TW201441332A - Adhesive tape for semiconductor processing - Google Patents

Abstract

The present invention provides an adhesive tape for semiconductor processing, in which the adhesive will not be dissolved to contaminate the semiconductor element even though the cleansing agent sprinkles to the adhesive during the cleansing solution being used to cleanse the residue of the adhesive laminating the supporting member onto the semiconductor wafer in the manufacturing step of the semiconductor element using the supporting element, and which has the physical properties of the supporting element and the firm adhesion necessary during the mechanical peeling. The adhesive tape for the semiconductor processing in the present invention is to form the radiation-curable adhesive layer of the adhesive tape for the semiconductor processing onto at least one surface of the substrate resin film, which is characterized by the gel refraction before the UV radiation of the aforementioned adhesive layer being above 65% and below 100%, and the peak value in the probe tack test before the UV radiation of the aforementioned adhesive layer being 100 to 600 kPa.

Description

Adhesive tape for semiconductor processing

The present invention relates to an adhesive tape for semiconductor processing used for semiconductor wafer dicing in the step of manufacturing a semiconductor device. More specifically, it relates to an adhesive tape for semiconductor processing used in the manufacture of a semiconductor element using a support member.

For the thin processing of the back surface of the semiconductor wafer on which the wiring pattern has been formed, in order to protect the pattern surface of the semiconductor wafer and the semiconductor wafer itself, the protective sheet is generally attached to the pattern surface, and the back surface is applied. Thin processing such as grinding and grinding. As such a protective sheet, an acrylic adhesive or the like is generally applied to a substrate made of a plastic film. However, in recent years, with the thinning and miniaturization of IC cards or mobile phones, the thickness of semiconductor wafers is required to be 50 μm or less. In the past, in the step of using protective tape, only the protective tape could not support the semiconductor wafer. The processing of the semiconductor wafer is difficult due to the warpage of the semiconductor wafer after the grinding or the deflection during storage in the wafer, and it is difficult to automate the processing or transportation.

For this problem, it has been proposed to have a glass base through an adhesive. A method in which a plate, a ceramic substrate, a tantalum wafer substrate, or the like is bonded to a semiconductor wafer to impart support to the semiconductor wafer (see, for example, Patent Document 1). By replacing such a protective sheet with a supporting member such as a glass substrate, a ceramic substrate, or a tantalum wafer substrate, the rationality of the semiconductor wafer can be greatly improved, and automation of transportation can be made possible.

When the semiconductor wafer is processed using the support member, it is necessary to peel the support member from the semiconductor wafer after grinding on the back surface of the semiconductor wafer. The peeling of the support member is generally performed by (1) dissolving or decomposing the adhesive between the support member and the semiconductor wafer by chemicals, and (2) irradiating the laser between the support member and the semiconductor wafer with laser light. Decomposition and so on. However, in the method of (1), there is a problem that it takes a long time to spread the chemical in the adhesive, and in the method of (2), there is a problem that the scanning of the laser requires a long time of processing. Moreover, either method requires the preparation of a special substrate as a support member.

Therefore, it has been proposed to form a peeling mark after the support member is peeled off, physical. Method of mechanical peeling (see, for example, Patent Documents 2 and 3). This method does not require the long-term treatment required for the dissolution or decomposition of the chemical by the chemical or the laser decomposition by laser scanning, and can be processed in a short time. After the support member is peeled off from the semiconductor wafer, the residue of the adhesive generated on the semiconductor wafer when the support member is peeled off by the chemical is washed.

The backside ground semiconductor wafer is then moved to a dicing step and cut into individual wafers. However, as described above, when the thickness of the semiconductor wafer is 50 μm or less, the semiconductor wafer is separately subjected to the ground semiconductor wafer after grinding. The warpage or the deformation during storage in the wafer is very difficult to process the semiconductor wafer. Therefore, the conventional method is to bond the dicing tape to the semiconductor wafer just after the back grinding of the semiconductor wafer and before the support member is peeled off. The ground surface is fixed by a ring frame. Therefore, the adhesive residue generated on the semiconductor wafer when the support member is peeled off is chemically cleaned, and the semiconductor wafer is bonded to the dicing tape, and the dicing tape is required to have high solvent resistance.

As a dicing tape having a high solvent resistance, an energy ray-curable acrylic resin composition is contained in the adhesive layer, and the gel fraction is 70% or more (see, for example, Patent Document 4).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2006-135272

[Patent Document 2] Japanese Patent Publication No. 2011-510518

[Patent Document 3] US Patent Application Publication No. 2011/0272092

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2009-224621

However, the adhesive tape for semiconductor processing described in Patent Document 4 does not have the support structure as shown in the above-mentioned Patent Documents 2 and 3. The physicality of the pieces. There is a strong adhesion required for mechanical peeling, and when the support member is peeled off from the semiconductor wafer, there is a problem that the semiconductor wafer is peeled off from the adhesive tape for semiconductor processing.

Accordingly, an object of the present invention is to provide an adhesive tape for semiconductor processing which is prepared by cleaning a cleaning agent for attaching a support member to a semiconductor wafer in a semiconductor element manufacturing step using a supporting member. In the liquid, even if the cleaning solution is dripped onto the adhesive, it will not dissolve the adhesive and contaminate the semiconductor component, and has the physical properties of the supporting member. The strong adhesion required for mechanical peeling.

In order to achieve the above object, the inventors of the present invention have repeatedly conducted intensive studies and found an adhesive tape for semiconductor processing having an adhesive layer on a base resin film, and the gel fraction thereof is set to a specific value. And set the peak of the probe tack to a specific value, including the physical properties of the support member. In the manufacturing step of the semiconductor element in the mechanical stripping step, even if the cleaning liquid is dripped onto the adhesive, the adhesive is not dissolved and contaminated to the semiconductor element, and the support member may be physically provided. The strong adhesion required for mechanical exfoliation, the present invention is based on this finding.

In other words, the adhesive tape for semiconductor processing of the present invention is an adhesive tape for semiconductor processing which forms a radiation curable adhesive layer on at least one surface of a base resin film, and is characterized in that the adhesive layer has a gel component before ultraviolet irradiation of the adhesive layer. The rate is 65% or more and 100% or less, and the aforementioned adhesion The peak of the probe tack test before the ultraviolet irradiation of the agent layer is 100 to 600 kPa.

In the above-mentioned adhesive tape for semiconductor processing, it is preferred that the adhesive layer contains at least an acrylic polymer having a radiation-curable carbon-carbon double bond in a molecule, a photopolymerization initiator, and polypropylene oxide, and the above-mentioned polypropylene oxide The total solid content of the pressure-sensitive adhesive layer is preferably 0.1% by mass or more and 2.0% by mass or less.

Further, in the above adhesive tape for semiconductor processing, it is preferred that the number average molecular weight of the polypropylene oxide is more than 3,000 and not more than 10,000.

Further, in the above-mentioned adhesive tape for semiconductor processing, it is preferred that the light having a wavelength of 1064 nm incident from the side of the base resin film has a parallel light transmittance of 88% or more and less than 100%.

Further, in the above-mentioned adhesive tape for semiconductor processing, the surface roughness Ra of the base resin film on the opposite side to the adhesive layer is preferably 0.1 μm or more and 0.3 μm or less. The surface roughness Ra is more preferably 0.12 μm or more and 0.19 μm or less.

