JP2003142433A - Dicing adhesive sheet and dicing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dicing adhesive sheet which is capable of improving a cut work such as a semiconductor wafer or the like in yield and preventing chipping form occurring in the cut work when the work is subjected to dicing, and to provide a dicing method using the same. SOLUTION: An adhesive agent layer is formed on a base film for the formation of a dicing adhesive sheet. The adhesive agent layer is as thick as 1 to 10 μm. The dicing adhesive sheet is adhered on a silicon mirror wafer. When the dicing adhesive sheet is peeled from the silicon mirror wafer (at a pulling rate of 300 mm/min) at a peed angle of 180 deg. at a temperature of 23 deg.C, the adhesion of the dicing adhesive sheet is 10 N/25 mm or above.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, a semiconductor wafer made of silicon, gallium, arsenic, or the like is manufactured in a large diameter state, cut into small pieces (dicing) into element pieces, and then transferred to a mounting step. At this time, the semiconductor wafer is subjected to the dicing process, the cleaning process, the expanding process, the pickup process, and the mounting process while being attached and held on the adhesive sheet. The pressure-sensitive adhesive sheet is formed by applying a pressure-sensitive adhesive layer having a thickness of about 10 to 30 μm on a base material made of a plastic film with an acrylic pressure-sensitive adhesive or the like. Generally, those having a temperature of 1.5 ° C. and peeling at 23 ° C. of about 1.5 to 6 N / 25 mm are generally used.

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

However, when a semiconductor wafer is cut into full cuts, as a pressure-sensitive adhesive sheet for dicing, a conventional pressure-sensitive adhesive layer has a thickness of about 10 to 30 μm and a peeling adhesive strength of about 1.5 to 6 N / 25 mm. When a sheet is used, cracks called chipping occur on the back surface of the semiconductor element (wafer). In recent years, with the widespread use of IC cards and the like, semiconductor elements have become thinner, and chipping of semiconductor elements has caused a problem that the strength of the semiconductor element is significantly reduced and the reliability thereof is significantly reduced.

It is assumed that the mechanism of chipping generation during dicing is roughly as follows.
That is, in the full-cut cutting method, as shown in FIG. 2, as a result of cutting with the round blade 3 to the inside of the base film 11 of the adhesive sheet 1, the adhesive layer 12 or the base film 11 is cut by the round blade 3. It is pressed and deformed in the rotational direction and the traveling direction, and at that time, as shown in FIG. 2, peeling occurs at a minute portion a at the interface between the pressure-sensitive adhesive layer 12 cut by the round blade 3 and the semiconductor wafer 2, and the semiconductor wafer 2 As a result of the end portion of the semiconductor wafer floating in the air, the rotation of the round blade 3 causes irregular vibrations in the cut portion of the semiconductor wafer 2 being cut. It is presumed that the cutting is not normally performed due to the irregular vibration of the body to be cut and chipping is caused.

As means for solving such a problem, for example, in Japanese Patent Laid-Open No. 5-335411, first, a groove having a predetermined depth is formed by dicing on a semiconductor wafer on which elements are formed, and then dicing is performed. There has been proposed a method (first dicing method) for manufacturing a thinned semiconductor element piece by performing back grinding (back surface grinding) to the depth of the formed groove. However, with this method, the occurrence of chipping can be suppressed, but since the semiconductor wafer is cut into tens to hundreds of μm by dicing in advance, the semiconductor wafer is broken at the cut portion during the transportation process to the back grinding process. This is liable to occur, leading to a reduction in the yield of semiconductor wafers.

[0007]

SUMMARY OF THE INVENTION The present invention is intended to solve the problems of the prior art as described above, and the yield of objects to be cut such as semiconductor wafers is good, and the occurrence of chipping during dicing is prevented. An object of the present invention is to provide a pressure-sensitive adhesive sheet for dicing. Another object of the present invention is to provide a dicing method using the pressure-sensitive adhesive sheet for dicing.

[0008]

Means for Solving the Problems The inventors of the present invention found that the above objects can be achieved by the following dicing method and pressure-sensitive adhesive sheet for dicing, as a result of intensive studies to solve the above problems, and completed the present invention. Came to do.

