KR102451856B1 - Dicing sheet and method for manufacturing semiconductor chip - Google Patents

Abstract

A dicing sheet (10) comprising a substrate (3), an intermediate layer (2) formed on one side thereof, and an adhesive layer (1) formed on the intermediate layer (2), wherein the pressure-sensitive adhesive layer (1) is an energy ray-curable double It contains the compound which has a bond in a molecule|numerator, and the storage elastic modulus G' in 23 degreeC before hardening of the adhesive layer (1) is larger than the storage elastic modulus G' in 23 degreeC of the intermediate|middle layer (2), The adhesive layer (1) ) of the dicing sheet 10 before curing, in accordance with JIS Z 0237: 2000, the adhesive force measured when a 180 ° peel adhesion test to a silicon mirror wafer is performed is 2000 mN/25 mm or more, The dicing sheet 10 whose loss coefficient tan-delta in 23 degreeC before hardening of the adhesive layer 1 is 0.23 or more. According to such a dicing sheet 10, even if it leaves still the laminated body obtained by sticking the dicing sheet 10 to the semiconductor wafer 30 for a predetermined period, partial peeling does not generate|occur|produce easily.

Description

The manufacturing method of a dicing sheet and a semiconductor chip TECHNICAL FIELD

The present invention relates to a dicing sheet used in order to fix a semiconductor wafer when a semiconductor wafer is divided into pieces for each circuit and a semiconductor chip is produced. Moreover, this invention relates to the manufacturing method of the semiconductor chip using the dicing sheet. In particular, the dicing sheet of the present invention is preferably used when manufacturing a chip by fixing and cutting a semiconductor wafer having a protruding electrode on its surface, for example, a semiconductor wafer having a so-called through electrode (TSV).

After a circuit is formed on the surface of a semiconductor wafer, a grinding process is performed on the back side of the wafer, a backside grinding process of adjusting the thickness of the wafer, and a dicing process of dividing the wafer into predetermined chip sizes are performed. Further, subsequent to the backside grinding step, there is a case where a treatment performed at a high temperature, such as a processing treatment involving heat generation such as an etching treatment or the like, or deposition of a metal film on the backside, may be performed. A semiconductor wafer (semiconductor chip) divided into chip sizes is picked up and transferred to the next step.

With the recent popularization of IC cards, thickness reduction of the semiconductor chip, which is a constituent member thereof, is progressing. For this reason, it has come to be calculated|required to thin the wafer which is about 350 micrometers in thickness conventionally to 50-100 micrometers or less.

Further, development of a multilayer circuit in which a plurality of semiconductor chips are three-dimensionally stacked is being developed in response to an increase in the capacity and high functionality of the electronic circuit. In such a multilayer circuit, conventionally, conductive connection of semiconductor chips has been generally performed by wire bonding. A method of forming a penetrating electrode (penetrating electrode) and directly conducting conductive connection between the upper and lower chips has been developed as an effective method.

As a method for manufacturing a chip with such a through electrode, for example, a through hole is formed by plasma at a predetermined position of a semiconductor wafer, a copper conductor is poured into the through hole, and then the semiconductor is etched. A method of forming a circuit and a through electrode on the surface of the wafer is exemplified. The semiconductor wafer with a circuit and a through electrode is diced using the dicing sheet in which the adhesive layer was formed on the base film, and the chip|tip with each through electrode is obtained.

In the dicing step for obtaining a chip with a through electrode as described above, the pressure-sensitive adhesive layer formed on the base film is deformed by being pressed by the through electrode protruding on the affixing surface, and the pressure-sensitive adhesive layer having substantially the same shape as the protrusion of the electrode is depressed. A method of affixing and fixing a semiconductor wafer with a through electrode to a dicing sheet by embedding an electrode in the portion, followed by dicing, to obtain individual chips has been proposed (Patent Documents 1 and 2). However, in the dicing sheet described in Patent Documents 1 and 2, the pressure-sensitive adhesive layer buried the through electrodes, and there was a fear that a residue of the pressure-sensitive adhesive was generated in a narrow range between the through electrodes. The residue may contaminate the chip surface and reduce the reliability of the semiconductor chip. Also in the methods of Patent Documents 1 and 2, such a means for reducing residual residue has been proposed, but it cannot be asserted that the possibility of residual residual can be completely eliminated. Moreover, in the dicing sheet described in patent documents 1 and 2, in order to embed a through electrode, it is necessary to adjust the elasticity at the time of dicing low. For this reason, there was also a problem that chip defects (chipping) are likely to occur due to vibration during dicing.

In order to solve this problem, there is provided a dicing sheet that can be diced and picked up without any residue of the pressure-sensitive adhesive layer remaining between the protruding electrodes (through electrodes) and without damaging the chips, comprising: a substrate, an intermediate layer formed on one side thereof; , the pressure-sensitive adhesive layer formed on the intermediate layer with a thickness of 8 to 30 µm, the pressure-sensitive adhesive layer contains a compound having an energy ray-curable double bond in its molecule, and the storage elastic modulus G' at 23°C before curing of the pressure-sensitive adhesive layer is larger than four times the storage elastic modulus G' at 23°C of the intermediate layer, and the columnar electrodes having a height of 15 µm and a diameter of 15 µm are formed in three rows and three columns at equal intervals at a pitch of 40 µm. A pressure-sensitive adhesive layer is interposed on the wafer Patent Document 3 discloses a dicing sheet characterized in that the pressure-sensitive adhesive layer does not contact a portion of the electrode having a height of 7.5 µm or less in the electrode at the center of the columnar electrode formed in 3 rows and 3 columns when the dicing sheet is adhered has been

Further, according to the invention described in Patent Literature 3, a dicing sheet having an intermediate layer made of a urethane-containing cured product is described in Patent Literature 4.

Japanese Laid-Open Patent Publication No. 2006-202926 Japanese Patent Laid-Open No. 2010-135494 Japanese Patent Laid-Open No. 2013-098408 Japanese Laid-Open Patent Publication No. 2013-197390

In Patent Documents 3 and 4, as shown in Fig. 2, when affixed to the semiconductor wafer 30, the pressure-sensitive adhesive layer 21 does not follow between the protruding electrodes 31, and the protruding electrodes 31 are formed. The dicing sheet 20 following the outer peripheral part 30A of the area|region (electrode formation area|region) is described. According to such a dicing sheet 20, the residue of the adhesive layer 21 does not remain between the protrusion-shaped electrodes 31, and the outer periphery part 30A of the electrode formation area by polymerization failure does not exist. Residue residue is also suppressed. In addition, since the pressure-sensitive adhesive layer 21 is adhered to the semiconductor wafer 30 in the outer peripheral portion 30A of the electrode formation region, and the pressure-sensitive adhesive layer 21 is not excessively softened, the penetration of water during dicing is prevented. Thus, the dicing property is excellent, and the occurrence of chipping can be prevented. Moreover, since the adhesive force can be controlled by energy-beam hardening of the adhesive layer 21, while pick-up of a chip|tip is easy, breakage of a chip|tip can be prevented.