According to the present invention, in the manufacturing step of the semiconductor device using the supporting member, the supporting member is attached to the adhesive residue of the semiconductor wafer by washing with the cleaning liquid, even when the cleaning liquid is dripped onto the adhesive. Does not dissolve the adhesive to contaminate the semiconductor components, and has the physical properties of the support member. The strong adhesion required for mechanical peeling.

Hereinafter, embodiments of the present invention will be described in detail.

In the adhesive tape for semiconductor processing according to the embodiment of the present invention, at least one adhesive layer is formed on at least one surface of the base resin film.

In the adhesive tape for semiconductor processing according to the embodiment of the present invention, the gel fraction of the adhesive layer is 65% or more, preferably 70% or more, more preferably 80% or more. When the gel fraction is applied to the back surface of the semiconductor wafer, the gel fraction of the drug for dissolving or decomposing the adhesive used for bonding the support member to the semiconductor wafer is preferably methyl Gel fraction of butyl ketone. When the gel fraction is too small, the adhesive layer is low in chemical resistance, and in the manufacturing steps of a semiconductor element in which the adhesive tape for semiconductor processing is exposed to a drug such as methyl isobutyl ketone or a derivative thereof, The molten adhesive contaminates the semiconductor wafer due to the above-mentioned drug.

Further, the gel fraction in the present invention means the ratio of the crosslinked adhesive component other than the crosslinked component in the adhesive layer. The calculation of the gel fraction was carried out using the method described below. Further, in the present invention, the gel fraction is a state in which the surface of the adhesive layer is protected by a separator or the like immediately after the formation of the adhesive layer, and the adhesive layer before the irradiation of the energy ray is measured.

(calculation of gel fraction)

Self-cutting adhesive for semiconductor processing that has been cut into 50mm × 50mm size With the separator removed, weigh the mass A. Then, the sample of the weighed adhesive tape for semiconductor processing is immersed in, for example, 100 g of methyl isobutyl ketone (MIBK) for 48 hours, and then dried in a constant temperature layer of 50 ° C, and the mass B is weighed. . Next, 100 g of ethyl acetate was used, and after removing the adhesive layer of the sample, the mass C of the sample was weighed, and the gel fraction was calculated by the following formula (1).

Gel fraction (%) = (B-C) / (A-C) (1)

In addition, the probe tipping test before the radiation exposure of the adhesive layer has a peak value of 200 to 600 kPa. When the peak of the probe touch test is too small, the adhesion of the adhesive layer to the adherend is insufficient, making peeling of the sample member difficult. When the peak of the probe touch test is too large, paste residue or debris is likely to occur. The probe touch assay is performed using the method described below.

(Measurement of probe contact viscosity)

The measurement of probe stickiness is carried out using, for example, the Tacking tester TAC-II of Rhesca Co., Ltd. The measurement mode is a constant load in which the probe is pressed to the set pressure value to maintain the pressurization value until the set time elapses. After peeling off the separator, the adhesive layer of the adhesive tape was faced upward, and a probe made of SUS304 having a diameter of 3.0 mm was contacted from the upper side. The probe was brought into contact with the test sample at a speed of 30 mm/min, a contact load of 0.98 N, and a contact time of 1 second. Subsequently, the probe was pulled upward at a peeling speed of 600 mm/min, and the measurement was performed. The force required to pull away. The probe temperature was 23 ° C and the plate temperature was set to 23 ° C.

Hereinafter, each constituent element of the adhesive tape for semiconductor processing of the present embodiment will be described in detail.

(substrate resin film)

When the UV is used as the radiation for curing the adhesive layer as the base resin film, the base resin film must have light permeability. Further, when it is necessary to incident a laser over an adhesive tape for semiconductor processing, light transmittance is also required. In order to make the laser incident over the adhesive tape for semiconductor processing, the parallel light transmittance of the adhesive tape for semiconductor processing must be 88% or more and less than 100%, but the substrate resin film may be reduced due to the application of the adhesive coating to reduce light diffusion. The diffused light is not required to be considered alone, and the parallel light transmittance of the base resin film is not necessarily 88% or more and less than 100%.

On the other hand, when an electron beam is used as the radiation, it is not necessary to form a modified region on the semiconductor wafer by causing the laser to enter the adhesive tape for semiconductor processing, and the base resin film is not necessarily required to have light transmittance.

The material constituting the base resin film is preferably a polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer and polybutene, such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer and ethylene. -Ethylene copolymer of (meth) acrylate copolymer, engineering plastics such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polymethyl methacrylate, soft polyvinyl chloride Polymer materials such as semi-rigid polyvinyl chloride, polyester, polyurethane, polyamide, polyamide rubber, and synthetic rubber. And may be a mixture of two or more selected from the group or a complex The stratifier can be arbitrarily selected depending on the adhesion to the adhesive layer. The base resin film is more preferably a film formed using an ionic polymer of an ethylene-acrylic acid copolymer.

The thickness of the base resin film is not particularly limited, but is preferably from 10 to 500 μm, more preferably from 40 to 400 μm, still more preferably from 70 to 250 μm.

The surface roughness (arithmetic mean roughness Ra) of the surface on the opposite side of the surface of the base resin film that is in contact with the adhesive layer is not particularly limited, but it is preferably 0.1 when the laser must be incident on the adhesive tape for semiconductor processing. ~0.3 μm, more preferably 0.12 to 0.19 μm. When the laser must be incident over the adhesive tape for semiconductor processing, when the surface roughness (arithmetic mean roughness Ra) of the surface on the opposite side of the surface of the base resin film contacting the adhesive layer is more than 0.3 μm, it is called a hidden thunder. A method of cutting a wafer (stealth dicing) (in the state where the dicing tape is attached to the back surface of the semiconductor wafer, the laser light having a light transmissive property to the dicing tape is aligned with the light collecting point inside the semiconductor wafer through the cutting The tape is incident from the back side of the semiconductor wafer, along a predetermined cutting line of the semiconductor wafer, and is absorbed by a plurality of photons inside the semiconductor wafer to form a modified region, and the modified region is used as a starting point to be cut along a predetermined cutting line. In the semiconductor wafer, in which the semiconductor wafer is cut, the incident laser light is diffused on the surface of the substrate resin film on the opposite side of the surface in contact with the adhesive layer, and is not available in the semiconductor wafer. The interior is effectively formed by multiphoton absorption to form a modified region. On the other hand, when the surface roughness (arithmetic mean roughness Ra) of the surface on the opposite side of the surface of the base resin film which is in contact with the adhesive layer is less than 0.1 μm, the surface of the base resin film which is in contact with the adhesive layer is The slidability of the opposite side becomes lower, by expanding The step makes it difficult to evenly spread the wafer spacing when the divided wafers are spaced apart. The surface roughness of the surface of the base resin film which is in contact with the adhesive layer is the surface on the opposite side, and can be controlled by adjusting the surface roughness of the cooling roll during film extrusion in the T-die method and the calendering method. In the solution casting method, it can be controlled by adjusting the surface roughness of the drum or the conveyor belt. Further, it can also be controlled by applying various resins to a film having any surface roughness.

In order to improve the adhesion, a corona treatment may be applied to the surface of the base resin film that is in contact with the adhesive layer, or a primer or the like may be applied.

(adhesive layer)

The adhesive layer is an energy ray-curable acrylic resin composition containing an acrylic compound having an unsaturated double bond in its molecule as a main component and containing an acrylic polymer as an auxiliary component such as a photopolymerization initiator or a curing agent. form.

