JPH0729861A - Adhesive tape for dicing of semiconductor wafer - Google Patents

Abstract

PURPOSE:To easily recognize an image of every element when the element is picked up by a method wherein an adhesive for fixation of a semiconductor wafer is provided with a photopolymerizing carbon-carbon double bond in a moelcule and a specific characteristic value, and contains a polyisocyanate, a melamine resin or an epoxy resin. CONSTITUTION:An adhesive tape for fixation of a semiconductor wafer is obtained in such a way that an adhesive layer composed of a prescribed adhesive is formed on a radiation-transmitting substrate. The adhesive which is used here contains, as main components, 100 pts.wt. of a compound having photopolymerizing carbon-carbon double bond in a molecule at an iodine value of 0.5 to 20, at a hydroxy value of 5 to 100, at an acid value of 0.5 to 30 and at a molecular weight of 10000 to 220000 and 0.1 to 10 pts.wt. of at least one kind selected from polyisocyanates, a melamine formaldehyde resin and an epoxy resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive tape used in the process of manufacturing various semiconductors. More specifically, for example, a pattern-formed semiconductor wafer is cut into individual patterns to obtain semiconductor devices. The present invention relates to a radiation curable adhesive tape used for fixing a semiconductor wafer when dividing.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a pickup system which uses a radiation curable adhesive tape when performing a dicing process for cutting and separating a semiconductor wafer having a circuit pattern into element pieces. This is a base film that transmits radiation, such as light such as ultraviolet rays, or ionizing radiation such as electron beams, and a pressure-sensitive adhesive layer coated on the base film and having the property of being cured by irradiation with radiation. It is a method of using an adhesive tape for fixing a semiconductor wafer. More specifically, the element fixing adhesive force during dicing is used as a strong adhesive force, and after cutting and separating the semiconductor wafer into element small pieces, radiation is irradiated from the base film side to cure the radiation-curable adhesive layer and the element fixing adhesive It significantly reduces the force, so that regardless of the size of the element small piece, even a large element of 25 mm ² or more can be picked up by the pickup device after being cut and separated from the base film. It is something to do.

According to this method, a radiation-curable compound contained in an adhesive layer of a semiconductor wafer fixing adhesive tape obtained by coating a radiation-transparent substrate film with a radiation-curable adhesive is cured by irradiation with radiation to produce an adhesive. It utilizes the fact that the agent is given a three-dimensional reticulated structure to significantly reduce its fluidity and adhesion to the device. Adhesive tapes for such applications include JP-A-60-196956,
JP-A-60-201642 and JP-A-61-28572.
JP-A-1-251737, JP-A-2-18747
No. 8 and the like are disclosed. However, such a pressure-sensitive adhesive tape is cured by irradiation to significantly reduce the fluidity of the pressure-sensitive adhesive so that the element can be peeled off from the substrate film and easily picked up.
As a result, the rubber-like elasticity of the pressure-sensitive adhesive tape possessed during the dicing process is almost lost during the pickup. For this reason, even if the adhesive tape is radially stretched after radiation irradiation and before picking up, the stretched portion has only a small gap between the elements from which the adhesive has been removed by dicing. Therefore, there is a problem that the element gap after stretching is insufficient, and it becomes difficult to image-recognize each element using a pickup device and pick up the element. Among the above-mentioned conventional techniques, Japanese Patent Laid-Open No. 1-25171
The pressure-sensitive adhesive tape described in No. 37 uses an acrylic polymer having an ethylenically unsaturated double bond as a main component of the pressure-sensitive adhesive, and in order to improve the above problems to some extent, radiation irradiation is partially performed in a pattern. A method is adopted in which the element gap after stretching is made as large as possible by leaving the uncured portion of the adhesive.

On the other hand, the pressure-sensitive adhesive tape described in JP-A-2-187478 is an acrylic acid having a radiation-polymerizable unsaturated bond having an iodine value of 0.5 to 2.0 in the molecule as a main component of the pressure-sensitive adhesive. A mixture of an alkyl ester-based or methacrylic acid alkyl ester-based polymerizable polymer and a radiation-polymerizable polyfunctional oligomer is used. However, the adhesive tape has a problem that the fluidity of the adhesive after irradiation with radiation is not sufficient, the element gap after stretching is insufficient, and it is difficult to pick up the element by image recognition. . Furthermore, depending on the combination of the polymerizable polymer and the polyfunctional oligomer used, the compatibility may be poor and the particles may not be uniformly dispersed.Therefore, even after irradiation with radiation, unpolymerized polyfunctional oligomer oozes out and picks up. There is a problem of contaminating the processed device.

