JP2003257894A - Adhesive sheet for dicing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive sheet for dicing in which lowering of product quality and disadvantage of cost are eliminated while suppressing generation of waste-thread like dust at the time of dicing. <P>SOLUTION: In the adhesive sheet 1 for dicing where an adhesive layer 12 is provided at least on one side of a basic material film, the basic material film 11 contains an olefin based thermoplastic elastomer containing propylene and ethylene and/or 4-8C α-olefin as polymerization components and having a peak melting point of 120-170°C, and a crystal nucleation having crystal nucleation action to polypropylene. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a pressure-sensitive adhesive sheet for dicing. Furthermore, the present invention relates to a method for dicing using the pressure-sensitive adhesive sheet for dicing, and a small piece to be cut obtained by the dicing method. INDUSTRIAL APPLICABILITY The pressure-sensitive adhesive sheet for dicing of the present invention is particularly useful as a pressure-sensitive adhesive sheet for dicing semiconductor wafers used for fixing an object to be cut such as a semiconductor wafer when dicing (cutting) element small pieces such as a semiconductor wafer. . For example, the adhesive sheet for dicing of the present invention can be used as an adhesive sheet for silicon semiconductor dicing, an adhesive sheet for compound semiconductor wafer dicing, an adhesive sheet for semiconductor package dicing, an adhesive sheet for glass dicing, and the like.

[0002]

2. Description of the Related Art Conventionally, a semiconductor wafer made of silicon, gallium, arsenic, or the like is manufactured in a large diameter state, cut into small pieces (dicing) into element pieces, and then transferred to a mounting step. At this time, the semiconductor wafer is subjected to the dicing process, the cleaning process, the expanding process, the pickup process, and the mounting process while being attached and held on the adhesive sheet. As the pressure-sensitive adhesive sheet, generally used is one in which an acrylic pressure-sensitive adhesive is applied to a substrate made of a plastic film in an amount of about 1 to 200 μm.

In the dicing step, the wafer is cut by a circular blade that moves while rotating, and at that time, a cutting called a full cut is performed to cut inside the base material of the pressure-sensitive adhesive sheet for dicing that holds the semiconductor wafer. The method is becoming mainstream.

And, in the cutting method by full cut,
As a result of cutting into the inside of the pressure-sensitive adhesive sheet, the plastic film itself, which is the base material, produces thread-like cutting waste. When the thread waste adheres to the side surface of the chip (the object to be cut) or the like, the adhered thread waste is mounted and sealed as it is in the subsequent process, which is a cause of markedly reducing the reliability of the semiconductor element. There was a problem.

As a means for solving such a problem, for example, Japanese Patent Laid-Open No. 5-156214 proposes an adhesive sheet using an ethylene-methacrylate copolymer as a base material. However, with this pressure-sensitive adhesive sheet, although the generation of filamentous waste is somewhat reduced, it is not possible to satisfy the level that can withstand the dicing process of manufacturing a highly reliable semiconductor in the future.

Further, in Japanese Unexamined Patent Publication No. 511234/1993,
A pressure-sensitive adhesive sheet has been proposed which uses a film obtained by irradiating a base film with radiation such as an electron beam or γ-ray of 1 to 80 MRad. However, with this adhesive sheet, film damage due to radiation irradiation is large, it is difficult to obtain a film having a good appearance, and a large cost is required in the film production, which is not preferable in terms of quality and price.

[0007]

SUMMARY OF THE INVENTION The present invention is intended to solve the problems associated with the prior art as described above, and is free from the deterioration of product quality and cost disadvantages, and moreover, the generation of filamentous scraps during dicing. It is an object of the present invention to provide a pressure-sensitive adhesive sheet for dicing. Moreover, it aims at providing the dicing method using the said adhesive sheet for dicing. Furthermore, it aims at providing the small piece of to-be-cut body obtained by the said dicing method.

[0008]

Means for Solving the Problems The inventors of the present invention have made earnest studies on a base film constituting a pressure-sensitive adhesive sheet for dicing in order to solve the above-mentioned problems, and as a result, as a base film, a specific olefinic thermoplastic elastomer was added. It was found that the above object can be achieved by using a crystal nucleating agent, and the present invention has been completed.

That is, the present invention relates to a pressure-sensitive adhesive sheet for dicing, which comprises a pressure-sensitive adhesive layer provided on at least one surface of a base film, wherein the base film is propylene and ethylene and / or α-C 4-8. An olefin-based thermoplastic elastomer containing olefin as a polymerization component, having a melting point peak temperature of 120 ° C. or higher 1
The present invention relates to a pressure-sensitive adhesive sheet for dicing, which contains an olefinic thermoplastic elastomer having a temperature of 70 ° C. or lower and a crystal nucleating agent having a crystal nucleating action on polypropylene.

The pressure-sensitive adhesive sheet for dicing according to the present invention,
Propylene and ethylene and / or C4-8
Among the olefin-based thermoplastic elastomers containing α-olefin as a polymerization component, the base film containing a melting point peak temperature of 120 ° C. or higher and 170 ° C. or lower can suppress the generation of filamentous scraps during dicing. That is what I found. Further, the present invention has found that the inclusion of the crystal nucleating agent can further suppress the generation of filamentous scraps. The melting point peak temperature of the olefinic thermoplastic elastomer is preferably 140 ° C. or higher, more preferably 160 ° C. or higher. The melting point peak temperature is generally measured by a differential scanning calorimeter (DSC) according to JIS K7121.

In the pressure-sensitive adhesive sheet for dicing, in the olefinic thermoplastic elastomer, the elution component at 0 ° C. in the temperature rising elution fractionation using o-dichlorobenzene as a solvent between 0 ° C. and 140 ° C. is the total elution weight. It is preferably 10 to 60% by weight.

