JP5578911B2 - Wafer processing tape - Google Patents

Description

The present invention relates to a wafer processing tape used in a semiconductor wafer dicing step, a pick-up step, a die bonding step, and the like.

In the manufacturing process of a semiconductor device, a semiconductor wafer is cut and separated (diced) into semiconductor chips, a separated semiconductor chip is picked up, and a die bonding (bonding the picked-up chip to a lead frame, a package substrate, etc.) mount)
A process is performed.

In recent years, as a wafer processing tape used in the manufacturing process of the semiconductor device, for example, a wafer processing tape in which an adhesive layer is provided on a base film, or an adhesive layer is further laminated on the adhesive layer Wafer processing tape having a structured structure (dicing die bond film: D
DF) has been proposed and already put into practical use.

When the above dicing die bond film is used, in the dicing process, thread-like waste is generated from the dicing die bond film and adheres to the semiconductor chip or the dicing die bond film, and in the die bonding process or the wire bonding process, the package substrate or the lead frame, Or it adheres to the semiconductor chip and not only significantly reduces workability,
There has been a problem that the reliability of the semiconductor chip is lowered. To solve these problems,
A wafer processing tape has been proposed in which the thickness of the pressure-sensitive adhesive layer is increased, the depth of cut at the time of dicing is stopped by the pressure-sensitive adhesive layer, and the generation of thread-like waste is prevented by not cutting the base film ( For example, see Patent Document 1).

JP 2007-35852 A

However, when using the wafer processing tape as described above in the manufacturing process of the semiconductor device, because the thickness of the adhesive layer is large, between the adjacent semiconductor chips during dicing,
Cutting scraps containing a large amount of adhesive layer are generated, and adjacent chips stick together via the cutting scraps, so that the semiconductor chip cannot be picked up in the semiconductor chip pick-up process, and a plurality of adjacent semiconductor chips are combined together. There was a problem that a problem (double die) occurred in that it was picked up. In particular, when a radiation-curable pressure-sensitive adhesive layer is used as the pressure-sensitive adhesive layer, the adhesive is cured while the semiconductor chips are stuck together in the next radiation irradiation step, and the cut and separated semiconductor chips are fixed to each other. More pickup mistakes were occurring. In particular, when the wafer processing tape having an adhesive layer thickness of 40 μm or more is used, many of the above-mentioned problems occur.

Therefore, the present invention has been made to solve the above problems, and suppresses generation of cutting waste during dicing and adhesion between adjacent semiconductor chips, generation of double dies in the pickup process, and semiconductor chips. An object of the present invention is to provide a wafer processing tape capable of suppressing the occurrence of a problem that the wafer cannot be picked up.

In order to solve the above problems, a wafer processing tape according to the present invention is a wafer processing adhesive tape in which an adhesive layer is laminated on a base film, and the thickness of the adhesive layer is 1 μm or more and 10 μ is less than m, the adhesive layer at 80 ℃ tanδ (a) is, is 0.05 to 0.20, and tan [delta of the adhesive layer at 25 ° C. in a state that is subjected to the pickup step (B ) Is 0.15 or more and 0.25 or less , and tan δ (A) / tan δ (B), which is the ratio of tan δ (A) and tan δ (B), is 0.30 or more and 0.77 or less . It is characterized by that.

In the wafer processing tape, on the side opposite to the base film of the adhesive layer,
An adhesive layer may be further laminated.

In the wafer processing tape, the pressure-sensitive adhesive layer is composed of a structural unit derived from a (meth) acrylic acid alkyl ester monomer having an alkyl group having 2 or more carbon atoms, and 2-hydroxypropyl acrylate and / or 2-hydroxybutyl acrylate. And a copolymer containing 5% by mass or more and 99.5% by mass or less of the structural unit derived from the (meth) acrylic acid alkyl ester monomer may be crosslinked with an isocyanate compound. .