Thus, although the dicing sheet 20 described in patent document 3 and 4 has the outstanding characteristic, in recent years, the dicing process after sticking the laminated body obtained by sticking the dicing sheet 20 to the semiconductor wafer 30. A phenomenon in which the pressure-sensitive adhesive layer 21 properly adhered to the semiconductor wafer 30 following the outer peripheral portion 30A of the electrode formation region is partially peeled from the semiconductor wafer 30 when left still for a predetermined period until the start of It was found that (in this specification, this phenomenon is also referred to as "partial peeling") can occur. Specifically, the part shown as the outer peripheral part 30A' of the electrode formation area in FIG. 3 is the part where the adhesive layer 21 peeled from the semiconductor wafer 30 partially, ie, the part which partial peeling generate|occur|produced. When the degree of peeling of the pressure-sensitive adhesive layer 21 based on this partial peeling is large, that is, when the area of the part where partial peeling occurs is large, when the above-mentioned laminate is subjected to a dicing process, the dicing operation There is a possibility that stability may be affected.

The present invention has been made in view of the actual situation as described above, and even if the laminate obtained by affixing a dicing sheet to a semiconductor wafer is left still for a predetermined period, specifically, about 24 hours, partial peeling as described above is not achieved. It makes it a subject to provide the dicing sheet which does not generate|occur|produce easily, and the manufacturing method of the semiconductor chip using the dicing sheet.

The present invention provided to achieve the above object is as follows.

(1) A dicing sheet comprising a substrate, an intermediate layer formed on one side thereof, and a pressure-sensitive adhesive layer formed on the intermediate layer, wherein the pressure-sensitive adhesive layer contains a compound having an energy ray-curable double bond in a molecule, the pressure-sensitive adhesive layer Storage elastic modulus G' at 23 degreeC before hardening is larger than the storage elastic modulus G' at 23 degreeC of the said intermediate|middle layer, with respect to the said dicing sheet before hardening the said adhesive layer, according to JISZ0237:2000 Therefore, the adhesive force measured when performing the 180 ° peel adhesion test to the silicon mirror wafer is 2000 mN/25 mm or more, and the loss coefficient tanδ at 23 ° C. before curing of the adhesive layer is 0.23 or more, characterized in that dicing sheet.

(2) The dicing sheet according to the above (1), wherein the compound having the energy ray-curable double bond in the molecule contains an energy ray-curable pressure-sensitive adhesive polymer in which an energy ray-polymerizable group is bonded to a main chain or a side chain of the polymer. .

(3) The dicing sheet according to (1) or (2), wherein the intermediate layer has a storage elastic modulus G' at 23°C of 1×10 ⁴ Pa or more and less than 1×10 ⁵ Pa.

(4) The storage elastic modulus G' at 23 degreeC before hardening of the said adhesive layer is 3 x 10 ⁵ Pa or more, The dicing sheet in any one of said (1)-(3) characterized by the above-mentioned.

(5) The pressure-sensitive adhesive layer contains an acrylic polymer having a reactive functional group and a crosslinking agent, and contains 5 parts by mass or more of a crosslinking agent with respect to 100 parts by mass of the acrylic polymer. The dicing sheet described in one.

(6) The dicing sheet according to (5) above, wherein the crosslinking agent is an isocyanate-based crosslinking agent.

(7) The dicing sheet according to any one of (1) to (6), wherein the dicing sheet is used by being pasted on a wafer on which the protruding electrode is formed.

(8) The dicing sheet according to the above (7), wherein the protruding electrode is a through electrode.

(9) The dicing sheet according to the above (7) or (8), wherein the intermediate layer has a thickness of not less than 0.5 times and not more than 1.5 times the height of the protruding electrode.

(10) Storage elastic modulus G' at 23 degreeC before hardening of the said adhesive layer is larger than 4 times the storage elastic modulus G' at 23 degreeC of the said intermediate|middle layer, in any one of said (1)-(9) The described dicing sheet.

(11) The dicing sheet according to any one of (1) to (10), wherein the pressure-sensitive adhesive layer has a thickness of 5 µm or more and 50 µm or less.

(12) The dicing sheet according to any one of (1) to (11), wherein the intermediate layer has a thickness of 5 µm or more and 50 µm or less.

(13) A step of affixing the dicing sheet according to any one of (1) to (12) above on the electrode-formed surface of a semiconductor wafer having protruding electrodes; A method for manufacturing a semiconductor chip, comprising: a step of manufacturing; and a step of picking up the semiconductor chip.

ADVANTAGE OF THE INVENTION According to this invention, even if the laminated body obtained by sticking a dicing sheet to a semiconductor wafer is left still for a predetermined period, the dicing sheet which does not generate|occur|produce the partial peeling as mentioned above easily, and manufacture of the semiconductor chip using the dicing sheet. A method is provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing of the dicing sheet which concerns on one Embodiment of this invention.
It is sectional drawing which shows conceptually the state in which the dicing sheet described in patent document 3 and 4 was stuck to the semiconductor wafer.
Fig. 3 is a cross-sectional view conceptually showing a dicing sheet in which partial peeling has occurred.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing of the adhesive sheet which concerns on one Embodiment of this invention. The dicing sheet 10 which concerns on one Embodiment of this invention is equipped with the base material 3, the intermediate|middle layer 2 formed on the single side|surface, and the adhesive layer 1 formed on the intermediate|middle layer 2.

(Adhesive layer (1))

The storage elastic modulus G' in 23 degreeC before hardening of the adhesive layer 1 (before energy-beam irradiation) is larger than the storage elastic modulus G' in 23 degreeC of the intermediate|middle layer 2. Thus, in the form which covers the intermediate|middle layer 2 of a low elastic modulus, by the presence of the adhesive layer 1 with relatively high elasticity, it suppresses preferably that the adhesive layer 1 follows between protrusion electrodes, and between protrusion electrodes. Generation|occurrence|production of the residue of the adhesive layer 1 in this, and the damage|damage of the chip|tip at the time of pick-up can be prevented. In addition, in the laminate of the pressure-sensitive adhesive layer (1) and the intermediate layer (2), since the pressure-sensitive adhesive layer (1) reinforces the low elasticity of the intermediate layer (2), compared to the case where only one layer of the low elastic modulus layer exists, The vibration of the wafer during dicing is suppressed, and chipping is less likely to occur. From a viewpoint of acquiring said effect more stably, the storage elastic modulus G' in 23 degreeC before hardening of the adhesive layer 1 is larger than 4 times of the storage elastic modulus G' in 23 degreeC of the intermediate|middle layer 2 Preferably, it is more preferably larger than 5 times the storage elastic modulus G' at 23°C of the intermediate layer (2), and more preferably larger than 10 times the storage elastic modulus G' at 23°C of the intermediate layer (2). , it is particularly preferably larger than 20 times the storage elastic modulus G' of the intermediate layer 2 at 23°C.

