size #200, W1 (g)). The separated first adhesive layer is dried for 1 hour at 110°C. The mass W2 (g) of the first adhesive layer including the metal mesh after drying is measured, and the gel fraction of the first adhesive layer is calculated using the following formula. Gel fraction (mass %) = 100 × (W2 - W1) / W0 (W0: initial mass of the first adhesive layer, W1: initial mass of the metal mesh, W2: mass of the first adhesive layer including the metal mesh after drying) However, when the first adhesive layer is not completely soluble in ethyl acetate, solvents such as toluene, hexane, or water are used instead of ethyl acetate. Specifically, when the first adhesive layer contains, for example, a styrene-based elastomer, toluene or hexane is used, and when it contains polyvinyl alcohol, hot water at 90 °C is used.

[0062] Examples of the method for adjusting the gel fraction of the first adhesive layer within the above range include, for example, adjusting the composition or weight average molecular weight (Mw) of the base polymer (P1) contained in the first adhesive layer, adjusting the type or content of the crosslinking agent to be contained in the first adhesive layer, and adjusting the content of the tackifier resin, the ultraviolet absorber, the antistatic agent, etc. to be contained in the first adhesive layer.

[0063] The first adhesive layer preferably has a lower limit of the shear storage modulus (G’) at 23 °C and a frequency of 10 Hz of 5×10 4 Pa, and a preferred upper limit of 1×10 6 Pa. By setting the shear storage modulus (G’) of the first adhesive layer at 23 °C and a frequency of 10 Hz to 5×10 4 Pa or more, the probe tack value (V1) of the first adhesive layer described above is reduced, so that the releasability of the adhesive tape for semiconductor manufacturing processes of the present invention with respect to semiconductor chips can be further improved. By setting the shear storage modulus (G’) of the first adhesive layer at 23 °C and a frequency of 10 Hz to 1×10 6 Pa or less, the probe tack value (V1) of the first adhesive layer described above is improved, so that the pick-up property of the adhesive tape for semiconductor manufacturing processes of the present invention with respect to semiconductor chips can be further improved. A more preferred lower limit of the shear storage modulus (G’) of the first adhesive layer at 23 °C and a frequency of 10 Hz is 8×10 4 Pa, a more preferred upper limit is 8×10 5 Pa, a further preferred lower limit is 1×10 5 Pa, and a further preferred upper limit is 6×10 5 Pa. Furthermore, the shear storage modulus (G') of the first adhesive layer described above can be measured by dynamic viscoelasticity measurement at 23°C and a frequency of 10Hz. Specifically, for example, the storage modulus at each temperature can be obtained from the dynamic viscoelastic spectrum measured under the conditions of a measurement temperature of -40 to 150°C, a heating rate of 5°C / min, and a frequency of 10Hz using a dynamic viscoelasticity measuring device (e.g., Rheometrics Dynamic Analyze RDA-700, manufactured by Rheometrics). In addition, if the thickness of the first adhesive layer is less than 500 μm, the first adhesive layer can be stacked to create a sample of only the first adhesive layer with a thickness of approximately 500 μm, and then measured. Furthermore, a sample consisting only of the first adhesive layer can be prepared by removing the substrate layer from an adhesive tape used in semiconductor manufacturing processes, separating 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 adhere the first adhesive layers together, then select an appropriate temperature and peeling speed, and peel them apart to separate the substrate layer from the first adhesive layer and remove the substrate layer, or to physically grind the substrate layer. Alternatively, a sample consisting only of the first adhesive layer may be prepared using a sheet made separately from the first adhesive layer.

[0064] Methods for adjusting the shear storage modulus (G') of the first adhesive layer at 23°C and a frequency of 10Hz 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.

[0065] The first adhesive layer described above has a preferred lower limit of 1.0 × 10⁻¹⁰ shear storage modulus (G') at 60°C and a frequency of 10 Hz.4 Pa is the preferred upper limit of 1.2 × 10⁻⁶. 5 The value is Pa. By setting the shear storage modulus (G') of the first adhesive layer at 60°C and a frequency of 10Hz within the above range, the probe tack value (V2) of the first adhesive layer can be adjusted to a suitable range, thereby further improving the pickup performance of the semiconductor manufacturing process adhesive tape of the present invention for semiconductor chips. A more preferable lower limit for the shear storage modulus (G') of the first adhesive layer at 60°C and a frequency of 10Hz is 2.0 × 10⁻⁶. 4 Pa, a more preferable upper limit is 8.0 × 10 4 Pa, a more preferable lower limit is 3.0 × 10 4 Pa, a more preferable upper limit is 7.0 × 10 4 It is Pa. The shear storage modulus (G') at 60°C and a frequency of 10Hz can be obtained from the dynamic viscoelastic spectrum of the first adhesive layer by performing a dynamic viscoelastic measurement using the same method as for measuring the shear storage modulus (G') of the first adhesive layer at 23°C and a frequency of 10Hz.