The ratio of the elution amount of the olefinic thermoplastic elastomer to the total elution weight at 0 ° C. is such that the generation of filamentous scraps during dicing can be suppressed, and the expandability and the adhesiveness with the adhesive layer of the base film can be suppressed. Is a preferable range that satisfies the above condition. When the proportion of elution at 0 ° C decreases,
Since the base film obtained by molding the olefin-based thermoplastic elastomer is hard, the expandability during expansion is poor, and the pick-up tends to be difficult, the proportion of the elution at 0 ° C. is 10% by weight. As described above, the content is preferably 20% by weight or more. Also, the above 0
When the proportion of the eluted portion at 0 ° C increases, the adhesiveness of the base film obtained by molding the olefinic thermoplastic elastomer with the pressure-sensitive adhesive layer tends to be poor. It is preferably 60% by weight or less, and more preferably 50% by weight or less.

The temperature rising elution fractionation (Temperatu
Re-rising Elution Fractionation (TREF) is a known analysis method. In principle, the polymer is completely dissolved in the solvent at elevated temperature and then cooled to form a thin polymer layer on the surface of the inert carrier which has been in solution. At this time, the polymer layer is formed in the order of the highly crystalline component which is easily crystallized and the low crystalline or amorphous component which is hard to be crystallized. Then, when the temperature is raised continuously or stepwise,
On the contrary, the low crystalline or amorphous component elutes, and finally the high crystalline component elutes. The composition distribution of the polymer is analyzed from the elution curve drawn by the elution amount at each temperature and the elution temperature.

As the measuring device, a cross sorting device (CFC / T150A manufactured by Mitsubishi Chemical Co., Ltd.) was used. Sample to be measured (olefin thermoplastic elastomer)
Using a solvent (o-dichlorobenzene), a concentration of 30 mg
It was dissolved at 140 ° C. so that the concentration became / ml, and this was injected into the sample loop in the measuring device. The following measurements were performed automatically according to the set conditions. The sample solution held in the sample loop is separated by utilizing the difference in melting temperature.
0.4 ml was injected into a REF column (a stainless steel column packed with inert glass beads and having an inner diameter of 4 mm and a length of 150 mm attached to the apparatus). The sample is 1
Cooled from 140 ° C to 0 ° C at a rate of ° C / min,
Coated on the inert carrier. At this time, a polymer layer is formed on the surface of the inert carrier in the order of high crystal component (those that are easily crystallized) to low crystal component (that is difficult to crystallize). After the TREF column was kept at 0 ° C. for another 30 minutes, the temperature was raised stepwise as follows, and the elution amount at that temperature was measured while being kept at each temperature for 30 minutes. Elution temperature (° C): 0, 5, 10, 1
5,20,25,30,35,40,45,49,5
2,55,58,61,64,67,70,73,7
6, 79, 82, 85, 88, 91, 94, 97, 10
0, 102, 120, 140.

In the pressure-sensitive adhesive sheet for dicing, the content of the crystal nucleating agent is preferably 0.0001 to 1% by weight based on the whole base film. The content of the crystal nucleating agent is not particularly limited, but the effects of the present invention are effectively exhibited when the content is adjusted within the above range. When the content of the crystal nucleating agent is small, the crystal nucleating action is poor,
Since it becomes difficult to obtain the effects of the present invention, the content of the crystal nucleating agent is 0.0001% by weight or more, preferably 0.001% by weight or more.
It is at least 05% by weight. On the other hand, when the content of the crystal nucleating agent is increased, the flexibility of the base film becomes poor, and the expandability at the time of expansion tends to deteriorate, and the picking tends to be difficult, so the crystal nucleating agent tends to be difficult. The above content of 1% by weight or less, preferably 0.1% by weight or less. In the pressure-sensitive adhesive sheet for dicing, poly-3-methyl-1-butene can be preferably used as the crystal nucleating agent.

In the pressure-sensitive adhesive sheet for dicing, it is preferable that the base film is a monolayer film and contains the olefinic thermoplastic elastomer in an amount of 50% by weight or more.

In the pressure-sensitive adhesive sheet for dicing, it is preferable that the base film is a multilayer film, and at least one layer of the multilayer film contains 50% by weight or more of the olefinic thermoplastic elastomer.

The content of the above-mentioned olefinic thermoplastic elastomer in the substrate film is usually 50% by weight or more, preferably 80% by weight, in order to prevent the generation of thread scraps, at least one layer of the monolayer film or the multilayer film. It should be at least%. When the base film is a multilayer,
For example, it is possible to prevent the generation of filamentous scraps at the time of dicing by providing at least one layer up to a depth at which a round blade is cut at the time of full cutting, with a layer having low elongation containing the olefinic thermoplastic elastomer. By providing a layer having excellent extensibility required for expansion in another layer, it is possible to compensate for the low extensibility of the layer containing the olefin-based thermoplastic elastomer. In addition, a functional layer such as a layer having an excellent antistatic property may be provided to form a multi-layer structure, and additional functions such as antistatic performance may be added.

In the pressure-sensitive adhesive sheet for dicing, it is effective when the pressure-sensitive adhesive layer has a thickness of 1 to 200 μm.

The thickening of the pressure-sensitive adhesive layer significantly lowers the dicing quality due to factors such as vibration of the semiconductor wafer during dicing, which is also disadvantageous in terms of cost. Therefore, the thickness of the pressure-sensitive adhesive layer is 1 to 200 μm. And particularly preferably 3 to 50 μm. Usually, in the dicing step, since the circular blade cuts and cuts the adhesive sheet for dicing to about 5 to 230 μm, the adhesive layer is thinner than the cutting depth, and the cut is made to the base film. The adhesive sheet for dicing of the present invention effectively functions when the thread-like waste due to the base film becomes a problem.

In the pressure-sensitive adhesive sheet for dicing, it is preferable that the pressure-sensitive adhesive layer is formed of a radiation-curable pressure-sensitive adhesive.

If a radiation-curable pressure-sensitive adhesive layer is used, the adhesive force can be reduced by irradiating with radiation,
After cutting and separating the wafer or the like, the adhesive sheet can be easily removed from the wafer or the like.