Storage elastic modulus G' at 23 degreeC before hardening of the adhesive layer 1 becomes like this. Specifically, Preferably it is 3 x 10 ⁵ Pa or more, More preferably, it is 3.5 x 10 ⁵ Pa or more and 1 x 10 ⁷ Pa or less. . By making storage elastic modulus G' in 23 degreeC before hardening of the adhesive layer 1 into the said range, the effect of suppressing the tracking between the protrusion-shaped electrodes of an adhesive, etc. are acquired more reliably.

Adhesive force measured when the dicing sheet in the state before irradiation with energy rays is subjected to a 180° peel adhesion test to a silicon mirror wafer based on JIS Z 0237:2000 (in this specification, "irradiation Total adhesive force") is 2000 mN/25 mm or more. In this specification, conditions until the adhesive force before irradiation are measured are as follows. The surface of the pressure-sensitive adhesive layer 1 of the dicing sheet is affixed on a silicon mirror wafer with a sticking load of 2 kgf using a rubber roller. Then, the state in which the dicing sheet is affixed to the silicon mirror wafer is maintained for 20 minutes in an environment of 23°C and 50% relative humidity. After 20 minutes have elapsed, a 180° peel adhesion test is performed in accordance with JIS Z 0237:2000.

When the adhesive force before irradiation is 2000 mN/25 mm or more, partial peeling becomes difficult to generate|occur|produce. From the viewpoint of more stably reducing the possibility of partial peeling, the pre-irradiation adhesive force is preferably 2200 mN/25 mm or more, more preferably 2300 mN/25 mm or more, and particularly preferably 2500 mN/25 mm or more. . From a viewpoint of reducing the possibility that partial peeling will occur, the upper limit of the adhesive force before irradiation is not set. From a viewpoint of improving handleability and manufacturing stability, it may be preferable that it is 10000 mN/25 mm or less, and, as for the adhesive force before irradiation, it may be more preferable that it is 8000 mN/25 mm or less.

Loss coefficient tan-delta in 23 degreeC before hardening of the adhesive layer 1 is 0.23 or more. When such loss coefficient tanδ is 0.23 or more, deformation of the pressure-sensitive adhesive layer 1 becomes easy. For this reason, the deformation|transformation of the adhesive layer 1 with time is suppressed, and partial peeling becomes difficult to generate|occur|produce. From the viewpoint of more stably reducing the possibility of partial peeling, the loss coefficient tanδ is preferably 0.25 or more, more preferably 0.3 or more, and particularly preferably 0.38 or more. From a viewpoint of suppressing generation|occurrence|production of partial peeling, the upper limit of said loss coefficient tan δ is not set. From a viewpoint of handleability and productivity, it may be preferable that said loss coefficient tanδ is 0.7 or less, and it may be more preferable that it is 0.65 or less.

It is preferable that the thickness of the adhesive layer 1 is 5 micrometers or more and 50 micrometers or less. When the thickness of the adhesive layer 1 exists in the said range, dicing property can improve and generation|occurrence|production of chipping can be suppressed. In addition, it preferably suppresses the tracking of the pressure-sensitive adhesive layer 1 between the protruding electrodes, and prevents the generation of residues of the pressure-sensitive adhesive layer 1 between the protruding electrodes and the chip breakage at the time of pickup. Furthermore, the followability of the dicing sheet in the outer peripheral portion of the region (electrode formation region) in which the protruding electrode is formed, which will be described later, is maintained. As for the thickness of the adhesive layer 1, it is more preferable that they are 5 micrometers or more and 40 micrometers or less, It is especially preferable that they are 5 micrometers or more and 30 micrometers or less.

The pressure-sensitive adhesive layer 1 contains a compound having an energy ray-curable double bond in a molecule and a component made of a substance for expressing adhesiveness (hereinafter, sometimes referred to as an “energy ray-curable pressure-sensitive adhesive component”).

The adhesive layer 1 is formed using the adhesive composition which mix|blended the energy ray hardening-type adhesive component and the photoinitiator as needed. Moreover, in order to improve various physical properties, the said adhesive composition may contain other components as needed. As another component, a crosslinking agent is preferable.

Hereinafter, the energy ray-curable pressure-sensitive adhesive component will be specifically described using an acrylic pressure-sensitive adhesive as an example.

An acrylic adhesive contains an acrylic polymer (A) in order to provide sufficient adhesiveness and film-forming property (sheet-forming property) to an adhesive composition, and also contains an energy-beam sclerosing|hardenable compound (B). An energy-beam-curable compound (B) contains an energy-beam polymeric group, and when irradiated with energy rays, such as an ultraviolet-ray and an electron beam, polymerization-hardens, and has the function of reducing the adhesive force of an adhesive composition. In addition, as having the properties of the components (A) and (B), an energy ray-curable adhesive polymer in which an energy ray polymerizable group is bonded to a main chain or a side chain (hereinafter referred to as component (AB)) ) is preferably used. Such an energy-ray-curable adhesive polymer (AB) has the property of having both adhesiveness and energy-beam sclerosis|hardenability.

As an acrylic polymer (A), a conventionally well-known acrylic polymer can be used. It is preferable that it is 10,000-2 million, and, as for the polystyrene conversion weight average molecular weight (Mw) of an acrylic polymer (A), it is more preferable that it is 100,000-1,500,000. Moreover, the glass transition temperature (Tg) of an acrylic polymer (A) becomes like this. Preferably it is -70-30 degreeC, More preferably, it exists in the range of -60-20 degreeC.

As a monomer which comprises an acrylic polymer (A), a (meth)acrylic acid ester monomer or its derivative(s) is mentioned. Specifically, an alkyl group having 1 to 18 carbon atoms, such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate phosphorus alkyl (meth)acrylate; Cycloalkyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyl oxyethyl ( (meth)acrylates having a cyclic skeleton such as meth)acrylate and imide (meth)acrylate; hydroxyl group-containing (meth)acrylates such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate; Acrylic acid, methacrylic acid, itaconic acid, glycidyl acrylate, glycidyl methacrylate, etc. are mentioned. Moreover, vinyl acetate, acrylonitrile, styrene, etc. may be copolymerized. These may be used individually by 1 type, and may use 2 or more types together. In addition, "(meth)acrylic acid" in this specification means both acrylic acid and methacrylic acid. The same is true for other similar terms.

Moreover, it is preferable that the acrylic polymer (A) in this invention has a reactive functional group. The reactive functional group reacts with the reactive functional group of the crosslinking agent preferably added to the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer (1) in the present invention to form a three-dimensional network structure, and storage at 23°C of the pressure-sensitive adhesive layer (1) It becomes easy to adjust the elastic modulus G' to a predetermined range. Although a carboxyl group, an amino group, an epoxy group, a hydroxyl group, etc. are mentioned as a reactive functional group of an acrylic polymer (A), From the point which is easy to react selectively with a crosslinking agent, it is preferable that it is a hydroxyl group. A reactive functional group can be introduce|transduced into an acrylic polymer (A) by comprising the acrylic polymer (A) using the monomer which has reactive functional groups, such as hydroxyl-containing (meth)acrylate and acrylic acid mentioned above.