[0066] Methods for adjusting the shear storage modulus (G') of the first adhesive layer at 60°C and a frequency of 10Hz 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.

[0067] The preferred lower limit of the 180° peel force of the first adhesive layer against a glass plate at 23°C is 0.2 N / 25 mm, and the preferred upper limit is 2.0 N / 25 mm. By setting the 180° peel force of the first adhesive layer against a glass plate at 23°C to 0.2 N / 25 mm or higher, the first adhesive layer can be made to have appropriate adhesive strength, and the pickability of the semiconductor manufacturing process adhesive tape of the present invention against semiconductor chips can be further improved. By setting the 180° peel force of the first adhesive layer against a glass plate at 23°C to 2.0 N / 25 mm or lower, the releaseability of the semiconductor manufacturing process adhesive tape of the present invention against semiconductor chips can be further improved. A more preferred lower limit of the 180° peel force of the first adhesive layer against a glass plate at 23°C is 0.4 N / 25 mm, a more preferred upper limit is 1.8 N / 25 mm, an even more preferred lower limit is 0.5 N / 25 mm, and an even more preferred upper limit is 1.7 N / 25 mm. Furthermore, the 180° peel strength of the first adhesive layer described above against glass at 23°C can be measured in accordance with JIS Z0237:2009. Specifically, for example, a semiconductor manufacturing process adhesive tape, in which a second adhesive layer is backed with a 23 μm thick biaxially oriented PET film, is cut to a width of 25 mm. The first adhesive layer is then pressed onto a glass plate using a 2 kg rubber roller at a speed of 300 mm / min for one back-and-forth motion. After standing for 30 minutes, the semiconductor manufacturing process adhesive tape is peeled off the glass plate at a speed of 300 mm / min in a 23°C environment using an autograph (Shimadzu Corporation, "AGS-500NX"), and the 180° peel force is measured.

[0068] Methods for adjusting the 180° peel force of the first adhesive layer to the glass plate at 23°C to within the above range include, for example, adjusting the composition or weight-average molecular weight (Mw) of the base polymer contained in the first adhesive layer, or the type or content of the crosslinking agent contained in the first adhesive layer.

[0069] The first adhesive layer described above is subjected to an irradiation intensity of 7.8 mW / cm² at a wavelength of 355 nm. 2The cumulative amount of ultraviolet light is 190 mJ / cm². 2 The preferred upper limit of the reduction in 180° peel strength against SUS at 23°C after irradiation (hereinafter sometimes simply referred to as "reduction in peel strength after UV irradiation") is 60%. By setting the reduction in peel strength of the first adhesive layer after UV irradiation to 60% or less, the adhesive tape for semiconductor manufacturing processes of the present invention can peel off semiconductor chips without irradiating them with UV light separately before laser ablation, thereby further improving the work efficiency of semiconductor chip manufacturing. The upper limit of the reduction in adhesive strength of the first adhesive layer after UV irradiation is more preferably 30%, even more preferably 20%, even more preferably 10%, and particularly preferably 5%. Furthermore, the lower limit of the reduction in adhesive strength of the first adhesive layer after UV irradiation may be 0%, but is preferably 1%. The method for measuring the rate of decrease in peel strength of the first adhesive layer after UV irradiation is as follows. Specifically, a semiconductor manufacturing process adhesive tape, with a second adhesive layer backed by a 23 μm thick biaxially oriented PET film, is cut into a flat rectangular shape measuring 25 mm wide x 75 mm long. The cut adhesive tape is then pressed onto a SUS304 plate (a SUS304 plate that has been cleaned with ethanol and then wiped dry) using a 2 kg rubber roller at a speed of 300 mm / min for one back-and-forth motion. The test specimen is 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 (such as Shimadzu Corporation's "AGS-X") in accordance with JIS Z0237, at 23°C, 50% RH, and a peeling speed of 300 mm / min, to obtain the 180° peel strength (mN / 25 mm) before UV irradiation. Furthermore, the adhesive tape, cut in the same manner as described above, 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 in this 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 rate of decrease in peeling force after UV irradiation is calculated using the following formula. Percentage decrease in peeling strength after UV irradiation (%) = 100 × {(180° peeling strength before UV irradiation) - (180° peeling strength after UV irradiation)} / (180° peeling strength before UV irradiation)

[0070] The preferred lower limit of the thickness of the first adhesive layer is 5 μm, and the preferred upper limit is 40 μm. By setting the thickness of the first adhesive layer to 5 μm or more, the adhesive strength of the first adhesive layer can be further increased, and the pickability of the semiconductor manufacturing process adhesive tape of the present invention on semiconductor chips can be further improved. By setting the thickness of the first adhesive layer to 40 μm or less, the release properties of the semiconductor manufacturing process adhesive tape on semiconductor chips can be further improved, thereby reducing adhesive residue on semiconductor chips. A more preferred lower limit of the thickness of the first adhesive layer is 10 μm, and a more preferred upper limit is 30 μm.