Further, according to the present invention, after the pressure-sensitive adhesive sheet for dicing is attached to a body to be cut, the body to be cut is cut into the base film of the pressure-sensitive adhesive sheet to dice the body to be cut, Regarding A semiconductor element is effective as the applicable cut object. Further, the present invention relates to a small piece of a cut object produced by dicing the cut object by the dicing method.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the pressure-sensitive adhesive sheet for dicing of the present invention will be described in detail with reference to FIG. As shown in FIG. 1, the pressure-sensitive adhesive sheet 1 for dicing of the present invention comprises a base film 11, a pressure-sensitive adhesive layer 12 provided on at least one surface of the base film 11, and, if necessary, a pressure-sensitive adhesive layer. The separator 13 is in contact with and is attached to the surface opposite to the base film. Although the pressure-sensitive adhesive layer 12 is provided on one side of the base film 11 in FIG. 1, the pressure-sensitive adhesive layer can be formed on both sides of the base film. The pressure-sensitive adhesive sheet for dicing may be rolled into a tape shape.

The base film contains an olefin-based thermoplastic elastomer containing propylene and ethylene and / or an α-olefin having 4 to 8 carbon atoms as a polymerization component. Examples of the α-olefin having 4 to 8 carbon atoms include butene-1,3-methylpentene-1,4-methylpentene-1, hexene-1, octene-1 and the like. As the olefin-based thermoplastic elastomer, a copolymer of propylene and ethylene is preferable.

The proportion of each polymerization component constituting the olefin-based thermoplastic elastomer is not particularly limited as long as the olefin-based thermoplastic elastomer satisfies the above melting point peak temperature and temperature rising elution fraction requirements. The ratio is usually 50 to 95% by weight, more preferably 60 to 92% by weight. Ethylene and / or α-olefin having 4 to 8 carbon atoms is the remaining amount after subtracting the proportion of propylene.

The olefinic thermoplastic elastomer of the present invention contains the above-mentioned polymerization component and satisfies the above-mentioned conditions concerning the melting point peak temperature and the temperature rising elution fraction. As the method for producing the olefin-based thermoplastic elastomer, for example, in the first stage, a propylene homopolymer or propylene and a small amount of ethylene and / or a carbon number of 4
After producing a random copolymer with α-olefin of
Producing a random copolymer of propylene and ethylene and / or another α-olefin having 4 to 8 carbon atoms in the second and subsequent stages, at least two or more stages of sequential polymerization method; propylene homopolymer or propylene and a small amount of ethylene. And / or a random copolymer of α-olefin having 4 to 8 carbon atoms and a random copolymer of ethylene and α-olefin having 4 to 8 carbon atoms, or ethylene and / or 4 to 8 carbon atoms and propylene. The method of producing by blending the random copolymers separately polymerized. As these methods, a sequential polymerization method of at least two stages or more is preferable.

The stepwise polymerization method will be described in detail below. The catalyst used in the sequential polymerization is not particularly limited, but an organoaluminum compound, a titanium atom,
Those composed of a magnesium atom, a halogen atom, and a solid component essentially containing an electron-donating compound are preferred.

Here, as the organoaluminum compound, the general formula (R ¹ ) _m A known in this type of polymerization is used.
a compound represented by lX _(3-m) (in the formula, R ¹ is a hydrocarbon residue having 1 to 12 carbon atoms, X is a halogen atom, and m is an integer of 1 to 3), for example, Trialkylaluminums such as trimethylaluminum and triethylaluminum, dialkylaluminum halides such as dimethylaluminum chloride and diethylaluminum chloride, alkylaluminum sesquihalides such as methylaluminum sesquichloride, ethylaluminum sesquichloride, methylaluminum dichloride and alkyls such as ethylaluminum dichloride. Alminium halides, alkyl aluminum hydrides such as diethyl aluminum hydride and the like can be mentioned.

As the solid component containing titanium atom, magnesium atom, halogen atom, and electron-donating compound as essential components, those known in this type of polymerization can be used. The titanium compound serving as the supply source of the titanium atom is represented by the general formula: Ti (OR ² ) _4-n) X _n (wherein R ²
The hydrocarbon residue X having 1 to 10 carbon atoms represents a halogen atom, and n is an integer of 0 to 4. ), And among them, titanium tetrachloride, tetraethoxy titanium, tetrabutoxy titanium and the like are preferable. Examples of the magnesium compound that serves as the supply source of magnesium atoms include dialkyl magnesium, magnesium dihalide, dialkoxy magnesium, and alkoxy magnesium halide. Among them, magnesium dihalide and the like are preferable. Examples of the halogen atom include fluorine, chlorine, bromine, and iodine. Among them, chlorine is preferable, and these are usually supplied from the titanium compound described above, but the halogen compound of aluminum, the halogen compound of silicon, and the tungsten compound of tungsten. It may be supplied from another halogen source such as a halogen compound.

Examples of the electron-donating compound include alcohols, phenols, ketones, aldehydes, carboxylic acids, oxygen-containing compounds such as organic acids or inorganic acids and their derivatives, ammonia, amines, nitriles, isocyanates, etc. The nitrogen-containing compounds of Among them, inorganic acid esters, organic acid esters, organic acid halides and the like are preferable, and silicon ester, acetic acid cellosolve ester, phthalic acid halide and the like are more preferable, and general formula: R ³ R ⁴ _(3-P) S
i (OR ⁵ ) _p (wherein R ³ is a branched aliphatic hydrocarbon residue having 3 to 20 carbon atoms, preferably 4 to 10 carbon atoms, or a cyclic aliphatic carbon atom having 5 to 20 carbon atoms, preferably 6 to 10 carbon atoms) Represents a hydrogen residue, R ⁴ has 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms
Represents a branched or straight chain aliphatic hydrocarbon residue, and p is 1 to
It is an integer of 3. ) Organosilicon compounds represented by, for example, t-butyl-methyl-diethoxysilane, cyclohexyl-methyl-dimesitoxysilane, cyclohexyl-methyl-diethoxysilane and the like are particularly preferable.

In the first step of the stepwise polymerization method, propylene or a small amount of ethylene and / or an α-olefin having 4 to 8 carbon atoms is fed and the temperature is 50 to 150 ° C., preferably in the presence of the catalyst. Is 50-100
C., propylene homopolymer and the like are polymerized under the conditions of .degree. C. and partial pressure of propylene of 0.5 to 4.5 MPa, preferably 1 to 3.5 MPa, and subsequently, in the second stage, propylene and ethylene and / or carbon number of 4 to 8 at a temperature of 50 to 150 ° C., preferably at 50 to 100 ° C. in the presence of the catalyst, propylene and ethylene and / or partial pressures of α to 4 olefins of 0 to 8 each. 3-4.
5 MPa, preferably 0.5 to 3.5 MPa,
Propylene and ethylene and / or α having 4 to 8 carbon atoms
-By carrying out the polymerization of the olefin copolymer.

