JPH10214800A - Method for dicing semiconductor wafer and adhesive film used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for dicing semiconductor wafer using an adhesive film having such a characteristic that the adhesion does not make any secular change, but moderately drops when the film is irradiated with ultraviolet rays, and the adhesive film used in the method. SOLUTION: In a method for dicing semiconductor wafer, a semiconductor wafer is diced by sticking an adhesive film formed by sticking an ultraviolet curing adhesive layer to one surface of a base material film to the rear surface of the wafer and, after irradiating the adhesive film with ultraviolet rays, the adhesive film is stripped off. The base material film contains a phthalocyanine pigment and has light transmittance not lower than 60% in a full wavelength region of 320-380nm and not higher than 20% in at least part of the wavelength region and a thickness of 30-500μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for dicing a semiconductor wafer and an adhesive film for dicing a semiconductor wafer used therefor. More specifically, a surface (hereinafter, referred to as a wafer surface) opposite to a surface (hereinafter, referred to as a wafer surface) of a semiconductor wafer such as silicon, gallium-arsenic, etc. on which integrated circuits are incorporated.
An adhesive film is attached to the back surface of the wafer), the wafer is fixed, the wafer is divided into small pieces, and then the small pieces are separated and removed from each element. The present invention relates to an adhesive film for dicing.

[0002]

2. Description of the Related Art Normally, a semiconductor integrated circuit is sliced from high-purity single-crystal silicon or the like to form a wafer, and then the integrated circuit is written by etching or the like. Is ground to about 100 to 600 μm, divided into element pieces (hereinafter, referred to as chips) (hereinafter, referred to as dicing), and manufactured by a method of mounting the obtained chips into a package through processes such as mounting, bonding, and sealing. Have been. Among these processes, in a dicing process for forming a semiconductor wafer into chips, an adhesive film is used to prevent chips from scattering at the time of dicing and to facilitate the dicing process.

[0003] Specifically, an adhesive film is attached to a metal or plastic circular or square frame called a ring frame, and a wafer is attached and fixed from the back side. After fixing the wafer, the wafer is divided (diced) into chips by a rotating round blade (hereinafter referred to as a dicing blade) while water is applied. After division, each chip is peeled off from the adhesive film and taken out (hereinafter referred to as pickup). Generally, an adhesive film is attached to a ring frame or a semiconductor wafer by an automatic attaching device called a wafer mounter, a wafer mount frame producing device, or the like. To pick up diced chips, expand the adhesive film radially, widen the distance between the chips, push up the chips with a needle or the like through the adhesive film, and suction with a vacuum collet, air tweezers, etc. Is used.

[0004] When dicing is performed by sticking an adhesive film on the back surface of a wafer and performing dicing, it is necessary to have a high adhesive force such that chips do not scatter during dicing. At the same time, when chips are picked up from the adhesive film, It is required to have a weak adhesive strength that can be easily peeled off. Therefore, in selecting an appropriate dicing adhesive film for a semiconductor wafer, it is necessary to sufficiently consider a dicing method, a time required for dicing, a chip size, and the like.

In recent years, chips having a length of about 0.5 to 20 mm have been introduced depending on the performance and type. In the case of a large chip, when the chip is picked up from the pressure-sensitive adhesive layer after completion of dicing, a problem may occur that the chip cannot be picked up by a vacuum collet, air tweezers or the like. Further, in the case of a small chip, there is a problem that the chip is scattered during dicing.

As a method for solving these problems, for example, Japanese Unexamined Patent Publication No. 60-196965 discloses an adhesive thin plate for fixing a semiconductor wafer at the time of cutting and separating a semiconductor wafer into element pieces. There is disclosed an adhesive thin plate for fixing a semiconductor wafer, which comprises an elastic support and a pressure-sensitive adhesive layer provided on the support and having a property of being hardened by light irradiation and formed into a three-dimensional network. However, when used in a semiconductor manufacturing process, the adhesive thin plate for fixing a semiconductor wafer disclosed in this publication may have a reduced adhesive strength even before irradiation with ultraviolet light, and after irradiation with ultraviolet light after dicing. Insufficient reduction in adhesive strength may occur.

If the adhesive strength is reduced before the ultraviolet irradiation, when dicing a semiconductor wafer, water, chips from the wafer during dicing, etc., enter between the back surface of the wafer and the adhesive film, and chips are cut during dicing. May fly.
If chips are scattered, the dicing blade may be damaged.In this case, not only must dicing be interrupted, but also much time is required for replacing the dicing blade, adjusting the entire process, etc. Will be reduced. In addition, if the adhesive strength after irradiation with ultraviolet rays is not sufficiently reduced, there is also a problem that it is difficult to pick up chips using a vacuum collet, air tweezers, or the like.

[0008]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide an adhesive having a very small change in adhesive force over time, and having a sufficient adhesive force when a semiconductor wafer is diced into chips and irradiated with ultraviolet light. An object of the present invention is to provide a method for dicing a semiconductor wafer using a pressure-sensitive adhesive film, and a pressure-sensitive adhesive film used in the method.

[0009]

Generally, an adhesive film for dicing a semiconductor wafer having an ultraviolet-curable adhesive layer is light-shielded and packaged immediately after production, transported, stored, stored, and the like, and then carried into a semiconductor wafer manufacturing factory. After that, it is opened. Usually, since the inside of a factory is illuminated with a fluorescent lamp, a mercury lamp, or the like, the adhesive film is exposed to ultraviolet rays radiated from lighting equipment after opening. The present inventors have conducted intensive studies on a solution to the above problem, and as a result, the cause of the change in the adhesive properties of the adhesive film for dicing of a semiconductor wafer is a fluorescent lamp for illumination in which the adhesive film is installed in a semiconductor manufacturing process chamber. It is presumed that it is due to exposure to ultraviolet rays emitted by mercury lamps and the like. Therefore, the present inventors include a phthalocyanine-based dye in a base film and control the light transmittance in a wavelength range of 320 to 380 nm to a specific range. Illuminance of 0.3 fluorescent light, mercury lamp, etc.
It is possible to reduce the amount of exposure to ultraviolet rays (hereinafter, referred to as weak ultraviolet rays) of about mW / cm ² or less to the adhesive layer, and to reduce the adhesive strength well under exposure to strong ultraviolet rays irradiated after dicing a semiconductor wafer. Heading, the present invention has been reached.

That is, the present invention provides an adhesive film having a pressure-sensitive adhesive layer formed on one surface of a base film and having a property of being cured by irradiation with ultraviolet light, which is adhered to the back surface of a semiconductor wafer via the pressure-sensitive adhesive layer. Dividing the semiconductor wafer into element pieces, irradiating ultraviolet rays from the adhesive film side after the division is completed, and then, from the adhesive film, a method of dicing a semiconductor wafer to pick up element pieces, wherein the base film is It contains a phthalocyanine dye and has a light transmittance of 60 in the entire wavelength range of 320 to 380 nm.
% Or less, a light transmittance in at least a part of the wavelength range is 20% or more, and a thickness of 30 to 500 μm,
And an adhesive film used in the method.