By using the wafer processing tape of the present invention, the generation of cutting waste during dicing and the adhesion of adjacent semiconductor chips are suppressed, and the occurrence of double dies in the pick-up process and the inability to pick up semiconductor chips are suppressed. can do. In particular, when the thickness of the adhesive layer is 40 μm or more, where the above-described problems are likely to occur, generation of cutting waste during dicing and adhesion between adjacent semiconductor chips are suppressed, and double die generation and semiconductors in the pickup process are suppressed. Occurrence of a problem that the chip cannot be picked up can be suppressed.

It is sectional drawing which shows typically the structure of the tape for wafer processing which concerns on embodiment of this invention. It is explanatory drawing which shows typically the state which bonded the semiconductor wafer and the wafer ring on the tape for wafer processing. It is explanatory drawing for demonstrating a dicing process typically. It is explanatory drawing for demonstrating an expand process typically. It is explanatory drawing for demonstrating a pick-up process typically.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, a wafer processing tape 10 according to this embodiment includes an adhesive film 12 including a film-like base film 12 a and an adhesive layer 12 b formed thereon, and the adhesive film 12 on the adhesive film 12. And an adhesive layer 13 laminated thereon. Thus, in the wafer processing tape 10, the base film 12a, the pressure-sensitive adhesive layer 12b, and the adhesive layer 13 are formed in this order.

The pressure-sensitive adhesive layer 12b may be composed of a single pressure-sensitive adhesive layer, or may be composed of a laminate of two or more pressure-sensitive adhesive layers. In FIG. 1, the adhesive layer 13
In order to protect the wafer, the release liner 11 is provided on the wafer processing tape 10.

The pressure-sensitive adhesive film 12 and the adhesive layer 13 may be cut (precut) into a predetermined shape in advance in accordance with the use process and the apparatus. The wafer processing tape 10 of the present invention includes a semiconductor wafer 1.
The form cut | disconnected for every sheet | seat and the form which wound up the long film in which this was formed in multiple numbers in roll shape are included.

Hereafter, each component of the tape 10 for wafer processing of this embodiment is demonstrated in detail.
(Adhesive layer)
The adhesive layer 13 is peeled off from the adhesive film 12 and attached to the semiconductor chip 2 when the semiconductor chip 2 is picked up after the semiconductor wafer 1 or the like is bonded and diced.
It is used as an adhesive when the semiconductor chip 2 is fixed to a substrate or a lead frame. Therefore, the adhesive layer 13 is separated from the separated semiconductor chip 2 in the pickup process.
Adhesive reliability sufficient to bond the semiconductor chip 2 to the substrate or lead frame in the die bonding process. It is what has.

The adhesive layer 13 is obtained by forming a film of an adhesive in advance. For example, a known polyimide resin, polyamide resin, polyetherimide resin, polyamideimide resin, polyester resin, polyesterimide resin, phenoxy used for the adhesive is used. Resins, polysulfone resins, polyether sulfone resins, polyphenylene sulfide resins, polyether ketone resins, chlorinated polypropylene resins, acrylic resins, polyurethane resins, epoxy resins, polyacrylamide resins, melamine resins, and the like and mixtures thereof can be used. Moreover, in order to reinforce the adhesive force with respect to a chip | tip or a lead frame, it is desirable to add a silane coupling agent or a titanium coupling agent to the said material and its mixture as an additive.

The thickness of the adhesive layer 13 is not particularly limited, but is usually preferably about 5 to 100 μm. The adhesive layer 13 may be laminated on the entire surface of the pressure-sensitive adhesive layer 12b of the pressure-sensitive adhesive film 12, but is cut into a shape corresponding to the semiconductor wafer 1 to be bonded in advance (pre-cut).
The adhesive layer 13 may be laminated on a part of the pressure-sensitive adhesive layer 12b. When the adhesive layer 13 cut into a shape corresponding to the semiconductor wafer 1 is laminated, as shown in FIG. 2, the adhesive layer 13 is provided at a portion where the semiconductor wafer 1 is bonded, and a ring frame 20 for dicing is provided. There is no adhesive layer 13 in the portion where the adhesive film is bonded, and only the adhesive layer 12b of the adhesive film 12 exists. In general, since the adhesive layer 13 is difficult to peel off from the adherend, the ring frame 20 can be attached to the adhesive film 12 by using the pre-cut adhesive layer 13, and the ring is peeled off when the film is peeled off after use. The effect that the adhesive residue to the frame 20 hardly occurs is obtained.