The acrylic compound having an unsaturated double bond in the molecule is exemplified by, for example, introducing a photopolymerizable carbon-carbon double bond into a polymer selected from one or more of the following or a mixture of several polymers (hereinafter referred to as " (Compound 1)"): amyl acrylate, n-butyl acrylate, isobutyl acrylate, ethyl acrylate, methyl acrylate, hexyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethyl acrylate Ester, dodecyl acrylate, decyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate or the same methacrylate, or acrylic acid, methacrylic acid, cinnamic acid, itaconic acid having functional groups , fumaric acid, phthalic acid, C Hydroxyalkyl enoates, hydroxyalkyl methacrylates, diol monoacrylates, diol monomethacrylates, N-methylol acrylamide, N-methylol methacrylate Indoleamine, allyl alcohol, N-alkylaminoethyl acrylate, N-alkylaminoethyl methacrylate, acrylamide, methacrylamide, maleic anhydride, clothing Tonic anhydride, fumaric anhydride, phthalic anhydride, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, vinyl acetate, styrene, acrylonitrile, vinyl alcohol.

Here, in order to increase the gel fraction of the adhesive layer, as disclosed in Patent Document 4, when a high molecular weight selected person is used as the acrylic resin composition, and a general method of crosslinking the crosslinking agent is used, This has the tendency to reduce the adhesion of the tape for semiconductor processing, and the result is the physical property of the support member. The strong adhesion required for mechanical peeling.

Here, the acrylic compound having a functional group copolymerized in (Compound 1) is not particularly limited, but when the obtained crosslinked structure is formed by reaction with a crosslinking agent to be described later, both the acrylic compound and the hardener are considered. The molecular weight of the acrylic adhesive is increased (that is, the number of crosslinking points is increased) and the softness (contact adhesive force) of the adhesive, and the acrylic compound having a functional group preferably has a large molecular weight, and the molecular weight thereof is preferably More than 100, more preferably 115 or more. For example, when a hydroxyalkyl acrylate is used as the acrylic compound having a functional group, 2-hydroxypropyl acrylate (molecular weight: 130) and 4-hydroxybutyl acrylate are compared with 2-hydroxyethyl acrylate (molecular weight 116). (Molecular weight 144) and 1,4-cyclohexanedimethanol monoacrylate (molecular weight 198) are preferred. Further, when a hydroxyalkyl acrylamide is used as the acrylic compound having a functional group, compared to N- (Hydroxymethyl) acrylamide (molecular weight 101), N-(2-hydroxyethyl) acrylamide (molecular weight 115), and N-(2-hydroxypropyl) acrylamide (molecular weight 129) are preferred. By using a monomer having a relatively large molecular weight as an acrylic compound having a functional group, the molecular motion of the crosslinking point is facilitated, and the adhesive layer can be made flexible.

The method of introducing a photopolymerizable carbon-carbon double bond (Compound 1) is exemplified by having a functional group on the side chain of (Compound 1) and having a functional group capable of reacting with it and a photopolymerizable carbon-carbon double The method of adding a compound of a bond to (Compound 1). The compound having a functional group capable of undergoing an addition reaction with (Compound 1) and a photopolymerizable carbon-carbon double bond is classified as a (meth)acrylic acid shrinkage when the side chain to be subjected to the addition reaction is a carboxyl group or an acid anhydride. When the side chain to be subjected to the addition reaction is an epoxy group, the glyceride or the like is exemplified by (meth)acrylic acid or the like, and when the side chain to be subjected to the addition reaction is a hydroxyl group, it is exemplified as (meth)acrylic acid 2- Isocyanate alkyl ester and the like.

The acrylic compound having an unsaturated double bond in the molecule preferably has a weight average molecular weight of 100,000 or more and 2,000,000 or less, more preferably a weight average molecular weight of 300,000 or more and 1,500,000 or less, from the viewpoint of chemical resistance. When the weight average molecular weight is 100,000 or less, the chemical resistance of the resin is low, so that the adhesive layer is dissolved by the cleaning liquid used when the support member is removed, and the semiconductor substrate is contaminated. On the other hand, since the high molecular weight body having a weight average molecular weight of 1,000,000 or more has a very high viscosity, it is difficult to produce a state suitable for use as an adhesive.

The photopolymerization initiators usable in the present invention are not particularly limited Any one known in the past can be used. Listed as, for example, benzophenone, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, 4,4'-dichlorobenzophenone, etc. Acetones, acetophenones such as acetophenone and diethoxyacetophenone, anthraquinones such as 2-ethylhydrazine and tert-butylhydrazine, 2-chlorothioxanthone , benzoin ethyl ether, benzoin isopropyl ether, diphenylethylenedione, 2,4,5-triarylimidazole dimer (triphenyline dimer), acridine A compound or the like may be used alone or in combination of two or more.

The amount of the photopolymerization initiator to be added is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 12 parts by mass, per 100 parts by mass of the acrylic compound to which the photopolymerizable carbon-carbon double bond is introduced.

The hardener is selected from the group consisting of polyisocyanates and melamines. The compound of the formaldehyde resin and the epoxy resin may be used singly or in combination of two or more. The crosslinked structure which is a result of the reaction with the acrylic compound increases the molecular weight of the acrylic-based adhesive containing the acrylic compound and the curing agent, and improves the solvent resistance after application of the adhesive.

The polyisocyanate is not particularly limited, and examples thereof include 4,4'-diphenylmethane diisocyanate, toluene diisocyanate, xylene diisocyanate, 4,4'-diphenyl ether diisocyanate, and 4,4'-. An aromatic isocyanate such as [2,2-bis(4-phenoxyphenyl)propane] diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethyl-hexamethylene diisocyanate, or different Fulcone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, diazonic acid diisocyanate, leucine triisocyanate, etc., specifically, commercially available Coronate L (Japan Polyurethane Industrial Co., Ltd.) and so on.

In addition, melamine. As the formaldehyde resin, a commercially available product such as Nikalac MX-45 (manufactured by Sanwa Chemical Co., Ltd.), Melan (manufactured by Hitachi Chemical Co., Ltd.), or the like can be used.

Polyisocyanates are preferably used in the present invention.

The type of the crosslinking agent is not particularly limited. When the crosslinking structure is formed by reacting with the functional group of (Compound 1), the molecular weight of the acrylic adhesive containing both the acrylic compound and the curing agent is used. The increase (that is, the increase in the number of crosslinking points) and the flexibility (contact force) of the adhesive, preferably the molecular weight per one functional group is larger, and the molecular weight per one functional group of the crosslinking agent is preferably 150 or more, more preferably 200 or more. For example, when a polyisocyanate is used as a crosslinking agent, the molecular weight per one isocyanate group is preferably large. Compared with the acetal type and the isocyanurate type, an allophonate type and an addition type are preferred. When the acrylic-based compound and the acrylic-based adhesive of the curing agent have the same number of crosslinking points, that is, if the molecular weight of the acrylic-based adhesive and the acrylic adhesive of the curing agent form a crosslinked structure, the molecular weight is substantially equal. The solvent resistance of the acrylic adhesive of the compound and the curing agent is equal. In this case, when the molecular weight per one isocyanate group is large, the molecular motion of the crosslinking point becomes easier, so the acrylic compound and the hardener are contained. Acrylic adhesives become softer and increase the adhesion.

The amount of the curing agent to be added is not particularly limited, but is preferably 0.1 to 15 parts by mass, more preferably 1 to 10 parts by mass, per 100 parts by mass of the acrylic compound having an unsaturated double bond in the molecule. The amount is less than 0.1 In the case of the amount of the component, the effect of improving the cohesive force is insufficient. When the amount is more than 15 parts by mass, the crosslinking agent is formed by the preparation of the adhesive and the hardening reaction in the coating operation, and the workability is impaired.