A feature of the present invention is an ultraviolet-curable pressure-sensitive adhesive film in which a pressure-sensitive adhesive layer having a property of being cured by irradiation of ultraviolet light is formed on one surface of a substrate film, wherein the substrate film has a wavelength range of 320 to 380 nm. The phthalocyanine dye is contained to such an extent that the light transmittance in the entire region is 60% or less and the light transmittance in at least a part of the wavelength region is 20% or more.

By using a base film containing a phthalocyanine dye, in the presence of weak ultraviolet light such as a fluorescent lamp, that is, in an environment where the illuminance of ultraviolet light having a wavelength of 320 to 380 nm is about 0.3 mW / cm ² or less, The amount of ultraviolet rays reaching the pressure-sensitive adhesive layer can be reduced, and the stability of the pressure-sensitive adhesive properties against environmental ultraviolet rays can be improved.

After dicing the semiconductor wafer,
Before picking up the obtained chip, a known ultraviolet-curable adhesive film (for example, Japanese Patent Publication No. 60-19695)
No. 6 publication), an illuminance of the order of 3 to 3000 mW / cm ² , which is approximately the same as the intensity of ultraviolet irradiation light that is normally irradiated, and an intensity of 30 to
3000 mJ / cm ² [manufactured by Oak Manufacturing Co., Ltd., digital indicator type UV illuminometer UV-M02, light receiver: UV-
A value obtained by multiplying the irradiation time (seconds) by the UV illuminance (mW / cm ² ) measured using No. 35] (hereinafter referred to as “strong UV”) to sufficiently reduce the adhesive strength. It is possible to do.

Therefore, according to the method of the present invention, the pressure-sensitive adhesive film is opened in the semiconductor manufacturing process, handled, left alone,
When the work is temporarily stopped while the adhesive film is set on the automatic application device due to storage, etc., or due to an unexpected process trouble, or when the work is temporarily interrupted with the adhesive film attached to the backside of the semiconductor wafer, etc. Even if there is, the adhesive force characteristics do not change over time, and when dicing the semiconductor wafer, water between the wafer back surface and the adhesive film,
No chips are scattered due to cutting chips or the like at the time of dicing, and chips are not scattered, and the back surface is not contaminated. Furthermore, after the dicing is completed, when irradiating with ultraviolet rays before picking up the chip, the adhesive force is sufficiently reduced, so that the chip can be picked up extremely easily.

When the base film contains a phthalocyanine dye, the amount of weak ultraviolet rays such as environmental ultraviolet rays caused by an illumination lamp reaching the pressure-sensitive adhesive layer is reduced. Illuminance of 3 to 3000 mW / cm ² , intensity 30 to be irradiated later
The reason why the adhesive strength decreases sufficiently when irradiated with strong ultraviolet light of about 3000 mJ / cm ² is unknown. However, when the ultraviolet light having the above intensity is irradiated, the temperature of the adhesive film is reduced by the photothermal conversion action of the phthalocyanine dye. It is estimated that the curing reaction of the pressure-sensitive adhesive is accelerated, which compensates for the decrease in the amount of the ultraviolet ray reaching the pressure-sensitive adhesive layer, and that the ultraviolet curing reaction is sufficiently occurring.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. First, a method for producing the pressure-sensitive adhesive film used in the present invention will be described. The pressure-sensitive adhesive film of the present invention is usually coated with a pressure-sensitive adhesive solution, an emulsion liquid or the like containing the components constituting the pressure-sensitive adhesive layer on one surface of the substrate film (hereinafter, these are collectively referred to as pressure-sensitive adhesive), and dried. It is manufactured by forming a pressure-sensitive adhesive layer. In this case, it is desirable to attach a release film to the surface of the pressure-sensitive adhesive layer in order to protect the pressure-sensitive adhesive layer from contamination due to the environment. Further, it is also manufactured by a method in which an adhesive layer is formed on one surface of a release film, a base film is attached, and the adhesive layer is transferred to the base film side. In this case, there is an advantage that the surface of the pressure-sensitive adhesive layer is not contaminated when the pressure-sensitive adhesive layer is dried.

Whether the adhesive is applied to one surface of the base film or the release film is determined in consideration of heat resistance, surface tension, contamination on the back surface of the semiconductor wafer, and the like of the base film and the release film. . For example, if the heat resistance of the release film is better than that of the base film,
After providing the pressure-sensitive adhesive layer on the surface of the release film, it is transferred to a base film. If the heat resistance is the same or the base film is better, a pressure-sensitive adhesive layer is provided on the surface of the base film, and a release film is attached to the surface.

However, in consideration of the fact that the pressure-sensitive adhesive film is attached to the back surface of the semiconductor wafer via the surface of the pressure-sensitive adhesive layer exposed when the release film is peeled off, the contamination of the rear surface of the semiconductor wafer by the pressure-sensitive adhesive layer is aimed at. For this purpose, a method is preferred in which a release film having good heat resistance is used, and a pressure-sensitive adhesive coating solution is applied to the surface of the release film and dried to form a pressure-sensitive adhesive layer.

As a method for applying the pressure-sensitive adhesive to one surface of the substrate film or the release film, a conventionally known application method, for example, a roll coater method, a reverse roll coater method, a gravure roll coater method, a comma coater method,
A bar coater method, a die coater method, or the like can be employed.

The base film used in the present invention is formed by mixing a raw resin pellet with a phthalocyanine dye, or mixing a raw resin pellet with a resin pellet containing a phthalocyanine dye, and forming the film by an extruder or the like. Produced. A phthalocyanine dye may be directly added to and mixed with the granular resin to form a film. The base film may be a single-layer body or a laminate.

As the resin used, synthetic resin, natural rubber,
And synthetic rubber. If specifically exemplified, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, polybutadiene, soft vinyl chloride resin, polyolefin, polyamide, ionomer, polyester and other resins and copolymer elastomers thereof, and diene And synthetic rubbers such as rubber based, nitrile based, silicone based, and acrylic based.

Considering the extensibility of the base material during expanding which is usually performed when picking up chips, J
Tensile breaking strength measured in accordance with IS K-7113 or JIS K-6760 is 0.8 to 6 kgf / mm.
^2. A resin obtained by processing a resin having a tensile elongation at break of 100 to 2000% into a film shape is preferable. For example, films such as ionomers and ethylene-methacrylic acid copolymers are preferably used.

The effect of incorporating the phthalocyanine dye used in the present invention into the base film is presumed as follows, although details are unknown. That is, the dye absorbs light in a wide wavelength range from the visible region to the ultraviolet region, and has a property of converting the absorbed light energy into heat energy. For this reason, by including this dye in the base film of the ultraviolet-curable adhesive film for dicing of the semiconductor wafer, in an environment where weak ultraviolet light such as a fluorescent lamp described above is present, the ultraviolet light may be applied to the adhesive layer. Can be reduced, and the stability of the adhesive properties of the ultraviolet-curable adhesive can be improved.

When the high-intensity ultraviolet ray described above is irradiated for the purpose of reducing the adhesive strength by the ultraviolet ray irradiation, the amount of the ultraviolet ray reaching the pressure-sensitive adhesive layer is reduced due to the ultraviolet absorption of the phthalocyanine dye. Due to the action of converting the light energy of the phthalocyanine dye into heat energy, the temperature of the pressure-sensitive adhesive film is increased, the curing reaction of the pressure-sensitive adhesive is promoted, and despite the reduced amount of ultraviolet rays, sufficient It is presumed that the curing reaction proceeds, the adhesive strength decreases, and the releasability improves.