(Adhesive film)
The adhesive film 12 has a sufficient adhesive force so that the semiconductor wafer 1 does not peel off when the semiconductor wafer 1 is diced, and can be easily peeled off from the adhesive layer 13 when the semiconductor chip 2 is picked up after dicing. It has such a low adhesive strength. In the present embodiment, as shown in FIG. 1, the adhesive film 12 is formed on the base film 12a and the adhesive layer 12b.
What was provided was used.

As the film-like base film 12a of the pressure-sensitive adhesive film 12, any conventionally known film can be used without particular limitation. When the pressure-sensitive adhesive layer 2 is a radiation curable type, a material that transmits at least a part of radiation such as X-rays, ultraviolet rays, and electron beams is used.

For example, as a material of the base film 12a, polyethylene, polypropylene, ethylene-propylene copolymer, polybutene-1, poly-4-methylpentene-1, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer , Homopolymers or copolymers of α-olefins such as ethylene-methyl acrylate copolymer, ethylene-acrylic acid copolymer, ionomer or mixtures thereof, polyurethane, styrene-ethylene-butene copolymer or pentene Listed are thermoplastic elastomers such as copolymers, polyamide-polyol copolymers, and mixtures thereof. Moreover, the base film 12
a may be a mixture of two or more materials selected from these groups, or may be a single layer or a multilayer. The thickness of the base film 12a is not particularly limited and may be set appropriately, but is preferably 50 to 200 μm.

A radiation curable or pressure sensitive adhesive is used for the adhesive layer. Since a thermosetting adhesive layer is laminated, no thermosetting pressure-sensitive adhesive is used.

The resin of the pressure-sensitive adhesive layer 12b has a constitutional unit derived from a (meth) acrylic acid alkyl ester monomer having an alkyl group having 2 or more carbon atoms and a constitution derived from 2-hydroxypropyl acrylate and / or 2-hydroxybutyl acrylate. A copolymer containing 5% by mass or more and 99.5% by mass or less, preferably 30% by mass or more and 97% by mass or less of a structural unit derived from the (meth) acrylic acid alkyl ester monomer. Those crosslinked with a compound are used. When there are too many structural units derived from the (meth) acrylic acid alkyl ester monomer, the crosslinking point of the pressure-sensitive adhesive is reduced, and sufficient characteristics cannot be obtained, and when it is too small, the pressure-sensitive adhesive composition is mixed, and the base film The pot life until it is applied to the wafer is shortened, which causes a problem when the pressure-sensitive adhesive tape for wafer processing of the present invention is produced.
Here, (meth) acrylic acid alkyl ester monomers having 2 or more carbon atoms in the alkyl group include ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and hexyl (meth) acrylate. , Octyl (meth) acrylate, 2-methylpropyl (meth) acrylate, 2-methylbutyl (meth) acrylate, (meth) acrylic acid 2
-Ethylbutyl, 2-methylhexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 1,2-dimethylbutyl (meth) acrylate, lauryl (meth) acrylate, etc. Among them, particularly alkyl groups Those having 8 or more carbon atoms are preferred.

Further, 2-hydroxypropyl acrylate and / or 2-hydroxybutyl acrylate is used as the crosslinkable functional group-containing monomer. The copolymer constituting the pressure-sensitive adhesive preferably contains 3% by mass or more and 30% by mass or less of structural units derived from 2-hydroxypropyl acrylate and / or 2-hydroxybutyl acrylate.

Moreover, 10-150 mgKOH / g is preferable and, as for the hydroxyl value of the copolymer which comprises the said adhesive, 15-100 mgKOH / g is more preferable.