[0071] The adhesive tape for semiconductor manufacturing processes of the present invention has a base layer. The adhesive tape for semiconductor manufacturing processes of the present invention has a base layer, which provides appropriate stiffness and excellent handling properties.

[0072] 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, and the release properties of the adhesive tape for semiconductor manufacturing processes from semiconductor chips can be further improved.

[0073] Examples of substrates containing the above-mentioned polyolefin resin include OPP film, CPP film, COP film, and the like. 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.

[0074] 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 adhesive tape for semiconductor manufacturing processes of the present invention can be suppressed, and by using the adhesive tape for semiconductor manufacturing processes of the present invention, chip transfer defects can be prevented. As a result, semiconductor chips can be transferred well, and the chip yield during chip manufacturing can be further improved.

[0075] 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 further reduced.

[0076] Examples of antistatic agents to be included in the above-mentioned substrate layer include those similar to the antistatic agent to be included in the first adhesive layer described above. In particular, when the above-mentioned antistatic agent is coated onto the surface of the substrate layer, it is preferable that the antistatic agent contains a compound having a polythiophene skeleton from the viewpoint of ultraviolet light transmission.

[0077] 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 semiconductor manufacturing process adhesive tape of the present invention 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 of the thickness of the applied antistatic agent is 0.1 μm, and a more preferred upper limit is 2 μm.

[0078] 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.

[0079] The adhesive tape for semiconductor manufacturing processes of the present invention has a second adhesive layer. By having a second adhesive layer in the adhesive tape for semiconductor manufacturing processes of the present invention, it becomes possible to adhere the support and the adhesive tape for semiconductor manufacturing processes of the present invention, thereby improving handling in the semiconductor manufacturing process. The above-mentioned support is not particularly limited and includes, for example, glass, a quartz substrate, a metal plate, etc.

[0080] 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.

[0081] The preferred lower limit of the 180° peel force of the second adhesive layer against a glass plate at 23°C is 2N / 25mm. By setting the 180° peel force of the second adhesive layer against a glass plate at 23°C to 2N / 25mm or more, the adhesive tape for semiconductor manufacturing processes of the present invention can be firmly attached to the support, and the tape can be prevented from peeling off 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 4N / 25mm. Furthermore, a preferred upper limit for the 180° peel force of the second adhesive layer against the glass plate at 23°C is 10 N / 25 mm. By setting the 180° peel force of the second adhesive layer against the glass plate at 23°C to 10 N / 25 mm or less, it becomes easier to re-peel the adhesive tape for semiconductor manufacturing processes of the present invention from the support, thereby improving the handling of the adhesive tape for semiconductor manufacturing processes in the semiconductor manufacturing process. A more preferred upper limit for the 180° peel force of the second adhesive layer against the glass plate at 23°C is 8 N / 25 mm. Furthermore, the 180° peel force of the second adhesive layer against the glass plate at 23°C can be measured using the same method as the 180° peel force of the first adhesive layer against the glass plate at 23°C described above.

[0082] 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 or 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.

[0083] 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 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 adhesive tape for semiconductor manufacturing processes of the present invention. 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.

[0084] The adhesive tape for semiconductor manufacturing processes of the present invention may have a base layer as described above, a first adhesive layer, and a second adhesive layer, but may also have other layers as long as they do not impair the effects of the present invention.

[0085] The method for manufacturing the adhesive tape for semiconductor manufacturing processes of the present invention is not particularly limited, but for example, first, the above-mentioned base polymer, ultraviolet absorber, and other necessary components such as tackifying resin and additives are added and stirred to obtain an adhesive solution, 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 to form a laminated and integrated film, and then cured to obtain the adhesive tape for semiconductor manufacturing processes of the present invention.

[0086] Furthermore, the adhesive tape for semiconductor manufacturing processes of the present invention can also be obtained by creating a laminated film in which a first adhesive layer and a second adhesive layer are formed on the release treatment surface of a separate release PET film, laminating each laminated film to separate surfaces of a base layer, laminating and integrating them, and then curing them.