On the other hand, the pressure-sensitive adhesive tape described in JP-A-1-278518 has, as a main component of the pressure-sensitive adhesive, a photopolymerizable oligomer which is an addition polymer of an epoxy group-containing acrylic copolymer and an α-olefincarboxylic acid, A mixture of monomers or oligomers having at least one vinyl group or acryloyl group is used. However, the adhesive tape is not intended to be used when a semiconductor wafer is cut and divided into semiconductor elements. Therefore, it does not have the characteristics actually required for cutting and separating elements (dicing, pickup). For example, the fluidity of the pressure-sensitive adhesive after irradiation with the radiation described above is not sufficient, the element gap after stretching is insufficient, and it is difficult to pick up the element by image recognition.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor wafer fixing adhesive tape which solves the above problems. That is, in the present invention, since the fluidity of the pressure-sensitive adhesive remains even when the whole is irradiated with radiation in the form of a pattern, even when the pressure-sensitive adhesive tape is radially stretched before pickup, the pressure-sensitive adhesive was removed by dicing. The parts other than the slight gaps between the elements (specifically, the parts that are in close contact with the respective elements inside the lattice-like gaps) are also stretched, so that the element gaps after stretching can be sufficient,
An object of the present invention is to provide an adhesive tape for fixing a semiconductor wafer, which facilitates image recognition of each element during pickup.
Another object of the present invention is to provide an adhesive tape for fixing a semiconductor wafer, which does not contaminate the picked up element. Furthermore, the present invention further reduces the risk of pick-up mistakes by reducing the adhesive force after irradiation of radiation, and improves the tape recoverability, thereby facilitating compatibility with used tape storage type models. An object is to provide an adhesive tape for fixing.

[0007]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in order to achieve the above object, the adhesive applied as an adhesive layer has a predetermined amount of photopolymerizable carbon
A compound having a carbon double bond and having a hydroxyl value and an acid value in a specific range and having a molecular weight of 10,000 to 220,000, and a polyisocyanate, a melamine-formaldehyde resin, or an epoxy resin as a main component in a predetermined ratio. Things
Even when the whole is irradiated with radiation instead of in a pattern, when the adhesive tape is radially stretched, the size of the element gap after stretching is made sufficient to facilitate image recognition of each element at the time of picking up, and moreover, it is picked up. It has been found that it does not contaminate the device. The present invention is based on this finding. That is, the present invention provides (1) an adhesive tape for fixing a semiconductor wafer, which comprises an adhesive layer provided on a radiation transmissive substrate, wherein the adhesive of the adhesive layer contains photopolymerizable carbon-carbon Having a heavy bond, iodine value 0.5-
20 and a hydroxyl value of 5 to 100 and an acid value of 0.5 to
Compound (A) 10 having a molecular weight of 10,000 to 220,000
For semiconductor wafer dicing, characterized by containing 0 parts by weight and 0.1 to 10 parts by weight of at least one kind (B) selected from polyisocyanates, melamine-formaldehyde resin and epoxy resin as main components. Adhesive tape, (2) The molecular weight of the compound (A) is 10
The adhesive tape for semiconductor wafer dicing according to item (1), characterized in that the molecular weight is less than 10,000, and (3) at least one photopolymerizable carbon-carbon double bond per repeating unit. The cyanurate compound or isocyanurate compound (C) of the above compound (A) 10
An adhesive tape for semiconductor wafer dicing according to item (1) or (2), characterized in that the content is 10 parts by weight or less based on 0 parts by weight.