The polymerization at that time may be carried out batchwise, continuously or semi-batchly, the first stage polymerization is carried out in a gas phase or a liquid phase, and the second stage polymerization is also carried out in a gas phase or a liquid phase. It is carried out in the phase, preferably in the gas phase.
The residence time in each stage is 0.5 to 10 hours, preferably 1 to 5 hours.

Further, when problems such as stickiness occur in the powder particles of the olefinic thermoplastic elastomer produced by the above method, after the polymerization in the first step, the Before or during the initiation of the polymerization in two stages, the active hydrogen-containing compound is 100 to 1000 times by mole with respect to the titanium atom in the solid component of the catalyst, and 2 to 5 times by mole with respect to the organoaluminum compound of the catalyst. It is preferable to add it in a molar range. Examples of the active hydrogen-containing compound include water, alcohols, phenols, aldehydes, carboxylic acids, acid amides ammonia, amines and the like.

The olefinic thermoplastic elastomer produced by the above method has a melt florate (MFR) measured at a temperature of 230 ° C. and a load of 21.18 N in accordance with JIS K7210 of 0.1 to 50 g / 10 min. ,
The density measured by the water displacement method according to JIS K7112 is about 0.87 to 0.89 g / cm ³ , and J
The flexural modulus measured at a temperature of 23 ° C. according to IS K7203 is 600 MPa or less.

The olefin thermoplastic elastomer is dynamically heat-treated in the presence of a known organic peroxide or a crosslinking agent having one or more, preferably two or more double bonds in the molecule to adjust the MFR. You can also do it.

The base film of the present invention may contain the above-mentioned olefinic thermoplastic elastomer as a constituent resin, and the base film can be composed of the olefinic thermoplastic elastomer alone, and if necessary, The base film can also be composed of a mixture with another plastic resin or elastomer. Examples of such plastic resin or elastomer include known polyolefins such as polypropylene, polyethylene and polybutene, polyethylene terephthalate, polyvinyl chloride,
Polyurethane, polystyrene, styrene elastomer, ethylene and propylene and / or C4-8
Conventional plastics such as ethylene-propylene rubber and ethylene-α-olefin copolymer (rubber) composed of α-olefin or the resin for elastomer sheet can be preferably used. In addition, as described above, the content of the olefinic thermoplastic elastomer in the base film is usually 50% by weight or more, preferably 80% by weight or more, from the viewpoint of the effect of preventing the generation of thread scraps.

Further, the base film of the present invention contains a crystal nucleating agent having a crystal nucleating action on polypropylene as an additive component. As described above, the content of the crystal nucleating agent in the base film is preferably 0.0001 to 1% by weight.

The crystal nucleating agent is not particularly limited, and various inorganic compounds, various carboxylic acids or metal salts thereof, dibenzylidene sorbitol compounds, aryl phosphate compounds, cyclic polyvalent metal aryl phosphate compounds and aliphatic compounds. Examples thereof include a mixture of an alkali metal monocarboxylic acid salt or basic aluminum / lithium / hydroxy / carbonate / hydrate, and an α-crystal nucleating agent such as various polymer compounds. These crystal nucleating agents can be used alone,
Also, two or more kinds can be used in combination.

Examples of the inorganic compound include talc, alum, silica, titanium oxide, calcium oxide, magnesium oxide, carbon black, clay mineral and the like.

Examples of carboxylic acids include carboxylic acids other than aliphatic monocarboxylic acids. For example, malonic acid, succinic acid, adipic acid, maleic acid, azelaic acid, sebacic acid, dodecanedioic acid, citric acid, butanetricarboxylic acid, butanetetracarboxylic acid, naphthenic acid, cyclopentanecarboxylic acid, 1-methylcyclopentanecarboxylic acid , 2-methylcyclopentanecarboxylic acid, cyclopentenecarboxylic acid, cyclohexanecarboxylic acid, 1
-Methylcyclohexanecarboxylic acid, 4-methylcyclohexanecarboxylic acid, 3,5-dimethylcyclohexanecarboxylic acid, 4-butylcyclohexanecarboxylic acid, 4
-Octylcyclohexanecarboxylic acid, cyclohexenecarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, benzoic acid, toluic acid, xylic acid, ethylbenzoic acid, 4-t-butylbenzoic acid, salicylic acid, phthalic acid,
Examples of the acid include trimellitic acid and pyromellitic acid. Examples of the metal salt of these carboxylic acids include normal salts or basic salts of lithium, sodium, potassium, magnesium, calcium, strontium, barium, zinc or aluminum.

Examples of the dibenzylidene sorbitol type compounds include 1,3,2,4-dibenzylidene sorbitol, 1,3-benzylidene-2,4-p-methylbenzylidene sorbitol, and 1,3-benzylidene-2,4. −
p-Ethylbenzylidene sorbitol, 1.3-p-Methylbenzylidene-2,4-benzylidene sorbitol, 1.3-p-Ethylbenzylidene-2,4-benzylidene sorbitol, 1.3-p-Methylbenzylidene-2,4 -P-Ethylbenzylidene sorbitol, 1 ・
3-p-Ethylbenzylidene-2,4-p-methylbenzylidene sorbitol, 1,3,2-4-bis (p-methylbenzylidene) sorbitol, 1,3,2,4-bis (p-ethylbenzylidene) sorbitol 1,3,3
2,4-bis (pn-propylbenzylidene) sorbitol, 1,3,2,4-bis (p-i-propylbenzylidene) sorbitol, 1,3,2,4-bis (p-)
n-Butylbenzylidene) sorbitol, 1,3,2
4-bis (ps-butylbenzylidene) sorbitol, 1,3,2,4-bis (pt-butylbenzylidene) sorbitol, 1.3- (2 ', 4'-dimethylbenzylidene) -2.4 -Benzylidene sorbitol, 1
-3-benzylidene-2,4- (2 ', 4'-dimethylbenzylidene) sorbitol, 1,3,2-4, -bis (2', 4'-dimethylbenzylidene) sorbitol,
1,3,2,4-bis (3 ', 4'-dimethylbenzylidene) sorbitol, 1,3,2,4-bis (p-methoxybenzylidene) sorbitol, 1,3,2,4-bis (p- Ethoxybenzylidene) sorbitol, 1.3
-Benzylidene-2,4-p-chlorobenzylidene sorbitol, 1.3-p-chlorobenzylidene-2,4-
Benzylidene sorbitol, 1,3-p-chlorobenzylidene-2,4-p-methylbenzylidene sorbitol, 1,3-p-chlorobenzylidene-2,4-p-ethylbenzylidene sorbitol, 1,3-p-methylbenzylidene- 2,4-p-chlorobenzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-p-
Examples thereof include chlorbenzylidene sorbitol, 1,3,2,4-bis (p-chlorobenzylidene) sorbitol and the like.