That is, according to the present invention, in a pressure-sensitive adhesive sheet for dicing in which a pressure-sensitive adhesive layer is provided on a substrate film, the pressure-sensitive adhesive layer has a thickness of 1 to 10 μm, and the pressure-sensitive adhesive sheet for dicing is attached to a silicon mirror wafer. After attaching, peel off 180 ° at 23 ° C (pull speed 300mm
/ Min), the pressure-sensitive adhesive sheet for dicing is characterized by having a pasting temperature at which the adhesive force is 10 N / 25 mm or more.

The pressure-sensitive adhesive sheet for dicing according to the present invention,
The adhesive layer is thin and has a strong adhesive force for peeling off the object to be cut at the time of dicing, thereby suppressing or preventing deformation of the adhesive layer which is easily deformed and peeling of the chip-adhesive layer interface. By doing so, the occurrence of chipping is suppressed or prevented.

If the thickness of the pressure-sensitive adhesive layer becomes thin, it tends to be impossible to secure sufficient pressure-sensitive adhesive strength. Therefore, the thickness of the pressure-sensitive adhesive layer must be 1 μm or more. From this viewpoint, the thickness of the pressure-sensitive adhesive layer is preferably 3 μm or more. On the other hand, when the pressure-sensitive adhesive layer becomes thicker, the amount of deformation of the whole pressure-sensitive adhesive layer due to the rotation of the round blade increases and promotes peeling at the semiconductor wafer-pressure-sensitive adhesive layer interface cut by the blade. Is 1
It is 0 μm or less. From this viewpoint, the thickness of the adhesive layer is
Further, it is preferably 7 μm or less. The thickness of the pressure-sensitive adhesive layer is particularly preferably 3 to 7 μm.

The peeling adhesive strength of the pressure-sensitive adhesive sheet for dicing is 10 N / 25 mm or more when it is adhered to a silicon mirror wafer and peeled at 180 ° at 23 ° C. (pulling speed 300 mm / min). . The adhesive force is defined by the adhesive force with respect to the silicon mirror wafer because the silicon mirror wafer has a stable surface state (roughness) and is suitable as an objective adherend. This is because it is silicon and the same material as the material to be cut that is the object of dicing. Moreover, since dicing is usually performed at room temperature (23 ° C.), the adhesive strength at 23 ° C. is used as a reference. The adhesive force of the adhesive sheet for dicing to the silicon mirror wafer is 10 N / 25 mm or more, preferably 12 N / 25 m.
It is m or more. When the adhesive strength is low, peeling easily occurs at the semiconductor wafer-adhesive layer interface when the adhesive layer is deformed by the rotation of the round blade during dicing.

In the pressure-sensitive adhesive sheet for dicing, it is preferable that the temperature for attaching the pressure-sensitive adhesive sheet for dicing to the silicon mirror wafer is 20 to 80 ° C.

The sticking temperature of the pressure-sensitive adhesive sheet for dicing on the silicon mirror wafer is not particularly limited as long as it shows the above-mentioned tackiness after sticking, but the pressure-sensitive adhesive sheet for dicing is usually at 20 to 80 ° C. Since it is attached, it is preferable that the adhesive exhibits the above-mentioned adhesive force after being attached to the silicon mirror wafer within such a temperature range.
The adhesive force to the silicon mirror wafer can be increased by appropriately adjusting the sticking temperature. For example, even if the adhesive strength cannot be satisfied at room temperature, the adhesive strength can be satisfied by increasing the temperature.

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

The above-mentioned pressure-sensitive adhesive sheet for dicing is designed to have a high peel-off pressure-sensitive adhesive strength, which makes it difficult to pick up in the subsequent steps. Therefore, the radiation-curable pressure-sensitive adhesive which can be cured by radiation to reduce the pressure-sensitive adhesive strength is used. It is preferable that an agent layer is formed. For example, by curing the adhesive layer after dicing, the adhesive force can be reduced and the chip can be peeled (picked up) with less stress. It is particularly suitable when used.