In the present invention, the iodine value is a value obtained by converting the weight of halogen absorbed when a halogen is applied to a sample into the weight of iodine and expressing it as a percentage with respect to the weight of the sample, and the molecular weight is It is a weight average molecular weight in terms of polystyrene. The hydroxyl value is the m of potassium hydroxide necessary to neutralize the acetic acid bound to the acetylated product obtained by reacting 1 g of the sample with an acetylating agent.
The acid value is the COOH contained in 1 g of the sample.
It is the number of mg of potassium hydroxide required to neutralize the group. Here, the radiation refers to light rays such as ultraviolet rays or ionizing radiation such as electron beams. The compound (A) having a photopolymerizable carbon-carbon double bond having an iodine value of 0.5 to 20 in the molecule of the present invention and having a molecular weight of 10,000 to 220,000 may be produced by any method, for example, acrylic. Compound () having a photopolymerizable carbon-carbon double bond and having a functional group such as a carboxyl group or a hydroxyl group, such as a copolymer or a methacrylic copolymer, and a functional group capable of reacting with the functional group What was manufactured by making it react with the compound () which has a can be used.

In this case, the compound () having a photopolymerizable carbon-carbon double bond and a functional group is a single compound having a photopolymerizable carbon-carbon double bond such as alkyl acrylate or methacrylic acid alkyl ester. Quantity (
It can be obtained by copolymerizing -1) with a monomer (-2) having a functional group. As the monomer (-1),
Hexyl acrylate having 6 to 12 carbon atoms, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, decyl acrylate, and pentyl acrylate, n-butyl acrylate, isobutyl which are monomers having 5 or less carbon atoms. Mention may be made of acrylates, ethyl acrylates, methyl acrylates, or similar methacrylates and the like. As the monomer (-1) having a larger number of carbon atoms is used, the glass transition point becomes lower, so that a monomer having a desired glass transition point can be prepared by appropriately selecting this monomer. In addition to the glass transition point, vinyl acetate, styrene, for the purpose of improving compatibility and various performances,
A low molecular weight compound having a carbon-carbon double bond, such as acrylonitrile, can be added within the range of 5% by weight or less. Examples of the functional group contained in the monomer (-2) include a carboxyl group, a hydroxyl group, an amino group, a cyclic acid anhydride group, an epoxy group, and an isocyanate group. Specific examples of the monomer (-2) include Is acrylic acid, methacrylic acid, cinnamic acid, itaconic acid, fumaric acid, phthalic acid, 2-
Hydroxyalkyl acrylates, 2-hydroxyalkyl methacrylates, glycol monoacrylates, glycol monomethacrylates, N-methylol acrylamide, N-methylol methacrylamide, allyl alcohol, N-alkylaminoethyl acrylates, N-alkylaminoethyl methacrylate , Acrylamides, methacrylamides, maleic anhydride, itaconic anhydride, fumaric anhydride, phthalic anhydride, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, a part of the isocyanate group of the polyisocyanate compound a hydroxyl group or a carboxyl group and The thing urethanized with the monomer which has a photopolymerizable carbon-carbon double bond etc. can be enumerated.

Next, in the compound (), the functional group contained therein is the compound (), that is, the monomer (-
When the functional group 2) has is a carboxyl group or a cyclic acid anhydride group, a hydroxyl group, an epoxy group, an isocyanate group and the like can be mentioned. When it is a hydroxyl group, a cyclic acid anhydride group, an isocyanate group, etc. When it is an amino group, an epoxy group, an isocyanate group, etc. can be mentioned, and when it is an epoxy group, a carboxyl group, a cyclic acid anhydride group, an amino group, etc. can be mentioned. As a specific example, a monomer (-
The same as those listed in the specific example of 2) can be listed. By leaving an unreacted functional group in the reaction between the compound () and the compound (), those specified in the present invention with respect to properties such as acid value or hydroxyl value can be produced.

In the synthesis of the above compound (A), when the reaction is carried out by solution polymerization, the organic solvent is a ketone type,
Ester-based, alcohol-based, and aromatic-based ones can be used, but among them, toluene, ethyl acetate, isopropyl alcohol, benzenemethyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, and other generally good solvents for acrylic polymers, Boiling point 60-120
A solvent at ℃ is preferable, and as the polymerization initiator, α, α'-
Radical generators such as azobis compounds such as azobisisobutyl nitrile and organic peroxide compounds such as benzobell peroxide are usually used. At this time, a catalyst and a polymerization inhibitor can be used in combination, if necessary, and the compound (A) having a desired molecular weight can be obtained by adjusting the polymerization temperature and the polymerization time. Further, for adjusting the molecular weight, it is preferable to use a mercaptan or a carbon tetrachloride-based solvent. Note that this reaction is not limited to solution polymerization, and other methods such as bulk polymerization and suspension polymerization may be used.