The phthalocyanine dye used in the present invention is
The following general formula (1)

[0026]

Embedded image (Wherein, A _{1 to} A ₈ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group. B _{1 to} B ₈ each independently represent a hydrogen atom Atom, halogen atom, substituted or unsubstituted alkyl group, or substituted or unsubstituted aryl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylthio group, or substituted or unsubstituted Represents an unsubstituted arylthio group, and M represents a divalent metal atom, a divalent or tetravalent substituted metal atom, or an oxymetal.

In the general formula (1), A _{1 to} A ₈ and B ₁ to
Examples of the substituted or unsubstituted alkyl group represented by B ₈ include a methyl group, an ethyl group, an n-propyl group and an iso-
Propyl group, n-butyl group, iso-butyl group, sec
-Butyl group, t-butyl group, n-pentyl group, iso-
Pentyl group, neo-pentyl group, 1,2-dimethyl-
Propyl group, n-hexyl group, cyclo-hexyl group, 1,3-dimethyl-butyl group, 1-iso-propylpropyl group, 1,2-dimethyl-butyl group, n-heptyl group, 1,4-dimethyl Pentyl group, 2-methyl-1
-Iso-propylpropyl group, 1-ethyl-3-methylbutyl group, n-octyl group, 2-ethylhexyl group,
A straight-chain having 1 to 20 carbon atoms such as a 3-methyl-1-iso-propylbutyl group, a 2-methyl-1-iso-propyl group, a 1-t-butyl-2-methylpropyl group, and an n-nonyl group; , A branched alkyl group, a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group, a propoxyethyl group, an alkoxyalkyl group such as a butoxyethyl group,
And halogenated alkyl groups such as 2,2 trichloroethyl group, trifluoromethyl group and chloromethyl group.

Examples of the substituted or unsubstituted alkoxy group include a methoxy group, an ethoxy group, an n-propyloxy group, an iso-propyloxy group, an n-butyloxy group, an iso-butyloxy group and a sec-butyloxy group. , T-butyloxy group, n-pentyloxy group, is
o-pentyloxy group, neo-pentyloxy group,
1,2-dimethyl-propyloxy group, n-hexyloxy group, 1,3-dimethylbutyloxy group, etc.
To 20 linear or branched alkoxy groups, methoxymethoxy groups, methoxyethoxy groups, propoxyethoxy groups, butoxyethoxy groups and other alkoxyalkoxy groups;
And alkoxyalkoxyalkoxy groups such as dimethoxymethoxy, diethoxymethoxy, dimethoxyethoxy, diethoxyethoxy, methoxyethoxyethoxy, and ethoxyethoxyethoxy. Examples of the substituted or unsubstituted aryl group include a phenyl group,
Chlorophenyl group, dichlorophenyl group, bromophenyl group, fluorinated phenyl group, halogenated phenyl group such as iodinated phenyl group, tolyl group, xylyl group, mesityl group, ethylphenyl group, methoxyphenyl group, ethoxyphenyl group, pyridyl group, etc. Is mentioned.

Examples of the divalent metal represented by M include C
u (II), Zn (II), Co (II), Ni (II), Ru
(II), Rh (II), Pd (II), Pt (II), Mn
(II), Mg (II), Ti (II), Be (II), Ca
(II), Cd (II), Ba (II), Hg (II), Pb
(II), Sn (II) and the like.

Examples of monosubstituted trivalent metals include Al-C
1, Al-Br, Al-F, Al-I, Ga-Cl, G
a-Br, Ga-F, Ga-I, In-Cl, In-B
r, In-F, In-I, and the like.

Examples of disubstituted tetravalent metals include CrCl
_Two, SiCl_Two, SiBr_Two, SiF_Two, SiI_Two, ZrC
l_Two, GeCl_Two, GeBr_Two, GeI_Two, GeF_Two, Sn
Cl_Two, SnBr_Two, SnF_Two, Si (OH)_Two, Ge (O
H)_Two, Zr (OH)_Two, Mn (OH)_Two, Sn (O
H)_Two, TiCl_Two, TiBr_Two, TiF_Two, CrR_Two, S
iR _Two, SnR_Two, TiR_Two, GeR_Two(R is an alkyl group,
Phenyl group, naphthyl group, and derivatives
You. ), Si (OR ')_Two, Sn (OR ')_Two, Ge (O
R ')_Two, Ti (OR ')_Two, Cr (OR ')_Two(R 'is
Alkyl, phenyl, naphthyl, trialkyl
Ryl group, dialkylalkoxysilyl group, and derivatives thereof
Represents a conductor. ), Sn (SR ")_Two, Ge (S
R ")_Two(R ″ represents an alkyl group, a phenyl group, a naph
Represents a tyl group and its derivatives. ) And the like.
Examples of oxymetals include VO, MnO, and TiO.
I can do it.

Among the above phthalocyanine dyes, considering the light and thermal stability, the metal represented by M is Cu
(II), Ni (II), Co (II), and A _{1 to} A ₈ , B
It is preferred that the majority of the ₁ .about.B ₈ is a hydrogen atom.
Further, in consideration of the availability of dyes, a compound in which the metal represented by M is Cu (II) and all of A _{1 to} A ₈ and B _{1 to} B ₈ are hydrogen atoms is particularly preferable. . This compound is called copper phthalocyanine (Pigment Blue 15, color index: 74160) and is commercially available.

As the content of the phthalocyanine dye contained in the base film increases, the amount of the ultraviolet ray reaching the ultraviolet-curable pressure-sensitive adhesive layer decreases, and the adhesive property of the pressure-sensitive adhesive changes due to irradiation with weak ultraviolet light. Tends to decrease. However, at the same time, there is a tendency that the adhesive strength does not decrease when irradiating with strong ultraviolet rays after dicing the semiconductor wafer. Considering this point, the content of the phthalocyanine-based dye contained in the base film is such that the light transmittance of the base film is 60% or less in the entire wavelength range of 320 to 380 nm, and the wavelength range is 320 nm to 380.
It is important to include at least 20% or more in at least a part of nm. Preferably, the light transmittance of the substrate film is 50 in a wavelength range of 320 to 380 nm.
% Or less and at least 35% or more in at least a part of the wavelength range of 320 to 380 nm.

The content of the phthalocyanine dye used to adjust the light transmittance of the base film to the above range depends on the type of the resin for the base film, the thickness of the base film, the type of the phthalocyanine dye, and the like. For example, when the resin for the base film is an ethylene-methacrylic acid copolymer, the thickness is 120 μm, and the phthalocyanine-based dye is copper phthalocyanine, the base film has a thickness of 0.05 to 0.3.
It may be intended to contain so that the amount is contained by weight%. The content of the phthalocyanine dye may be appropriately reduced when the thickness of the base film is increased, and may be appropriately increased when the thickness of the base film is reduced.