Further, according to the present invention, after the pressure-sensitive adhesive sheet for dicing is attached to a body to be cut on a silicon mirror wafer, it is peeled off by 180 ° at 23 ° C. (pulling speed: 300 mm).
/ Min), the adhesive force of 10 N / 25 mm or more is applied, and the object to be cut is diced after the application at an application temperature.

The pressure-sensitive adhesive sheet for dicing is adhered to the object to be cut at a bonding temperature at which the pressure is not less than the above-mentioned adhesive force, and the peeling adhesive force is strong and is used for dicing with the object to be cut being fixed. Suppression of the
Has the effect of prevention.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the pressure-sensitive adhesive sheet 1 for dicing of the present invention will be described in detail with reference to FIG. As shown in FIG. 1, the pressure-sensitive adhesive sheet for dicing of the present invention is provided with a base film 11 and a pressure-sensitive adhesive layer 12. Further, a separator 13 is provided on the pressure-sensitive adhesive layer 12 as needed. In FIG. 1, the pressure-sensitive adhesive layer is provided on one side of the base film, but it is also possible to form the pressure-sensitive adhesive layer on both sides of the base film. The pressure-sensitive adhesive sheet for dicing may be rolled into a tape shape.

The substrate film 11 is not particularly limited, but a plastic film can be used particularly preferably. As typical materials thereof, for example, low density polyethylene, linear polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, polymethylpentene. Such as polyolefin, ethylene-vinyl acetate copolymer, ionomer resin, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester (random, alternating) copolymer, ethylene-butene copolymer, Polyethylene such as ethylene-hexene copolymer, polyurethane, polyethylene terephthalate, polyimide, polyether ketone, polystyrene, polyvinyl chloride, polyvinylidene chloride, fluororesin, silicone resin, cellulosic resin and their bridges. Polymer, such as a body, and the like. The above-exemplified materials constituting the base film may be grafted with a functional group, a functional monomer, a modifying monomer, or the like, if necessary.

The substrate film can be formed by a conventionally known film forming method. For example, calender film formation, casting film formation, inflation extrusion, T-die extrusion and the like can be preferably used.

The thickness of the base film thus obtained is
It is usually 10 to 300 μm, preferably about 30 to 200 μm. The base film may be either a single-layer film or a multi-layer film, and may be a blend base material obtained by dry blending the two or more resins.
The multilayer film is a coextrusion method using the resin or the like,
It can be produced by a conventional film laminating method such as a dry laminating method. The substrate film may be used without stretching, or may be subjected to uniaxial or biaxial stretching treatment as necessary. If necessary, the surface of the substrate film thus formed may be subjected to a conventional physical or chemical treatment such as matting treatment, corona discharge treatment, primer treatment, and crosslinking treatment.

The adhesive layer 12 has a thickness of 1 to 10 as described above.
is 18 μm for the silicon mirror wafer by adjusting the attachment temperature to the silicon mirror wafer.
It is not particularly limited as long as it can be peeled off at 0 ° (pulling speed 300 mm / min) and the adhesive force can be 10 N / 25 mm or more. For forming such a pressure-sensitive adhesive layer, a known or common pressure-sensitive adhesive can be appropriately selected and used. The pressure-sensitive adhesive is not particularly limited, but various pressure-sensitive adhesives such as rubber-based, acrylic-based, silicone-based, and polyvinyl ether-based pressure-sensitive adhesives are used. Among them, acrylic adhesives having an acrylic polymer as a base polymer are preferable from the viewpoint of adhesiveness to a semiconductor wafer.

The acrylic polymer is, for example, a polymer of (meth) acrylic acid alkyl ester or a (meth) acrylic acid alkyl ester copolymerizable monomer for the purpose of modifying cohesive force, heat resistance and the like as required. A copolymer obtained by copolymerizing is used. (Meta)
Acrylic acid ester means acrylic acid ester and / or methacrylic acid ester, and (meth) of the present invention has the same meaning. Examples of the alkyl ester of (meth) acrylic acid alkyl ester include methyl ester, ethyl ester, butyl ester, 2-ethylhexyl ester, octyl ester, isononyl ester and the like. Among them, the glass transition temperature of homopolymer (hereinafter, Tg
(Referred to as “) is -25 ° C. or higher is suitable as the main monomer. Those containing 50% by weight or more of such a main monomer are preferable.

