TWI506118B - Dicing tape - Google Patents

Description

Cutting tape

The present invention relates to dicing tape. In particular, the present invention relates to a dicing tape for fixing a semiconductor wafer or the like when the semiconductor wafer or the like is cut (separated) into small pieces of the element.

In the past, semiconductor wafers made of germanium, gallium, arsenic, and the like were fabricated in a large-diameter state, and then separated (cut) into small pieces by cutting, and then transferred to a mounting step. At this time, the semiconductor wafer is subjected to the steps of the cutting step, the cleaning step, the stretching step, the pickup step, and the mounting step in a state in which the dicing tape is attached and held. The dicing tape is formed by applying an adhesive layer such as an acrylic adhesive to a substrate made of a plastic film (see, for example, Patent Document 1).

The foregoing picking step is as shown in FIG. 5, and the dicing tape 1 on the lower portion of the picked semiconductor wafer 10 is lifted up by the pin 12, lifted in a dot shape or a line shape, or rubbed against each other to promote the semiconductor wafer 10 and In a state in which the dicing tape 1 is peeled off, the semiconductor wafer 10 is picked up by suction from the upper portion by the adsorption jig 13 or the like.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] JP-A-2010-225753

However, as the thickness of the semiconductor element progresses, especially when the thickness of the semiconductor wafer is 100 μm or less, the conventional dicing tape may be picked up by the ejector pin as long as the ejector pin is quickly lifted up to pick up the semiconductor wafer. The impact caused by the jacking causes the semiconductor wafer to be very susceptible to cracking. Therefore, when the impact on the semiconductor wafer is suppressed and the jacking pin is slowly lifted up, there is a problem that the pickup time becomes long. Further, in the conventional dicing tape, the peeling force of the dicing tape and the semiconductor wafer is larger as the peeling speed is faster. Therefore, even if the jacking pin is quickly lifted up while suppressing the impact on the semiconductor wafer, the peeling force is also changed when the peeling speed is fast, when the peeling speed is fastened by the lifting of the dicing tape and the semiconductor wafer by the ejector pin. Large, thin semiconductor chips with low rigidity can be deformed at their ends and easily cause wafer cracking. Therefore, after the dicing tape and the semiconductor wafer are peeled off, the semiconductor wafer is picked up by vacuum adsorption of the adsorption jig after securing a sufficient peeling area, and the pick-up time is still long.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a dicing tape which can be efficiently picked up in a short time without causing wafer breakage in a thin semiconductor wafer in the pickup step after the dicing step.

As a result of repeated active research to achieve the above object, the inventors of the present invention found a dicing tape having an adhesive layer on at least one side of a base resin film, and various types of mirror-finished wafers polished by #2000. The peeling force is a specific value, and it is possible to suppress the wafer from scattering when the semiconductor wafer is diced, and to apply stress to the wafer even if it is lifted up by a pin or the like at the time of the pick-up step, and can be picked up without defects such as wafer cracking. And can shorten the pickup step time. The present invention has been completed based on this finding.

That is, the dicing tape of the present invention has a radiation-curable adhesive layer on at least one side of the base resin film, and the wafer is bonded to the adhesive layer and the dicing tape of the wafer is cut. It is characterized in that the adhesive layer is 100 parts by mass of one or more polymers selected from the group consisting of an acrylic polymer, a vinyl acetate polymer, and an acrylic polymer having a carbon-carbon double bond. Containing 0.5 to 30 parts by mass of phthalate ester, peeling angle of 90 degrees, peeling speed of 50 mm/min under conditions of 23 ° C and 50% RH, and peeling off the mirror wafer with #2000 grinding The force is 0.5N/25mm or more before the adhesive layer is cured by radiation, and is 0.05~0.4N/25mm after the radiation layer is hardened by radiation, and the adhesive layer is hardened by radiation. Under the conditions of 23 ° C and 50% RH, the peeling force at a peeling angle of 90 degrees and the mirror wafer polished by #2000 is set to (i) at a peeling speed of 50 mm/min, and will be 1000 mm. When the peel force of /min is (ii), (ii)/(i) is 1 or less.

Moreover, the above dicing tape is preferably the aforementioned phthalate ester The solubility in water is 0.1 mg/L or less.

According to the present invention, in the pickup step after the cutting step, the wafer of the thin semiconductor wafer is not broken, and the pickup can be performed efficiently in a short time.

1‧‧‧Cut Tape

2‧‧‧Substrate resin film

3‧‧‧Adhesive layer

4‧‧‧Isolation layer

6‧‧‧Semiconductor wafer

7‧‧‧ ring frame

8‧‧‧Adsorption station

9‧‧‧Cutter

10‧‧‧Semiconductor wafer

11‧‧‧ jacking members

12‧‧‧Top pin

13‧‧‧Adsorption fixture

Fig. 1 is a cross-sectional view schematically showing the structure of a dicing tape according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view schematically showing a cutting step of using the dicing tape of the embodiment of the present invention.

Fig. 3 is a cross-sectional view schematically showing a cutting step of using the dicing tape of the embodiment of the present invention.

Figure 4 is a cross-sectional view schematically showing an expanded step of using the dicing tape of the embodiment of the present invention.

Fig. 5 is a cross-sectional view schematically showing a pickup step of using the dicing tape of the embodiment of the present invention.