It is preferable to contain 5-30 mass % of the monomer which has a reactive functional group among all the monomers which comprise, and, as for an acrylic polymer (A), it is more preferable to contain 10-30 mass %. By making the compounding ratio of the monomer having a reactive functional group into such a range, the acrylic polymer (A) is efficiently crosslinked by the crosslinking agent, and the storage elastic modulus G' at 23°C of the pressure-sensitive adhesive layer (1) is adjusted to a predetermined range it becomes easier Moreover, it is preferable that the reactive functional group (for example, hydroxyl group) equivalent of an acrylic polymer (A) is 0.17 to 2.0 times the reactive functional group (for example, isocyanate group) equivalent of a crosslinking agent. By making the relationship between the reactive functional group equivalent of an acrylic polymer (A) and the reactive functional group equivalent of a crosslinking agent into the said range, it becomes further easier to adjust the storage elastic modulus G' in 23 degreeC of the adhesive layer 1 to a predetermined range.

An energy-beam-curable compound (B) is a compound which polymerization-hardens when irradiated with energy rays, such as an ultraviolet-ray and an electron beam. Examples of this energy-ray-curable compound include low-molecular-weight compounds (monofunctional and polyfunctional monomers and oligomers) having an energy-beam polymerizable group, and specifically, trimethylolpropane triacrylate, tetramethylolmethanetetra Acrylate, pentaerythritol triacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, etc. acrylates, dicyclopentadienedimethoxydiacrylate, and cyclic aliphatic skeleton-containing acrylates such as isobornyl acrylate, polyethylene glycol diacrylate, oligoester acrylate, urethane acrylate oligomer, epoxy-modified acrylate, poly An acrylate-based compound such as ether acrylate or itaconic acid oligomer is used. Such a compound has an energy ray-curable double bond in a molecule|numerator, and molecular weight is 100-30000 normally, Preferably it is about 300-10000.

In general, the low molecular weight compound having an energy ray polymerizable group is preferably 0 to 200 parts by mass, more preferably 0 to 200 parts by mass relative to 100 parts by mass of the component (A) (including the energy ray-curable adhesive polymer (AB) described later). is used in an amount of 1 to 100 parts by mass, more preferably 1 to 30 parts by mass. The low molecular weight compound which has an energy-beam polymeric group softens the adhesive layer 1 before energy-beam hardening by adding from the low molecular weight. Then, there exists a possibility that the adhesive layer 1 will become easy to follow between the protrusion-shaped electrodes, and there exists a possibility that it may become easy to generate|occur|produce an adhesive residue between the protrusion-shaped electrodes. For this reason, it is preferable to limit the usage-amount of the low molecular-weight compound which has an energy-beam polymeric group small.

The energy-beam-curable adhesive polymer (AB) which has the property of the said component (A) and (B) consists of an energy-beam polymeric group couple|bonded with the main chain or side chain of a polymer. As described above, it is preferable to limit the amount of the low-molecular-weight compound having an energy-beam polymerizable group to a small extent, but in this case, curing of the pressure-sensitive adhesive layer (1) by irradiation with energy rays becomes insufficient, and the pressure-sensitive adhesive layer ( 1) The effect which suppresses this remaining may fall. Then, by applying an energy-beam hardening type adhesive polymer (AB) to the adhesive layer 1, without softening the adhesive layer 1 before energy-beam irradiation, and also by irradiation of an energy-beam, hardening of the adhesive layer 1 is sufficient. can proceed. Moreover, since an energy-beam curable adhesive polymer (AB) has an energy-beam polymeric group in a molecule|numerator and can also have a reactive functional group, the probability that one molecule couple|bonds with another molecule is high. For this reason, after irradiating an energy ray and hardening the adhesive layer 1, the possibility that a low molecular component will remain|survive without being blown into a three-dimensional network structure is low. Accordingly, generation of residues due to low molecular weight components remaining without being incorporated into the three-dimensional network structure is suppressed.

The main skeleton of the energy ray-curable pressure-sensitive adhesive polymer is not particularly limited, and may be an acrylic copolymer widely used as an adhesive.

The energy ray polymerizable group bonded to the main chain or the side chain of the energy ray-curable pressure-sensitive adhesive polymer is, for example, a group containing an energy ray-curable carbon-carbon double bond, specifically, a (meth) acryloyl group, etc. can do. The energy-beam polymerizable group may be couple|bonded with the energy-beam curable adhesive polymer via an alkylene group, an alkyleneoxy group, and a polyalkyleneoxy group.

It is preferable that it is 10,000-2 million, and, as for the weight average molecular weight (Mw) of the energy-beam curable adhesive polymer (AB) to which the energy-beam polymeric group couple|bonded, it is more preferable that it is 100,000-1,500,000. Moreover, the glass transition temperature (Tg) of an energy ray-curable adhesive polymer (AB) becomes like this. Preferably it is -70-30 degreeC, More preferably, it exists in the range of -60-20 degreeC.

The energy ray-curable adhesive polymer (AB) is, for example, an acrylic adhesive polymer containing a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group and an epoxy group, and a substituent reactive with the functional group and energy ray polymerizable carbon- It is obtained by reacting a polymerizable group-containing compound having 1 to 5 carbon double bonds per molecule. The acrylic adhesive polymer is preferably a copolymer comprising a (meth)acrylic acid ester monomer or derivative thereof having a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, and an epoxy group, and a monomer constituting the component (A) described above. . Examples of the polymerizable group-containing compound include (meth)acryloyloxyethyl isocyanate, meta-isopropenyl-α,α-dimethylbenzyl isocyanate, (meth)acryloyl isocyanate, allyl isocyanate, glycidyl (meth)acryl. rate; (meth)acrylic acid etc. are mentioned.

The acryl-type adhesive containing the above acrylic polymer (A), an energy-beam curable compound (B), or an energy-beam hardening type adhesive polymer (AB) is hardened|cured by energy-beam irradiation. As an energy beam, an ultraviolet-ray, an electron beam, etc. are specifically used.

Examples of the photopolymerization initiator include photoinitiators such as benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, thioxanthone compounds and peroxide compounds, and photosensitizers such as amines and quinones. , specifically, 1-hydroxycyclohexylphenyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutylo Nitrile, dibenzyl, diacetyl, β-chloranthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and the like can be exemplified. When using an ultraviolet-ray as an energy beam, irradiation time and irradiation amount can be decreased by mix|blending a photoinitiator.