Further, the ratio of the acrylic compound having an unsaturated double bond in the molecule and the crosslinking agent reactive with the acrylic compound to the total solid content of the adhesive layer is preferably 85% by mass or more.

In addition, the back surface of the semiconductor wafer is bonded to the grinding surface of the semiconductor wafer, and the adhesive tape for semiconductor processing is bonded to the back surface of the semiconductor wafer. When the wafer surface before the formation of the oxide film is formed after the grinding, there is a problem that the subsequent peeling becomes difficult. Therefore, in order to adhere to the wafer surface immediately before the formation of the oxide film on the back surface, the subsequent peeling is also easy, and it is preferable to add polypropylene oxide.

The polypropylene oxide is not particularly limited and may be appropriately selected from the past polypropylene oxide. The number average molecular weight of the polypropylene oxide is preferably more than 3,000 and 10,000 or less, more preferably 4,000 to 10,000. When the number average molecular weight of the polypropylene oxide is too large, the affinity between the polypropylene oxide and the acrylic polymer (X) is poor, and contamination by the adherend is generated. When the number average molecular weight of the polypropylene oxide is too large, the water resistance of the adhesive layer becomes insufficient, and the adhesive layer is swollen by the cutting water to cause a crystal grain cutting line.

From the viewpoint of contamination by the adherend, a polyoxypropylene-glyceryl ether having a number average molecular weight of more than 3,000 and 10,000 or less, more preferably 4,000 to 10,000 is preferred. By using a polyoxypropylene-glyceryl ether having a number average molecular weight in this range, the number of hydroxyl groups in the polypropylene oxide molecule is increased from 2 When it is added to 3, the probability of adding polypropylene oxide to the crosslinked structure increases due to the reaction with a crosslinking agent such as polyisocyanate, and the polypropylene oxide is transferred to the interface of the adherend, thereby reducing the contamination of the surface of the adherend. .

Examples of the polypropylene oxide having a number average molecular weight of more than 3,000 and not more than 10,000 include Uniol D-4000 (number average molecular weight: 4000) ((trade name), manufactured by Nippon Oil Co., Ltd.) and Preminol S4007 (number average molecular weight: 5000) (( Product name), Asahi Glass Co., Ltd.), Preminol S4011 (number average molecular weight 10000) ((trade name), manufactured by Asahi Glass Co., Ltd.). The polyoxypropylene-glyceryl ether having a number average molecular weight of more than 3,000 and not more than 10,000 is exemplified by Uniol TG-4000 (number average molecular weight: 4000) ((trade name), manufactured by Nippon Oil Co., Ltd.), and Preminol S3006 (number average molecular weight: 5,000). ((trade name), manufactured by Asahi Glass Co., Ltd.), Preminol S3011 (number average molecular weight: 10,000) ((trade name), manufactured by Asahi Glass Co., Ltd.), etc., but is not limited thereto.

The amount of the polypropylene oxide having a number average molecular weight of more than 3,000 and not more than 10,000 may be 0.1 by mass relative to 100 parts by mass of the acrylic polymer (X) and/or the acrylic polymer (Y) having a radiation curable carbon-carbon double bond in the molecule. ~3.0 parts by mass, preferably selected from the range of 0.5 to 2.0 parts by mass. When the amount of the polypropylene oxide is too small, the unstable wafer polishing surface in a state in which the natural oxide film is not completely formed can be effectively sandwiched from the large-diameter semiconductor wafer when the adhesive tape or sheet for cutting is bonded. Thin semiconductor wafers. When the amount of polypropylene oxide is too large, the adhesion before radiation hardening is insufficient, and the end of the wafer is peeled off during cutting to make the cutting powder Dust adheres to the back of the wafer.

The adhesive composition for forming the adhesive layer may optionally contain, for example, an adhesion-imparting agent, an anti-aging agent, a filler, a coloring agent, a flame retardant, an antistatic agent, a softener, an ultraviolet absorber, an antioxidant, Conventional additives such as plasticizers, surfactants, and the like.

Further, an ultraviolet curable monomer, an ultraviolet curable oligomer, an adhesion-imparting agent, an adhesion adjuster, a surfactant, or the like may be blended in the acrylic resin composition forming the adhesive layer used in the present invention, or the like. a modifier, etc., but the addition of these materials is preferable because the gel fraction of the adhesive is lowered and the chemical resistance is impaired, so that 100 parts by mass of the acrylic compound having an unsaturated double bond in the molecule is preferable. It is 20 parts by mass or less, more preferably 10 parts by mass or less, and still more preferably 5 parts by mass or less.

The thickness of the adhesive layer is preferably 5 μm or more and 70 μm or less, more preferably 8 μm or more and 50 μm or less, and still more preferably 10 μm or more and 30 μm or less. When the adhesive layer is too thin, the unevenness of the electrode cannot be followed, and the problem of the cutting water or the cutting dust immersing during the cutting process occurs. On the contrary, when the thickness is too thick, the chips become large during the cutting process, and the quality of the semiconductor element is lowered.

In the present invention, the energy line for curing the adhesive layer is preferably radiation, and the radiation is exemplified by light such as ultraviolet rays (UV), electron beam, or the like.

In the present invention, the adhesive layer preferably contains all of the following compounds (a) to (c).

(a) It is unsaturated by the following compounds (a1) to (a3) And a double bond acrylic compound, and the weight average molecular weight of 100000 or more and 2,000,000 or less,

(a1) from amyl acrylate, n-butyl acrylate, isobutyl acrylate, ethyl acrylate, methyl acrylate, hexyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, acrylic acid Diester, decyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate or the same methacrylate, acrylic acid, methacrylic acid, cinnamic acid, itaconic acid, fumaric acid, phthalic acid , hydroxyalkyl acrylates, hydroxyalkyl methacrylates, diol monoacrylates, diol monomethacrylates, N-methylol acrylamide, N-methylol methacryl Indoleamine, allyl alcohol, N-alkylaminoethyl acrylate, N-alkylaminoethyl methacrylate, acrylamide, methacrylamide, maleic anhydride, itaconic anhydride One or more selected from the group consisting of fumaric anhydride, phthalic anhydride, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, vinyl acetate, styrene, acrylonitrile, and vinyl alcohol Polymer or a mixture of several polymers

(a2) an acrylic compound having a functional group copolymerized with the compound (a1), which is a hydroxyalkyl acrylate or a hydroxyalkyl acrylamide, and has a molecular weight of 100 or more.

(a3) a compound having a functional group capable of undergoing an addition reaction with the compound (a1) and a photopolymerizable carbon-carbon double bond, when the side chain to be subjected to the addition reaction is a carboxyl group or an acid anhydride, When the side chain to be subjected to the addition reaction is an epoxy group, the glycidyl acrylate is a (meth)acrylic acid, and when the side chain to be subjected to the addition reaction is a hydroxyl group, 2-isocyanate alkyl (meth)acrylate

(b) Photopolymerization initiator

(c) a polyisocyanate of 0.1 to 15 parts by mass based on 100 parts by mass of the above compound (a).

The method of forming the adhesive layer on the base resin film is not particularly limited. For example, the acrylic resin composition can be applied onto a base resin film by a coating method which is usually used, dried, and formed. The adhesive layer coated on the separator is bonded to the base resin film and transferred onto the base resin film to be produced.