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

In the dicing tape 1 according to the embodiment of the present invention, at least one adhesive layer 3 is formed on at least one side of the base resin film 2. Figure 1 shows A schematic cross-sectional view showing a preferred embodiment of the radiation-curable dicing tape 1 of the present invention, the dicing tape 1 has a base resin film 2, and an adhesive layer 3 is formed on the base resin film 2. Further, an isolation layer 4 as needed is formed on the adhesive layer 3. In FIG. 1, although the dicing tape 1 in which the adhesive layer 3 is provided on one surface of the base resin film 2 is shown, in the base resin film 2, an adhesive layer may be provided on the other surface on which the adhesive layer 3 is provided (not Graphic).

Hereinafter, various constituent elements of the dicing tape 1 of the present embodiment will be described in detail.

(Substrate Resin Film 2)

The base resin film 2 is not particularly limited, and can be appropriately selected from the conventional base resin film 2. Since the adhesive used as the adhesive layer 3 is a radiation curable resin, the base resin film 2 must be permeable to radiation so as to reduce the adhesive force of the adhesive layer 3 to be cut after being picked up and cut. The extent of the semiconductor wafer 10 (see Fig. 3). The base resin film 2 to be used is preferably a polyolefin such as polyethylene, polypropylene, an ethylene-propylene copolymer, and polybutene, such as a styrene-hydrogenated isoprene-styrene block copolymer, Thermoplastic elastomers of styrene-isoprene-styrene copolymer, styrene-hydrogenated butadiene-styrene copolymer and styrene-hydrogenated isoprene/butadiene-styrene copolymer, such as Ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate copolymer, and ethylene-(meth)acrylic acid metal salt-based ionic polymer ethylene copolymer, poly pair Engineering plastics such as ethylene phthalate, polybutylene terephthalate, polycarbonate, polymethyl methacrylate, etc., soft polyvinyl chloride Polymer materials such as olefin, semi-rigid polyvinyl chloride, polyester, polyurethane, polyamide, polyimine, natural rubber, and synthetic rubber. Further, it may be a mixture of two or more types selected from the group or a stratified layer, and may be arbitrarily selected depending on the adhesion to the adhesive layer 3.

The thickness of the base resin film 2 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 of the base resin film 2 adjacent to the adhesive layer 3 may be subjected to a corona treatment or a primer or the like in order to improve the adhesion.

(adhesive layer 3)

If the adhesive layer 3 is a radiation-curable adhesive layer 3 and has a specific peeling force, the resin composition constituting the adhesive layer 3 is not particularly limited, and is preferably from a polymer side chain or a main chain or A resin composition of a polymer having a carbon-carbon double bond at the end of the main chain, or a resin composition of an ultraviolet curable resin such as a monomer component or an oligomer component of an ultraviolet curable resin, in a general adhesive. Further, the above resin composition preferably has urethane acrylate, epoxy acrylate, polyester acrylate, polyether acrylate, (meth)acrylic oligomer, itaconic acid oligomer, and acetic acid. At least one adhesive selected from the group consisting of vinyl esters is used as a main component.

a resin composition composed of a polymer side chain or a polymer having a carbon-carbon double bond in the main chain or at the end of the main chain, using an acrylic polymer (A) and/or a vinyl acetate polymer (B), An adhesive composition comprising a crosslinking agent (C) and, if necessary, a photopolymerization initiator (D). Furthermore, this implementation The form contains a phthalate (E).

(A) acrylic polymer

The acrylic polymer (A) is exemplified by a (meth) acrylate component as a monomer main component (% by mass in the polymer exceeds 50%), and for the (meth) acrylate component, copolymerization is copolymerizable A monomer having a hydroxyl group (a monomer having a hydroxyl group) in the molecule or the like. In the present specification, the (meth) acrylate includes both an acrylate and a methacrylate.

In the acrylic polymer (A), the (meth) acrylate component as a monomer main component is exemplified by, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (a) Isopropyl acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate Ester, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (methyl) ) decyl acrylate, isodecyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate , tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, cetyl (meth)acrylate, heptadecyl (meth)acrylate An alkyl (meth)acrylate such as octadecyl (meth)acrylate; a cycloalkyl (meth)acrylate such as cyclohexyl (meth)acrylate; or a phenyl (meth)acrylate; Base) acrylate acrylate and the like. The (meth) acrylate may be used singly or in combination of two or more.

The acrylic polymer (A) preferably permeates the polyisocyanate of the crosslinking agent (C) The acid ester is bonded to the urethane bond, reacted with the polyether polyol, and crosslinked by a crosslinking agent to increase the mass average molecular weight (Mw). In this case, the acrylic polymer (A) must have a hydroxyl group bonded to the main chain. The acrylic polymer (A) having a hydroxyl group bonded to the main chain can copolymerize the above (meth) acrylate and can be obtained by copolymerizing a monomer having a hydroxyl group. Monomers which are copolymerizable with (meth) acrylate and have a hydroxyl group are exemplified by 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. 6-hydroxyhexyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, glycerol mono(meth)acrylate, and the like.

In the acrylic polymer (A), in addition to the hydroxyl group (laterally chained) to the main chain, the functional group of the carboxyl group or the glycidyl group may be side-chained. The acrylic polymer (A) having a functional group other than a hydroxyl group can be obtained by copolymerizing a monomer which can copolymerize a (meth) acrylate and has a functional group other than a hydroxyl group. The monomer which can copolymerize (meth) acrylate and has a carboxyl group is exemplified by (meth)acrylic acid (acrylic acid, methacrylic acid), itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid Wait. The monomer which can copolymerize a (meth)acrylate and has a glycidyl group is a glycidyl (meth)acrylate, etc..