[0087] The adhesive tape for semiconductor manufacturing processes of the present invention has a preferred lower limit of 80% ultraviolet absorption at a wavelength of 355 nm. By setting the ultraviolet absorption rate of the adhesive tape for semiconductor manufacturing processes of the present invention to 80% or higher at a wavelength of 355 nm, heat or vibration is generated more efficiently by laser irradiation, and deformation due to ablation becomes more likely, thereby improving the release properties of the adhesive tape for semiconductor manufacturing processes of the present invention from semiconductor chips. Furthermore, because the adhesive tape for semiconductor manufacturing processes of the present invention absorbs laser light to an appropriate degree, the absorption of light by the adhered chip can be further suppressed, thereby improving the manufacturing quality of chips manufactured using the adhesive tape for semiconductor manufacturing processes of the present invention. A more preferred lower limit for the ultraviolet absorption rate of the adhesive tape for semiconductor manufacturing processes of the present invention at a wavelength of 355 nm is 90%, and an even more preferred lower limit is 95%. Furthermore, the ultraviolet absorption rate of the semiconductor manufacturing process adhesive tape of the present invention at a wavelength of 355 nm is preferably as high as possible, and may be 100%. Furthermore, as a method for measuring the ultraviolet absorption rate of the semiconductor manufacturing process adhesive tape of the present invention at a wavelength of 355 nm, for example, one method is to measure the semiconductor manufacturing process adhesive tape of the present invention using a spectrophotometer (such as Shimadzu Corporation's "UV-2600i") in accordance with JIS L1925.

[0088] Methods for adjusting the ultraviolet absorption rate of the semiconductor manufacturing process adhesive tape of the present invention at a wavelength of 355 nm to 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 semiconductor manufacturing process adhesive tape.

[0089] The surface resistance value of the semiconductor manufacturing process adhesive tape of the present invention, 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 (logΩ / sq). By setting the surface resistance value of the semiconductor manufacturing process adhesive tape to 15 (logΩ / sq) or less, the accumulation of static electricity on the semiconductor manufacturing process adhesive tape of the present invention can be suppressed. Therefore, when transferring semiconductor chips using the semiconductor manufacturing process adhesive tape of the present invention, chip transfer defects (chip bounce-back) 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 value of the semiconductor manufacturing process adhesive tape is 14 (logΩ / sq), and an even more preferred upper limit is 13 (logΩ / sq). Furthermore, while there is no specific lower limit for the surface resistance of the adhesive tape used in the semiconductor manufacturing process, the practical lower limit is 6 (logΩ / sq). The surface resistance of the adhesive tape used in the semiconductor manufacturing process can be measured by a method conforming to JIS K7194.

[0090] Methods for adjusting the surface resistance of the adhesive tape for semiconductor manufacturing processes include: adding an antistatic agent to the base layer, the first adhesive layer, and the second adhesive layer; adjusting the composition of the base polymer contained in the first adhesive layer and the second adhesive layer; adjusting the type or content of the tackifying resin, crosslinking agent, ultraviolet absorber, and antistatic agent contained in the first adhesive layer and the second adhesive layer; and adjusting the thickness of each layer constituting the adhesive tape for semiconductor manufacturing processes.

[0091] The adhesive tape for semiconductor manufacturing processes of the present invention can be suitably used in the manufacture of semiconductor chips, and is suitably used in semiconductor chip manufacturing methods that include a transfer process. The adhesive tape for semiconductor manufacturing processes of the present invention has excellent pickability for semiconductor chips, which can improve the yield of manufactured semiconductor chips, and at the same time has excellent release properties for semiconductor chips, which can reduce adhesive residue on semiconductor chips when peeling and transferring semiconductor chips placed on the adhesive layer.

[0092] The semiconductor manufacturing process adhesive tape of the present invention is preferably used in a semiconductor chip manufacturing method in which semiconductor chips are continuously arranged on a first adhesive layer of the semiconductor manufacturing process adhesive tape, the semiconductor chips are peeled off the semiconductor manufacturing process adhesive tape, and the peeled semiconductor chips are brought into contact with a carrier material, wherein the peeling of the semiconductor chips from the semiconductor manufacturing process adhesive tape and the contact of the peeled semiconductor chips with the carrier material occur continuously in the transfer step. In this transfer step, the semiconductor chips are released from the semiconductor manufacturing process adhesive tape by ablation by irradiation with laser light and transferred to the carrier material, but the semiconductor manufacturing process adhesive tape, semiconductor chips and carrier material do not come into contact simultaneously, and the release of the semiconductor chips from the semiconductor manufacturing process adhesive tape and the contact of the semiconductor chips with the carrier material occur continuously. As described above, the adhesive tape for semiconductor manufacturing processes of the present invention has excellent pick-up and release properties for semiconductor chips. Therefore, even when the size of the semiconductor chips to be manufactured is small, using the adhesive tape for semiconductor manufacturing processes of the present invention in the semiconductor chip manufacturing method described above allows for accurate positional transfer of the semiconductor chips, thereby improving the yield of the manufactured chips. In the above transfer process, semiconductor chips are continuously arranged on the first adhesive layer of the adhesive tape for semiconductor manufacturing processes. Although the distance between each semiconductor chip is very small and accurate positional transfer of each semiconductor chip is required, the use of the adhesive tape for semiconductor manufacturing processes of the present invention makes it possible to perform the above transfer process without problems. Consequently, the above semiconductor chip manufacturing method makes it possible to efficiently manufacture a large number of semiconductor chips.