Further, a synthetic resin film used as a general separator for protecting the adhesive layer may be attached to the side of the adhesive layer as needed before being supplied to the utility. The constituent material of the synthetic resin film is exemplified by a synthetic resin film such as polyethylene, polypropylene, or polyethylene terephthalate or paper. In order to improve the releasability of the self-adhesive layer 3, the surface of the synthetic resin film may be subjected to a release treatment such as polyfluorination treatment, long-chain alkyl treatment, or fluorine treatment, as needed. The thickness of the synthetic resin film is usually from 10 to 100 μm, preferably from about 25 to 50 μm.

Further, when the adhesive tape for semiconductor processing according to the embodiment of the present invention is required to be incident on the semiconductor processing adhesive tape, for example, when it is provided in the above-described method called dicing laser wafer cutting, the substrate resin film side is provided. The parallel light transmittance of the incident light having a wavelength of 1064 nm is 88% or more and less than 100%, and is a viewpoint of preventing the laser light from attenuating or diffusing before reaching the semiconductor wafer and appropriately forming a modified layer inside the semiconductor wafer. Preferably. Of course, in the case where the laser light does not need to be incident over the adhesive tape for semiconductor processing, the parallel light of the light having a wavelength of 1064 nm The line transmittance is not particularly limited.

Next, the support member will be described.

(support member)

The support member is composed of a material selected from the group consisting of ruthenium, sapphire, crystal, metal (for example, aluminum, copper, steel), various glasses, and ceramics. The support member may also have other materials deposited on the surface of the adhesive. For example, tantalum nitride can also be deposited on a tantalum wafer, whereby the bonding characteristics can be changed.

(attachment of support members)

When the support member is attached, the adhesive agent of the adhesive described later is applied onto the circuit formation surface of the semiconductor wafer, and then the applied adhesive is dried in an oven or a hot plate. Further, in order to obtain the necessary thickness of the adhesive (adhesive layer), the adhesive liquid coating and pre-drying may be repeated several times.

Further, when an adhesive agent liquid is applied to the circuit formation surface of the semiconductor wafer, before the application of the adhesive agent liquid is performed, as shown in Japanese Patent Laid-Open Publication No. 2009-528688, The slurry polymer separation layer is deposited on the circuit surface of the semiconductor wafer, and when the support member is peeled off, there is a case where it is peeled off between the circuit formation surface of the semiconductor wafer and the plasma polymer separation layer.

Further, when the adhesive liquid is applied to the circuit formation surface of the semiconductor wafer by the spin coater, there is a possibility that the peripheral portion is elevated by a bead portion. In this case, it is preferred to pre-dry the adhesive liquid. Before, the bead portion is removed with a solvent.

(adhesive)

As the adhesive, a commercially available person can be used in the present invention. For example, Wafer BONDTM material sold by Brewer Science (Lola, Missouri) (Wafer BONDTM HT 10.10 for sliding bonding process, WaferBONDTM CR200 for chemical bonding process), or ELASTOSIL LR 3070 of WACKER company, etc. .

Further, it is preferably a resin or a polymer which exhibits a high adhesion to a semiconductor material, glass or metal, and is preferably a high solid content such as a reactive epoxy resin and an acrylic UV curable resin.贰) a thermosetting resin of the same type as a 2-liquid epoxy or a bismuth adhesive, or a polymer of a thermoplastic acrylic resin, a styrene resin, an ethylene halide (non-fluorine-based) resin or a vinyl ester or Copolymers are coated with polyamidosamines, polyimines, polyfluorenes, polyether oximes or polyurethanes in a molten state or a solution coating film, and then sintered after coating. Drying makes the support member more dense with the semiconductor wafer, and (or) a cyclic olefin, a polyolefin rubber (for example, polyisobutylene) or a resin-based adhesive resin.

As the adhesive, since water is used during polishing, it is preferably a water-insoluble polymer compound, and it is desired that the softening point is high. Examples of such a polymer compound include a novolac resin, an epoxy resin, a guanamine resin, an anthraquinone resin, an acrylic resin, a urethane resin, polystyrene, polyvinyl ether, polyvinyl acetate, and a modified product thereof. Or a mixture of them dissolved in a solvent In the middle. Among them, the acrylic resin material has heat resistance of 200 ° C or more, and generates less gas, which is preferable because cracking is less likely to occur. Further, the novolac resin is also free from scum, and the heat resistance, the amount of generated gas, and the generation of cracks are inferior to those of the acrylic resin, but the softening point is high, and the peeling after the subsequent step is preferable in terms of solvent peeling. In addition to this, a plasticizer may be mixed to prevent cracking during film formation.

Further, as the solvent, the resin may be dissolved and uniformly formed on the wafer, and examples thereof include ketones (for example, acetone, methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, and the like). Methyl isoamyl ketone, 2-heptanone, etc.), polyols or derivatives thereof (eg ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol monoacetate, propylene glycol monoacetate, diethyl a diol monoacetate or such monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether, etc., a cyclic ether (for example, dioxane), an ester Class (eg, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, etc.) or aromatic Hydrocarbons (eg, benzene, toluene, xylene, etc.). Among these, a ketone or a derivative thereof as described above is particularly preferred.

These may be used singly or in combination of two or more. In order to increase the uniformity of the film thickness, an active agent may also be added thereto.

(adhesive residue cleaning agent)

After removing the adhesive and the supporting member from the semiconductor wafer, the cleaning liquid for removing the adhesive residue remaining on the semiconductor wafer 1 may be used in addition to the organic solvent used for the above-mentioned adhesive. , A Alcohol, ethanol, propanol, isopropanol, butanol, etc.), lactones (for example, γ-butyrolactone, etc.), indoleamines (for example, γ-butyrolactam, etc.), ethers (for example) , diethyl ether or anisole, etc.), aldehydes (eg, dimethylformaldehyde, dimethylacetaldehyde, etc.)). Among these, a ketone or a derivative thereof as described above is preferred.

These may be used singly or in combination of two or more. Further, in order to effectively wash the adhesive residue, an active agent may be added thereto.

The invention will now be described in more detail on the basis of examples. The invention is illustrated by the following examples, but the invention is not limited to the examples.

(Example 1)

NCO group of 2-methylpropenyloxyethyl isocyanate which is a compound having a photopolymerizable carbon-carbon double bond and a functional group, 2-ethylhexyl acrylate (70 mol%), methacrylic acid ( 1 mol%), 2-hydroxypropyl acrylate (29 mol%) copolymer of 2-hydroxypropyl acrylate side chain OH group is subjected to an addition reaction to obtain an acrylic compound having a photopolymerizable carbon-carbon double bond ( A1: molecular weight 700,000). To 100 parts by mass of the compound (A1), 1 part by mass of trimethylolpropane-modified hexamethylene diisocyanate was added as a polyisocyanate, and 5.0 parts by mass of BASF Corporation: Irgacure 184 as a photopolymerization initiator. A resin composition of a radiation curable adhesive is prepared. The resin composition was applied to a release-treated surface of a polyethylene terephthalate separator previously subjected to release treatment so that the thickness of the adhesive layer after drying became 10 μm. After drying at ° C for 10 minutes, it was bonded to a corona-treated surface of a low-density polyethylene which was subjected to corona treatment in advance, and the adhesive was transferred onto a base resin film to prepare an adhesive tape for semiconductor processing.