(B) vinyl acetate polymer

As the vinyl acetate polymer (B), a vinyl acetate polymer may also be a homopolymer obtained by polymerizing only a vinyl acetate monomer. The monomer component copolymerized with the vinyl acetate monomer in the vinyl acetate polymer is not particularly limited as long as it does not impede the above effects. Listed as, for example, the propylene described above Ethyl ethers such as esters or lauryl vinyl ether, octadecyl vinyl ether, perfluoropropyl vinyl ether, 2-chloroethyl vinyl ether, cyclohexyl vinyl ether, methyl vinyl ether, vinyl octanoate (vinyl versatate), vinyl stearate, acrylamide, methacrylamide, N,N-dimethyl decylamine, acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, ethylene Sulfonic acid, propylene sulfonic acid, dimethylaminoethyl methacrylate, vinyl imidazole, vinyl pyridine, vinyl succinimide, vinyl carbonate, allyl alcohol, allyl acetate, and the like.

In the synthesis of the acrylic polymer (A) and the vinyl acetate polymer (B), the organic solvent in the case of copolymerization by solution polymerization is exemplified by a ketone-based, ester-based, alcohol-based or aromatic organic solvent. a good solvent for general acrylic polymers such as toluene, ethyl acetate, isopropanol, benzyl fibrin, ethyl cellosolve, acetone, methyl ethyl ketone, etc., and a solvent having a boiling point of 60 to 120 ° C. For the polymerization initiator, a radical generator such as an azobisnitrile such as α,α'-azobisisobutyronitrile or an organic peroxide such as benzamidine peroxide is usually used. At this time, the acrylic polymer (A) and the vinyl acetate polymer of the desired molecular weight can be obtained by adjusting the polymerization temperature and the polymerization time, and then performing the addition reaction of the functional groups, as needed. (B). Further, as the molecular weight to be adjusted, a solvent of a mercaptan or a carbon tetrachloride type is preferably used. Further, the copolymerization is not limited to solution polymerization, and may be any other method such as bulk polymerization or suspension polymerization.

The acrylic polymer (A) and the vinyl acetate polymer (B) are preferably contained in a low molecular weight content from the viewpoint of preventing contamination of a workpiece such as the semiconductor wafer 6 and the like. From this point of view, acrylic polymer The mass average molecular weight (Mw) of the (A) and vinyl acetate polymer (B) is preferably 100,000 or more, more preferably 200,000 to 2,000,000. When the mass average molecular weight (Mw) of the acrylic polymer (A) and the vinyl acetate polymer (B) is too small, the contamination prevention property of the workpiece such as the semiconductor wafer 6 is lowered, and the mass average molecular weight (Mw) is too large. At this time, the viscosity of the adhesive composition for forming the radiation curable adhesive layer 3 becomes extremely high, which makes it difficult to manufacture the dicing tape 1.

The acrylic polymer (A) and the vinyl acetate polymer (B) preferably have a glass transition point of -70 ° C to 0 ° C, more preferably -65 ° C to -20 ° C from the viewpoint of exhibiting adhesion. When the glass transfer point is too small, the viscosity of the acrylic polymer (A) and the vinyl acetate polymer (B) is too low, and it is difficult to form a stable coating film. When the glass transition point is too high, the adhesive becomes too hard and is placed on the surface. The wettability of the body deteriorates.

(C) crosslinker

The crosslinking agent (C) uses at least a polyisocyanate as a crosslinking agent, preferably crosslinked before radiation hardening. The polyisocyanate crosslinking agent is not particularly limited as long as it is an isocyanate group-containing crosslinking agent. Examples thereof include toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, etc., or such urerea type, isocyanurate type, addition molding, and blocking type. A variety of polymers and the like. By using a hydroxyl group-reactive polyisocyanate as a crosslinking agent, it is possible to incorporate a polyether polyol into a crosslinked structure, which prevents the polyether polyol from moving to the surface of the semiconductor wafer 6 and contaminating the surface of the wafer 6. In addition, it can be used in combination with a crosslinking agent other than polyisocyanate. As a crosslinking agent. However, in the acrylic polymer (A) or the vinyl acetate polymer (B), it is necessary to have a functional group reactive with a crosslinking agent. Such a crosslinking agent may, for example, be an epoxy crosslinking agent, an aziridine crosslinking agent, a melamine resin crosslinking agent, a urea resin crosslinking agent, an acid anhydride crosslinking agent, a polyamine crosslinking agent, or the like. A carboxyl group-containing polymer crosslinking agent or the like is appropriately selected and used.

(D) Photopolymerization initiator

In the radiation curable adhesive layer 3, in order to efficiently polymerize and harden an acrylic polymer (or a radiation curable component) having a carbon-carbon double bond in the molecule when irradiated with radiation, it may contain Photopolymerization initiator. The photopolymerization initiator is exemplified by a benzoin alkyl ether initiator such as benzoin methyl ether, benzoin ether, benzoin propyl ether, benzoin isopropyl ether or benzoin isobutyl ether; a benzophenone-based initiator such as benzophenone, benzhydrylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone or polyvinylbenzophenone; α-hydroxyl Cyclohexyl phenyl ketone, 4-(2-hydroxyethoxy)phenyl (2-hydroxy-2-propyl) ketone, α-hydroxy-α, α'-dimethylacetophenone, methoxybenzene Ethyl ketone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio)-phenyl An aromatic ketone initiator such as -2-morpholinylacetone-1; an aromatic ketal initiator such as benzyl dimethyl ketal; thioxanthone, 2-chlorothioxanthone, 2-methyl Thiophenone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-dodecylthioxanthone, 2,4-dichlorothioxanthone, 2,4-dimethylthiophene a thioxanthone-based initiator such as ketone, 2,4-diethylthioxanthone or 2,4-diisopropylthioxanthone; a benzylic initiator of benzyl or the like; benzoin, etc. a benzoin-based initiator, and an α-ketal compound (2-methyl-2-hydroxyl) Benzene, acetone, etc.), an aryl An aromatic sulfonium chloride compound (2-naphthalenesulfonium chloride, etc.), a photoactive quinone compound (1-benzophenone-1, 1-propanedione-2-(o-ethoxycarbonyl) hydrazine, etc.), Camphorquinone, halogenated ketone, decylphosphine oxide, decylphosphonate, and the like. The photopolymerization initiators may be used singly or in combination of two or more.