The content of the photoinitiator should, in theory, be determined based on the amount of unsaturated bonds (the amount of energy ray-curable double bonds) present in the pressure-sensitive adhesive layer 1 and its reactivity and the reactivity of the photoinitiator used, but a complex mixture It is not necessarily easy in the system. As a general guideline, content of a photoinitiator becomes like this with respect to 100 mass parts of energy-beam sclerosing|hardenable compounds (B), Preferably it is 0.1-10 mass parts, More preferably, it is 1-5 mass parts. When the content of the photoinitiator is less than the above range, satisfactory pickup properties may not be obtained due to insufficient photopolymerization. There are cases in which the hardenability of the resin becomes insufficient.

Examples of the crosslinking agent include an organic polyvalent isocyanate compound, an organic polyvalent epoxy compound, and an organic polyvalent imine compound, and an organic polyvalent isocyanate compound (isocyanate-based crosslinking agent) is preferable.

Examples of the organic polyvalent isocyanate compound include an aromatic polyvalent isocyanate compound, an aliphatic polyvalent isocyanate compound, an alicyclic polyvalent isocyanate compound, a trimer of these organic polyvalent isocyanate compounds, and a terminal isocyanate urethane-free polymer obtained by reacting these organic polyvalent isocyanate compounds with a polyol compound. and the like.

More specific examples of the organic polyvalent isocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane-4,4 '-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dish Chlohexylmethane-2,4'-diisocyanate, trimethylolpropane adduct tolylene diisocyanate, and lysine isocyanate are mentioned.

Specific examples of the organic polyvalent epoxy compound include 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-xylylenediamine , ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl aniline, diglycidyl amine, and the like.

Specific examples of the organic polyvalent imine compound include N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethyl and olmethane-tri-β-aziridinyl propionate and N,N'-toluene-2,4-bis(1-aziridinecarboxamide)triethylenemelamine.

The crosslinking agent is preferably 5 parts by mass or more, more preferably 8 to 35 parts by mass, particularly preferably 12 to 100 parts by mass of the acrylic polymer (A) (including the energy ray-curable adhesive polymer (AB)). It is used in a proportion of 30 parts by mass. By making the compounding quantity of a crosslinking agent into the said range, it becomes easy to adjust the storage elastic modulus G' in 23 degreeC of the adhesive layer 1 to a preferable range.

Moreover, as another component, you may add dye, a pigment, a deterioration inhibitor, an antistatic agent, a flame retardant, a silicone compound, a chain transfer agent, etc. other than a crosslinking agent.

The adhesive layer 1 may contain the polymerizable branched polymer which is a polymer which has a branched structure. The polymerizable branched polymer has a function of improving the peelability (pickup property) of the dicing sheet. The specific structure for the polymerizable branched polymer (specific examples include molecular weight, degree of branched structure, number of energy ray-curable double bonds in one molecule, etc.) is not limited. As a method of obtaining such a polymerizable branched polymer, for example, a monomer having two or more energy ray-curable double bonds in a molecule, a monomer having an active hydrogen group and one energy ray-curable double bond in a molecule, 1 By reacting a polymer having a branched structure, obtained by polymerizing a monomer having two energy ray-curable double bonds in a molecule, and a compound having a functional group capable of forming a bond by reacting with an active hydrogen group and at least one energy ray-curable double bond in the molecule can be obtained

From the viewpoint of facilitating moderately suppressing the interaction with the acrylic polymer (A) (including the energy ray-curable adhesive polymer (AB)), the polystyrene conversion weight average molecular weight (Mw) of the polymerizable branched polymer is 1,000 or more and 100,000 It is preferable that they are below, and it is more preferable that they are 3,000 or more and 30,000 or less. The number of energy-beam polymeric groups in 1 molecule in a polymerizable branched polymer is not limited.

In addition, in this specification, the value of polystyrene conversion weight average molecular weight (Mw) means the value measured as a standard polystyrene conversion value by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent. do. Specifically, it shall implement on the conditions shown below using a GPC measuring apparatus ("HLC-8220GPC" by Tosoh Corporation).

Column: TSKgelGMHXL → TSKgelGMHXL → TSKgel2000HXL

Measuring temperature: 40℃

Flow rate: 1 ml/min

Detector: Differential Refractometer

(middle floor (2))

The intermediate|middle layer 2 can be formed with resin compositions, such as a conventionally well-known various adhesives, for example. Although it does not limit at all as such an adhesive, For example, adhesives, such as a rubber type, an acrylic type, a urethane type, a silicone type, polyvinyl ether, are used. Moreover, the adhesive of an energy-beam hardening type, a heat foaming type, and a water swelling type can also be used. As an energy-beam hardening (ultraviolet-ray hardening, electron beam hardening, etc.) type adhesive, it is preferable to use especially an ultraviolet-curing type adhesive.

When the material which comprises the intermediate|middle layer 2 is an acrylic material, the same material as the acrylic adhesive illustrated as a material which comprises the adhesive layer 1 may be sufficient. If the acrylic polymer (A) is contained among the components contained in the acrylic adhesive which comprises the adhesive layer 1, it is not necessary to have the property to harden|cure with an energy beam.

When the material constituting the intermediate layer 2 is a urethane-based material, the material may consist of a urethane-containing cured product described in Patent Document 4. The hardened|cured material which carried out energy-beam hardening of the compound containing a urethane oligomer and/or a urethane (meth)acrylate oligomer, and the energy-beam curable monomer added as needed may be sufficient as a urethane-containing hardened|cured material.

The specific value of the storage elastic modulus G' in 23 degreeC of the intermediate|middle layer 2 is not limited, as long as the relationship with the storage elastic modulus G' in 23 degreeC of the above-mentioned adhesive layer 1 is satisfied. The storage elastic modulus G' at 23°C of the intermediate layer 2 is preferably 1 × 10 ⁴ Pa or more and less than 1 × 10 ⁵ Pa, more preferably 1 × 10 ⁴ Pa or more and 9 × 10 ⁴ Pa or less, More preferably, they are 1 x 10 ⁴ Pa or more and 8 x 10 ⁴ Pa or less. By adjusting the storage elastic modulus G' at 23 degreeC of the intermediate|middle layer 2 to such a range, the effect of improving the trackability of the dicing sheet in the outer peripheral part of an electrode formation area|region is acquired more reliably. When the storage elastic modulus G' at 23° C. of the intermediate layer 2 is too low, the pressure-sensitive adhesive layer 1 follows between the protruding electrodes, and there is a possibility that a residue of the pressure-sensitive adhesive layer 1 is generated between the protruding electrodes. sometimes it rises. In addition, when the intermediate|middle layer 2 has the property to harden|cure by energy-beam irradiation, the storage elastic modulus G' in 23 degreeC of the intermediate|middle layer 2 is the storage elastic modulus before energy-beam irradiation.

Moreover, it is preferable that the thickness of the intermediate|middle layer 2 is 5 micrometers or more and 50 micrometers or less. When the thickness of the intermediate|middle layer 2 exists in the said range, it becomes easy that the intermediate|middle layer 2 deform|transforms according to the deformation|transformation of the adhesive layer 1. The intermediate layer 2 is more preferably 10 µm or more and 40 µm or less, still more preferably 15 µm or more and 35 µm or less, and particularly preferably 20 µm or more and 30 µm or less.