(Example 2)

NCO-based ethyl acrylate (70 mol%), methacrylic acid (1 mol%), 2-methylpropenyloxyethyl isocyanate, which is a compound having a photopolymerizable carbon-carbon double bond and a functional group, The OH group of the 4-hydroxybutyl acrylate side chain of the copolymer of 4-hydroxybutyl acrylate (29 mol%) is subjected to an addition reaction to obtain an acrylic compound having a photopolymerizable carbon-carbon double bond (A2: molecular weight: 180000) ). To 100 parts by mass of the compound (A2), 1 part by mass of trimethylolpropane-modified hexamethylene diisocyanate was added as a polyisocyanate, and 5 parts by mass of BASF Corporation: Irgacure 184 was used as a photopolymerization initiator. A resin composition of a radiation curable adhesive is prepared. The resin composition was applied onto a release-treated surface of a polyethylene terephthalate separator previously subjected to release treatment so that the thickness of the adhesive layer after drying became 10 μm, and dried at 80 ° C for 10 minutes. After that, the corona-treated surface of the ionic polymer film (base resin film) of the ethylene-acrylic acid copolymer prepared in such a manner that the surface roughness of the surface on the opposite side of the surface is corona-treated is 0.3. The adhesive is transferred onto the base resin film to form an adhesive tape for a semiconductor wafer.

(Example 3)

In addition to blending 3 parts by mass of trimethylolpropane modified hexamethylene di An isocyanate was used as the polyisocyanate, and an adhesive tape for semiconductor processing was produced in the same manner as in Example 1.

(Example 4)

An adhesive tape for semiconductor processing was produced in the same manner as in Example 1 except that 0.1 parts by mass of trimethylolpropane-modified hexamethylene diisocyanate was blended as a polyisocyanate.

(Example 5)

In the same manner as in Example 1, except that 20.0 parts by mass of pentaerythritol tetraacrylate was further blended as the ultraviolet curable resin in the radiation curable adhesive of Example 1, an adhesive tape for semiconductor processing was produced.

(Example 6)

In the same manner as in Example 1, except that 0.1 mass part of Preminol S3011 (number average molecular weight: 10,000) manufactured by Asahi Glass Co., Ltd. was blended as the polypropylene oxide in the radiation curable adhesive of Example 1, the same was used for the semiconductor processing. Adhesive tape.

(Example 7)

In the same manner as in Example 1, except that 1.0 mass part of Preminol S3006 (number average molecular weight: 5000) manufactured by Asahi Glass Co., Ltd. was blended as the polypropylene oxide in the radiation curable adhesive of Example 1, the same was used for the semiconductor processing. Adhesive tape.

(Example 8)

In the same manner as in Example 1, except that 2.0 parts by mass of Uniol TG-4000 (number average molecular weight: 4000) manufactured by Nippon Oil Co., Ltd. was blended as the polypropylene oxide in the radiation curable adhesive of Example 1. Adhesive tape for semiconductor processing.

(Example 9)

In the same manner as in Example 1, except that 2.5 parts by mass of Preminol S3006 (number average molecular weight: 5000) manufactured by Asahi Glass Co., Ltd. was blended as the polypropylene oxide in the radiation curable adhesive of Example 1, the semiconductor processing was carried out. Adhesive tape.

(Embodiment 10)

A semiconductor processing adhesive was produced in the same manner as in Example 1 except that the low-density polyethylene prepared by subjecting the surface to a corona treatment in advance and having a surface roughness of 0.19 μm on the opposite side was used as the base resin film. tape.

(Example 11)

The same as in Example 1, except that the ionic polymer film of the ethylene-acrylic acid copolymer prepared by the surface having the surface roughness of 0.12 μm on the opposite side was used as the base resin film. Making adhesive tape for semiconductor processing.

(Embodiment 12)

The semiconductor processing was carried out in the same manner as in Example 1 except that the ethylene-methacrylic acid copolymer prepared by subjecting the surface to a corona treatment in advance and having a surface roughness of 0.1 μm on the opposite side was used as the base resin film. Use adhesive tape.

(Example 13)

A semiconductor processing was carried out in the same manner as in Example 1 except that the ethylene-vinyl acetate copolymer prepared by subjecting the surface to a corona treatment in advance and having a surface roughness of 0.08 μm on the opposite side was used as the base resin film. Use adhesive tape.

(Comparative Example 1)

In the same manner as in Example 1, except that 30.0 parts by mass of pentaerythritol tetraacrylate was further blended as the ultraviolet curable resin in the radiation curable adhesive of Example 1, an adhesive tape for semiconductor processing was produced.

(Comparative Example 2)

NCO group of 2-methylpropenyloxyethyl isocyanate which is a compound having a photopolymerizable carbon-carbon double bond and a functional group, 2-ethylhexyl acrylate (75 mol%), methacrylic acid ( 1 mol%), 2-hydroxyethyl acrylate (24 mol%) copolymer of 2-hydroxyethyl acrylate at the side of the side chain of the OH group is subjected to an addition reaction to obtain a photopolymerizable carbon-carbon double The acrylic compound of the bond (A1: molecular weight: 800,000). To 100 parts by mass of the compound (A1), one part by mass of Japan Polyurethane Industrial Co., Ltd. was used: Coronate L as a polyisocyanate, and 5.0 parts by mass of BASF Corporation: Irgacure 184 as a photopolymerization initiator to prepare radiation curability. The resin composition of the adhesive. The resin composition was applied onto a release-treated surface of a polyethylene terephthalate separator previously subjected to release treatment so that the thickness of the adhesive layer after drying became 10 μm, and dried at 80 ° C for 10 minutes. After that, the corona-treated surface of the ethylene-vinyl acetate copolymer film (base resin film) prepared by applying a corona treatment to the surface on the opposite side and having a surface roughness of 0.41 is adhered to the surface. The agent is transferred onto a base resin film to form an adhesive tape for a semiconductor wafer.

(Comparative Example 3)

An adhesive tape for semiconductor processing was produced in the same manner as in Example 1 except that 5 parts by mass of trimethylolpropane-modified hexamethylene diisocyanate was blended as a polyisocyanate.

(Comparative Example 4)

An adhesive tape for semiconductor processing was produced in the same manner as in Example 1 except that 0.05 parts by mass of hexamethylene diisocyanate modified by trichloromethylpropane manufactured by Japan Polyurethane Industrial Co., Ltd. was used as the polyisocyanate.

Condensation of each of the samples of Examples 1 to 13 and Comparative Examples 1 to 4. The gel fraction, the probe contact, the solvent resistance, the peeling property of the support member, the wafer pick-up property, the adhesion of the adhesive to the back surface of the semiconductor wafer (residue residue), and the infiltration of the cutting dust were evaluated as follows. The results obtained are summarized in Tables 1 and 2 below.

<gel fraction>

The separator is removed from the adhesive tape for semiconductor processing cut into a size of 50 mm × 50 mm, and the mass A is weighed. Next, the sample of the weighed semiconductor processing dicing tape was immersed in 100 g of methyl isobutyl ketone (MIBK) for 48 hours, and then dried at 50 ° C in a constant temperature layer, and the mass B was weighed. Further, after removing the adhesive layer of the sample by using 100 g of ethyl acetate, the mass C of the sample was weighed, and the gel fraction was calculated by the following formula (1).