As a method for producing a base film, a T-die extrusion method, an inflation method, a calendar method, and the like can be mentioned. The thickness of the base film affects the strength of the film when dicing the semiconductor wafer, the workability of sticking to the back surface of the wafer, and the expandability and strength of the base material during expanding which is usually performed during pickup.
From such a viewpoint, the thickness of the base film is usually 30 to
It is 500 μm. Preferably, it is 50 to 300 μm. In order to improve the adhesive strength between the base film and the pressure-sensitive adhesive layer, it is preferable to perform a corona discharge treatment or a chemical treatment on the surface of the base film on which the pressure-sensitive adhesive layer is provided. Also,
An undercoat may be used between the base film and the pressure-sensitive adhesive layer.

The pressure-sensitive adhesive layer used in the pressure-sensitive adhesive film of the present invention is a layer whose adhesive strength is reduced by ultraviolet irradiation, and has a diameter of a semiconductor wafer to be diced, a chip size, and irregularities after grinding the back surface of the wafer. Taking into consideration the conditions such as the above conditions, any one can be used as long as it is designed so that there is no pick-up failure when picking up the chip after scattering of the chip during dicing or irradiation with ultraviolet rays. Usually, a coating liquid (solution or emulsion liquid) containing an adhesive polymer, a photopolymerization initiator, a thermal crosslinking agent, a monomer and / or an oligomer having two or more polymerizable carbon-carbon double bonds in a molecule, or the like is used. It is formed by coating a base film or a release film.

As the adhesive polymer, natural rubber, SB
Examples include rubbers such as R and acrylics such as alkyl acrylate and alkyl methacrylate.
Among them, an acrylic pressure-sensitive adhesive is preferably used for the ultraviolet-curable pressure-sensitive adhesive film for dicing a semiconductor wafer.

When an acrylic pressure-sensitive adhesive is used as the pressure-sensitive adhesive polymer, the monomer units constituting the pressure-sensitive adhesive polymer include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, and methacrylic acid. Acrylates such as butyl, 2-ethylhexyl acrylate and 2-ethylhexyl methacrylate, methacrylates, and functional groups such as acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate One or more acrylic monomers and methacrylic monomers are combined, and if necessary, glycidyl acrylate, glycidyl methacrylate, isocyanate ethyl acrylate, isocyanate ethyl methacrylate, 2- (1-
Monomers having a self-crosslinking functional group such as aziridinyl) ethyl acrylate and 2- (1-aziridinyl) ethyl methacrylate, and polyfunctional monomers such as divinylbenzene, vinyl acrylate, vinyl methacrylate, allyl acrylate, and allyl methacrylate , Styrene, acrylonitrile, vinyl acetate, acrylamide and the like, and a monomer having a polymerizable carbon-carbon double bond.

It is particularly preferable to use a polymer in which a polymerizable carbon-carbon double bond is introduced into the pressure-sensitive adhesive polymer. When synthesizing a pressure-sensitive adhesive polymer having a heavy bond, various known methods can be used. After previously copolymerizing a monomer having a functional group in the polymer, a monomer having a polymerizable carbon-carbon double bond having a functional group that undergoes an addition reaction with a functional group in the polymer is left with a polymerizable carbon-carbon double bond. The method of performing an addition reaction as it is is preferable in that the amount of the polymerizable carbon-carbon double bond in the polymer is controlled.

For example, a monomer having a carboxylic acid group such as acrylic acid or methacrylic acid is copolymerized, and glycidyl acrylate or glycidyl methacrylate having an epoxy group capable of undergoing an addition reaction with the carboxylic acid group in the polymer after polymerization is added. Or a conversely, a method in which glycidyl acrylate or glycidyl methacrylate is copolymerized, and after the polymerization, an epoxy group in the polymer is subjected to an addition reaction with acrylic acid, methacrylic acid, or the like. The combination of these functional groups is preferably a combination in which an addition reaction easily occurs, such as a carboxylic acid group and an epoxy group, a carboxylic acid group and an aziridyl group, and a hydroxyl group and an isocyanate group. The reaction is not limited to an addition reaction, and any reaction may be used as long as a polymerizable carbon-carbon double bond can be easily introduced, such as a condensation reaction between a carboxylic acid group and a hydroxyl group. The amount of double bond of the polymer is 1 to 30% by weight based on the monomer as the main component.
It is desirable to copolymerize a monomer having a functional group of the above, and to add a monomer having a polymerizable carbon-carbon double bond within a range equal to or less than the number of the functional groups.

When a pressure-sensitive adhesive polymer is synthesized by a polymer reaction between a polymer obtained by polymerizing a polymer having a functional group and a monomer having a functional group in advance,
The monomer having a functional group preferably has a boiling point of 250 ° C. or lower. When the boiling point is 250 ° C. or less, unreacted monomers evaporate during drying during application of the pressure-sensitive adhesive (usually, drying in hot air at 100 ° C. to 150 ° C. for about 20 seconds to 5 minutes) and do not contaminate the back surface of the wafer. . Examples of such a monomer include acrylic acid, methacrylic acid, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, isocyanate ethyl acrylate, and isocyanate ethyl methacrylate.

A cross-linking agent having two or more cross-linkable functional groups in one molecule may be used in order to carry out a cross-linking reaction with the functional group of the pressure-sensitive adhesive polymer to adjust the adhesive strength and cohesive strength. As the crosslinking agent, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether,
Epoxy compounds such as pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, resorcin diglycidyl ether, toluene diisocyanate of tetramethylene diisocyanate, hexamethylene diisocyanate, and trimethylol propane 3 Adducts, isocyanate compounds such as polyisocyanates, tetramethylolmethane-tri-β-aziridinylpropionate, trimethylolpropane-tri-β-aziridinylpropionate, N, N′-diphenylmethane-4, 4′-bis (1-aziridinecarboxamide), N, N′-hexamethylene-1,6-bis (1-aziridinecarboxamide), N, N′-toluene Down-2,4-bis (1-aziridine carboxyamide), trimethylolpropane - tri-.beta.-(2-methyl aziridine) aziridine compounds such as propionate, and melamine-based compounds such as hexamethoxymethylolmelamine the like. These may be used alone or as a mixture of two or more.

The content of the thermal cross-linking agent is determined in consideration of conditions such as the diameter of a semiconductor wafer to be adhered, the size of a chip, and the state of unevenness on the back surface of the wafer, and the like, so that chips are not scattered during dicing. Is set as appropriate, but usually JI
In accordance with the method specified in SZ-0237, a SUS-304BA plate was used as the adherend, and the peeling speed was 300 m.
m / min. , Measured under the condition of a peel angle of 180 degrees,
Adhesive strength before strong UV irradiation is 150-2000g / 25
It is designed to be in the range of mm. More preferably, it is in the range of 200 to 2000 g / 25 mm. The content of the thermal crosslinking agent having two or more crosslinking functional groups in one molecule is as follows:
0.1 to 20 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive polymer. Preferably it is 0.5 to 10 parts by weight.

When the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film for dicing a semiconductor wafer is exposed to weak ultraviolet rays emitted from a fluorescent lamp for lighting, a mercury lamp or the like installed in a room in a semiconductor manufacturing process or the like, the pressure-sensitive adhesive layer changes over time. If the adhesive force to the back surface of the semiconductor wafer is reduced, water and chips from the wafer may enter between the adhesive film and the back surface of the wafer when dicing the semiconductor wafer, causing chips to scatter and contamination of the back surface of the wafer. Cause. In addition, the adhesive layer is deteriorated with time when exposed to weak ultraviolet rays emitted from fluorescent lamps for lighting, mercury lamps, etc., and as a result, after dicing the semiconductor wafer, the adhesive strength is sufficient when irradiated with strong ultraviolet rays. Otherwise, it may fail when picking up the chip. Therefore, it is important that the adhesive property of the adhesive film for dicing of the semiconductor wafer does not change with time even when exposed to weak ultraviolet rays emitted from a fluorescent lamp for illumination, a mercury lamp, or the like.