In this way, the compound (A) having a molecular weight of 10,000 to 220,000 can be obtained. In the present invention, the molecular weight of the compound (A) is 10,000 to 220,000. Molecular weight is 22
If it exceeds 10,000, when the whole is irradiated with radiation, not with a pattern, the fluidity of the adhesive after irradiation is insufficient, so the element gap after stretching is insufficient, making it difficult to recognize images during pickup. This is because when the molecular weight is less than 10,000, the cohesive force before irradiation with radiation becomes small, and when the wafer is diced, the elements are likely to be displaced, which makes image recognition difficult. In addition, the deviation of this element
In order to prevent it as much as possible, it is preferable that the molecular weight is 100,000 or more.

In the present invention, the amount of the photopolymerizable carbon-carbon double bond introduced in the compound (A) is 0.5-20, preferably 0.8-10, expressed by iodine value. If the iodine value is less than 0.5, the effect of reducing the adhesive strength after irradiation with radiation is insufficient, and if the iodine value exceeds 20, the flowability of the adhesive after irradiation with radiation is insufficient, and the element after stretching is insufficient. There is a problem that the gap becomes insufficient and the image recognition of each element becomes difficult at the time of picking up, and further, the compound (A) itself lacks stability and becomes difficult to manufacture.
Further, in the present invention, the hydroxyl value of the compound (A) is 5
To 100, preferably 30 to 90, and an acid value of 0.5 to 3
It is set to 0, preferably 4 to 12. When the hydroxyl value is less than 5, the effect of reducing the adhesive strength after irradiation with radiation is insufficient, and when the hydroxyl value exceeds 100, the fluidity of the adhesive after irradiation is impaired. When the acid value is less than 0.5, the effect of improving the tape restoration property is not sufficient, and when the acid value exceeds 30, the fluidity of the pressure-sensitive adhesive is impaired.

Next, as one of the main components of the pressure-sensitive adhesive of the present invention, polyisocyanates, melamine-formaldehyde resin, or epoxy resin (B) is used in an amount of 0.1 to 100 parts by weight of compound (A). It is contained in a ratio of 10 to 10 parts by weight. The component (B) acts as a cross-linking agent, and the cross-linking structure formed as a result of the reaction with the compound (A) or the base film causes the cohesive force of the pressure-sensitive adhesive mainly containing the compounds (A) and (B) to be applied to the pressure-sensitive adhesive. Can be improved later. The amount of component (B) added is 0.1 to 10 parts by weight, preferably 0.4 to 3 parts by weight, based on 100 parts by weight of compound (A). If the amount added is less than 0.1 part by weight, the effect of improving the cohesive force is not sufficient, and if it exceeds 10 parts by weight, the curing reaction proceeds rapidly during the mixing and application of the pressure-sensitive adhesive to form a crosslinked structure. Therefore, workability is impaired. Further, in the present invention, to further improve the effect of reducing the adhesive strength of the pressure-sensitive adhesive thus obtained after irradiation with radiation, and to more effectively prevent the decrease in the fluidity of the pressure-sensitive adhesive after irradiation with radiation, the compound (A) 0.1 to 10 parts by weight of a cyanurate compound or isocyanurate compound (C) having a molecular weight of less than 10,000 and having at least one photopolymerizable carbon-carbon double bond per 100 parts by weight. Good.

In the present invention, a cyanurate compound or isocyanurate compound (C) having a molecular weight of less than 10,000 and having at least one photopolymerizable carbon-carbon double bond per repeating unit is a triazine ring or an isotriazine ring in the molecule. And a photopolymerizable carbon-carbon double bond having a molecular weight of less than 10,000. A compound having a triazine ring or an isotriazine ring can be generally synthesized by a conventional cyclization reaction using a halocyan compound, a dianiline compound, a diisocyanate compound or the like as a raw material. Further, it can be obtained by introducing a photopolymerizable carbon-carbon double bond-containing group, for example, a functional group containing a vinyl group, an allyl group, an acryloxy group, a methacryloxy group, or the like, into the compound thus synthesized. Compound (C) is
Other than the above-mentioned point, it is not particularly limited, but the carbon-carbon double bond-containing group introduced into the triazine ring or the isotriazine ring includes a so-called rigid molecular structure, for example, an aromatic ring, a heterocyclic group and the like. Those that do not exist are preferred. The reason is that by imparting excessive rigidity to the adhesive by these, the fluidity of the adhesive after irradiation with radiation is impaired. Therefore, the linking group between the carbon-carbon double bond preferably contains a group rich in free rotation of atoms,
Examples of these groups include an aliphatic group such as an alkylene group and an alkylidene group, and these groups include -O- and -O.
It may have a CO-, -COO-, -NHCO-, -NHCOO- bond or the like.