[0093] In the manufacturing method described above, the adhesive tape for semiconductor manufacturing processes of the present invention is preferably used in a method for manufacturing small semiconductor chips, and more specifically, in a method for manufacturing a rectangular semiconductor chip with a side length of 500 μm or less. Among these, it is more preferable to use it in a method for manufacturing a rectangular semiconductor chip with a total side length of 500 μm or less. In the manufacturing method using the adhesive tape for semiconductor manufacturing processes of the present invention, the more preferable lower limit for the side length of the rectangular semiconductor chip to be manufactured is 5 μm, the more preferable upper limit is 400 μm, the even more preferable lower limit is 10 μm, the even more preferable upper limit is 300 μm, the even more preferable upper limit is 200 μm, and the particularly preferable upper limit is 100 μm.

[0094] As described above, the manufacturing method described above can efficiently produce a large number of semiconductor chips. The number of chips produced at one time in this manufacturing method is not particularly limited, and one or more is sufficient, 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, the preferred upper limit for the number of chips manufactured at one time using this manufacturing method is 100,000, and the more preferred upper limit is 50,000.

[0095] Examples of the carrier material in the manufacturing method described above include adhesive tape, liquid polyimide-based adhesive, and liquid silicone-based adhesive. [Effects of the Invention]

[0096] According to the present invention, it is possible to provide an adhesive tape for semiconductor manufacturing processes that exhibits excellent pick-up and release properties for semiconductor chips, even when the size of the semiconductor chip is small. [Modes for carrying out the invention]

[0097] 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.

[0098] (Synthesis of (meth)acrylic copolymers) (Synthesis Examples 1-8) 52 parts by mass of ethyl acetate and the monomer mixture 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 initiate 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. A solution containing a (meth)acrylic copolymer was obtained by cooling while diluting the reactor with ethyl acetate. The weight-average molecular weight of the obtained (meth)acrylic copolymer was measured by GPC. The measurement was performed using a Waters 2690 Separations Module, 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.

[0099] [Table 1]

[0100] (Preparation of adhesive) (Combination examples A~Y) The obtained base polymer was dissolved in ethyl acetate to a solid content of 20% by mass. Each component shown in Table 2 was added to 100 parts by mass of the base polymer, and the mixture was thoroughly stirred to prepare adhesive solutions of adhesives A to Y.

[0101] [Table 2]

[0102] (Manufacturing of adhesive tape) (Examples 1-25, Comparative Examples 1-4) The adhesive solutions of the adhesives shown in Tables 3-5 were applied to the surface of the substrate layers shown in Tables 3-5 using an applicator, and dried at 110°C for 3 minutes to form a first adhesive layer with the thickness shown in Tables 3-5. A 75 μm thick release PET film was then layered on top of the first adhesive layer with its release surface facing the first adhesive layer to produce a laminated film (a). Next, the adhesive solutions of the adhesives shown in Tables 3-5 were applied to the release surface of the 75 μm thick release PET film using an applicator, and dried at 110°C for 3 minutes to obtain a laminated film (b) having a second adhesive layer. The second adhesive layer of laminated film (b) was then laminated and integrated onto the side of the substrate layer of laminated film (a) that did not have the first adhesive layer, and then cured at 40°C for 48 hours to obtain an adhesive tape for semiconductor manufacturing processes having the first adhesive layer, the substrate layer, and the second adhesive layer in that order.

[0103] (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 specimens. For the first adhesive layer of the obtained test specimens, the probe tack value was measured using a probe tack measuring device (RHESCA, "Tacking Tester TAC-2") with a 5 mm diameter stainless steel probe under the following conditions: 23°C, pressurized pressure of 0.05 MPa, pressurization speed of 10 mm / sec, pressurization time of 10 seconds, and release speed of 0.1 mm / sec. The probe tack value (V1) of the first adhesive layer was obtained. The measured value was calculated from the average of 5 measurements. The results are shown in Tables 3 to 5. 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.

[0104] (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 specimens. For the first adhesive layer of the obtained test specimens, the probe tack value was measured using a probe tack measuring device (RHESCA, "Tacking Tester TAC-2") with a 5 mm diameter stainless steel probe under the following conditions: 23°C, pressurized pressure of 0.05 MPa, pressurization speed of 10 mm / sec, pressurization time of 10 seconds, and release speed of 15 mm / sec. The probe tack value (V2) of the first adhesive layer was obtained. The measured value was calculated from the average of 5 measurements. The results are shown in Tables 3 to 5. The probe tack value (V2) was measured by peeling off the release PET film protecting the first adhesive layer of the adhesive tape used in semiconductor manufacturing processes.