Examples of aryl phosphate compounds include lithium-bis (4-t-butylphenyl) phosphate, sodium-bis (4-t-butylphenyl) phosphate and lithium-bis (4-cumylphenyl). ) Phosphate, sodium-bis (4-cumylphenyl) phosphate, potassium-bis (4-
t-butylphenyl) phosphate, calcium-mono (4-t-butylphenyl) phosphate, calcium-bis (4-t-butylphenyl) phosphate, magnesium-mono (4-t-butylphenyl) phosphate, Magnesium-bis (4-t-butylphenyl) phosphate, zinc-mono (4-t-butylphenyl) phosphate, zinc bis (4-t-)
Butylphenyl) phosphate, aluminum dihydrooxy- (4-t-butylphenyl) phosphate, aluminum hydroxy-bis (4-t-butylphenyl) phosphate, aluminum-tris (4
-T-butylphenyl) phosphate, sodium-
2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate, sodium-2,2'-ethylidene-bis (4,6-di-t-butylphenyl) phosphate, sodium- 2,2'-methylene-bis (4-cumyl-6-t-butylphenyl) phosphate, lithium-2,2'-methylene-bis (4,6-
Di-t-butylphenyl) phosphate, lithium-
2,2′-Ethylidene-bis (4,6-di-t-butylphenyl) phosphate, lithium-2,2′-methylene-bis (4-cumyl-6-t-butylphenyl)
Phosphate, sodium-2,2'-ethylidene-
Bis (4-i-propyl-6-t-butylphenyl) phosphate, lithium-2,2'-methylene-bis (4-methyl-6-t-butylphenyl) phosphate, lithium-2,2'- Methylene-bis (4-ethyl-6-t-butylphenyl) phosphate, sodium-2,2'-butylidene-bis (4,6-di-methylphenyl) phosphate, sodium-2,2'-butylidene- Bis (4,6-di-t-butylphenyl) phosphate, sodium-2,2'-t-octylmethylene-bis (4,6-di-methylphenyl) phosphate, sodium-2,2'-t -Octylmethylene-bis (4,6-di-t-butylphenyl) phosphate, sodium-2,2'-methylene-bis (4-methyl-6-t-butylphenyl) phosphate Sufeto, sodium -2, 2 '- methylene - bis (4-ethyl-6-
t-Butylphenyl) phosphate, sodium (4,4'-dimethyl-6,6'-di-t-butyl-2)
, 2'-Biphenyl) phosphate, sodium-2
, 2'-Ethylidene-bis (4-s-butyl-6-t
-Butylphenyl) phosphate, sodium-2,
2'-methylene-bis (4,6-di-methylphenyl)
Phosphate, sodium-2,2'-methylene-bis (4,6-di-ethylphenyl) phosphate, potassium-2,2'-ethylidene-bis (4,6-di-t)
-Butylphenyl) phosphate, calcium-bis [2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate], magnesium-bis [2
, 2'-Methylene-bis (4,6-di-t-butylphenyl) phosphate], zinc-bis [2,2'-
Methylene-bis (4,6-di-t-butylphenyl) phosphate], aluminum-tris [2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate], calcium-bis [2,2'-methylene-bis (4-methyl-6-t-butylphenyl) phosphate], calcium-bis [2,2'-ethylidene-bis (4,6-di-t-butylphenyl) phosphate Fate], calcium-bis “2,2′-thiobis (4-
Methyl-6-t-butylphenyl) phosphate],
Calcium-bis [2,2'-thiobis (4-ethyl-
6-t-butylphenyl) phosphate], calcium-bis [2,2'-thiobis (4,6-di-t-butylphenyl) phosphate], magnesium-bis [2,2'-thiobis (4,4) 6-di-t-butylphenyl) phosphate], magnesium-bis [2,2 '
-Thiobis (4-t-octylphenyl) phosphate], barium-bis [2,2'-methylene-bis (4
, 6-Di-t-butylphenyl) phosphate],
Calcium-bis [(4,4'-dimethyl-6,6'-
Di-t-butyl-2,2'-biphenyl) phosphate], magnesium-bis [2,2'-ethylidene-bis (4,6-di-t-butylphenyl) phosphate], barium-bis [2 , 2'-Ethylidene-bis (4,6-di-t-butylphenyl) phosphate], Aluminum-tris [2,2'-ethylidene-
Bis (4,6-di-t-butylphenyl) phosphate], aluminum dihydrooxy-2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate, aluminum dihydrooxy-2, 2'-methylene-bis (4-cumyl-6-t-butylphenyl)
Phosphate, aluminum hydroxy-bis [2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate], aluminum hydroxy-bis [2,2'-methylene-bis (4-cumyl) −
6-t-butylphenyl) phosphate], titanium dihydrooxy-bis [2,2'-methylene-bis (4,4
6-di-t-butylphenyl) phosphate], tindihydrooxy-bis [2,2'-methylene-bis (4,6-di-t-butylphenyl) phosphate], zirconiumoxy-bis [2,2] 2′-methylene-bis (4,6-di-t-butylphenyl) phosphate], aluminum dihydrooxy-2,2′-methylene-bis (4-methyl-6-t-butylphenyl) phosphate, aluminum Hydroxy-bis [2,2
2'-methylene-bis (4-methyl-6-t-butylphenyl) phosphate], aluminum dihydrooxy-2,2'-ethylidene-bis (4,6-di-t-butylphenyl) phosphate, aluminum And hydroxy-bis [2,2'-ethylidene-bis (4,6-di-t-butylphenyl) phosphate].