As for the thickness of the intermediate|middle layer 2, it may be preferable that they are 0.5 times or more and 1.5 times or less of the height of a protruding electrode, and it may be more preferable that they are 1.0 times or more and 1.5 times or less. The specific thickness of the intermediate layer 2 may be selected from the above-mentioned preferred range, calculated from the height of the protruding electrode of the applied wafer, and determined. When the thickness of the intermediate layer 2 is in the above range, the non-trackability of the dicing sheet between the protruding electrodes and the followability of the dicing sheet in the outer periphery of the electrode formation region are excellent, and the dicing property is improved, The occurrence of chipping can be suppressed.

(List (3))

Although it does not specifically limit as the base material 3, For example, Polyethylene films, such as a low-density polyethylene (LDPE) film, a linear low-density polyethylene (LLDPE) film, a high-density polyethylene (HDPE) film, a polypropylene film, a polybutene film , polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, polyimide film, ethylene vinyl acetate copolymer film, ionomer A resin film, an ethylene/(meth)acrylic acid copolymer film, an ethylene/(meth)acrylic acid ester copolymer film, a polystyrene film, a polycarbonate film, a fluororesin film, and a film made of an additive or modified product thereof, etc. are used. Moreover, these crosslinked films and copolymer films are also used. The above-mentioned base material 3 may be used individually by 1 type, and the composite film which combined these 2 or more types may be sufficient as it.

Moreover, when using ultraviolet-ray as an energy beam irradiated in order to harden the adhesive layer 1 and/or the intermediate|middle layer 2, it is preferable that the base material 3 is comprised with the material which has transparency with respect to an ultraviolet-ray. In addition, when an electron beam is used as an energy beam, light transmittance is not required for the base material 3. When the visibility of the to-be-adhered surface is calculated|required, it is preferable that the base material 3 is transparent. The base material 3 may be colored.

In addition, in order to improve the adhesiveness with the intermediate|middle layer 2 on the upper surface of the base material 3, ie, the surface of the base material 3 on the side where the intermediate|middle layer 2 is formed, you may corona-treat or you may form a primer layer. . Moreover, you may apply various coating films to the surface opposite to the intermediate|middle layer 2. The dicing sheet which concerns on one Embodiment of this invention is manufactured by forming the intermediate|middle layer 2 on the single side|surface of the above base material 3, and forming the adhesive layer 1 on the intermediate|middle layer 2. The thickness of the base material 3 is preferably in the range of 20 to 200 µm, more preferably 25 to 110 µm, and particularly preferably 50 to 90 µm. When the thickness of the base material 3 is large, the force against bending of the base material 3 becomes large, and the peeling angle between the chip and the dicing sheet at the time of pickup is less likely to become large. For this reason, the force required for pick-up increases, and pick-up property may be inferior. When the thickness of the base material 3 is small, film forming may become difficult depending on a material.

In the method of forming the intermediate layer 2 on the surface of the substrate 3, the intermediate layer 2 is formed by applying a composition for an intermediate layer constituting the intermediate layer 2 on a release sheet to a predetermined film thickness, You may transfer to the surface of the base material 3, and you may apply|coat the composition for intermediate|middle layer directly to the surface of the said base material 3, and you may form the intermediate|middle layer 2. The method of forming the adhesive layer 1 on the intermediate|middle layer 2 is the same as the method of forming the intermediate|middle layer 2 on the base material 3 using an adhesive composition. In this way, the dicing sheet which concerns on one Embodiment of this invention is obtained.

In addition, in the dicing sheet which concerns on one Embodiment of this invention, in order to protect the adhesive layer 1 before the use, the peeling sheet may be laminated|stacked. The release sheet is not particularly limited, and for example, a film made of a resin such as polyethylene terephthalate, polypropylene, or polyethylene, or a foamed film thereof, or a paper such as glassine paper, coated paper, or laminated paper, silicone-based or fluorine-based paper. , a long-chain alkyl group-containing carbamate can be used that has been peeled off with a release agent.

It is preferable that the dicing sheet which concerns on one Embodiment of this invention is used for sticking to the electrode-formed surface of the semiconductor wafer which has a protruding electrode. As a protruding electrode, a columnar electrode, a spherical electrode, etc. are mentioned. The dicing sheet according to one embodiment of the present invention can be particularly preferably used for a wafer having a through electrode, which has been increasingly used in recent years. The affixing method of the dicing sheet with respect to a semiconductor wafer is not specifically limited.

Next, using cutting means, such as a dicing blade, a semiconductor wafer is segmented for every circuit, and a semiconductor chip is produced. The cutting depth at this time is made into the depth which added the thickness of a semiconductor wafer, the sum total of the thickness of the adhesive layer 1 and the intermediate|middle layer 2, and the abrasion powder of a dicing blade.

After dicing, if necessary, the dicing sheet according to the embodiment of the present invention is expanded to space the semiconductor chips apart, and then each semiconductor chip is picked up by a general-purpose means such as a suction collet, whereby the semiconductor The chip is manufactured. Moreover, after irradiating an energy ray to the adhesive layer 1 and reducing adhesive force, it is preferable to expand and pick-up.

In this way, the step of affixing the dicing sheet according to the embodiment of the present invention to the electrode-formed surface of the semiconductor wafer having the projecting electrode, the step of dividing the semiconductor wafer into individual circuits to produce a semiconductor chip, and a semiconductor A semiconductor chip can be manufactured by including the process of picking up a chip. In such a manufacturing method, since it does not have problems, such as partial peeling of a dicing sheet, dicing of a semiconductor wafer is easy to be performed stably (there are few problems resulting from chipping etc.). Therefore, according to the above manufacturing method, a semiconductor chip of excellent quality can be stably manufactured.

The embodiments described above are described in order to facilitate the understanding of the present invention, and are not described in order to limit the present invention. Accordingly, each element disclosed in the above embodiment is intended to include all design changes and equivalents falling within the technical scope of the present invention.

For example, another layer may exist between the adhesive layer 1 and the intermediate|middle layer 2. When the property as an elastic body of the layer is an intermediate property of the adhesive layer 1 and the intermediate|middle layer 2, the possibility that partial peeling may generate|occur|produce can be reduced more stably.

Alternatively, the pressure-sensitive adhesive layer 1 and the intermediate layer 2 do not have a clear boundary, and may continuously change from the composition of the pressure-sensitive adhesive layer 1 to the composition of the intermediate layer 2 . When it has such a structure, the possibility that partial peeling may generate|occur|produce can be reduced more stably in some cases. As a specific example in such a case, the layer to which the pressure-sensitive adhesive layer (1) and the intermediate layer (2) is provided contains an acrylic pressure-sensitive adhesive, and the dicing sheet 10 is irradiated with electron beams to the side opposite to the base material 3 can be heard In this case, superposition|polymerization in the vicinity of an irradiation surface advances preferentially, and the area|region corresponding to the adhesive layer 1 can be formed.