In the present embodiment, the copolymer constituting the pressure-sensitive adhesive is crosslinked with an isocyanate compound.
There is no restriction | limiting in particular as an isocyanate compound, For example, 4,4'- diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, 4,4
Aromatic isocyanates such as '-diphenyl ether diisocyanate, 4,4'-[2,2-bis (4-phenoxyphenyl) propane] diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethyl-hexamethylene diisocyanate, isophorone diisocyanate 4,4'-dicyclohexylmethane diisocyanate, 2,4'-
Examples include dicyclohexylmethane diisocyanate, lysine diisocyanate, and lysine triisocyanate. Specifically, Coronate L (trade name, manufactured by Nippon Polyurethane Co., Ltd.) or the like can be used as a commercial product.

In the present invention, the content of the isocyanate compound in the pressure-sensitive adhesive layer 12b is such that the copolymer 10
0.1-12 mass parts is preferable with respect to 0 mass part, More preferably, it is 0.5-12 mass part.

The pressure-sensitive adhesive layer 12b is not limited to the above-mentioned ones, and is usually a known chlorinated polypropylene resin, acrylic resin, polyester resin, polyurethane resin used for pressure-sensitive adhesives,
Epoxy resin, addition reaction type organopolysiloxane resin, silicon acrylate resin,
Such as ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-acrylic acid copolymer, polyisoprene, styrene-butadiene copolymer and hydrogenated products thereof. A pressure-sensitive adhesive may be prepared by appropriately blending a radiation-polymerizable compound into various elastomers and the like and mixtures thereof. Various surfactants and surface smoothing agents may be added.

The radiation-polymerizable compound is substituted with a low-molecular weight compound having at least two photopolymerizable carbon-carbon double bonds or a photopolymerizable carbon-carbon double bond group in a molecule that can be formed into a three-dimensional network by light irradiation, for example. Polymers and oligomers possessed by groups are used. Specifically, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butylene glycol diacrylate, 1,6 hexanediol diacrylate For example, acrylate, polyethylene glycol diacrylate, oligoester acrylate, silicon acrylate, etc., acrylic acid, copolymers of various acrylic esters, and the like are applicable.

In addition to the above acrylate compounds, urethane acrylate oligomers can also be used. The urethane acrylate oligomer includes a polyol compound such as a polyester type or a polyether type, and a polyvalent isocyanate compound (for example, 2, 4
Terminal obtained by reacting tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane 4,4-diisocyanate, etc. An acrylate or methacrylate having a hydroxyl group on an isocyanate urethane prepolymer (for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, polyethylene glycol acrylate, polyethylene glycol methacrylate, etc.) It is obtained by reacting. The pressure-sensitive adhesive layer 12b may be a mixture of two or more selected from the above resins.

The resin of the pressure-sensitive adhesive layer 12b is irradiated with radiation on the pressure-sensitive adhesive film 12, and the pressure-sensitive adhesive layer 12 is used.
In addition to the radiation polymerizable compound that cures b, an acrylic pressure-sensitive adhesive, a photopolymerization initiator, a curing agent, and the like can be appropriately blended to prepare the pressure-sensitive adhesive layer 12b.

When using a photopolymerization initiator, for example, isopropyl benzoin ether, isobutyl benzoin ether, benzophenone, Michler's ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, benzyldimethyl ketal, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethylphenyl Propane or the like can be used.

The resin of the pressure-sensitive adhesive layer 12b has a thickness of 1 μm or more and less than 10 μm, preferably 5 μm.
It is 9 μm or less. Further, the tan δ (A) of the pressure-sensitive adhesive layer 12b at 80 ° C. was 0.
Tan δ (B) of the pressure-sensitive adhesive layer 12b at 25 ° C. in the state of 05 or more and 0.20 or less and used in the pickup process is 0.15 or more and 0.25 or less, and tan δ
Tan δ (A) / tan δ (B), which is the ratio of (A) to tan δ (B), is 0.30 or more and 0
. 77 or less. Here, “in a state where it is used for the pickup process” means that when the radiation curable pressure-sensitive adhesive film 12 is used, it is in a state after being cured by irradiation with radiation.