The amount of the photopolymerization initiator to be added is preferably from 0.5 to 30 parts by mass, more preferably from 1 to 20 parts by mass, per 100 parts by mass of the acrylic polymer (A) or the vinyl acetate polymer (B).

(E) Phthalates

The phthalic acid esters (E) are exemplified by, for example, dimethyl phthalate, diethyl phthalate, diallyl phthalate, dibutyl phthalate, phthalic acid N-hexyl ester, dioctyl phthalate, di-n-octyl phthalate, diisononyl phthalate, dinonyl phthalate, diisononyl phthalate, phthalic acid Butyl benzyl ester, etc., but with good compatibility with the adhesive, and low solubility in water, dioctyl phthalate, di-n-octyl phthalate, diisononyl phthalate, Dinonyl phthalate is preferred. The reason for this is that if the compatibility with the adhesive is poor, it is likely to be deposited on the surface due to bleed out, which may become a source of contamination and cannot be stably produced. Further, the reason is that if the solubility in water is high, it is dissolved in the cutting water at the time of cutting, which may cause contamination of the surface of the wafer 6. The solubility in water ranges from 0 mg/L to 0.1 mg/L, preferably from 0 mg/L to 0.05 mg/L.

In the present embodiment, since the adhesive layer 3 contains the phthalic acid ester (E), it is excellent in flexibility and can suppress scattering of the wafer during dicing. When the radiation layer is hardened, the adhesive layer 3 is not changed depending on the peeling speed, and the peeling force is made constant or less. Therefore, the wafer crack can be satisfactorily suppressed and the semiconductor wafer 10 can be easily picked up. This effect is particularly remarkable when the dicing tape 1 is bonded to the surface of the unstable wafer 6 on which the natural oxide film is not fully formed, immediately after the polishing of the wafer 6, for example, within one hour after the completion of the polishing.

The amount of the phthalic acid ester may be from 0.5 to 30 parts by mass, preferably from 1 to 20 parts by mass, more preferably from 5 to 10 parts by mass per 100 parts by mass of the acrylic polymer (A) or the vinyl acetate polymer (B). The range of mass parts is appropriately selected. When the amount of addition is small, the effect cannot be exhibited, and when it is too large, it is exuded by the deterioration of the compatibility with the adhesive and becomes a cause of contamination.

(F) Other formulating agents

The adhesive composition for forming the adhesive layer 3 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, and an antioxidant. , conventional additives such as plasticizers and surfactants.

Further, in the above-mentioned adhesive composition, in place of the acrylic polymer (A) and/or the vinyl acetate polymer (B), it is also possible to prepare a functional group by containing an acrylic polymer containing a functional group. The functional group based on the functional group reacted with the carbon-carbon double bond in the acrylic polymer maintains the radiation hardenability (radiation polymerizability) of the carbon-carbon double bond, and the acrylic group containing the functional group The polymer undergoes a condensation reaction or an addition reaction, and an acrylic polymer having a carbon-carbon double bond in the molecule (A2) is used. . As the acrylic polymer containing a functional group, the above acrylic polymer (A) can be used. Further, an acrylic polymer (A) and/or a vinyl acetate polymer (B) and an acrylic polymer (A2) having a carbon-carbon double bond in the molecule may be used in combination.

The compound having a functional group reactive with a functional group in the functional group-containing acrylic polymer and a carbon-carbon double bond is exemplified as (meth)acrylic acid in the case of a side chain carboxyl group or an acid anhydride to be reacted. The glycidyl ester or the like is exemplified by (meth)acrylic acid or the like in the case of the side chain epoxy group to be reacted, and the 2-isocyanate group (meth)acrylic acid is used in the case of the side chain hydroxyl group to be reacted. Alkyl esters and the like.

Further, when a condensation reaction or an addition reaction of a compound having a functional group and a carbon-carbon double bond is carried out on the functional group-containing acrylic polymer, the above reaction can be efficiently carried out by using a catalyst. The catalyst is not particularly limited, but a tin-based catalyst (especially dibutyltin dilaurate) is preferred. The amount of the catalyst to be used is not particularly limited. For example, it is preferably about 0.05 to 1 part by mass based on 100 parts by mass of the acrylic polymer containing a functional group.

The adhesive layer 3 can be formed by a conventional method of forming the adhesive layer 3. For example, the adhesive composition may be applied to a specific surface of the base resin film 2, or the adhesive composition may be applied to a release layer (for example, a release agent has been applied). After the adhesive layer 3 is formed on a plastic film or sheet, the adhesive layer 3 is transferred onto a specific surface of the substrate, whereby the adhesive layer 3 is formed on the base resin film 2. Further, the adhesive layer 3 may have a single layer form or a laminated form.