Examples of the alkali metal salt of an aliphatic monocarboxylic acid used as a mixture with the cyclic polyvalent metal arylphosphate compound among the arylphosphate compounds include acetic acid, lactic acid, propionic acid, acrylic acid,
Octylic acid, isooctylic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, 12-hydroxystearic acid, ricinoleic acid, behenic acid, erucic acid, Montanic acid, melissic acid, stearoyl lactic acid, β-
Dodecyl mercaptoacetic acid, β-dodecyl mercaptopropionic acid, β-N-laurylaminopropionic acid, β-
Examples include lithium, sodium or potassium salts such as N-methyl-N-lauroylaminopropionic acid.

Examples of the polymer compound include polyethylene, poly-3-methyl-1-butene, poly-3-methyl-1.
-Pentene, poly 3-ethyl-1-pentene, poly 4-
Methyl-1-pentene, poly-4-methyl-1-hexene, poly4,4-dimethyl-1-pentene, poly4,4
-Dimethyl-1-hexene, poly-4-ethyl-1-hexene, poly-3-ethyl-1-hexene, polyallylnaphthalene, polyallylnorbornane, atactic polystyrene, syndiotactic polystyrene, polydimethylstyrene , Polyvinylnaphthalene, polyallylbenzene, polyallyltoluene, polyvinylcyclopentane, polyvinylcyclohexane, polyvinylcycloheptane, polyvinyltrimethylsilane, polyallyltrimethylsilane and the like.

It is to be noted that these polymer compounds are preferably used as disclosed in JP-A-2-43204 and the like.
A method in which 0.01 to 100 g of a monomer constituting the polymer compound is polymerized per 1 g of a solid catalyst component, followed by prepolymerization, or homopolymerization of propylene or copolymerization of propylene with a small amount of ethylene and / or α-olefin. The above polymer compound is added in an amount of 0.01 to 0.15.
It can be obtained as a propylene polymer containing at a concentration of about wt%. By adding this to the olefin-based thermoplastic elastomer, the polymer compound as a crystal nucleating agent can be uniformly and efficiently mixed with the olefin-based thermoplastic elastomer, and an excellent crystal nucleation effect can be obtained in a very small amount. It is possible.

As the crystal nucleating agent in the present invention, in the case of a low molecular weight compound, a high molecular weight compound is preferably used from the viewpoint of lowering the adhesiveness between the substrate and the pressure-sensitive adhesive layer and the semiconductor contamination by metal ions. Among the polymer compounds, poly-3-methyl-1-butene is preferable.

In the base film, softeners such as mineral oil, fillers such as calcium carbonate, silica, talc, mica and clay, antioxidants, light stabilizers, antistatic agents, lubricants, dispersants, Various additives such as a neutralizing agent may be blended as necessary.

The base film of the present invention can be produced by a conventional method such as an extrusion method. Its thickness is usually 10
The thickness is 300 μm, preferably about 30 to 200 μm.
The base film may be either a single-layer film or a multi-layer film, but is 150 μm from the surface in contact with the pressure-sensitive adhesive layer.
It is preferable that the layer which is assumed to reach the round blade during dicing up to about m is a layer containing the olefinic thermoplastic elastomer. The multilayer film can be produced, for example, by using the above-mentioned polyolefin or the like as a material for the other layer and by a conventional film laminating method such as a coextrusion method or a dry laminating method.

Further, the obtained base film may be subjected to a uniaxial or biaxial stretching treatment, if necessary. When performing the stretching treatment, it is preferable to perform the stretching treatment at about 60 to 100 ° C. The substrate film thus formed can be subjected to a conventional physical or chemical treatment such as matting treatment, corona discharge treatment and primer treatment, if necessary.

For the pressure-sensitive adhesive layer, known or common pressure-sensitive adhesives can be used. Such pressure-sensitive adhesives are not particularly limited, but various pressure-sensitive adhesives such as rubber-based, acrylic-based, silicone-based, and polyvinyl ether-based pressure-sensitive adhesives are used.

The adhesive is preferably an acrylic adhesive. As the acrylic polymer that is the base polymer of the acrylic pressure-sensitive adhesive, a polymer of alkyl (meth) acrylate or a copolymer with a copolymerizable monomer is usually used. As the main monomer of the acrylic polymer, the homopolymer has a glass transition temperature of 20 ° C. or lower (meth).
Alkyl acrylate is preferred.

Examples of the alkyl group of the alkyl (meth) acrylate include a methyl group, an ethyl group, a butyl group, 2
Examples thereof include an ethylhexyl group, an octyl group and an isononyl group. The copolymerizable monomer may be a hydroxyalkyl ester of (meth) acrylic acid (for example, hydroxyethyl ester, hydroxybutyl ester, hydroxyhexyl ester, etc.), (meth) acrylic acid glycidyl ester, (meth) acrylic acid, Itaconic acid, maleic anhydride, (meth) acrylic acid amide,
Examples thereof include (meth) acrylic acid N-hydroxymethylamide, (meth) acrylic acid alkylaminoalkyl, (eg, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, etc.), vinyl acetate, styrene, acrylonitrile, and the like.

Further, as the pressure-sensitive adhesive, a radiation-curable pressure-sensitive adhesive which is cured by ultraviolet rays, electron beams or the like or a heat-foamable pressure-sensitive adhesive can be used. Further, it may be an adhesive that can be used for both dicing and die bonding. In the present invention, it is preferable to use a radiation-curable pressure-sensitive adhesive, particularly an ultraviolet-curable pressure-sensitive adhesive. When a radiation-curable pressure-sensitive adhesive is used as the pressure-sensitive adhesive, the pressure-sensitive adhesive is irradiated with radiation before or after the dicing step, so that the base film preferably has sufficient radiation transparency.