For the purpose of reducing the adhesive strength after ultraviolet curing, a monomer and / or oligomer having two or more polymerizable carbon-carbon double bonds in the molecule may be used.
Examples of the monomer and / or oligomer include those having a molecular weight of 5,000 or less, and specific examples thereof include urethane acrylate oligomer, urethane methacrylate oligomer, epoxy acrylate oligomer, epoxy methacrylate oligomer, bis (acryloxy). Ethyl) hydroxyethyl isocyanurate, bis (methacryloxyethyl) hydroxyethyl isocyanurate, tris (acryloxyethyl) isocyanurate, tris (methacryloxyethyl) isocyanurate, bisphenol A di (meth) acrylate, bisphenol F di (meth) Acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate Relate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tris (methacrylic) Roxyethyl) isocyanurate, various modifications of bisphenol A di (meth) acrylate,
Various modified products of bisphenol F di (meth) acrylate, various modified products of trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth)
Various modified acrylates are used. They are,
One type may be used alone, or two or more types may be used in combination. Here, the descriptions of (meth) acrylic acid and (meth) acrylate are acrylic acid and methacrylic acid, and
It means acrylate and methacrylate.

The content of the monomer or oligomer having two or more polymerizable carbon-carbon double bonds in the molecule is usually 1 to 100 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive polymer. Monomers and / or oligomers having two or more polymerizable carbon-carbon double bonds in the molecule may contaminate the back surface of the semiconductor wafer, cause poor adhesion with mold resin and the like during packaging, and cause cracks in the package. Could be. Therefore, it is preferable to reduce the content as much as possible. From such a viewpoint, it is preferable to introduce a polymerizable carbon-carbon double bond into the acrylic or methacrylic polymer which is a main component of the pressure-sensitive adhesive as described above, and in this case, an ultraviolet curable pressure-sensitive adhesive The amount of monomers and / or oligomers having two or more polymerizable carbon-carbon double bonds in the molecule contained therein can be reduced. In that case, it is about 1 to 20 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive polymer. When a polymerizable carbon-carbon double bond is introduced into the main chain or side chain of the pressure-sensitive adhesive polymer, the content of the monomer and / or oligomer may be set to zero.

Further, the adhesive strength after the adhesive layer is cured by the irradiation of ultraviolet rays is appropriately determined in consideration of conditions such as the diameter of a semiconductor wafer to be diced, the size of a chip, and the state of unevenness after grinding the back surface of the wafer. SUS-
It is preferable that the setting is made to be 100 g / 25 mm or less for the 304BA plate adherend. More preferably 50
g / 25 mm or less. Therefore, a monomer having two or more polymerizable carbon-carbon double bonds in the molecule and / or
Alternatively, the oligomer is preferably contained so as to satisfy the above set conditions.

The photopolymerization initiator constituting the ultraviolet-curable pressure-sensitive adhesive has a property of generating radicals by absorbing ultraviolet light, and is used for the purpose of initiating the ultraviolet-curing reaction of the pressure-sensitive adhesive layer. Specific examples include benzoin [Nisso Cure BO, manufactured by Nippon Soda Co., Ltd.] and benzoin methyl ether [Nisso Cure MBO, manufactured by Nippon Soda Co., Ltd.]
Benzoin ethyl ether [manufactured by Nippon Soda Co., Ltd.
Nissocure EBO], benzoin isopropyl ether [Nissocure IBPO, manufactured by Nippon Soda Co., Ltd.]
Benzoin isobutyl ether, benzyldimethyl ketal [Nippon Ciba Geigy Co., Ltd., Irgacure-
651, etc.], 1-hydroxycyclohexyl phenyl ketone [Nippon Ciba Geigy Co., Ltd., Irgacure-184, etc.], 2-methyl-1 [4- (methylthio) phenyl] -2-monophorinopropane- 1
[Nippon Ciba Geigy Co., Ltd., Irgacure-907,
Etc.], diethoxyacetophenone, 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl)
Ketone [Merck Japan K.K., Darocure 295
9, etc.], acetophenones such as 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzophenone [Kayacure BP manufactured by Nippon Kayaku Co., Ltd.], benzophenones such as hydroxybenzophenone, thioxanthone [ Nissocure-TX, manufactured by Nippon Soda Co., Ltd.
Etc.], 2-methylthioxanthone [produced by Nippon Soda Co., Ltd.
Nissocure-MTX, etc.], 2,4-diethylthioxanthone [manufactured by Nippon Kayaku Co., Ltd., Kayacure-DETX,
Thioxanthone, dimethylthioxanthone, dodecylthioxanthone, diethylthioxanthone, and the like, benzyl, anthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, and the like.

One of these may be used alone, or
Two or more kinds may be used in combination. Since the content itself causes contamination of the back surface of the semiconductor wafer, the content is preferably as small as possible. However, considering the curing speed, the content varies depending on the photopolymerization initiation effect. Preferred is 1 to 15 parts by weight. More preferably, it is 1 to 15 parts by weight.

The UV-curable pressure-sensitive adhesive used in the present invention may further comprise a photo-initiating auxiliary, if necessary, for the purpose of accelerating the reaction, reducing polymerization inhibition by oxygen, etc., in addition to the above-mentioned photo-polymerization initiator. May be contained. Examples of the photoinitiating auxiliary include triethanolamine, methyldiethanolamine, 2-dimethylaminoethylbenzoic acid, and ethyl 4-dimethylaminobenzoate [manufactured by Nippon Kayaku Co., Ltd., Kayacure-EPA,
And p-dimethylaminobenzoic acid isoamyl ester. These photoinitiating aids may be used alone or in combination of two or more. Usually, the content of the photoinitiator is preferably adjusted so that the sum of the photoinitiator and the photoinitiator is within the range of the content of the photopolymerization initiator. In addition, various kinds of polymerization inhibitors such as phenothiazine and hydroquinone may be contained to the extent that the rear surface of the semiconductor wafer is not contaminated in order to improve the preservability of the adhesive film for dicing of the ultraviolet-curable semiconductor wafer.

The thickness of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film used in the present invention is determined in consideration of the diameter of the semiconductor wafer to be adhered, the size of the chip, the state of the back surface unevenness after the back surface grinding of the wafer, the dicing method, and the like. It is appropriately set, but in consideration of the adhesive force at the time of dicing, the cutting of the dicing blade, the pick-up property of the chip after irradiating strong ultraviolet rays after the dicing, and the like, it is usually about 2 to 100 μm. Preferably, it is 5 to 70 μm.