As for the thickness of the adhesive layer 3, there is no particular limitation, but Good for 3~20μm. When the thickness of the adhesive layer 3 is too thin, the workpiece is easily peeled off during the cutting, so that the semiconductor wafer 10 which has been subjected to the cutting process cannot be held, and the wafer is scattered. When the adhesive layer 3 is too thick, the vibration amplitude of the vibration generated when the semiconductor wafer 6 is diced becomes large, and a defect called a chip occurs, or the adhesive layer rolled up at the time of cutting adheres to the side or surface of the wafer. And the situation of contaminating the wafer.

(isolation layer 4)

The separator 4 is provided for protecting the adhesive layer 3, for the purpose of facilitating the marking process for cutting the dicing tape 1 into a specific shape, or for the purpose of smoothing the adhesive. The constituent material of the separator 4 is exemplified by a synthetic resin film such as paper, polyethylene, polypropylene, or polyethylene terephthalate. The surface of the separator 4 is formed to improve the releasability of the self-adhesive layer 3, and therefore, a stripping treatment such as polyfluorination treatment, long-chain alkyl treatment, or fluorine treatment may be applied as needed. Moreover, anti-ultraviolet treatment may be applied as needed to prevent the adhesive sheet from reacting due to the surrounding ultraviolet rays. The thickness of the separator 4 is usually from 10 to 100 μm, preferably from about 25 to 50 μm.

The dicing tape 1 according to the embodiment of the present invention is bonded to the adhesive layer 3 by a #2000-polished enamel mirror surface under the conditions of 23° C. and 50% RH, and after passing for 1 hour at 23° C. and 50% RH. The peeling force before the radiation curing of the adhesive layer 3 (for the mirror surface, the peeling angle: 90°, the peeling speed: 50 mm/min, under the condition of 23 ° C 50% RH) is 0.5 N/25 mm or more, preferably It is 10 N/25 mm or less, more preferably 2 N/25 mm or less. Cutting tape 1 having adhesive force in this range is cutting The semiconductor wafer 10 that has been cut and processed can be effectively held, and the effect of preventing wafer scattering or cutting dust from entering the back surface of the semiconductor wafer 10 can be exhibited.

Further, in the same manner as described above, the peeling force (the peeling angle: 90°, the peeling speed: 50 mm/min, and the condition of 23° C., 50% RH) of the adhesive layer 3 after the radiation layer hardening was 0.05 to be measured. 0.4 N / 25 mm, preferably 0.1 to 0.3 N / 25 mm, more preferably 0.1 to 0.2 N / 25 mm. When the peeling force exceeds 0.4 N/25 mm, peeling at the interface between the adhesive layer 3 and the semiconductor wafer 6 (see Fig. 2) at the time of pick-up is difficult, and it is impossible to pick up, or it is assumed that the semiconductor wafer 6 may be broken after picking up. . On the other hand, when the peeling force is as low as 0.05 N/25 mm or less, the adjacent semiconductor wafer 10 (see FIG. 4) may be scattered during picking up.

Further, a peeling speed of 1000 mm/min was measured, and the peeling force (the spectacles surface, the peeling angle: 90°, and the condition of 23° C., 50% RH) of the adhesive layer 3 was measured in the same manner as described above. 0.4N/25mm or less. Further, the peeling force of the peeling speed of 50 mm/min is (i), and the peeling force of 1000 mm/min is (ii), (ii)/ (i) is 1 or less, preferably 0.9 or less, more preferably 0.8 or less. When the ratio exceeds 1, the jacking speed of the jacking pin 12 (see FIG. 5) at the time of picking up is slow, and since the peeling force is low, there is no hindrance to picking up, but when the jacking speed is high, the peeling force is increased. There is a drawback that wafer breakage or the like occurs particularly in the semiconductor wafer 6 of the film. Further, the value of (ii)/(i) is preferably 0.2 or more.

<Instructions>

Next, a method of using the dicing tape 1 of the present invention will be described.

After the dicing tape 1 of the present invention is attached to the semiconductor component of the object to be cut, it is supplied to the cutting step in accordance with a usual method, and then moved to the radiation irradiation step and the pickup step. Semiconductor components are exemplified by germanium semiconductors, compound semiconductors, semiconductor packages, glass, ceramics, and the like.

The mounting step is generally performed after the back grinding process of the semiconductor wafer 6, or the crushing layer removing step after the back grinding process of the semiconductor wafer 6, and the like (continuously performing the back grinding step or the crush layer removal of the semiconductor wafer 6). After the step) or in a short period of time (within the back grinding process of the semiconductor wafer 6 or within a few hours after the completion of the crush layer removal step).

As shown in FIG. 2, the mounting step is such that the workpiece such as the semiconductor wafer 6 and the dicing tape 1 are superposed on each other in such a manner that the ground surface of the workpiece and the adhesive layer 3 are in contact with each other. When the conventional pressing mechanism such as the pressing mechanism of the pressure roller presses, the workpiece and the dicing tape 1 are attached. Further, the ring frame 7 for holding the dicing tape 1 in each step is attached to the outside of the bonding position of the workpiece (semiconductor wafer 6) to the adhesive layer 3.

In the cutting step, as shown in FIG. 3, the dicing tape 1 to which the object to be cut is attached is placed on the adsorption table 8, and the cutter 9 is rotated at a high speed to cut the object to be cut into a specific size. The cutting may be performed by a cutting method called full cutting in which a part of the dicing tape 1 is cut. After cutting, the adhesive layer 3 is hardened by irradiation with ultraviolet rays, preferably ultraviolet rays, to make adhesion. When it is lowered, the cut piece of the semiconductor wafer 10 or the like can be easily cut from the dicing tape 1.