In blade dicing in which a semiconductor wafer is cut into semiconductor chips using a dicing blade, the cutting by the dicing blade usually reaches the adhesive film 12. For this reason, when the thickness of the pressure-sensitive adhesive layer is 10 μm or more, a large amount of cutting waste containing the pressure-sensitive adhesive is generated in the dicing process. Further, if the tan δ (A) of the pressure-sensitive adhesive layer at 80 ° C. is less than 0.05, the pressure-sensitive adhesive force is too high, and the pressure-sensitive adhesive is entangled with the dicing blade, and dicing failure tends to occur. When tan δ (A) exceeds 0.20, chip jump occurs in the dicing process. Further, when tan δ (B) of the pressure-sensitive adhesive layer 12b at 25 ° C. in a state where it is used for the pickup process is less than 0.15, the pressure-sensitive adhesive layer 12b and the adhesive layer 13 are peeled in the pickup process. Cannot be picked up, resulting in a pickup error. tan δ (B
) Exceeds 0.25, the pressure-sensitive adhesive is too hard at the time of pick-up, pin responsiveness at the time of pin push-up is poor, and pick-up mistakes occur. Further, tan δ (A) / tan δ (B) is 0.30.
If it is less than that, the cutting waste containing the adhesive generated in the dicing process is hardened between the adjacent chips, so that a pickup error occurs. tan δ (A) / tan δ (B) is 0.7.
If it exceeds 7, the generated cutting scraps are fused between adjacent chips, and a pickup error occurs.

For tan δ (A) and tan δ (B), the value is within the above range, and t
In order to adjust so that an δ (A) / tan δ (B) is included in the above range, the following may be performed. In order to increase tan δ (A), for example, the structural unit derived from butyl acrylate in the copolymer composition may be increased, the structural unit derived from 2-hydroxypropyl acrylate may be decreased, and tan δ (A) is decreased. To do this, you should do the reverse. In the case of the radiation curable type, the structural unit derived from butyl acrylate and the structural unit derived from acrylic acid may be increased, and the structural unit derived from 2-hydroxypropyl acrylate may be decreased to reduce tan δ (A). The reverse is better. ta
In order to increase nδ (B), for example, the cross-linking agent is increased or the structural unit derived from acrylic acid is decreased. To decrease tanδ (B), the reverse is performed. In the case of the radiation curable type, tan δ (B) increases when the amount of a reactive agent such as a photoinitiator is increased. Furthermore, when irradiating radiation, tan δ (B
) Can also be raised.

(How to use wafer processing tape)
In the semiconductor device manufacturing process, the wafer processing tape 10 is used as follows.
FIG. 2 shows a state in which the semiconductor wafer 1 and the ring frame 20 are bonded to the wafer processing tape 10. First, as shown in FIG. 2, the adhesive layer 12 b of the adhesive film 12 is attached to the ring frame 20, and the semiconductor wafer 1 is attached to the adhesive layer 13. There is no limitation on the order of these attachments, and the adhesive layer 12b of the adhesive film 12 may be attached to the ring frame 20 after the semiconductor wafer 1 is attached to the adhesive layer 13. Further, the adhesion of the adhesive film 12 to the ring frame 20 and the adhesion of the semiconductor wafer 1 to the adhesive layer 13 may be performed simultaneously.

And as shown in FIG. 3, the dicing process of the semiconductor wafer 1 is implemented, and then, when the adhesive film 12 is a radiation ray curing type, the process of irradiating the adhesive film 12 with radiation is performed. Specifically, since the semiconductor wafer 1 and the adhesive layer 13 are diced by the dicing blade 21, the wafer processing tape 10 is sucked and supported from the lower surface side of the adhesive film 12 by the suction stage 22. Then, the semiconductor wafer 1 and the adhesive layer 13 are cut into units of semiconductor chips 2 by the dicing blade 21 and separated into individual pieces. Then, when the adhesive film 12 is a radiation curable type, radiation is irradiated from the lower surface side of the adhesive film 12, the adhesive layer 12b is cured, and the adhesive force is reduced. When the pressure-sensitive adhesive layer 12b is formed by laminating two or more pressure-sensitive adhesive layers, one or all of the pressure-sensitive adhesive layers are cured by radiation irradiation, and one of the pressure-sensitive adhesive layers or The adhesive strength of all layers may be reduced.