Specific examples of these cyanurate compounds or isocyanurate compounds (C) include 2-propenyl di-3-butenyl cyanurate, 2-hydroxyethyl bis (2-acryloxyethyl) isocyanurate, tris (acrylate). Roxyethyl) isocyanurate, tris (methacryloxyethyl) isocyanurate, bis (2-acryloxyethyl) 2- (5-acryloxy) hexyloxyethyl isocyanurate, tris (1,3-diacryloxy-2-propyl-oxycarbonyl) Amino-n-hexyl) isocyanurate, tris (1-acryloxyethyl-3-methacryloxy-2)
-Propyl-oxydicarbonylamino-n-hexyl) isocyanurate, tris (4-acryloxy-n
-Butyl) isocyanurate and the like can be listed. The addition amount of the compound (C) is preferably 10 parts by weight or less based on 100 parts by weight of the compound (A). If this amount exceeds 10 parts by weight, the cohesive force of the pressure-sensitive adhesive before irradiation with radiation becomes small, and the element is likely to shift when dicing the wafer, which makes image recognition difficult. When the adhesive tape of the present invention is cured by irradiation with ultraviolet rays, a photopolymerization initiator, for example, isopropyl benzoin ether,
Isobutyl benzoin ether, benzophenone, Michler's ketone, chlorothioxanthone, dodecyl thioxanthone, dimethyl thioxanthone, diethyl thioxanthone, benzyl dimethyl ketal, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethyl phenyl propane and the like can be used in combination. By adding one or more of these to the pressure-sensitive adhesive, the curing reaction proceeds at least efficiently with the ultraviolet irradiation time or the ultraviolet irradiation amount, and the element fixing adhesive force can be reduced.

If necessary, the radiation-curable pressure-sensitive adhesive used in the present invention may be mixed with a tackifier, a pressure-sensitive adhesive, a surfactant, etc., or other modifiers and conventional components. The thickness of the radiation curable pressure-sensitive adhesive layer is not particularly limited, but is usually 2 to 50 μm. The radiation-transparent substrate in the present invention is usually preferably plastic, rubber or the like, and is not particularly limited as long as it transmits radiation, but when curing the radiation-curable pressure-sensitive adhesive by ultraviolet irradiation, As this base material, it is necessary to select one having good light transmittance. Examples of polymers that can be selected as such a substrate include polyethylene, polypropylene, ethylene-propylene copolymer, polybutene-1, poly-4-methylpentene-1, ethylene-vinyl acetate copolymer, ethylene-acryl. Ethyl acid copolymers, ethylene-methyl acrylate copolymers, ethylene-acrylic acid copolymers, homopolymers or copolymers of α-olefins such as ionomers, or mixtures thereof, polyethylene terephthalate, polycarbonate, polymethyl methacrylate. Engineering plastics such as polyurethanes, thermoplastic elastomers such as polyurethanes, styrene-ethylene-butene or pentene copolymers, polyamide-polyol copolymers, and mixtures thereof. Polymers such as polyvinyl chloride containing halogen, vinyl chloride-ethylene copolymer, FEP, and PFA are not preferable because free halogen or free halogen acid adversely affects the device.

In order to increase the element gap, it is preferable that necking (partial elongation due to poor propagation of force occurring when the base film is radially stretched is partially generated) is minimized. Examples thereof include styrene-ethylene-butene or pentene-based copolymers having a limited styrene content, and it is effective to use a crosslinked base film for preventing elongation or bending during dicing. The thickness of the base film is usually 30 to 30 from the viewpoint of the strength and elongation characteristics and the radiation transparency.
300 μm is suitable. If the surface of the base film opposite to the side on which the radiation-curable pressure-sensitive adhesive layer is applied is embossed or coated with a lubricant, blocking is prevented and friction between the pressure-sensitive adhesive tape and the jig during radial stretching of the pressure-sensitive adhesive tape is reduced. This is preferable because it has the effect of preventing necking of the base film.