Radiation, preferably after UV irradiation, is provided for the picking step. The picking step is shown in Figure 4, and an expansion step can be set. The expansion step is performed by causing the cylindrical lifting member 11 to rise from the lower side of the dicing tape 1 so as to protrude between the ring frame 7 and the cut piece, thereby stretching the dicing tape 1 in the peripheral direction and the radial direction. The picking method is not particularly limited, and various picking methods can be employed in the past. For example, as shown in FIG. 5, each of the cut pieces (semiconductor wafer 10) is lifted up from the lower side of the dicing tape 1 by the ejector pin 12, and the picked-up piece is picked up by the pick-up device such as the suction jig 13 ( The method of the semiconductor wafer 10) and the like.

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)

Ethyl acrylate and butyl acrylate and 2-hydroxyethyl acrylate were copolymerized in ethyl acetate in a usual manner at a mass ratio of 7:2:1 to obtain an acrylic acid polymerization having a hydroxyl group bonded to the main chain. A solution of the substance (A) (solution Aa containing an acrylic copolymer). Next, 5 parts by mass of dioctyl phthalate and 30 parts by mass of the product of the radiation curing agent, "UV3000" (manufactured by Nippon Synthetic Chemical Co., Ltd.), were added to 100 parts by mass of the acrylic polymer (A). And 2.5 parts by mass of the product name "Irgacure 651" (manufactured by BASF Corporation) as a photopolymerization initiator, and 1 part by mass of a polyisocyanate compound as a crosslinking agent (trade name "Coronate L", Japanese The polyurethane-based adhesive solution X1 was obtained from the present Polyurethane Industry Co., Ltd.).

The low-density polyethylene film (thickness: 100 μm) which was subjected to corona discharge treatment on one side was used as a base resin film, and the ultraviolet curable acrylic adhesive solution X1 was applied onto a corona discharge treated surface. The mixture was heated at 80 ° C for 10 minutes to carry out heat crosslinking. Thereby, an ultraviolet curable adhesive layer (thickness: 10 μm) as a radiation-curable adhesive layer was formed on the base resin film. Next, the separator was bonded to the surface of the ultraviolet curable adhesive layer to prepare an ultraviolet curing type dicing tape of Example 1.

(Example 2)

An ultraviolet curable dicing tape of Example 2 was produced in the same manner as in Example 1 except that the dioctyl phthalate was 0.5 parts by mass.

(Example 3)

An ultraviolet curable dicing tape of Example 3 was produced in the same manner as in Example 1 except that the dioctyl phthalate was 30 parts by mass.

(Example 4)

An ultraviolet curable dicing tape of Example 4 was produced in the same manner as in Example 1 except that 5 parts by mass of diisononyl phthalate was added instead of dioctyl phthalate.

(Example 5)

An ultraviolet curable dicing tape of Example 5 was produced in the same manner as in Example 1 except that 5 parts by mass of dibutyl phthalate was added instead of dioctyl phthalate.

(Example 6)

Vinyl acetate was polymerized in a usual manner in ethyl acetate to obtain a solution containing a vinyl acetate polymer (B) (solution Ba containing a vinyl acetate polymer). Next, 5 parts by mass of dioctyl phthalate and 30 parts by mass of the product name "UV3000" as a radiation curing agent are added to 100 parts by mass of the vinyl acetate polymer (B) (polyvinyl acetate) ( 2.5 parts by mass of the product name "Irgacure 651" (manufactured by BASF Corporation) as a photopolymerization initiator, and 1 part by mass of a polyisocyanate compound (trade name) as a crosslinking agent Coronate L", manufactured by Japan Polyurethane Industrial Co., Ltd.), obtained an ultraviolet curable vinyl acetate adhesive solution X2.

Then, in the same manner as in Example 1, an ultraviolet curable adhesive was formed on the base resin film, and the separator was bonded to the surface of the ultraviolet curable adhesive layer to prepare an ultraviolet curable dicing tape of Example 6.

(Example 7)

Copolymerization of 2-ethylhexyl acrylate as a monomer component with 2-hydroxyethyl acrylate in ethyl acetate at a mass ratio of 8:2 A solution (acrylic copolymer-containing solution Ab) containing an acrylic polymer (A) having a hydroxyl group bonded to the main chain. Next, 2-methylpropenyloxyethyl isocyanate which is a compound having a photopolymerizable carbon-carbon double bond and a functional group is added to the solution Ab containing the acrylic copolymer, and dilauric acid is added as a catalyst. Dibutyltin was reacted at 50 ° C for 24 hours to obtain a solution (solution A2b containing an acrylic copolymer) having an acrylic polymer (A2) having a carbon-carbon double bond at the end of the side chain. The hydroxyl group valence of the acrylic polymer (A2) having a carbon-carbon double bond at the end of the side chain was 9.8 mgKOH/g as measured by an acetylation method using pyridine-acetic anhydride described in JIS K 0070. Next, 5 parts by mass of dioctyl phthalate and 2.5 parts by mass of the acrylic polymer (A2) having a carbon-carbon double bond at the end of the side chain are added as a photopolymerization initiator. "Irgacure 651" (manufactured by BASF Corporation), a mass of a polyisocyanate compound (trade name "Coronate L", manufactured by Japan Polyurethane Co., Ltd.), and an ultraviolet curable acrylic adhesive solution X3.