The radiation-curable pressure-sensitive adhesive contains, for example, the above-mentioned base polymer (acrylic polymer) and a radiation-curable component. As the radiation-curable component, a monomer, oligomer or polymer having a carbon-carbon double bond in the molecule and curable by radical polymerization can be used without particular limitation. Examples of the radiation-curable component include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentane. Esterification products of (meth) acrylic acid and polyhydric alcohols such as ethyl glycol di (meth) acrylate and dipentaerythritol hexa (meth) acrylate; ester acrylate oligomers; 2-propenyl-di-3-butenyl cyanurate , 2-hydroxyethylbis (2-acryloxyethyl) isocyanurate, isocyanurates such as tris (2-methacryloxyethyl) isocyanurate, or isocyanurate compounds.

The radiation-curable pressure-sensitive adhesive may also be a radiation-curable polymer having a carbon-carbon double bond in the polymer side chain, as the base polymer (acrylic polymer). It is not necessary to add a hardening component.

When the radiation-curable pressure-sensitive adhesive is cured by ultraviolet rays, a photopolymerization initiator is required. Examples of the polymerization initiator include benzoin alkyl ethers such as benzoyl methyl ether, benzoin propyl ether and benzoin isobutyl ether; aromatic ketones such as benzyl, benzoin, benzophenone and α-hydroxycyclohexyl phenyl ketone; Aromatic ketals such as dildimethylketal; polyvinylbenzophenone; thioxanthones such as chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone and diethylthioxanthone.

The above-mentioned pressure-sensitive adhesive may further contain a conventional additive such as a cross-linking agent, a tackifier, a filler, an antioxidant and a colorant, if necessary. As a cross-linking agent,
For example, polyisocyanate compound, melamine resin, urea resin, aziridine compound, epoxy resin, anhydride,
Examples thereof include polyamines and carboxyl group-containing polymers.

In the pressure-sensitive adhesive sheet 1 for dicing of the present invention, for example, the pressure-sensitive adhesive layer 12 is obtained by applying a pressure-sensitive adhesive to the surface of the base film 11 and drying (heat-crosslinking if necessary).
Can be formed, and a separator 13 can be attached to the surface of the pressure-sensitive adhesive layer 12 if necessary. Alternatively, a method in which the pressure-sensitive adhesive layer 12 is separately formed on the separator 13 and then the pressure-sensitive adhesive layer 12 is attached to the base film 11 can be adopted.

The thickness of the pressure-sensitive adhesive layer can be appropriately determined depending on the type of pressure-sensitive adhesive or the dicing depth of cut, but is usually 1 to 200 μm, preferably 3 to 50 μm.

The separator is optionally provided for label processing or for the purpose of smoothing the pressure-sensitive adhesive layer. Examples of the constituent material of the separator include paper, synthetic resin films such as polyethylene, polypropylene and polyethylene terephthalate. The surface of the separator may be subjected to a peeling treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment, if necessary, in order to enhance the peelability from the pressure-sensitive adhesive layer. In addition, uniaxial or biaxial stretching treatment or lamination with another plastic film or the like may be performed depending on the purpose of increasing rigidity. The thickness of the separator is usually 10 to 200 μm, preferably 25 to
It is about 100 μm.

[0062]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited by these examples.

Example 1 (Preparation of base material film) "Product name: manufactured by Mitsubishi Chemical Corporation"
Zelas 5053 "and poly-3-methyl-1-prepolymerized
MFR with 0.08% butene introduced (230 ℃, 2
1.18N) A propylene homopolymer of 4.8 g / 10 min was used in the ratio of the former: the latter (weight ratio) = 100: 1, a twin-screw kneader (cylinder diameter 45 mm, L / D = 34, manufactured by Ikegai Co., Ltd.). PCM-45 "at a preset temperature of 200 ° C) and melt-kneaded to form pellets. Next, the pellets were put into a T-die molding machine (set temperature 2
30 ° C) to form a film, thickness 100 μm, width 29 cm
The base film of was produced. The content of the crystal nucleating agent (poly-3-methyl-1-butene) in the produced base film was 0.00079% by weight.

"Product name: Zelas 50" manufactured by Mitsubishi Chemical Corporation
53 "is an olefin-based thermoplastic elastomer containing 79% by weight of a propylene component and 21% by weight of an ethylene component, using o-dichlorobenzene as a solvent, and having a temperature of 0.
The elution fraction at 0 ° C in the temperature rising elution fractionation between ˜140 ° C is 41.7% by weight based on the total elution amount, the melting point peak temperature is 164 ° C, the density is 0.88 g / cm ³ , and the MFR is
(230 ° C., 21.18 N) 6.8 g / 10 minutes.

(Preparation of pressure-sensitive adhesive) A solution containing an acrylic copolymer having a weight average molecular weight of 500,000 obtained by copolymerizing 90 parts by weight of butyl acrylate and 10 parts by weight of acrylic acid in toluene by a conventional method. In addition, dipentaerythritol hexaacrylate (trade name "Kayarad DPH
A ”, manufactured by Nippon Kayaku Co., Ltd., 60 parts by weight, photopolymerization initiator (trade name“ Irgacure 184 ”, manufactured by Ciba Specialty Chemicals) 3 parts by weight, polyisocyanate compound (trade name“ Coronate L ”) 5 parts by weight of Nippon Polyurethane Co., Ltd. was added to prepare an acrylic UV-curable adhesive solution.

(Preparation of pressure-sensitive adhesive sheet for dicing) The pressure-sensitive adhesive solution prepared above was applied onto the corona-treated surface of the substrate film obtained above and heat-crosslinked at 80 ° C. for 10 minutes to give a thickness of 20 μm. The UV-curable pressure-sensitive adhesive layer was formed.
Then, a separator was attached to the pressure-sensitive adhesive layer surface to prepare a UV-curable pressure-sensitive adhesive dicing sheet.