[0019]

The present invention will be described in more detail based on the following examples. In Examples 1 to 5 and Comparative Examples 1 to 8, pressure-sensitive adhesives were prepared as described below and applied on ethylene-vinyl acetate copolymer films as described below. The characteristics of the pressure-sensitive adhesive tape thus produced were tested and evaluated as follows. 1) Adhesive force (g / 25 mm) This is an index for examining the size of the adhesive force for fixing the element before irradiation and the degree of decrease after irradiation, and 120 (g / 25 mm) before irradiation
As described above, 80 (g / 25 mm) or less after irradiation is acceptable. A silicon wafer having a diameter of 5 inches is adhered to the prepared radiation-curable adhesive tape, and JIS-023 is used.
Adhesion before and after UV irradiation was measured based on 7 (90 °
Peeling, peeling speed 50 mm / min). At this time, the surface state of the wafer bonded to the adhesive tape was a mirror surface state. 2) Element gap (μm) This is an index for examining the extent of the element gap when the adhesive tape is stretched. 3 silicon wafers with a diameter of 5 inches
Element gaps in the vertical and horizontal directions when fully cut into a size of × 3 mm, UV-cured (irradiating the entire surface, not a pattern), and stretching with a wafer expansion device (air pressure 2.0 kg / cm ² ). The amount was measured and the average value was calculated. The element gap amount includes a blade thickness of 40 μm at the time of dicing. Size of element gap (q) q ≧ 100 μm: Image recognition of element is possible 100> q ≧ 80 μm: Image recognition of element is difficult q <80 μm: Image recognition of element is impossible

3) Element contamination rate (× 10 ^-5 %) This is an index for examining the extent of the radiation-curable pressure-sensitive adhesive adhering to the picked-up element, and 1000 × 10 ^-5 % or less is acceptable. After bonding a silicon wafer with a diameter of 5 inches to the prepared radiation-curable adhesive tape, 3
After being fully cut into a size of 3 mm and cured by ultraviolet rays, the ratio (area ratio) of the radiation curable pressure sensitive adhesive adhering to the tape bonding surface of the picked up element was measured. At this time, the surface state of the wafer bonded to the adhesive tape was a mirror surface state. 4) Pickup error rate This is an index for checking the degree of pickup error when picking up a small element piece, and 50/100000 or less is passed. When 50 silicon wafers each having a diameter of 5 inches (element small piece 100000) were picked up, the number of elements for which a pickup was missed was examined. There are several possible causes of pickup error, but when the element gap is large and image recognition is easy, it tends to occur when the adhesive force after irradiation is large. 5) Tape restoration property It is an index for examining how much the slack of the tape after stretching the adhesive tape can be restored by heat, and 5 mm or less is a pass. A 5 inch diameter silicon wafer is fully cut into a size of 3 × 3 mm, and after UV curing (irradiating the whole, not a pattern), a wafer expansion device (air pressure 2.0 kg /
cm ² ), put the adhesive tape stretched in a constant temperature layer set at 50 ° C. for 30 seconds, and change the outer diameter difference (m) between the adhesive tape before and after that.
m) was measured.