Gel fraction (%) = (B-C) / (A-C) (1)

<probe touch sticky>

The Tacking test machine TAC-II of Rhesca Co., Ltd. was used. The measurement mode is a "constant load" in which the probe is pressed to the set pressure value and the pressurization value is maintained until the set time elapses. After the separator was peeled off, the adhesive layer of the adhesive tape for semiconductor processing was faced upward, and a probe made of SUS304 having a diameter of 3.0 mm was contacted from the upper side. The speed at which the probe is in contact with the assay sample is 30 mm/min, contact load was 0.98 N, and contact time was 1 second. Subsequently, the probe was pulled upward at a peeling speed of 600 mm/min, and the required pull-off was measured, and the peak value was read. The probe temperature was 23 ° C and the plate temperature was set to 23 ° C.

<surface roughness Ra>

The surface of the adhesive tape for semiconductor processing obtained in the examples and the comparative examples, which was coated with the adhesive, was bonded to a smooth mirror wafer and fixed, and a surface roughness measuring device (manufactured by Mitsu Toyo Co., Ltd., trade name: SURFTEST SJ-301) The arithmetic mean roughness Ra of the uncoated side of the adhesive was measured at any five locations in the extrusion direction (MD direction) of the base resin film, and the average value was obtained.

<Parallel light transmittance>

The transmittance of any five parts was measured by the transmittance tester (product name: UV3101 PC & MPC-3100, manufactured by Shimadzu Corporation), from the surface of the uncoated adhesive of the adhesive tape for semiconductor processing obtained in the examples and the comparative examples. The parallel light transmittance is averaged. This apparatus is a device capable of measuring the total light transmittance of a light receiving unit having an integrating sphere type. However, the parallel light transmittance is measured by pulling the fixed position of the sample away from the integrating sphere incident window by 70 mm.

<Solvent resistance>

Adhesive tape for semiconductor wafer processing obtained in the examples and comparative examples After being bonded to an 8-inch semiconductor wafer and fixed to a ring frame, methyl isobutyl ketone (MIBK) as an organic solvent was blown from the side of the semiconductor wafer, and rotated by rotation at 20 rpm. Wash. After the completion of the drying, the adhesive layer in the region where the semiconductor wafer was not attached to the dicing tape for semiconductor processing was observed. If the adhesive was not dissolved or swollen, it was judged as ○, and it was judged that it was acceptable, and it was noted that the adhesive was dissolved or swollen. It was judged to be unqualified.

<Support member peelability>

The plasma polymer separation layer, the polyoxyethylene rubber adhesive layer, and the support member are sequentially laminated on a 6-inch wafer having a thickness of about 700 μm using the method disclosed in the specification of the US Patent Application Publication No. 2011/0272092. A glass plate having a thickness of 2.5 mm was used to obtain the structure 1. The adhesive tape for semiconductor processing obtained in the examples and the comparative examples is bonded to the back surface of the wafer (the surface on which the plasma polymer separation layer or the like is not laminated) of the structure 1 obtained as described above, and is fixed to the ring frame and then supplied. The De-Bonder DB12T manufactured by Suss Microtec Co., Ltd. was used to evaluate the peelability of the support member. The separator between the plasma polymer separation layer and the wafer surface of the support member was judged to be ○, and the plasma polymer separation layer of the support member was not peeled off from the wafer surface, and the wafer back surface and the adhesive tape for semiconductor processing were used. The inter-peeler was recorded as x and was judged as unacceptable.

<Pickup>

The pickup property was evaluated in the following order.

(1) Grinding 8 吋 semiconductor wafers to thickness under the following conditions Degree 50 μm.

(grinding conditions)

Grinding machine: "DFG-840" made by DISCO Co., Ltd.

Single axis: #600 grinding stone (number of revolutions: 4800 rpm, descending speed: P1: 3.0 μm/sec, P2: 2.0 μm/sec)

2 axes: #2000 grinding stone (number of revolutions: 5500 rpm, descending speed: P1: 0.8 μm/sec, P2: 0.6 μm/sec)

After grinding the back surface of the wafer by 30 μm in two axes, the thickness of the tantalum wafer was 50 μm.

(2) After the grinding of (1) is completed, the dicing tape of each example is attached to the above in 5 minutes (hereinafter referred to as condition (ii)) or after standing for 24 hours (hereinafter referred to as condition (i)). 1) The ground surface of the obtained semiconductor wafer is fixed to the ring frame.

(3) Using a dicing apparatus (DAD 340 manufactured by DISCO Corporation), the semiconductor wafer fixed to the ring frame in (2) was cut into a square of 15 × 10 mm along the set dividing line by the following conditions.

(cutting conditions)

Cutter: "DFD-340" made by DISCO Co., Ltd.

Cutting knife: "27HECC" manufactured by DISCO Co., Ltd.

Cutting knife revolutions: 40,000 rpm

Cutting speed: 100mm/sec

Cutting depth: 25μm

Cutting mode: descending cutting

Cutting size: 10.0×10.0mm

(4) After 7 days from the bonding of the adhesive tape for semiconductor processing, ultraviolet rays of 100 mJ/mm ^{2 were} irradiated from the side of the base resin film of the adhesive tape for semiconductor processing to harden the adhesive layer, and a dice picker was used. (CAP-300II, manufactured by Canon Machinery Co., Ltd.) picks up a singulated semiconductor wafer. Any 50 semiconductor wafers are picked up under the following pick-up conditions, and the number of successfully picked semiconductor wafers is counted. When all 50 semiconductor wafers in the above conditions (i) and (ii) are successfully picked up, they are marked as ◎, and all of the conditions (i) are 50. The semiconductor wafer was successfully picked up. However, in the case of condition (ii), the pick-up was recorded as ○, in the condition (i), the pick-up was recorded as ×, ◎ and ○ were judged as pass, and × was judged as unacceptable.

(pick condition)

Wafer bonding machine: "CAP-300II" manufactured by Canon Machinery Co., Ltd.

Number of stitches: 4

Needle spacing: 7.8 × 7.8mm

Needle tip curvature: 0.25mm

Needle top amount: 0.4mm

<paste residue>

The back surface of the semiconductor wafer obtained by the pick-up evaluation was observed by a microscope, and those who had no paste residue at all were judged as ○, and those who had residual paste were judged as unacceptable.

<Cutting dust immersion>

The back surface of the semiconductor wafer obtained by the evaluation of the pick-up property by the microscope was observed as ○ when the cutting dust was not completely immersed, and a part of the cutting dust was infiltrated, but the level which was practically not problematic was judged as △, and it was judged that the cutting dust was severely immersed. Those who have problems in use are recorded as x and are judged as unqualified.

<Wafer division rate>

The adhesive tape for semiconductor processing obtained in the examples and the comparative examples was bonded to a 100 μm thick 8 Å semiconductor wafer, fixed to a ring frame, and adhered to the semiconductor processing adhesive under the following conditions. After the laser was irradiated with a tape to form a modified region inside the semiconductor wafer, the expansion device (DDS2300, manufactured by DISCO Corporation) was used to expand the adhesive tape for semiconductor processing under conditions of 300 mm/sec and 10 mm. Divided into wafer units. Subsequently, the number of wafers that are completely singulated is calculated by visual inspection, and 98% or more of the total number is divided into ○, 90% or more, and less than 98% of the divided persons are practically allowable and recorded as Δ, and are judged as Qualified, less than 90% of the divided persons recorded as × is judged as unqualified.