As the copolymerizable monomer, a hydroxyalkyl ester of (meth) acrylic acid (for example, hydroxyethyl ester, hydroxybutyl ester, hydroxyhexyl ester, etc.), (meth) acrylic acid glycidyl ester, (meth) acrylic acid, Itaconic acid, maleic anhydride, (meth) acrylamide, (meth) acrylic acid N-hydroxymethylamide, (meth) acrylic acid alkylaminoalkyl ester (eg, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, etc.), acetic acid Examples thereof include vinyl, styrene, acrylonitrile and the like. These copolymerizable monomers are
One kind or two or more kinds can be used. Furthermore, since the acrylic polymer is crosslinked, a polyfunctional monomer or the like can be included as a monomer component for copolymerization, if necessary.

The acrylic polymer can be obtained by subjecting a single monomer or a mixture of two or more kinds of monomers to polymerization. The polymerization can be carried out by any method such as solution polymerization, emulsion polymerization, bulk polymerization and suspension polymerization. From the viewpoint of preventing contamination of semiconductor wafers and the like, the adhesive layer preferably has a low content of low molecular weight substances. From this point, the number average molecular weight of the acrylic polymer is preferably 300,000 or more, and more preferably about 600,000 to 3,000,000.

A cross-linking agent may be appropriately added to the pressure-sensitive adhesive in order to increase the number average molecular weight of the acrylic polymer as the base polymer. Examples of the cross-linking agent include polyisocyanate compounds, epoxy compounds, aziridine compounds, melamine resins, urea resins, anhydrous compounds, polyamines and carboxyl group-containing polymers. When a cross-linking agent is used, the amount of the cross-linking agent used is generally 0.01 to 5 parts by weight based on 100 parts by weight of the base polymer, considering that the peeling adhesive strength does not decrease too much. Is preferred. Further, the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer contains, if necessary, conventional additives such as various conventionally known tackifiers, antioxidants, fillers, antioxidants, colorants, etc., in addition to the above components. Can be made.

In order to improve the releasability from the chip, the pressure-sensitive adhesive is preferably a radiation-curable pressure-sensitive adhesive which is cured by ultraviolet rays, electron beams and the like. When a radiation-curable pressure-sensitive adhesive is used as the pressure-sensitive adhesive, the pressure-sensitive adhesive layer is irradiated with radiation after the dicing step, and therefore the substrate film preferably has sufficient radiation transparency.

As the radiation-curable pressure-sensitive adhesive, one having a radiation-curable functional group such as a carbon-carbon double bond and exhibiting adhesiveness can be used without particular limitation. Examples of the radiation-curable pressure-sensitive adhesive include the radiation-curable pressure-sensitive adhesive obtained by blending the above-mentioned acrylic polymer with a radiation-curable monomer component or oligomer component.

Examples of the radiation-curable monomer component or oligomer component to be blended include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tetraethylene glycol di (meth) acrylate and 1,6- Esters of (meth) acrylic acid and polyhydric alcohols such as xanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate; ester acrylate oligomers; 2-propenyl-di -3-butenyl cyanurate,
Examples thereof include isocyanurates such as tris (2-methacryloxyethyl) isocyanurate or isocyanurate compounds. The viscosity of the above-mentioned monomer component or oligomer component is not particularly limited, but the viscosity at 25 ° C. (measured by a B-type rotational viscometer) is 5 Pa · s in order to enhance the peeling adhesive strength of the silicon mirror wafer.
ec or more, particularly 10 Pa · sec or more is preferable.

The amount of the radiation-curable monomer component or oligomer component to be blended is not particularly limited, but considering that the peeling adhesive strength of the silicon mirror wafer is enhanced, the acrylic polymer constituting the adhesive is considered. 30 to 1 with respect to 100 parts by weight of the base polymer such as
It is about 50 parts by weight, preferably about 50 to 120 parts by weight.