The low-density polyethylene film (thickness: 100 μm) which was subjected to corona discharge treatment on one side was used as a base resin film, and the ultraviolet curable acrylic adhesive solution X3 was applied onto a corona discharge treated surface at 80 The mixture was heated at ° C for 10 minutes to carry out heat crosslinking. Thereby, an ultraviolet curable adhesive layer (thickness: 10 μm) as a radiation-curable adhesive layer was formed on the base resin film. Next, the separator was bonded to the surface of the ultraviolet curable adhesive layer to prepare an ultraviolet curable dicing tape of Example 7.

(Comparative Example 1)

An ultraviolet curable dicing tape of Comparative Example 1 was produced in the same manner as in Example 1 except that dioctyl phthalate was not added.

(Comparative Example 2)

An ultraviolet curable dicing tape of Comparative Example 2 was produced in the same manner as in Example 1 except that the dioctyl phthalate was changed to 0.45 parts by mass.

(Comparative Example 3)

An ultraviolet curable dicing tape of Comparative Example 3 was produced in the same manner as in Example 1 except that the dioctyl phthalate was used in an amount of 35 parts by mass.

(Comparative Example 4)

An ultraviolet curable dicing tape of Comparative Example 4 was produced in the same manner as in Example 6 except that dioctyl phthalate was not added.

(Comparative Example 5)

An ultraviolet curable dicing tape of Comparative Example 5 was produced in the same manner as in Example 7 except that dioctyl phthalate was not added.

<Compatibility>

The ultraviolet curable acrylic adhesive solution prepared in the production of Examples 1 to 7 and Comparative Examples 2 and 3 was visually evaluated for o-phthalic acid. The compatibility of the acid ester. Those who remained transparent after 10 hours were recorded as ◎, and those who were opaque after 7 hours were recorded as ○, those who were opaque after 3 hours were recorded as Δ, and those who were opaque after 1 hour were recorded as ×. The results are shown in Tables 1 and 2.

<Peel force>

(1) Peel force before radiation hardening

The dicing tapes obtained in Examples 1 to 7 and Comparative Examples 1 to 5 were attached to the mirror surface of the mirror wafer of #2000 polished at 23 ° C and 50% RH. After 1 hour at 23 ° C and 50% RH, the peeling force of the adhesive layer before radiation hardening was measured (optical mirror surface, peeling angle: 90°, peeling speed: 50 mm/min, 23 ° C, 50%) RH). The results are shown in Tables 1 and 2. Further, various peeling forces were measured in accordance with JIS Z 0237.

(2) Peel force after radiation hardening

The dicing tapes obtained in Examples 1 to 7 and Comparative Examples 1 to 5 were attached to the mirror surface of the mirror wafer of #2000 polished at 23 ° C and 50% RH. After passing for 1 hour at 23 ° C and 50% RH, ultraviolet rays of 200 mJ/cm ^{2 were} irradiated from the back surface of the dicing tape, and the peeling force after the radiation layer of the adhesive layer was hardened was measured (optical mirror surface, peeling angle: 90°, Peeling speed: 50 mm/min and 1000 mm/min, respectively, 23 ° C, 50% RH). The ratio ((ii)/(i)) of the peeling force (ii) at the tensile speed of 1000 mm/min to the peeling force (i) at a tensile speed of 50 mm/min was calculated. These results are shown in Tables 1 and 2.

<Pickup>

The dicing tapes obtained in Examples 1 to 7 and Comparative Examples 1 to 5 were tested in the following order, and the pick-up properties were evaluated.

(1) After grinding the back surface of the 8 Å wafer by 30 μm in two axes, the final thickness of the wafer was ground to 50 μm or 300 μm. The grinding conditions are as follows.

(grinding conditions)

Grinding machine: manufactured by DISCO Co., Ltd., trade name "DFG-840"

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

2 axes: #200 grinding stone (number of revolutions: 5500 rpm, descending speed: P1: 0.8 μm/sec, P2: 0.6 μm/sec)

(2) The dicing tape of each example was adhered to the grinding surface of the semiconductor wafer obtained in the above (1) within 5 minutes after the completion of the grinding of (1), and fixed by a ring frame.

(3) Using the dicing apparatus, the semiconductor wafer fixed in the ring frame in (2) is completely cut along the set dividing line by the following cutting conditions.

(Cutting condition 1: 矽 wafer 300 μm thick)

Slicer: manufactured by DISCO Co., Ltd., trade name "DFD-340"

Cutter: made by DISCO Co., Ltd., trade name "27 HEEE"

Cutter revolution: 40,000 rpm

Cutting speed: 100mm/sec

Cutting depth: 25μm

Cutting mode: undercut

Cutting size: 5.0×5.0mm

(Cutting condition 2: 矽 wafer 50 μm thick)

Slicer: manufactured by DISCO Co., Ltd., trade name "DFD-340"

Cutter: made by DISCO Co., Ltd., trade name "27 HECC"

Cutter revolution: 40,000 rpm

Cutting speed: 100mm/sec

Cutting depth: 25μm

Cutting mode: undercut

Cutting size: 15.0 × 10.0mm

(4) After 7 days from the adhesion of the dicing tape, ultraviolet rays of 200 mJ/cm ^{2 were} irradiated from the side of the base resin film of the dicing tape to harden the adhesive layer, and the singulated semiconductor wafer was picked up using a pick-up device. 50 semiconductor wafers were arbitrarily picked up under the following pick-up conditions, and the number of semiconductor wafers successfully picked up without causing wafer cracking or wafer scattering was counted, and the picking success rate was evaluated. The results are shown in Tables 1 and 2. Moreover, if the picking success rate is 90% or more, it can be judged as pass.