<Invisible laser wafer cutting conditions>

. Device: Nd-YAG laser

. Wavelength: 1064nm

. Repeat frequency: 100kHz

. Pulse width: 30ns

. Cutting speed: 100mm / sec

. Cutting wafer size: 5mm × 5mm

<Wafer spacing ratio>

The semiconductor wafer used for the evaluation of the wafer division ratio was observed using an optical microscope, and 20 wafers were randomly extracted from the successfully divided wafer, and the wafer interval between the wafers adjacent to each other above and below the wafer was measured. The ratio of the average of the wafer spacing of the wafers adjacent to the upper and lower sides and the average of the wafer spacing of the wafers adjacent to the left and right in the wafer interval (average of the wafer spacing from the wafers adjacent to the upper and lower sides/the wafer adjacent to the left and right) The average value of the wafer interval is 0.8 or more and 1.25 or less, which is considered to be extremely good. ◎ 0.6 or more to less than 0.8%, and more than 1.25 and 1.67 or less are regarded as relatively good ○, 0.4 or more and less than 0.6%. When it is more than 1.67 and not more than 2.5, it is judged as a practically acceptable Δ, and it is judged that it is a pass, and it is judged that it is unsatisfactory, and it is judged that it is unqualified at the time of the evaluation of the wafer division rate.

As shown in Tables 1 and 2, the gel fraction of the adhesive layer is 65% or more, and the semiconductor processing of Examples 1 to 13 in which the peak of the adhesive layer of the adhesive layer before the ultraviolet irradiation is 200 to 600 kPa is shown. The adhesive tape was judged to be acceptable in all evaluation items, and it was practically used without problems in the manufacture of the semiconductor element including the glass supporting step. In particular, the adhesive layer uses at least an acrylic polymer having a radiation-curable carbon-carbon double bond in the molecule, a photopolymerization initiator, and polypropylene oxide, and the total solid of the polypropylene oxide relative to the radiation-curable adhesive layer. In Examples 6 to 8 in which the component was 0.1% by mass or more and 2.0% by mass or less, the pick-up property was more excellent, and dicing dust did not occur, which was particularly excellent. Polyacrylic acid In Example 9 in which the total solid content of the aerogel to the radiation curable adhesive layer exceeded 2.0% by mass, the pick-up property was superior to those of Examples 1 to 5, but some of the cutting dust was infiltrated, but it was a practically no problem. Further, the wafer splitting ratio of any of Examples 1 to 13 in which the parallel light transmittance of light having a wavelength of 1064 nm incident on the substrate resin film side in the adhesive tape for semiconductor processing is 88% or more and less than 100% is Practically no problem grade, it can be preferably used to irradiate a laser over an adhesive tape for semiconductor processing, and after forming a modified region inside the semiconductor wafer, the wafer is divided into wafer unit stealth laser wafers using an expansion device. Cutting. In particular, in Examples 10 to 13 in which the parallel light transmittance was 93 to 99%, the results of excellent wafer division ratio were obtained. Further, Examples 1 to 12 in which the surface roughness Ra of the base resin film on the opposite side to the pressure-sensitive adhesive layer was 0.1 μm or more and 0.3 μm or less were excellent in the wafer spacing ratio.

On the other hand, in Comparative Example 1 in which the gel fraction of the adhesive layer was less than 65%, the adhesive member was dissolved or swollen in the solvent resistance test, and the support members of Comparative Examples 2 and 3 having a peeling force of less than 200 kPa were peeled off. In Comparative Example 3, in which the contact viscosity was greater than 600 kPa, paste residue occurred on the back surface of the wafer, and the display was not applicable to the manufacture of the semiconductor element including the glass supporting step. Further, in Comparative Example 2, the parallel light transmittance of light having a wavelength of 1064 nm incident on the resin film side of the base material for the semiconductor processing adhesive tape was less than 88%, and the wafer division ratio was insufficient.

Claims (6)

An adhesive tape for semiconductor processing, which is obtained by bonding a support member that bonds a semiconductor wafer and polishing a back surface of the semiconductor wafer, and then bonding the surface of the semiconductor wafer to a polishing surface before the support member is peeled off, and After mechanically peeling off the support member, the adhesive tape for semiconductor processing used for cutting the semiconductor wafer is characterized in that a radiation-curable adhesive layer is formed on at least one surface of the base resin film, and the adhesive layer contains the following (a) All of the compounds of (a) to (c), (a) an acrylic compound having an unsaturated double bond formed by the following compounds (a1) to (a3), and having a weight average molecular weight of 100,000 or more and 2,000,000 or less (a1) from amyl acrylate, n-butyl acrylate, isobutyl acrylate, ethyl acrylate, methyl acrylate, hexyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, Dodecyl acrylate, decyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate or the same methacrylate, acrylic acid, methacrylic acid, laurel Acid, itaconic acid, fumaric acid, phthalic acid, hydroxyalkyl acrylates, hydroxyalkyl methacrylates, glycol monoacrylates, glycol monomethacrylates, N-hydroxyl Methyl acrylamide, N-methylol methacrylamide, allyl alcohol, N-alkylaminoethyl acrylate, N-alkylaminoethyl methacrylate, acrylamide, Methacrylamide, maleic anhydride, itaconic anhydride, fumaric anhydride, phthalic anhydride, glycidyl acrylate, A a polymer or a mixture of several polymers (a2) selected from the group consisting of glycidyl acrylate, allyl glycidyl ether, vinyl acetate, styrene, acrylonitrile, vinyl alcohol, and the like The acrylic compound having a functional group in which the compound (a1) is copolymerized is a hydroxyalkyl acrylate or a hydroxyalkyl acrylamide, and the molecular weight of 100 or more (a3) is added as the compound (a1). When the side chain to be subjected to the addition reaction is a carboxyl group or an acid anhydride, the compound having a functional group and a photopolymerizable carbon-carbon double bond is a glycidyl (meth)acrylate which is on the side of the addition reaction. When the chain is an epoxy group, it is a (meth)acrylic acid, and when the side chain to be subjected to the addition reaction is a hydroxyl group, it is a 2-isocyanate alkyl (meth)acrylate (b) photopolymerization initiator (c) The methyl isomer of the polyisocyanate-based pressure-sensitive adhesive layer of the above-mentioned compound (a) in an amount of 0.1 to 15 parts by mass based on 100 parts by mass of the compound (a), which is used for cleaning the adhesive residue used for bonding the support member before ultraviolet irradiation. The gel fraction of butyl ketone is 65%. In addition, the compounds (a) to (c) of the pressure-sensitive adhesive layer are adjusted so that the probe layer of SUS304 having a diameter of 3.0 mm at 23 ° C before the ultraviolet irradiation is 30 mm/min. After the contact speed of 0.98 N was contacted for 1 second, the peak of the probe touch test for measuring the force required to pull the probe upward at a peeling speed of 600 mm/min was 200 to 600 kPa. The adhesive tape for semiconductor processing according to claim 1, wherein the pressure-sensitive adhesive layer further contains polypropylene oxide, and the polypropylene oxide is contained in an amount of 0.1% by mass or more and 2.0% by mass or less based on the total solid content of the pressure-sensitive adhesive layer. The adhesive tape for semiconductor processing according to claim 2, wherein the number average molecular weight of the polypropylene oxide is more than 3,000 and not more than 10,000. The adhesive tape for semiconductor processing according to any one of claims 1 to 3, wherein a parallel light transmittance of light having a wavelength of 1064 nm incident from the side of the base resin film is 88% or more and less than 100%. The adhesive tape for semiconductor processing according to any one of claims 1 to 4, wherein a surface roughness Ra of the base resin film opposite to the adhesive layer is 0.1 μm or more and 0.3 μm or less. The adhesive tape for semiconductor processing according to any one of claims 1 to 5, wherein a surface roughness Ra of the base resin film opposite to the adhesive layer is 0.12 μm or more and 0.19 μm or less.