As the radiation-curable pressure-sensitive adhesive, a base polymer having a carbon-carbon double bond in the side chain of the polymer or in the main chain or at the end of the main chain can be used. As such a base polymer, one having an acrylic polymer as a basic skeleton is preferable. In this case, the radiation-curable monomer component or oligomer component may not be added, and its use is optional.

The radiation-curable pressure-sensitive adhesive contains a photopolymerization initiator when it is cured by ultraviolet rays or the like.
Examples of the photopolymerization initiator include benzoin alkyl ethers such as benzoin methyl ether, benzoin propyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; benzyl, benzoin,
Aromatic ketones such as benzophenone and α-hydroxycyclohexyl phenyl ketone; aromatic ketals such as benzyl dimethyl ketal; polyvinyl benzophenone,
Examples thereof include thioxanthones such as chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone and diethylthioxanthone. The blending amount of the photopolymerization initiator is, for example, 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, relative to 100 parts by weight of the base polymer such as an acrylic polymer that constitutes the pressure-sensitive adhesive.

In the pressure-sensitive adhesive sheet for dicing of the present invention, for example, a pressure-sensitive adhesive solution is applied to the surface of the base film 11,
After dried (heat-crosslinked if necessary), the pressure-sensitive adhesive layer 1
2 can be formed, and the separator 13 can be attached to the surface of the pressure-sensitive adhesive layer 12 if necessary. Alternatively, a method of separately forming the pressure-sensitive adhesive layer 12 on the release liner 13 and then bonding the pressure-sensitive adhesive layer 12 to the base film 11 can be adopted.

The separator 13 is provided as needed for label processing or for the purpose of smoothing the pressure-sensitive adhesive. Examples of the constituent material of the separator include paper, synthetic resin films such as polyethylene, polypropylene, and polyethylene terephthalate. The surface of the separator may be subjected to a peeling treatment such as a silicone treatment, a long-chain alkyl treatment and a fluorine treatment, if necessary, in order to enhance the peelability from the pressure-sensitive adhesive layer. Further, if necessary, the pressure-sensitive adhesive sheet may be subjected to ultraviolet ray transmission preventing treatment or the like so as not to react with ambient ultraviolet rays. The thickness of the separator is usually 10 to 200 μm, preferably 2
It is about 5 to 100 μm.

The pressure-sensitive adhesive sheet for dicing according to the present invention has a pressure-sensitive adhesive force of 10 N / 25 mm on an object to be cut such as a semiconductor component.
It is pasted at the temperature as described above. After the pressure-sensitive adhesive sheet for dicing is attached, it is subjected to dicing according to a conventional method. The dicing temperature is about 10 to 35 ° C., but it is generally performed at room temperature (23 ° C.). In the dicing step, the blade is rotated at high speed to cut the object to be cut into a predetermined size. For the dicing, a cutting method called a full cut, which cuts inside the base material of the pressure-sensitive adhesive sheet, can be adopted. When a radiation-curable pressure-sensitive adhesive is used for the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is cured after the dicing by irradiation with radiation depending on the type of the pressure-sensitive adhesive to reduce the adhesiveness. By irradiation with radiation after dicing, the adhesiveness of the pressure-sensitive adhesive layer is reduced by curing, and peeling can be facilitated. The means of irradiation is not particularly limited,
For example, it is performed by ultraviolet irradiation.

[0037]

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

Example 1 (Base Film) As the base film, a linear low density polyethylene film having a thickness of 70 μm was used. One side of this film was corona treated.

(Preparation of adhesive) 60 parts by weight of methyl acrylate (Tg of homopolymer = 8 ° C.), 30 parts by weight of butyl acrylate (Tg of homopolymer = −54 ° C.) and acrylic acid (of homopolymer) Of Tg = 106 ° C.) was mixed with ethyl acetate by a conventional method, and a solution containing an acrylic copolymer having a weight average molecular weight of 800,000 was reacted with pentaerythritol triacrylate and diisocyanate. 60 parts by weight of the radiation curable oligomer (viscosity at 25 ° C .: 10 Pa · sec) obtained by
Photopolymerization initiator (trade name "Irgacure 651", Ciba
3 parts by weight of Specialty Chemicals) and 2 parts by weight of a polyisocyanate compound (trade name "Coronate L", made by Nippon Polyurethane) were added to obtain an acrylic radiation-curable adhesive solution.