The adhesive film of the present invention obtained as described above is applied to the back surface of the chip in a series of steps from the step of adhering to the back surface of the semiconductor wafer to the step of dicing the wafer and before the irradiation with strong ultraviolet rays. It is an adhesive film that has sufficient adhesive strength to adhere firmly and prevent chips from scattering. Here, the adhesive force sufficient to prevent the chips from scattering is an adhesive force such that the chips do not fall off the adhesive film due to the water pressure of the cooling water or the momentum of the rotation of the dicing blade during dicing, and specifically, ,
In accordance with the method specified in JIS Z-0237, a SUS304-BA plate was used as an adherend, and a peeling speed of 30 was used.
0 mm / min. The adhesive force measured under the condition of a peel angle of 180 degrees is in the range of 150 to 2000 g / 25 mm. Preferably 200 to 2000 g /
It is within the range of 25 mm. Further, the adhesive strength after the adhesive layer is cured by strong ultraviolet irradiation is appropriately determined in consideration of conditions such as the diameter of a semiconductor wafer to be diced, the size of a chip, and the state of unevenness after grinding the back surface of the wafer. Is usually 100 g / 2 for the SUS-304BA plate adherend.
It is preferable to set the distance to 5 mm or less. More preferably, it is 50 g / 25 mm or less. However, the adhesive properties before and after ultraviolet irradiation set in consideration of the conditions such as the diameter of the semiconductor wafer to be adhered, the size of the chip, the state of the back surface unevenness after grinding the back surface of the wafer, the dicing method, etc. On the other hand, it is important that there is no change over time.

Examples of the release film disposed on the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film of the present invention include synthetic resin films such as polypropylene and polyethylene terephthalate. Preferably, the surface thereof is subjected to a silicone treatment or the like as necessary. The thickness of the release film is usually 10 to
It is 500 μm, preferably 30-100 μm.

Next, a method for dicing a semiconductor wafer using the adhesive film for dicing a semiconductor wafer of the present invention will be described. Since a release film is usually attached to the pressure-sensitive adhesive film for dicing a semiconductor wafer of the present invention to protect the pressure-sensitive adhesive layer, the release film is first peeled to expose the pressure-sensitive adhesive layer. Next, this adhesive film is attached to a metal or plastic ring frame via an adhesive layer, and the semiconductor wafer is attached to the adhesive film attached to the ring frame from the back surface. After that, the semiconductor wafer is divided into chips by using a dicing blade while applying water for the purpose of removing frictional heat and removing wafer cuttings. After the dicing is completed, a specific amount of strong ultraviolet rays is irradiated from the substrate film side to cure the pressure-sensitive adhesive layer. Thereafter, the chip on the adhesive film is picked up.

The operation of attaching the adhesive film to the back surface of the semiconductor wafer may be performed manually, or may be performed by using a device for attaching an adhesive film to the semiconductor wafer, which is called a wafer mounter or a wafer mount manufacturing device. May go. Examples of such a device include, for example, ATM-8100 manufactured by Takatori Co., Ltd.

The method of dicing a semiconductor wafer to which the method of the present invention can be applied is not particularly limited, and a known dicing method can be applied. As a dicing method, for example,
There is a full cut system in which an adhesive film for dicing a semiconductor wafer is attached to a ring frame made of metal or the like, the wafer is attached thereto, and the wafer is completely divided into chips by a dicing blade. Dicing is preferably performed while cooling the semiconductor wafer, dicing blade or the like with water.

After the dicing of the wafer is completed, the adhesive layer is hardened by irradiating strong ultraviolet rays from the base film side of the adhesive film to reduce the adhesive strength. Thereafter, the chip is picked up from the adhesive film. For example, this method includes radially expanding the adhesive film (hereinafter, referred to as “adhesive film”).
After expanding the chips at a constant interval, the chips are pushed up with a needle or the like, and are picked up by a method such as suction using a vacuum collet, air tweezers, or the like. As a dicing apparatus, for example, Disco Co., Ltd., model: DF
D-2S / 8 and the like.

Conditions for irradiating strong ultraviolet rays are disclosed in
The conditions may be similar to those disclosed in Japanese Patent Application Laid-Open No. 196956. Specifically, high-pressure mercury lamps, low-pressure mercury lamps,
A metal halide lamp, a xenon lamp, or the like is used as a light source, and the illuminance is 3 to 30 depending on the characteristics of the adhesive film.
00mW / cm ² [Digital indicating type UV illuminometer UV-M02 (receiver: UV-3, manufactured by Oak Manufacturing Co., Ltd.)
5) UV light having an intensity of about 30 to 3000 mJ / cm ² [a value obtained by multiplying the irradiation time (second) by the irradiation time obtained above]]. . As an ultraviolet irradiation device, for example, a high-pressure mercury lamp [Oak Manufacturing Co., Ltd., type: OHD-320]
M] and the like.

When the illuminance and intensity of the ultraviolet irradiation light are lower than the above lower limits, the adhesive strength tends to be insufficiently reduced, and a pick-up defect may occur when picking up a chip from the adhesive film. The upper limit of the intensity of the ultraviolet irradiation light is 3000 mJ / c in consideration of the influence of the heat of the light source that emits ultraviolet light on the semiconductor wafer, the melting point or softening point of the base film, workability, worker safety, and the like.
m ² is preferable.

As a semiconductor wafer to which the present invention can be applied,
Silicon wafers, wafers of germanium, gallium-arsenic, gallium-arsenic-aluminum and the like can be mentioned. In addition, from the viewpoint of preventing contamination of the semiconductor wafer, the manufacturing environment of all raw materials such as a base film, a release film, and an adhesive, the application of the adhesive, the drying environment, and the semiconductor wafer using the adhesive film for dicing the semiconductor wafer. Is preferably maintained in a class 1,000 or less cleanliness defined in US Federal Standard 209b.

[0061]

The present invention will be described below in further detail with reference to examples. The various characteristic values shown in the examples were obtained by the following methods. (1) Light transmittance (%) of base film Self-recording spectrophotometer (manufactured by Hitachi, Ltd., type: U-3500)
Form). At the time of measurement, nothing was set as a sample on the reference side, and the base films (thickness: 120 μm) prepared in Examples and Comparative Examples were set on the sample side, and the wavelength range 3
The light transmittance at 20 to 380 nm is measured.

(2) Adhesive force of adhesive film (g / 25m
m) SUS304-BA plate (JIS G-4305 regulation,
JIS-Z02 for a sample stuck on the surface of (length: 200 mm, width: 50 mm) in an atmosphere of 23 ° C.
37, the end of the 50 mm side of the sample was sandwiched, and the peeling speed was 300 mm / min. , Peeling under the condition of a peeling angle of 180 degrees, measuring the stress at that time,
The adhesive strength is converted to a width of 25 mm. The above-mentioned operation is performed twice and the adhesive strength is indicated by an average value.