Example

Hereinafter, the present invention will be more specifically described by way of Examples and the like, but the scope of the present invention is not limited to these Examples and the like.

(Example 1)

[Preparation of the pressure-sensitive adhesive composition A]

Per 100 moles of the acrylic adhesive polymer obtained by reacting butyl acrylate/methyl methacrylate/2-hydroxyethyl acrylate = 62/10/28 (mass ratio), and 2-hydroxyethyl acrylate units of the acrylic adhesive polymer 100 parts by mass of an energy ray-curable adhesive polymer obtained by reacting 80 moles of methacryloyloxyethyl isocyanate (MOI) (polystyrene conversion weight average molecular weight (Mw): 400,000, hereinafter also referred to as “acrylic polymer A”), photopolymerization 3 parts by mass of an initiator (α-hydroxycyclohexylphenylketone (“Irgacure 184” manufactured by BASF)) 8 parts by mass of a crosslinking agent (polyhydric isocyanate compound (“BHS-8515” manufactured by Toyochem)) (in terms of solid content), and 0.15 mass parts of polymerizable branched polymers ("OD-007" by Nissan Chemical Industry Co., Ltd., polystyrene conversion weight average molecular weight (Mw): 14,000) were mixed in a solvent, and the adhesive composition A was obtained.

[Preparation of composition for intermediate layer]

2-ethylhexyl acrylate/2-hydroxyethyl acrylate = 95/5 (mass ratio) was made to react, and the acrylic polymer (polystyrene conversion weight average molecular weight (Mw): 900,000) was obtained. 100 parts by mass of the acrylic polymer and 0.5 parts by mass (in terms of solid content) of a crosslinking agent (polyhydric isocyanate compound ("BHS-8515" manufactured by Toyochem Corporation)) were mixed in a solvent to obtain a composition for an intermediate layer.

[Production of dicing sheet]

The intermediate layer (thickness: 20 µm) formed on a release film (“SP-PET381031 (PF)” manufactured by Lintec Co., Ltd.) by applying and drying the composition for an intermediate layer (drying conditions: 100° C., 1 minute) on the release film got Next, the intermediate|middle layer and the base material (ethylene methacrylic acid copolymer film 80 micrometers thickness) were bonded together, the peeling film was peeled from the intermediate|middle layer, and the intermediate|middle layer was transcribe|transferred on the base material.

Further, the pressure-sensitive adhesive composition was applied and dried (drying conditions: 100° C., 1 minute) to a release film (“SP-PET381031 (PF)” manufactured by Lintec Co., Ltd.), and a pressure-sensitive adhesive layer formed on the release film (thickness: 10) μm) was obtained.

Then, the intermediate|middle layer in which the base material was formed, and the adhesive layer in which the peeling film was formed were bonded together, and the dicing sheet was obtained.

(Example 2)

Per 100 moles of the acrylic adhesive polymer obtained by reacting butyl acrylate/methyl methacrylate/2-hydroxyethyl acrylate = 62/10/28 (mass ratio), and 2-hydroxyethyl acrylate units of the acrylic adhesive polymer 100 parts by mass of an energy ray-curable adhesive polymer obtained by reacting 80 moles of methacryloyloxyethyl isocyanate (MOI) (polystyrene conversion weight average molecular weight (Mw): 600,000), a photopolymerization initiator (α-hydroxycyclohexylphenyl) 3 parts by mass of a ketone ("Irgacure 184" manufactured by BASF)) 8 parts by mass of a crosslinking agent (a polyvalent isocyanate compound ("BHS-8515" manufactured by Toyochem)) (in terms of solid content), and a polymerizable branched polymer (Nissan Chemical Industries, Ltd.) 0.15 mass parts of manufacture "OD-007" and polystyrene conversion weight average molecular weight (Mw): 14,000) were mixed in a solvent, and the adhesive composition B was obtained.

Except having used the obtained adhesive composition B, the same operation|work as Example 1 was performed and the dicing sheet was obtained.

(Example 3)

100 parts by mass of acrylic polymer A, 3 parts by mass of a photoinitiator (α-hydroxycyclohexylphenyl ketone ("Irgacure 184" manufactured by BASF)), 3 parts by mass of a crosslinking agent (polyhydric isocyanate compound ("BHS-8515" manufactured by Toyochem)) ) 10 parts by mass (in terms of solid content) and 0.15 parts by mass of a polymerizable branched polymer ("OD-007" manufactured by Nissan Chemical Industry Co., Ltd., polystyrene conversion weight average molecular weight (Mw): 14,000) were mixed in a solvent to obtain an adhesive composition C.

Except having used the obtained pressure-sensitive adhesive composition C, the same operation as in Example 1 was performed to obtain a dicing sheet.

(Example 4)

100 parts by mass of acrylic polymer A, 3 parts by mass of a photoinitiator (α-hydroxycyclohexylphenyl ketone (“Irgacure 184” manufactured by BASF)), and 3 parts by mass of a crosslinking agent (polyvalent isocyanate compound (“BHS-8515” manufactured by Toyochem) )) 8 mass parts (conversion of solid content) was mixed in the solvent, and the adhesive composition D was obtained.

Except having used the obtained pressure-sensitive adhesive composition D, the same operation as in Example 1 was performed to obtain a dicing sheet.

(Example 5)

A dicing sheet was obtained in the same manner as in Example 1 except that the thickness of the intermediate layer was set to 30 µm.

(Example 6)

Except having made the thickness of the adhesive layer into 30 micrometers, it carried out similarly to Example 2, and obtained the dicing sheet.

(Example 7)

An acrylic adhesive polymer obtained by reacting 2-ethylhexyl acrylate/2-hydroxyethyl acrylate = 80/20 (mass ratio) and 80 moles of meta per 100 moles of 2-hydroxyethyl acrylate units of the acrylic adhesive polymer 100 parts by mass of an energy ray-curable adhesive polymer obtained by reacting acryloyloxyethyl isocyanate (MOI) (polystyrene reduced weight average molecular weight (Mw): 1 million), a photopolymerization initiator (α-hydroxycyclohexylphenylketone (BASF) Manufacture "Irgacure 184")) 3 mass parts and 10 mass parts (solid content conversion) of a crosslinking agent (polyhydric isocyanate compound (Toyochem company "BHS-8515")) were mixed in a solvent, and the adhesive composition E was obtained.

Except having used the obtained adhesive composition E, the same operation|work as Example 1 was performed and the dicing sheet was obtained.