Example 2 (Preparation of substrate film) (1) "Product name Zelas 5053" manufactured by Mitsubishi Chemical Co., Ltd. used in Example 1 and (2) "Product name: Nippon Polychem Co., Ltd." Novatec HD HB330 "and (3) MFR (230 ° C., 21.18N) 4.8 g / 10 into which 0.08% by weight of poly-3-methyl-1-butene was introduced by prepolymerization.
Min propylene homopolymer (1) :( 2) :( 3)
(Weight ratio) = 80: 20: 1, twin-screw kneader (cylinder diameter 45 mm, L / D = 34, "PCM" manufactured by Ikegai Co., Ltd.
-45 ", set temperature 200 ° C), and melt-kneaded to form a pellet, and then a film was formed in the same manner as in Example 1 to obtain a base film. The content of the crystal nucleating agent (poly-3-methyl-1-butene) in the produced base film was 0.00079% by weight.

"Product name: Novatic HD HB330" manufactured by Nippon Polychem Co., Ltd. has a density of 0.953 g / cm 3.
³ , MFR (190 ° C, 21.18N) 0.35g / 1
It is a 0 minute high density polyethylene.

(Preparation of pressure-sensitive adhesive sheet for dicing) The pressure-sensitive adhesive solution prepared in Example 1 was applied onto the corona-treated surface of the substrate film obtained above, and heat-crosslinked at 80 ° C. for 10 minutes to give a thick film. An ultraviolet curable pressure-sensitive adhesive layer having a thickness of 50 μm was formed. Then, a separator was attached to the pressure-sensitive adhesive layer surface to prepare a UV-curable pressure-sensitive adhesive dicing sheet.

Comparative Example 1 In the production of the pressure-sensitive adhesive sheet for dicing of Example 1, a low-density polyethylene (MFR = 1.
For UV curable dicing in the same manner as in Example 1 except that 5) was formed into a film having a thickness of 100 μm by the T-die extrusion method and a corona treatment was applied to one surface of the substrate film. An adhesive sheet was produced.

Comparative Example 2 In the production of the pressure-sensitive adhesive sheet for dicing of Example 1, an ethylene-methacrylic acid copolymer (MFR = 2.0) was used as a substrate film to have a thickness of 100 by T-die extrusion.
A UV-curable dicing pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that a substrate film obtained by forming a film having a thickness of μm and performing corona treatment on one surface was used.

(Evaluation Test) The pressure-sensitive adhesive sheets for dicing obtained in Examples and Comparative Examples were evaluated by the following methods.
The results are shown in Table 1.

(1) Evaluation of dicing property A 6-inch wafer having a thickness of 350 μm was mounted on a pressure-sensitive adhesive sheet for dicing, and dicing was performed under the following conditions.

(Dicing Conditions) Dicer: DISCO, DFD-651 Blade: DISCO, NBC-ZH205O 2
7HEDD Blade rotation speed: 45000 rpm Dicing speed: 100 mm / sec Dicing depth: 30 μm with respect to the base film Dicing size: 2.5 mm × 2.5 mm Cut mode: Down-cut dicing after cutting The generation state was observed with an optical microscope (200), and the number was counted for each size of filamentous waste.

[0075]

[Table 1] From Table 1, it is recognized that the dicing pressure-sensitive adhesive sheets of the examples generate less filamentous waste. Moreover, 100 μm
The above filamentous waste has not occurred. The wafers of Examples and Comparative Examples did not deteriorate in product quality.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a pressure-sensitive adhesive sheet for dicing according to the present invention.

[Explanation of symbols]

1 Adhesive sheet for dicing 11 Base film 12 Adhesive layer 13 separator

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenjiro Takayanagi             1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Chemical Corporation             Inside the company F-term (reference) 4J004 AA01 AA05 AA08 AA10 AA11                       AA17 AB06 AB07 CA04 CC03                       DB02 FA05 FA08                 4J040 CA001 DD051 DF001 DF041                       DF051 EK001 FA131 FA141                       JA09 JB07 JB08 JB09 KA13                       KA37 NA20

Claims (11)

[Claims] 1. A pressure-sensitive adhesive sheet for dicing, comprising a substrate film and a pressure-sensitive adhesive layer provided on at least one surface of the substrate film, wherein the substrate film polymerizes propylene, ethylene and / or an α-olefin having 4 to 8 carbon atoms. An olefin-based thermoplastic elastomer contained as components, which contains an olefin-based thermoplastic elastomer having a melting point peak temperature of 120 ° C. or higher and 170 ° C. or lower, and a crystal nucleating agent having a crystal nucleating action on polypropylene. A pressure-sensitive adhesive sheet for dicing. 2. The olefin-based thermoplastic elastomer has a temperature of 0 to 0 using o-dichlorobenzene as a solvent.
The pressure-sensitive adhesive sheet for dicing according to claim 1, wherein an elution amount at 0 ° C in the temperature rising elution fractionation between 140 ° C is 10 to 60% by weight based on the total elution weight. 3. The pressure-sensitive adhesive sheet for dicing according to claim 1, wherein the content of the crystal nucleating agent is 0.0001 to 1% by weight based on the entire base film. 4. The crystal nucleating agent is poly-3-methyl-1-
The pressure-sensitive adhesive sheet for dicing according to any one of claims 1 to 3, which is butene. 5. The pressure-sensitive adhesive sheet for dicing according to claim 1, wherein the base film is a monolayer film and contains the olefinic thermoplastic elastomer in an amount of 50% by weight or more. . 6. The substrate film is a multi-layer film, and at least one layer of the multi-layer film contains 50% by weight or more of the olefin-based thermoplastic elastomer. A pressure-sensitive adhesive sheet for dicing as described in Crab. 7. The pressure-sensitive adhesive sheet for dicing according to claim 1, wherein the pressure-sensitive adhesive layer has a thickness of 1 to 200 μm. 8. The pressure-sensitive adhesive sheet for dicing according to claim 1, wherein the pressure-sensitive adhesive layer is formed of a radiation-curable pressure-sensitive adhesive. 9. The dicing adhesive sheet according to any one of claims 1 to 8 is diced by cutting the base film of the adhesive sheet after attaching the dicing adhesive sheet to the cutting object. A dicing method characterized by the above. 10. The dicing method according to claim 9, wherein the object to be cut is a semiconductor element. 11. A small piece of an object to be cut, which is produced by dicing the object to be cut by the dicing method according to claim 9.