Thereafter, as shown in FIG. 4, an expanding process is performed in which the adhesive film 12 holding the diced semiconductor chip 2 and the adhesive layer 13 is stretched in the radial direction and the circumferential direction of the ring frame 20. Specifically, a plurality of diced semiconductor chips 2 and an adhesive layer 13
The hollow cylindrical push-up member 30 is raised from the lower surface side of the adhesive film 12 and the adhesive film 12 is stretched in the radial direction and the circumferential direction of the ring frame 20. Expanding the gap between the semiconductor chips 2 by the expanding process, CC
It is possible to improve the recognizability of the semiconductor chip 2 by a D camera or the like, and to prevent re-adhesion of the semiconductor chips 2 caused by contact between the adjacent semiconductor chips 2 at the time of pickup.

After performing the expanding process, as shown in FIG. 5, the pick-up process which picks up the semiconductor chip 2 is implemented with the adhesive film 12 being expanded. Specifically, the semiconductor chip 2 is pushed up by the pins 31 from the lower surface side of the adhesive film 12 and the semiconductor chip 2 is separated from the upper surface side of the adhesive film 12 by adsorbing the semiconductor chip 2 by the adsorption jig 32. Is picked up together with the adhesive layer 13.

Then, after performing the pickup process, the die bonding process is performed. Specifically, the semiconductor chip 2 is bonded to a lead frame, a package substrate, or the like by the adhesive layer 13 picked up together with the semiconductor chip 2 in the pickup process.
(Example)

Next, examples of the present invention will be described. The present invention is not limited to these examples.

[Examples 1-3 and Comparative Examples 1-3]
As shown below, the wafer processing tapes of Examples 1 to 3 and Comparative Examples 1 to 3 as shown in Table 3 were produced and evaluated.

(Base film)
As the base films 1A to 1B, film base films having a thickness of 70 to 100 μm shown in Table 1 below were used.

(Preparation of adhesive layer composition)
<Adhesive composition 2A>
Coronate L (manufactured by Nippon Polyurethane Co., Ltd.) is used as a crosslinking agent for 100 parts by mass of a copolymer containing 77% by mass of structural units derived from 2-ethylhexyl acrylate and 23% by mass of structural units derived from 2-hydroxypropyl acrylate. ) Was prepared.

<Adhesive composition 2B>
In the composition of the pressure-sensitive adhesive composition 2A, the crosslinking agent coronate L was set to 12 parts by mass to obtain a pressure-sensitive adhesive composition 2B.

<Adhesive composition 2C>
100% by mass of a copolymer containing 65% by mass of structural units derived from butyl acrylate, 25% by mass of structural units derived from 2-hydroxypropyl acrylate, and 10% by mass of trimethylolpropane triacrylate as structural units derived from acrylic acid. Part 2C containing 6 parts by mass of Coronate L (manufactured by Nippon Polyurethane) as a crosslinking agent
A pressure-sensitive adhesive composition 2C containing 1 part by mass of α-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator was obtained.

<Adhesive composition 2D>
Copolymer 100 containing 65% by mass of structural units derived from butyl acrylate, 25% by mass of structural units derived from 2-hydroxyethyl acrylate, and 10% by mass of trimethylolpropane triacrylate as a structural unit derived from acrylic acid Adhesive composition 2C containing 3 parts by mass of Coronate L (manufactured by Nippon Polyurethane Co., Ltd.) as a crosslinking agent with respect to parts by mass
And pressure-sensitive adhesive composition 2D containing 1 part by mass of α-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator was obtained.

<Adhesive composition 2E>
In the composition of the pressure-sensitive adhesive composition 2D, the pressure-sensitive adhesive composition 2E was obtained with 2 parts by mass of the crosslinking agent coronate L.

The pressure-sensitive adhesive layer compositions 2A to 2E are formed on the base film 1A to 1B and the dry film thickness is 6 to 10 μm.
The pressure-sensitive adhesive film 12 was prepared by coating at a temperature of 110 ° C. for 3 minutes.