<Preparation of Sample-1> (i) Adhesion of SUS plate-irradiation of fluorescent lamp The adhesive film was placed on the SUS304-B via the adhesive layer.
A plate (JIS G-4305 standard, vertical: 200 mm,
(Width: 50 mm), and an illuminance of 0.1 mW is applied to the surface of the substrate film side using a fluorescent lamp (manufactured by Toshiba Corporation, Toshiba fluorescent lamp, Neoline Rapid Master, FLR40SW / M / 36). / Cm ² [The illuminance of ultraviolet rays is indicated by a digital indicator type UV illuminometer UV-M02 [Receiver: U
V-35, measured by Oak Manufacturing Co., Ltd.] for 1 hour, 24 hours, 48 hours, and 96 hours. Thereafter, the adhesive strength of each sample is measured by the above method. The test results are shown in [Table 1] as "Before high-pressure mercury lamp UV irradiation". (Ii) SUS plate sticking-fluorescent lamp irradiation-high pressure mercury lamp irradiation In the same manner as in (i), the sample was irradiated with ultraviolet light having an illuminance of 0.1 mW / cm ² for 1 hour, 24 hours, 48 hours, and 96 hours, respectively. On the other hand, ultraviolet rays (illuminance: 10 mW / cm ² , intensity: 400 mJ / cm ² ) were further obtained using a high-pressure mercury lamp (Oak Manufacturing Co., Ltd., type: OHD-320M).
Is irradiated. The adhesive strength of each sample is measured by the above method. In addition, the illuminance of ultraviolet rays is measured using a digital indicating type ultraviolet illuminometer UV-M02 [receiver: UV-35, manufactured by Oak Manufacturing Co., Ltd.]. The test results are shown in [Table 1] as "after irradiation with high-pressure mercury lamp UV".

<Preparation of Sample-2> (iii) Before sticking the SUS plate-irradiation with a fluorescent lamp At 23 ° C., a flat adhesive film (width: 30 c)
m, length: 200 cm) on the base film side surface,
Illuminance 0.1 mW using a fluorescent lamp in the same manner as (i).
/ Cm ² for 3 hours, 3 days, and 10 days. Next, the sample was placed on a SUS304-BA plate (JI
SG-4305, vertical: 200 mm, horizontal: 50 m
m) in a dark place where UV light is not applied.
Leave for a time. Thereafter, the adhesive strength is measured by the above method. The test results are shown in [Table 2] as "Before UV irradiation with high pressure mercury lamp". (Iv) Before sticking the SUS plate-irradiation with fluorescent lamp-irradiation with high-pressure mercury lamp
In the same manner as in item i), ultraviolet rays having an illuminance of 0.1 mW / cm ² were irradiated for 3 hours, 3 days, and 10 days, respectively. The sample was placed on a SUS304-BA plate (JIS G-4305 standard,
(Length: 200 mm, width: 50 mm) and left in a dark place for 1 hour. Furthermore, for the attached sample,
Ultraviolet rays (illuminance: 10 mW / cm ² , intensity: 400 mJ / cm ² ) are irradiated using a high-pressure mercury lamp in the same manner as in (ii). The adhesive strength of each sample is measured by the above method. The test results are shown in [Table 2] as "after irradiation with UV light from a high-pressure mercury lamp".

(3) Proportion of chips scattered during dicing (%) The back surface grinding is completed, and the respective surfaces are formed on the back surface of a semiconductor silicon wafer (diameter: 6 inches, thickness 300 μm) on which an integrated circuit is formed. The pressure-sensitive adhesive film obtained in each of Examples and Comparative Examples was adhered, and a free automatic dicing saw [manufactured by Disco Co., Ltd., type: DFD-2S / 8] was used. Full cut into 2mm chips. Three semiconductor silicon wafers are used in each of the examples and comparative examples, and dicing is performed three times. At this time, the number of scattered chips is counted, and the ratio (%) of the scattered chips is obtained.

<Preparation of Sample> (i) Adhesion of Wafer Backside—Irradiation of Fluorescent Light At 23 ° C., an adhesive film was adhered to a ring frame via the adhesive layer, and semiconductor silicon was adhered to the ring frame via the adhesive layer. Wafer (diameter: 6 inches, thickness: 300 μm)
Is adhered from the back surface, and an illuminance of 0.1 mW / cm ^{2 is} applied to the surface of the base film of the adhesive film using a fluorescent lamp [Toshiba Corporation, Toshiba fluorescent lamp, Neoline Rapid Master, FLR40SW / M / 36]. For 1 hour, 24 hours, 48 hours, and 96 hours. Dicing is performed on each wafer to which the sample is attached by the above method. The test results are shown in [Table 3]. (Ii) Before bonding the back surface of the wafer-irradiation with a fluorescent lamp Flat adhesive film (width: 250 mm, length: 550)
cm) to the surface of the base film side in the same manner as in (2)-(iii), using a fluorescent lamp to irradiate ultraviolet rays having an illuminance of 0.1 mW / cm ² for 3 hours, 3 days, and 10 days, respectively. These samples are adhered to the back surface (the surface on which an integrated circuit is not formed) of a semiconductor silicon wafer (diameter: 6 inches, thickness: 300 μm), and the semiconductor wafer is diced by the above method. The test results are shown in [Table 4].

(4) Ratio of defective chip pickup
(%) After the dicing described in the previous section, pressurized water
Silver lamp [Oak Manufacturing Co., Ltd., model: OHD-320
M], using ultraviolet rays (illuminance: 10 mW / cm ^Two,strength
Degree: 400mJ / cm^Two). After a while, adhesive
Push up with a needle from the base film side of the film,
Pick up the chip by suction with
Step. Number of chips that did not scatter during dicing,
Count the number of chips that could not be picked up
Then, the ratio (%) of the latter to the former is determined.

Preparation Example 1 <Preparation of Adhesive> 65 parts by weight of toluene and 50 parts by weight of ethyl acetate were added to a flask purged with nitrogen, and at 80 ° C. with stirring, 48 parts by weight of ethyl acrylate and 2 parts of acrylic acid A mixture of 27 parts by weight of ethylhexyl, 20 parts by weight of methyl acrylate, 5 parts by weight of glycidyl methacrylate, and 0.2 parts by weight of benzoyl peroxide was dropped, and a polymerization reaction was carried out for 10 hours. After the reaction, cool down
To this were added 25 parts by weight of xylene, 2.5 parts by weight of acrylic acid and 1.5 parts by weight of tetradecyldimethylbenzylammonium chloride.
The reaction was carried out for 0 hour to obtain a main solution of an acrylic pressure-sensitive adhesive polymer. The adhesive polymer solid content of the obtained solution is 10
7 parts by weight of 2,2-dimethoxy-2-phenylacetophenone (manufactured by Ciba Geigy, trade name: Irgacure 651) per 0 parts by weight, isocyanate-based crosslinking agent [manufactured by Mitsui Toatsu Chemicals, trade name: ole Star P49-75
S] (1.5 parts by weight (as solid content)) and 11.7 parts by weight of dipentaerythritol hexaacrylate were added to produce an acrylic pressure-sensitive adhesive.