[0105] (Measurement of gel fraction of the first adhesive layer) Only the first adhesive layer (W0 g) was extracted from the obtained adhesive tape for semiconductor manufacturing processes, and each layer was immersed in 50 mL of ethyl acetate. The layers were shaken in a shaker at 23°C and 200 rpm for 24 hours. After shaking, the ethyl acetate and the adhesive layer that had absorbed and swollen with ethyl acetate were separated using a metal mesh (mesh size #200, W1 g). The separated adhesive layers were dried at 110°C for 1 hour. The mass W2 g of the adhesive layer including the metal mesh after drying was measured, and the gel fraction of the first adhesive layer was calculated using the following formula. The results are shown in Tables 3-5. Gel fraction (mass %) = 100 × (W2 - W1) / W0 (W0: Mass of the initial adhesive layer, W1: Initial mass of the metal mesh, W2: Mass of the adhesive layer including the metal mesh after drying)

[0106] (Measurement of the shear storage modulus (G') of the first adhesive layer at 23°C and a frequency of 10 Hz) From the obtained adhesive tape for semiconductor manufacturing processes, only the first adhesive layer was extracted, and a sample with a thickness of approximately 500 μm (6 mm wide x 10 mm long) was prepared by stacking the first adhesive layer. 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 frequency 10 Hz. The shear storage modulus (G') at 23 °C and frequency 10 Hz was obtained from the measured dynamic viscoelasticity spectrum. The results are shown in Tables 3 to 5.

[0107] (Measurement of the shear storage modulus (G') of the first adhesive layer at 60°C and a frequency of 10Hz) From the obtained adhesive tape for semiconductor manufacturing processes, only the first adhesive layer was extracted, and a sample with a thickness of approximately 500 μm (6 mm wide x 10 mm long) was prepared by stacking the first adhesive layer. 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 frequency 10 Hz. The shear storage modulus (G') at 60°C and frequency 10 Hz was obtained from the measured dynamic viscoelasticity spectrum. The results are shown in Tables 3 to 5.

[0108] (Measurement of the 180° peel force of the first adhesive layer against the glass plate at 23°C) The second adhesive layer of the obtained semiconductor manufacturing process adhesive tape was backed onto a 23 μm thick biaxially oriented PET film (Futamura Chemical Co., Ltd., "FE2002") and then cut to a width of 25 mm. The first adhesive layer of the cut adhesive tape was pressed onto a glass plate (Matsunami Glass Industry Co., Ltd., "Large Slide Glass White Edge Polished No. 2") using a 2 kg rubber roller at 23°C, 50% RH, and a speed of 300 mm / min for one back-and-forth motion, and then left to stand for 30 minutes under conditions of 23°C and 50% RH to prepare a measurement sample. For the prepared measurement samples, the 180° peel force of the first adhesive layer from the glass plate at 23°C was measured using an Autograph (Shimadzu Corporation, "AGS-500NX") by peeling off semiconductor manufacturing process adhesive tape from the glass plate at a speed of 300 mm / min in an environment of 23°C. The results are shown in Tables 3-5.

[0109] (Calculation of the rate of decrease in peel strength of the first adhesive layer after UV irradiation) The second adhesive layer of the obtained adhesive tape for semiconductor manufacturing processes was backed onto a 23 μm thick biaxially oriented PET film (Futamura Chemical Co., Ltd., "FE2002"), then cut into a flat rectangular shape measuring 25 mm wide x 75 mm long. The cut adhesive tape was then bonded to a glass plate by rolling it back and forth once using a 2 kg rubber roller at 23°C, 50% RH, and a speed of 300 mm / min. The test specimens were then left to stand for 20 minutes under the conditions of 23°C and 50% RH to prepare the test specimens. The obtained test specimens were 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 peeling speed of 300 mm / min, to measure the 180° peel force (mN / 25 mm) before UV irradiation. Similarly, after backing the second adhesive layer, the release PET film protecting the first adhesive layer is peeled off the cut adhesive tape, and a UV irradiator using a black light (NEC, "FL20SBL") is used from the first adhesive layer 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 rate of decrease in peel force after UV irradiation was then calculated using the following formula. The results are shown in Tables 3-5. Percentage decrease in peeling strength after UV irradiation (%) = 100 × {(180° peeling strength before UV irradiation) - (180° peeling strength after UV irradiation)} / (180° peeling strength before UV irradiation)

[0110] (Measurement of the 180° peel force of the second adhesive layer against the glass plate at 23°C) Except for preparing a sample in which the first adhesive layer was backed onto a 23 μm thick biaxially oriented PET film (Futamura Chemical Co., Ltd., "FE2002"), and then the second adhesive layer was pressed onto a glass plate, the 180° peel force of the second adhesive layer against the glass plate at 23°C was measured using the same method as described above for "(Measurement of 180° peel force of the first adhesive layer against the glass plate at 23°C)". The results are shown in Tables 3 to 5.