(Preparation of adhesive layer composition)
<Adhesive layer composition 3A>
The adhesive layer composition 3A is an epoxy-acrylic adhesive composition. Epoxy resin 55
Cyclohexanone is added to a composition composed of 45 parts by mass, phenol resin 45 parts, silane coupling agent (1) 1.7 parts by mass, silane coupling agent (2) 3.2 parts by mass, and filler 32 parts by mass and stirred. They were mixed and further kneaded for 90 minutes using a bead mill. Acrylic rubber HTR-860 containing 3% by weight of glycidyl acrylate or glycidyl methacrylate.
280 parts by mass of P-3 (trade name, manufactured by Nagase ChemteX Corporation, weight average molecular weight of 800,000),
And 0.5 mass part of hardening accelerators were added, and it stirred and mixed, vacuum deaerated, and obtained adhesive-layer composition 3A. YDCN-703 (trade name, manufactured by Toto Kasei Co., Ltd., cresol novolac type epoxy resin, epoxy equivalent 210, molecular weight 1200, softening point 80 ° C.) was used as an epoxy resin.
Millex XLC-LL (trade name, manufactured by Mitsui Chemicals, Inc., the following formula (1) as a phenol resin
And a hydroxyl equivalent 175, a water absorption rate of 1.8%, and a heating weight loss rate at 350 ° C. of 4%). Moreover, NUC A-18 as a silane coupling agent (1)
9 (Nippon Unicar Co., Ltd., trade name, γ-mercaptopropyltrimethoxysilane), and as the silane coupling agent (2), NUC A-1160 (Nippon Unicar Corporation trade name, γ-ureidopropyltriethoxy) Silane) was used. Further, Aerosil R972 as a filler (filler having an organic group such as a methyl group coated with dimethyldichlorosilane on a silica surface and hydrolyzed in a reactor at 400 ° C., a product name manufactured by Nippon Aerosil Co., Ltd., Silica, average particle size 0.016 μm) was used. Further, Curazole 2PZ-CN (trade name, 1-cyanoethyl-2-phenylimidazole manufactured by Shikoku Kasei Co., Ltd.) was used as a curing accelerator.

The above adhesive layer composition 3A is coated on a 25 μm-thick polyethylene terephthalate (PET) film subjected to a release treatment, and dried at 140 ° C. for 5 minutes to form a B-stage coating film having a thickness of 60 μm. Then, an adhesive film was produced.

The produced adhesive film 12 and adhesive film were 370 mm and 320 mm in diameter, respectively.
The adhesive layer 12b of the adhesive film 12 and the adhesive layer 13 of the adhesive film were bonded together. Finally, the PET film of the adhesive film was peeled from the adhesive layer 13 to obtain the wafer processing tape 10 according to Examples 1 to 3 and the wafer processing tape according to Comparative Examples 1 to 3 shown in Table 2 below. .

(Characteristic test)
About the adhesive film 12 produced as mentioned above, the test was each performed as described below. The test results are shown together in Table 2.
<Tan δ>
About the adhesive layer 12b of the tape for wafer processing which concerns on the created Example and a comparative example, a measurement is started from 0 degreeC using a viscoelasticity meter (made by a rheometric science company, brand name: ARES), and the temperature increase rate is 5 Loss tangent was measured at 0 ° C./min and a frequency of 1 Hz, and the loss tangent at the time when the temperature reached 80 ° C. was defined as tan δ (A) at each 80 ° C. In addition, for the adhesive layer 12b of the wafer processing tape according to Examples and Comparative Examples, in the case of an ultraviolet curable adhesive film, a test piece obtained by irradiating the adhesive layer with ultraviolet rays was used as a viscoelasticity meter (rheometric science). Measurement was started from 0 ° C using a product name: ARES), and the rate of temperature increase was 5 ° C / min, and the frequency was 1 Hz.
Then, the loss tangent was measured, and the loss tangent at the time when the temperature reached 25 ° C. was defined as tan δ (B) at 25 ° C. in a state where the loss tangent was used for the pickup process. Furthermore, tan δ (A) and tan
The ratio A / B of δ (B) was calculated.