Example 1 100 parts by weight of ethylene-methacrylic acid copolymer pellets (methacrylic acid content: 9% by weight) and copper phthalocyanine (Pigment Blue 15, color index: 74)
0.5) by weight of ethylene-methacrylic acid copolymer pellets (containing 30 parts by weight of copper phthalocyanine and 100 parts by weight of ethylene-methacrylic acid copolymer (methacrylic acid content: 9% by weight)) containing It was formed into a film having a thickness of 120 μm using a T-die extruder, and used as a base film. The light transmittance of the obtained substrate film was measured by the above method. The obtained light transmittance spectrum (A) is shown in FIG. The pressure-sensitive adhesive obtained in Preparation Example 1 was applied to a 50 μm thick polypropylene film (release film) using a roll coater while maintaining the pressure-sensitive adhesive at about 5 ° C., and dried at 100 ° C. for 2 minutes to obtain a 10 μm thick pressure-sensitive adhesive. An agent layer was formed. Next, the obtained pressure-sensitive adhesive surface was subjected to a corona discharge treatment to a thickness of 120 μm.
Then, the treated surfaces of the m base film were stuck together and pressed to transfer the adhesive layer, thereby producing an adhesive film for dicing a semiconductor wafer. Immediately after production, it was protected from exposure to ultraviolet rays and stored in an environment at 23 ° C. The adhesive strength of the obtained adhesive film was measured by the above method. Further, the obtained adhesive film was adhered to the back surface of the semiconductor wafer, a dicing test of the semiconductor wafer was performed, and a pickup test was further performed. The obtained results are shown in [Table 1] to [Table 4].

Examples 2-3, Comparative Examples 1-2 Ethylene-methacrylic acid copolymer pellets containing copper phthalocyanine (Pigment Blue 15, color index: 74160) [30 parts by weight of copper phthalocyanine and ethylene-methacrylic acid copolymer (Methacrylic acid content: 9% by weight) containing 100 parts by weight] of 0.25 part by weight (Example 2), 1 part by weight (Example 3), 0.05 part by weight (Comparative Example 1), or 1 part by weight. Except having replaced with 0.8 weight part (comparative example 2), it carried out similarly to Example 1, and manufactured the adhesive film for dicing of the semiconductor wafer, respectively. The light transmittance of the obtained base film was measured in the same manner as in Example 1, and the light transmittance spectrum (Example 2-B), (Example 3-C),
(Comparative Example 1-D) and (Comparative Example 2-E) are shown in FIG. In addition, the same test as in Example 1 was performed on the obtained dicing adhesive film of the semiconductor wafer by the above method. The obtained results are shown in [Table 1] to [Table 4].

[0071]

[Table 1]

[0072]

[Table 2]

[0073]

[Table 3]

[0074]

[Table 4]

[0075]

The adhesive film for dicing a semiconductor wafer according to the present invention uses a base film containing a phthalocyanine dye. Therefore, in the presence of weak ultraviolet light such as a fluorescent lamp, that is, in an environment where the illuminance of ultraviolet light having a wavelength of 320 to 380 nm is about 0.3 mW / cm ² or less, the amount of ultraviolet light that reaches the pressure-sensitive adhesive layer can be reduced. Excellent stability of adhesive properties against environmental UV rays. On the other hand, after the dicing of the semiconductor wafer is completed, the illuminance that is normally irradiated before picking up the obtained chip is 3 to 3000 m.
By irradiating ultraviolet rays of about W / cm ² and intensity of about 30 to 3000 mJ / cm ^2, it is possible to sufficiently reduce the adhesive strength. Thus, according to the method of the present invention,
If the adhesive film is opened during the dicing process of the semiconductor wafer and handled, left or stored, etc., or if the work is temporarily interrupted while the adhesive film is set on the automatic attaching device due to unexpected process trouble, etc., the adhesive film will adhere to the semiconductor wafer. Even if the work is interrupted while the film is attached, the adhesive strength does not decrease over time, and water and water are cut between the back surface of the wafer and the adhesive film when dicing the semiconductor wafer. There is no intrusion of debris and the like, and chips are not scattered. Furthermore, after the dicing process,
When irradiating with ultraviolet rays prior to picking up the chip, the adhesive force is sufficiently reduced, so that no chip pick-up failure occurs.

[Brief description of the drawings]

FIG. 1 is a light transmittance spectrum (wavelength range of 310 to 390 nm) of a substrate film.

[Explanation of symbols]

 A: The base film obtained in Example 1. B: Base film obtained in Example 2. C: Base film obtained in Example 3. D: Base film obtained in Comparative Example 1. E: Base film obtained in Comparative Example 2.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Kentaro Hirai 2-1-1 Tango-dori, Minami-ku, Nagoya-shi, Aichi Mitsui Toatsu Chemicals Co., Ltd.

Claims (8)

[Claims] An adhesive film having an adhesive layer having a property of being cured by ultraviolet irradiation on one surface of a substrate film is adhered to the back surface of a semiconductor wafer through the adhesive layer to form a semiconductor wafer. Dividing into element pieces, irradiating ultraviolet rays from the pressure-sensitive adhesive film side after the division is completed, and then, from the pressure-sensitive adhesive film, a method of dicing a semiconductor wafer for removing element pieces, wherein the base film contains a phthalocyanine dye The light transmittance in the entire wavelength range of 320 to 380 nm is 60% or less, the light transmittance in at least a part of the wavelength range is 20% or more, and the thickness is 30 to 500 μm. Dicing method for semiconductor wafer. 2. A phthalocyanine dye represented by the general formula (1):
[Chemical 1] [Chemical 1] (Wherein, A _{1 to} A ₈ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group. B _{1 to} B ₈ each independently represent a hydrogen atom Atom, halogen atom, substituted or unsubstituted alkyl group, or substituted or unsubstituted aryl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylthio group, or substituted or unsubstituted 2 represents an unsubstituted arylthio group, wherein M represents a divalent metal atom, a divalent or tetravalent substituted metal atom, or an oxymetal. Dicing method for semiconductor wafer. 3. M in the general formula (1) is Cu (I
3. The dicing method for a semiconductor wafer according to claim 2, wherein I) and A _{1 to} A ₈ and B _{1 to} B ₈ are all hydrogen atoms. 4. The substrate film has a wavelength range of 320 to 380.
The method for dicing a semiconductor wafer according to any one of claims 1 to 3, wherein a light transmittance in an entire region of nm is 50% or less, and a light transmittance in at least a part of the wavelength region is 35% or more. 5. An adhesive film for dicing a semiconductor wafer having a pressure-sensitive adhesive layer having a property of being cured by ultraviolet irradiation on one surface of a substrate film, wherein the substrate film contains a phthalocyanine dye. , Wavelength range 320
Light transmittance of 60% or less in the entire region of ３380 nm;
20% light transmittance in at least a part of the wavelength range
An adhesive film for dicing a semiconductor wafer, wherein the adhesive film has a thickness of 30 to 500 μm. 6. The phthalocyanine dye represented by the general formula (1)
[Formula 2] [Formula 2] (Wherein, A _{1 to} A ₈ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group. B _{1 to} B ₈ each independently represent a hydrogen atom Atom, halogen atom, substituted or unsubstituted alkyl group, or substituted or unsubstituted aryl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkylthio group, or substituted or unsubstituted An unsubstituted arylthio group, wherein M represents a divalent metal atom, a divalent or tetravalent substituted metal atom, or an oxymetal.) Adhesive film for dicing semiconductor wafers. 7. M in the general formula (1) is Cu (I
Is I), A ₁ ~A ₈ and dicing adhesive film of the semiconductor wafer according to claim 6, wherein the all are hydrogen atoms B ₁ ~B _8. 8. A substrate film having a wavelength range of 320 to 380.
8. The pressure-sensitive adhesive film for dicing a semiconductor wafer according to claim 5, wherein the light transmittance in the entire region of nm is 50% or less, and the light transmittance in at least a part of the wavelength region is 35% or more.