[0111] (Measurement of UV absorption rate at a wavelength of 355 nm for adhesive tape used in semiconductor manufacturing processes) The obtained adhesive tapes for semiconductor manufacturing processes were measured using a spectrophotometer (Shimadzu Corporation, UV-2600i) in accordance with JIS L1925, with the ultraviolet absorption rate at a wavelength of 355 nm measured from the first adhesive layer side. The results are shown in Tables 3 to 5. The ultraviolet absorption rate was measured by peeling off the release PET film that protects the adhesive layers on both sides of the adhesive tape used in semiconductor manufacturing processes.

[0112] (Measurement of surface resistance of adhesive tape used in semiconductor manufacturing processes) For the obtained adhesive tape for semiconductor manufacturing processes, the surface resistance values ​​were measured at nine points from the first adhesive layer side using probes (Nitto Seiko Co., Ltd., "Hiresta-UX MCP-HT800") with a probe spacing of 5 mm arranged in a straight line at equal intervals, in accordance with JIS K7194. The average value of these measurements was taken as the surface resistance value (logΩ / sq) of the adhesive tape for semiconductor manufacturing processes. The results are shown in Tables 3 to 5. The surface resistance was measured by peeling off the release PET film that protects the adhesive layers on both sides of the adhesive tape used in semiconductor manufacturing processes.

[0113] <Rating> The adhesive tapes obtained in the examples and comparative examples were evaluated using the following method. The results are shown in Tables 3 to 5.

[0114] (Preparation of single-sided adhesive tape for testing) 52 parts by mass of ethyl acetate were placed in a reactor equipped with a thermometer, stirrer, and condenser, and after purging with nitrogen, the reactor was heated and reflux was started. Thirty 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. Thirty 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 copolymer was obtained by cooling while diluting the reactor with ethyl acetate. To the obtained (meth)acrylic copolymer solution, Coronate L-45 (manufactured by Tosoh Corporation) was added as an isocyanate crosslinking agent to 100 parts by mass of the (meth)acrylic copolymer, 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 the substrate layer, so that the dry film thickness would be 75 μm, and the adhesive layer was formed by drying at 110°C for 3 minutes to obtain a single-sided adhesive tape for testing.

[0115] (Pickup ability) A wafer containing 10 Si chips (500 μm x 500 μm square, 50 μm thick) was placed on top of a single-sided adhesive tape for testing, facing the Si chip side of the wafer. The tape was then bonded to the wafer by pressing it for 10 seconds under conditions of 23°C, 50% RH, and 0.1 MPa. After that, the wafer was peeled off, and the Si chips were placed on the single-sided adhesive tape for testing. A single-sided adhesive tape for testing, on which Si chips were placed, was placed opposite an adhesive tape for semiconductor manufacturing processes obtained in an example or comparative example. 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. The Si chips were peeled off and transferred 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 pickup performance was evaluated as follows: "A" if 9 or more Si chips were attached to the adhesive tape, "B" if 8 were attached, "C" if 7 were attached, and "D" if 6 or fewer Si chips were attached.

[0116] (Release) After the second adhesive layer of the semiconductor manufacturing process adhesive tape obtained in the example or comparative example was bonded to a glass plate, the first adhesive layer of the semiconductor manufacturing process tape, which was bonded to the glass plate, was placed on top of the second adhesive layer so that it faced the Si chip side of a wafer on which one Si chip (500 μm × 500 μm square, 50 μm thick) was arranged, and the two layers were pressed together for 10 seconds under conditions of 23°C, 50% RH, and 0.1 MPa to bond the first adhesive layer of the obtained semiconductor manufacturing process adhesive tape. Subsequently, the wafer was peeled off to place the Si chip on the semiconductor manufacturing process adhesive tape and obtain a measurement sample. Furthermore, the 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 semiconductor solid-state laser was used to irradiate the Si chip with a 355nm laser beam at an output of 4W and 4KHz from the glass plate side of the measurement sample. The Si chip was peeled off the adhesive tape used in the semiconductor manufacturing process and transferred to the adhesive layer of a single-sided adhesive tape 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. Evaluation was performed according to the following criteria. The release characteristics were evaluated as follows: "A" if the angle was 5° or less, "B" if the angle was greater than 5° but 10° or less, "C" if the angle was greater than 10° but 20° or less, and "D" if the angle was greater than 20°.

[0117] (residue) In the "(Release Properties)" section described above, the peeled surface of a Si chip removed from adhesive tape used in semiconductor manufacturing processes was observed using 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 10% or less of the peeled surface of the Si chip; "C" if the area of ​​the residue was greater than 10% but 20% or less of the peeled surface of the Si chip; and "D" if the area of ​​the residue was greater than 20% of the peeled surface of the Si chip.