Example 1 A mixture of 340 g of n-butyl acrylate, 67 g of methyl methacrylate, 19 g of methacrylic acid and 0.5 g of benzoyl peroxide as a polymerization initiator was added dropwise to 400 g of toluene as a solvent over about 2 hours. While
The reaction was carried out at a temperature of 100 ° C. for 2 hours, and then 6.5 g of ethylene glycol was added dropwise over about 0.5 hours, and the reaction was carried out at a temperature of 100 ° C. for 1 hour to obtain a solution of a compound () having a functional group. It was Next, to this polymer solution, as a compound () having a photopolymerizable carbon-carbon double bond and a functional group, 2.5 g of 2-hydroxyethyl methacrylate synthesized separately from methacrylic acid and ethylene glycol, and hydroquinone as a polymerization inhibitor. By adding 0.1 g and reacting at a temperature of 120 ° C. for 6 hours,
A solution of the compound (A) having a photopolymerizable carbon-carbon double bond having the iodine value, the molecular weight, the hydroxyl value and the acid value shown in Table 1 was obtained. The iodine value was calculated based on the Das method under the reaction conditions of 40 ° C. for 24 hours, and the molecular weight was 1% solution obtained by dissolving in tetrahydrofuran, and gel permeation chromatography (Waters Co., Ltd.) was used. Manufactured by trade name: 150-C ALC / GPC) and calculated as a polystyrene-equivalent weight average molecular weight. The hydroxyl value is acetylated by reacting with excess acetic anhydride, before and after the reaction. The acid value was calculated from the neutralization amount obtained by dissolving in a benzene-ethanol mixed solvent and titrating with a potassium hydroxide solution. The same method was used in the following examples and comparative examples. Then, the polyisocyanate (B) was added to 100 parts by weight of the compound (A) in the compound (A) solution.
As a photopolymerization initiator, 1 part by weight of Coronate L manufactured by Nippon Polyurethane Company, 0.5 part by weight of Irgacure 184 manufactured by Nippon Ciba Geigy Co., Ltd., and 150 parts by weight of ethyl acetate as a solvent are added to the compound (A) solution and mixed. Then, a radiation curable pressure-sensitive adhesive composition was prepared.

Example 2 The reaction time of the solution during the preparation of compound () was 4 instead of 2 hours.
The radiation-curable pressure-sensitive adhesive composition shown in Table 1 was prepared in the same manner as in Example 1 except that the time was set. Example 3 The reaction time of the solution during the preparation of compound () was 6 instead of 2 hours.
The radiation-curable pressure-sensitive adhesive composition shown in Table 1 was prepared in the same manner as in Example 1 except that the time was set. Example 4 The reaction time of the solution during compound () preparation was 5 instead of 2 hours.
The radiation-curable pressure-sensitive adhesive composition shown in Table 1 was prepared in the same manner as in Example 1 except that the time was set. Example 5 A radiation-curable pressure-sensitive adhesive composition was prepared in the same manner as in Example 4 except that the compound (C) was added to the radiation-curable pressure-sensitive adhesive composition prepared in Example 4 as shown in Table 1. .

Comparative Example 1 The reaction time of the solution during the preparation of compound () was 1 instead of 2 hours.
The radiation-curable pressure-sensitive adhesive composition shown in Table 2 was prepared in the same manner as in Example 1 except that the time was set. Comparative Example 2 The reaction time of the solution during the preparation of compound () was set to 8 instead of 2 hours.
The radiation-curable pressure-sensitive adhesive composition shown in Table 2 was prepared in the same manner as in Example 1 except that the time was set. Comparative Examples 3 and 4 A radiation-curable pressure-sensitive adhesive composition was prepared in the same manner as in Example 4 except that the compound (C) was added to the radiation-curable pressure-sensitive adhesive composition prepared in Example 4 as shown in Table 2. Prepared. Comparative Example 5 In the preparation of the compound () having a functional group, 340 g of n-butyl acrylate, in 400 g of toluene as a solvent,
67 g of methyl methacrylate, 1.5 of methacrylic acid
g, benzoyl peroxide 0.5 g as a polymerization initiator
The radiation curable pressure-sensitive adhesive composition shown in Table 2 was prepared in the same manner as in Example 4 except that the compound () was added by dropping the mixed solution of the above for about 2 hours.

Comparative Example 6 A table was prepared in the same manner as in Example 1 except that the compound (A) was not synthesized but a mixture of the compound () and the compound () was used instead of the compound (A). The radiation-curable pressure-sensitive adhesive composition shown in 2 was prepared. Comparative Example 7 In the preparation of the compound () having a functional group, 340 g of n-butyl acrylate, in 400 g of toluene as a solvent,
Methyl methacrylate 67 g, methacrylic acid 71.
5 g, benzoyl peroxide 0.5 as a polymerization initiator
The radiation-curable pressure-sensitive adhesive composition shown in Table 2 was prepared in the same manner as in Example 4 except that the mixed solution of g was added dropwise over about 2 hours and then ethylene glycol was added dropwise. Comparative Example 8 In the preparation of the compound () having a functional group, 340 g of n-butyl acrylate, in 400 g of toluene as a solvent,
67 g of methyl methacrylate, 19 methacrylic acid
g, benzoyl peroxide 0.5 g as a polymerization initiator
The radiation-curable pressure-sensitive adhesive composition shown in Table 2 in the same manner as in Example 4 except that the mixed solution of 1 was added dropwise over about 2 hours, and then 78 g of ethylene glycol was added over about 0.5 hour. The thing was prepared.