<Pickup success rate>
After the wafer processing tape is heat bonded to the wafer at 80 ° C. for 10 seconds, 10 mm ×
Dicing to 10 mm. Thereafter, in the case of the pressure-sensitive adhesive film as it is, in the case of the ultraviolet curable pressure-sensitive adhesive film, ultraviolet light is applied to the pressure-sensitive adhesive layer (80 W / cm, irradiation distance 1).
After irradiating to 50-100 mJ / cm 2 by 0 cm), a die bonder device (
A pickup test was conducted using NEC Machinery (trade name CPS-100FM), and the success rate of pickup with 100 pickup chips was determined.

As can be seen from Table 2, in Examples 1 to 3 of the present invention, the pickup success rate was 100%. From these results, the adhesive tape for wafer sticking of the present invention can be used as a dicing tape at the time of dicing, and can be used by easily peeling the adhesive layer at the time of mounting,
It can be seen that generation of cutting waste during dicing and adhesion between adjacent semiconductor chips can be suppressed, and generation of a double die in a pickup process and generation of a problem that a semiconductor chip cannot be picked up can be suppressed.

In Comparative Example 1, tan δ (A) at 80 ° C. is 0.26, tan δ (B) at the pick-up process is 0.32, and tan δ ratio is 0.8. 0% at 25 ° C. At the time of dicing, tan δ at the time of pick-up was large and the cutting performance was deteriorated, and the cutting chips generated at the time of dicing fixed semiconductor chips adjacent to each other, so that the pick-up performance was lowered.

Looking at Comparative Example 2, the tan δ at 80 ° C. is 0.21, the tan δ at 25 ° C. is 0.25, the tan δ ratio is 0.8, and the pick-up property is 35%. . Since the tan δ at the time of pick-up was large and the cutting chips generated at the time of dicing fixed semiconductor chips adjacent to each other, pick-up performance was lowered.

In Comparative Example 3, tan δ at 80 ° C. is 0.02, tan δ at 25 ° C. in a state where it is used for the pickup process is 0.22, tan δ ratio is 0.1, and pickup property is 35%. . Since tan δ at the time of dicing is small and the machinability is deteriorated, and the cutting chips generated at the time of dicing fix the adjacent semiconductor chips to each other, the pick-up property is lowered.

From the above, by using the wafer processing tape 10 according to the present embodiment, it is possible to suppress the occurrence of problems such as the occurrence of double dies in the pickup process and the inability to pick up semiconductor chips.

1: Semiconductor wafer 2: Semiconductor chip 10: Wafer processing tape 12a: Base film 12b: Adhesive layer 12: Adhesive film 13: Adhesive layer 20: Ring frame 21: Dicing blade 22: Suction stage 30: Push-up member 31 : Pin 32: Adsorption jig

Claims (3)

A pressure-sensitive adhesive tape for wafer processing in which a pressure-sensitive adhesive layer is laminated on a base film, wherein the pressure-sensitive adhesive layer has a thickness of 1 μm or more and less than 10 μm , and tan δ (A ) it is, is 0.05 to 0.20, and tanδ of the pressure-sensitive adhesive layer at 25 ° C. in a state that is subjected to the pickup step (B) is 0.15 to 0.25, further, the tan [delta (a) and tan [delta (B) and which is the ratio tanδ (a) / tanδ (B ) a wafer processing adhesive tape, characterized in that is at least 0.30 0.77 less.   The pressure-sensitive adhesive tape for wafer processing according to claim 1, wherein an adhesive layer is further laminated on the side of the pressure-sensitive adhesive layer opposite to the base film.   The pressure-sensitive adhesive layer comprises a structural unit derived from a (meth) acrylic acid alkyl ester monomer having an alkyl group having 2 or more carbon atoms, and a structural unit derived from 2-hydroxypropyl acrylate and / or 2-hydroxybutyl acrylate. The copolymer containing 5% by mass or more and 99.5% by mass or less of a structural unit derived from the (meth) acrylic acid alkyl ester monomer is crosslinked with an isocyanate compound, The pressure-sensitive adhesive tape for wafer processing according to any one of claims 1 and 2.

Images