[0118] [Table 3]

[0119] [Table 4]

[0120] [Table 5] [Industrial applicability]

[0121] According to the present invention, it is possible to provide an adhesive tape for semiconductor manufacturing processes that exhibits excellent pick-up and release properties for semiconductor chips, even when the size of the semiconductor chip is small.

Claims

1. A double-sided adhesive tape having a first adhesive layer, a base layer, and a second adhesive layer in this order, The first adhesive layer is It contains a base polymer and a UV absorber. Under the conditions of 23°C, pressurized pressure of 0.05 MPa, pressurizing rate of 10 mm / sec, pressurizing time of 10 seconds, and release rate of 0.1 mm / sec, the probe tack value measured was 10 N / 5 mmφ or more and 30 N / 5 mmφ or less. The probe tack value measured under the conditions of 23°C, pressurizing pressure of 0.05 MPa, pressurizing rate of 10 mm / sec, pressurizing time of 10 seconds, and release rate of 15 mm / sec is between 1 N / 5 mmφ and 20 N / 5 mmφ. A semiconductor manufacturing process adhesive tape characterized by the following features.

2. The adhesive tape for semiconductor manufacturing processes according to claim 1, wherein the base polymer comprises a (meth)acrylic copolymer.

3. The (meth)acrylic copolymer contains 20% by mass or more and 99% by mass or less of structural units derived from alkyl (meth)acrylate having an alkyl group with 4 or fewer carbon atoms at its ester terminus, as described in claim 2, for use in semiconductor manufacturing processes.

4. The (meth)acrylic copolymer contains 20% by mass or more and 80% by mass or less of constituent units derived from alkyl (meth)acrylates whose homopolymer has a glass transition temperature of 0°C or higher, as described in claim 2, for use in semiconductor manufacturing processes.

5. The (meth)acrylic copolymer has constituent units derived from t-butyl acrylate, wherein the adhesive tape for semiconductor manufacturing processes is as described in claim 2.

6. The (meth)acrylic copolymer has constituent units derived from methyl acrylate, wherein the adhesive tape for semiconductor manufacturing processes is as described in claim 2.

7. The (meth)acrylic copolymer has constituent units derived from hydroxyl group-containing (meth)acrylate, as described in claim 2, 3, 4, 5, or 6, for use in semiconductor manufacturing processes.

8. The first adhesive layer contains a tackifying resin, as described in claim 1, 2, 3, 4, 5, or 6, for use in semiconductor manufacturing processes.

9. The first adhesive layer comprises an antistatic agent, as described in claim 1, 2, 3, 4, 5, or 6, for use in semiconductor manufacturing processes.

10. The adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, or 6, wherein the first adhesive layer has a gel fraction of 50% by mass or more.

11. The first adhesive layer has a shear storage modulus of 5 × 10 at 23°C and 10 Hz. ４ Pa or more 1×10 ６ An adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, or 6, wherein the pressure is Pa or less.

12. The first adhesive layer has a 180° peel force to a glass plate at 23°C of 0.2 N / 25 mm or more and 2.0 N / 25 mm or less, as described in claim 1, 2, 3, 4, 5, or 6, which is the adhesive tape for semiconductor manufacturing processes.

13. The first adhesive layer was treated with an irradiation intensity of 7.8 mW / cm at a wavelength of 355 nm. ２ The cumulative amount of ultraviolet light is 190 mJ / cm². ２ The adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, or 6, wherein the rate of decrease in 180° peel strength against SUS at 23°C after irradiation to such a extent is 60% or less.

14. The adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, or 6, wherein the second adhesive layer has a 180° peel force to a glass plate at 23°C of 2 N / 25 mm or more.

15. The adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, or 6, wherein the ultraviolet absorption rate at a wavelength of 355 nm is 80% or more.

16. The adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, or 6, wherein the surface resistance value measured from the first adhesive layer side is 15 (log Ω / sq) or less.

17. A semiconductor chip is continuously arranged on the first adhesive layer of the adhesive tape for the semiconductor manufacturing process. The process includes a transfer step in which the semiconductor chip is peeled off the adhesive tape used for the semiconductor manufacturing process, and then the peeled semiconductor chip is brought into contact with a carrier material. In the transfer process, the semiconductor chip is peeled off the adhesive tape for the semiconductor manufacturing process and the peeled semiconductor chip is brought into contact with the carrier material in a continuous manner. Used in the manufacturing method of semiconductor chips, Adhesive tape for semiconductor manufacturing processes according to claim 1, 2, 3, 4, 5, or 6.

18. The semiconductor manufacturing process adhesive tape according to claim 17, used in a method for manufacturing a semiconductor chip having a rectangular shape with a side length of 500 μm or less.

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