(Preparation of Adhesive Tape for Fixing Semiconductor Element and Evaluation of Properties) The compositions of Examples 1 to 5 and Comparative Examples 1 to 8 were applied to an ethylene-vinyl acetate copolymer film having a thickness of 100 μm to give a dry film thickness. Apply to 10 μm, 110
The adhesive tape for fixing a semiconductor element was prepared by drying at 3 ° C. for 3 minutes, and this tape was evaluated by the above evaluation method. The results are shown in Tables 1 and 2. From the results of Tables 1 and 2, it can be seen that the comparative example has a bad performance test. That is, in Comparative Examples 1 and 3, the element spacing is large, but the variation is large, Comparative Example 1 has a high pick-up error rate, and Comparative Example 3 is difficult to adjust the image recognition. Comparative example 2
In Nos. 4 and 4, since the element spacing is small, image recognition is difficult, and in Comparative Example 2, the adhesive strength is insufficient. In Comparative Example 5, the tape recoverability is poor and the pickup error rate is high. Comparative Example 6 has a high element contamination ratio, Comparative Examples 7 and 8 have a small element interval, and image recognition is difficult, and the adhesive has poor fluidity and is difficult to apply.
In contrast, Examples 1 to 5 are excellent in adhesive strength, element spacing, element contamination prevention, pickup mistake prevention, and tape restoration.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

When the pressure-sensitive adhesive tape for fixing a semiconductor wafer according to the present invention is used for cutting a semiconductor wafer or the like, the fluidity of the pressure-sensitive adhesive remains even when the whole is irradiated with radiation, not in a partial pattern. When the adhesive tape is radially stretched before the pickup, portions other than the slight gaps between the respective elements from which the adhesive has been removed by dicing are also stretched, and the element gaps after stretching can be made sufficient. Therefore, it is easy to recognize the image of each element by the pickup device at the time of picking up, and there is an excellent effect that the pickup error rate is low. Moreover, the picked up element is not contaminated by the adhesive. Further, according to the adhesive tape of the present invention, it is possible to further reduce the risk of a pickup error by reducing the adhesive force after irradiation of radiation, and improve the tape restoration property, so that the used tape in the pickup device can be used. It also has the effect of facilitating support for storage models.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number in the agency FI Technical display location C09J 7/02 JKA JKD JKE JLE 163/00 JFP 175/04 JFC (72) Inventor Kazushige Iwamoto Chiyoda-ku, Tokyo 2-6-1, Marunouchi Furukawa Electric Co., Ltd.

Claims (3)

[Claims] 1. A pressure-sensitive adhesive tape for fixing a semiconductor wafer, comprising an adhesive layer provided on a radiation transparent substrate, wherein the adhesive of the adhesive layer contains a photopolymerizable carbon-carbon double bond in the molecule. 100 parts by weight of a compound (A) having a molecular weight of 10,000 to 220,000, having an iodine value of 0.5 to 20, a hydroxyl value of 5 to 100, and an acid value of 0.5 to 30, and polyisocyanates. , At least one selected from melamine-formaldehyde resin and epoxy resin (B) 0.1 to 1
An adhesive tape for semiconductor wafer dicing, characterized by containing 0 part by weight as a main component. 2. The compound (A) in the pressure-sensitive adhesive of the pressure-sensitive adhesive layer.
The pressure-sensitive adhesive tape for semiconductor wafer dicing according to claim 1, wherein the molecular weight of is 100,000 to 220,000. 3. A cyanurate compound having a molecular weight of less than 10,000 or an isocyanurate compound (C) having at least one photopolymerizable carbon-carbon double bond per repeating unit is used as the pressure-sensitive adhesive of the pressure-sensitive adhesive layer (A). 3. The adhesive tape for semiconductor wafer dicing according to claim 1, which is contained in an amount of 10 parts by weight or less based on 100 parts by weight.