(Pickup condition 1: 矽 wafer 300μm thick)

Bonding machine: "CAP-300II" made by CANON Mechinery Co., Ltd.

Number of sales: 4

Pin spacing: 3.8 × 3.8mm

Pin tip curvature: 0.25mm

Pin top amount: 0.40mm

Pin top speed: 50mm/min

Pin top hold time: 1000ms

(Pickup condition 2: 矽 wafer 50 μm thick)

Bonding machine: "CAP-300II" made by CANON Mechinery Co., Ltd.

Number of sales: 4

Pin spacing: 7.8 × 7.8mm

Pin tip curvature: 0.25mm

Pin top amount: 0.40mm

Pin top speed: 800mm/min

Pin top hold time: 100ms

<Wafer surface contamination>

XPS (X-ray photoelectron spectroscopy, X-ray photoelectron spectroscopy) was used to measure the surface of the picked-up wafer bonded to the dicing tape by the following measurement conditions, and the dicing tape was derived from the wafer not bonded to the dicing tape. The carbon increase of the pollutant is calculated in mol%. The results are shown in the table 1 and Table 2. If the carbon increase is less than 5 mol%, the good product is represented by ◎, 5 to less than 10 mol% is good as ○, 10 to less than 30 mol% is acceptable as △, and 30 mol% or more is defective.

(measurement conditions)

X-ray source: MgKα

X-ray: exit angle 45°

Measuring area: 1.1mm

As shown in Table 1, under the condition of 23 ° C and 50% RH, the peeling force of the peeling angle of 90 degrees, the peeling speed of 50 mm/min and the peeling force of the mirror wafer polished by #2000 was irradiated on the aforementioned adhesive layer. Before the wire hardening, it is 0.5N/25mm or more, and the adhesive layer is 0.05~0.4N/25mm after radiation hardening, and the adhesive layer is cured by radiation and is under the condition of 23°C and 50% RH. The peeling force of the peeling angle of 90 degrees and the mirror wafer of #2000 polished, the peeling force at the peeling speed of 50 mm/min is (i), and when the peeling force at 1000 mm/min is (ii), (ii)/(i) The dicing tapes of Examples 1 to 7 of 1 or less were excellent in pick-up properties in both of the picking conditions 1 and 2. That is, wafer cracking or wafer scattering of the thin semiconductor wafer is favorably suppressed, and can be efficiently picked up in a short time.

On the other hand, as shown in Table 2, in the dicing tapes of Comparative Examples 1, 2, 4, and 5 in which the above (ii)/(i) exceeded 1, the pick-up property in the pick-up condition 1 was a good result, but in the pick-up condition. 2 is the result of poor pickup. In other words, the conventional semiconductor wafer can be picked up without any problem. However, when the semiconductor wafer is thinned, the pin is lifted up at a rapid jacking speed, and the adhesive layer and the semiconductor wafer are peeled off. The force becomes larger and the wafer is broken. Further, the above (ii)/(i) is 1 or less, but the peeling force of the adhesive layer at the peeling speed of 50 mm/min before the radiation hardening is less than 0.5 N/25 mm, and the adhesive layer is peeled off by the radiation hardening. In Comparative Example 3 in which the force was less than 0.05 N/25 mm, no wafer rupture occurred during picking up of the picking conditions 1 and 2, but a wafer which was adjacent to the wafer was scattered during picking up, and many wafers were scattered, which was a result of poor pickup property.

Further, Comparative Example 3 containing more than 30 parts by mass of phthalic acid ester per 100 parts by mass of the acrylic polymer (A) is inferior in compatibility with the adhesive, and is 0.5 to 30 parts by mass in comparison with the addition amount. In this case, it is a result of a slightly less contaminated wafer. Further, Example 4 in which dinonyl phthalate was added was found to be inferior in compatibility with the case of adding other phthalic acid esters, but there was no problem in practical use. In Example 5, which added dibutyl phthalate having a solubility in water of more than 0.1 mg/L, the cutting water during the cutting dissolves dibutyl phthalate, which deteriorates the surface contamination of the wafer. But for the allowable range.

1‧‧‧Cut Tape

2‧‧‧Substrate resin film

3‧‧‧Adhesive layer

4‧‧‧Isolation layer

Claims (2)

A dicing tape which is provided with a radiation-curable adhesive layer on at least one side of a base resin film, and a wafer is bonded to the adhesive layer and cuts the dicing tape of the wafer, and is characterized by The adhesive layer is contained in an amount of 0.5 part by mass or less per 100 parts by mass of the polymer selected from the group consisting of an acrylic polymer, a vinyl acetate polymer, and an acrylic polymer having a carbon-carbon double bond. ~30 parts by mass of phthalate ester, at a peeling angle of 90 degrees and a peeling speed of 50 mm/min under conditions of 23 ° C and 50% RH, and the peeling force of the mirror wafer polished by #2000, The adhesive layer is 0.5 N/25 mm or more and 10 N/25 mm or less before being cured by radiation, and is 0.05 to 0.4 N/25 mm after the adhesive layer is cured by radiation, and the adhesive layer is hardened by radiation. Under the conditions of 23 ° C and 50% RH, the peeling force at a peeling angle of 90 degrees and the mirror wafer polished with #2000 is set to (i) at a peeling force of 50 mm/min. When the peeling force of 1000 mm/min is (ii), (ii) / (i) is 0.2 or more and 1 or less. The dicing tape of claim 1, wherein the phthalate ester has a solubility in water of 0.1 mg/L or less.