(Test Example 1) Measurement of storage modulus G' and loss coefficient tanδ

Each of the pressure-sensitive adhesive compositions A to D prepared in the Examples was applied to a release film (“SP-PET381031 (PF)” manufactured by Lintec Co., Ltd.) and dried (drying conditions: 100° C., 1 minute), and on the release film The formed adhesive layer (thickness: 25 micrometers) was obtained. The pressure-sensitive adhesive layer was peeled from the release film and superposed to have a total thickness of about 1 mm to prepare a test sample for the pressure-sensitive adhesive layer. The same operation|work was performed also about the composition for intermediate|middle layer prepared in the Example, and the test sample whose total thickness regarding an intermediate|middle layer is about 1 mm was produced.

The obtained test sample was punched out in the disk shape of diameter 8mm, pinched|interposed with the parallel plate, and measured on the following conditions using the viscoelasticity measuring apparatus ("ARES" manufactured by Rheometrics). From the taken-in data, the value of the storage elastic modulus G' in 23 degreeC of an adhesive layer and an intermediate|middle layer, and the value of the loss coefficient tan-delta in 23 degreeC of an adhesive layer were calculated|required. Those results are shown in Table 1 with the ratio with respect to the storage elastic modulus G' in 23 degreeC of the intermediate|middle layer of the storage elastic modulus G' in 23 degreeC of an adhesive layer.

Measurement temperature: -30 ~ 120 ℃

Temperature increase rate: 3 °C/min

Measurement frequency: 1 Hz

(Test Example 2) Measurement of adhesive force before irradiation

The release sheet was peeled from the dicing sheet produced in the Example, and the surface of the exposed adhesive layer was affixed on the silicon mirror wafer with the sticking load of 2 kgf using the rubber roller. After the state in which the dicing sheet was affixed to the silicon mirror wafer was hold|maintained for 20 minutes in 23 degreeC and the environment of 50% of relative humidity, based on JISZ0237:2000, the 180 degree peeling adhesive force test was implemented. The results are shown in Table 1.

(Test Example 3) Confirmation of occurrence of partial peeling

The release sheet was peeled from the dicing sheet produced in the Example, and the surface of the exposed pressure-sensitive adhesive layer was applied to a wafer having irregularities of 28 µm in diameter, 35 µm in pitch, and 12 µm in height, formed in 2 rows and 5 columns, with a sticking device ( It was affixed using Lintec's "RAD-3510F/12"). The conditions of the affixing device were as follows.

Indentation amount: 15 ㎛

Protrusion amount: 150 ㎛

Adhesive stress: 0.35 MPa

Attachment speed: 5 mm/sec

Attachment temperature: 23℃

From the surface on the side of the base material of the dicing sheet, the state of sticking of the pressure-sensitive adhesive layer around the unevenness was observed. Specifically, bubbles generated between the dicing sheet and the wafer were observed. After standing still in the environment of 23 degreeC and 50% of relative humidity for 24 hours, from the surface of the base material side of a dicing sheet, the adhesion state of the adhesive layer around an unevenness|corrugation was observed again, and partial peeling was generated based on the shape change of a bubble. The presence or absence was evaluated. The thing without a change was judged as good ("A" in Table 1), and the thing which bubble spread or the bubble connected was called bad ("B" in Table 1).

In the dicing sheets produced in Examples 1 and 4 to 6, which are examples of the present invention, the storage elastic modulus G' of the pressure-sensitive adhesive layer before curing at 23°C is larger than the storage elastic modulus G' of the intermediate layer at 23°C, and a loss Coefficient tanδ was 0.23 or more, and the adhesive force before irradiation was 2000 mN/25 mm or more. When such a dicing sheet was used, partial peeling was not confirmed. On the other hand, when the dicing sheets produced in Examples 2, 3, and 7 which are comparative examples were used, partial peeling was confirmed.

The dicing sheet according to the present invention can be suitably used as a dicing sheet for a semiconductor wafer having irregularities such as a so-called through electrode (TSV).

10, 20; dicing sheet
1, 21 ; adhesive layer
2 ; mezzanine
3 ; write
30 ; semiconductor wafer
30A; The outer periphery of the electrode formation region
30A'; part where partial peeling occurred
31 ; dendritic electrode

Claims (13)

A dicing sheet comprising a substrate, an intermediate layer formed on one side thereof, and a pressure-sensitive adhesive layer formed on the intermediate layer, the dicing sheet comprising:
The pressure-sensitive adhesive layer contains a compound having an energy ray-curable double bond in the molecule,
Storage elastic modulus G' in 23 degreeC before hardening of the said adhesive layer is larger than storage elastic modulus G' in 23 degreeC of the said intermediate|middle layer,
With respect to the dicing sheet before curing the pressure-sensitive adhesive layer, in accordance with JIS Z 0237: 2000, the adhesive force measured when a 180 ° peel adhesion test to a silicon mirror wafer is performed is 2000 mN/25 mm or more,
The loss coefficient tanδ in 23 degreeC before hardening of the said adhesive layer is 0.44 or more, The dicing sheet characterized by the above-mentioned. The method of claim 1,
The dicing sheet wherein the compound having the energy ray-curable double bond in the molecule contains an energy ray-curable pressure-sensitive adhesive polymer in which an energy ray-polymerizable group is bonded to a main chain or a side chain of the polymer. The method of claim 1,
The dicing sheet whose storage elastic modulus G' at 23 degreeC of the said intermediate|middle layer is 1x10 ⁴ Pa or more and less than 1x10 ⁵ Pa. The method of claim 1,
The storage elastic modulus G' in 23 degreeC before hardening of the said adhesive layer is 3x10 ⁵ Pa or more, The dicing sheet characterized by the above-mentioned. The method of claim 1,
The said adhesive layer contains the acrylic polymer which has a reactive functional group, and a crosslinking agent, 5 mass parts or more of crosslinking agents are contained with respect to 100 mass parts of acrylic polymers, The dicing sheet characterized by the above-mentioned. 6. The method of claim 5,
The dicing sheet, characterized in that the crosslinking agent is an isocyanate-based crosslinking agent. The method of claim 1,
A dicing sheet characterized in that the dicing sheet is used by being pasted on a wafer on which a protruding electrode is formed. 8. The method of claim 7,
The dicing sheet, wherein the protruding electrode is a through electrode. 8. The method of claim 7,
The dicing sheet, characterized in that the intermediate layer has a thickness of 0.5 times or more and 1.5 times or less of the height of the protruding electrode. The method of claim 1,
The dicing sheet whose storage elastic modulus G' in 23 degreeC before hardening of the said adhesive layer is larger than 4 times of the storage elastic modulus G' in 23 degreeC of the said intermediate|middle layer. The method of claim 1,
The thickness of the pressure-sensitive adhesive layer is 5 μm or more and 50 μm or less, a dicing sheet. The method of claim 1,
The thickness of the said intermediate|middle layer is 5 micrometers or more and 50 micrometers or less, The dicing sheet. A step of affixing the dicing sheet according to any one of claims 1 to 12 on the electrode-formed surface of a semiconductor wafer having a protruding electrode, a step of dividing the semiconductor wafer into pieces for each circuit to produce a semiconductor chip and picking up the semiconductor chip.

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