(Preparation of pressure-sensitive adhesive sheet for dicing) The pressure-sensitive adhesive solution prepared as described above was applied to the corona-treated surface of the base film and heat-crosslinked at 80 ° C. for 10 minutes to give a radiation-curable pressure-sensitive adhesive having a thickness of 7 μm. Layers were formed. Then, a separator was attached to the surface of the pressure-sensitive adhesive layer to prepare an ultraviolet-curable dicing sheet.

Example 2 (Preparation of pressure-sensitive adhesive) 50 parts by weight of ethyl acrylate (Tg of homopolymer = -22 ° C.), 25 parts by weight of 2-ethylhexyl acrylate (Tg of homopolymer = −85 ° C.), Contains an acrylic copolymer having a weight average molecular weight of 700,000 obtained by copolymerizing 20 parts by weight of acryloylmorpholine and 5 parts by weight of acrylic acid (Tg = 106 ° C. in a homopolymer) in ethyl acetate by a conventional method. To the solution
Penta acrylate ester (trade name "KAYARAD
SR-9041 ", manufactured by Nippon Kayaku, viscosity 15 at 25 ° C
Pa · sec) 50 parts by weight, a photopolymerization initiator (trade name “Irgacure 651”, manufactured by Ciba Specialty Chemicals) 3 parts by weight, and a polyisocyanate compound (trade name “Coronate L”, manufactured by Nippon Polyurethane) 3 parts by weight In addition, an acrylic radiation-curable adhesive solution was obtained.

(Preparation of pressure-sensitive adhesive sheet for dicing) In Example 1, except that the pressure-sensitive adhesive solution obtained above was used and the thickness of the pressure-sensitive adhesive layer was 5 μm.
An ultraviolet-curable dicing pressure-sensitive adhesive sheet was prepared in the same manner as in (1).

Comparative Example 1 (Preparation of adhesive) 95 parts by weight of 2-ethylhexyl acrylate (Tg of homopolymer = −85 ° C.) and 5 parts by weight of acrylic acid (Tg of homopolymer = 106 ° C.) were added to ethyl acetate. In a solution containing an acrylic copolymer having a weight average molecular weight of 700,000 obtained by copolymerization in a conventional manner,
60 parts by weight of penerythritol triacrylate (viscosity 1 Pa · sec at 25 ° C.), 3 parts by weight of a photopolymerization initiator (trade name “Irgacure 651”, manufactured by Ciba Specialty Chemicals) and polyisocyanate compound (trade name “Coronate L”) , Manufactured by Nippon Polyurethane Co., Ltd.) to obtain an acrylic radiation-curable adhesive solution.

(Production of pressure-sensitive adhesive sheet for dicing) An ultraviolet-curable pressure-sensitive adhesive sheet for dicing was produced in the same manner as in Example 1 except that the adhesive solution obtained above was used.

Comparative Example 2 An ultraviolet-curable pressure-sensitive adhesive sheet for dicing was manufactured in the same manner as in Example 1 except that the thickness of the radiation-curable pressure-sensitive adhesive layer was 20 μm in the preparation of the pressure-sensitive adhesive sheet for dicing of Example 2. .

(Adhesive force for peeling off silicon wafer)
The pressure-sensitive adhesive sheets for dicing obtained in Examples and Comparative Examples were cut into strips each having a width of 25 mm, and a silicon mirror wafer surface (manufactured by Shin-Etsu Semiconductor Co., Ltd .; on a hot plate set at 23 ° C. (room temperature) and 70 ° C .; CZN <100> 2.
It was attached to 5-3.5 (4 inches). After leaving it to stand at room temperature for 30 minutes, keep it in a constant temperature room at 23 ℃ for 180 minutes.
Peeling (pulling speed: 300 mm / min) Adhesive force was measured. The results are shown in Table 1.

(Chipping Evaluation) The backside of each of the pressure-sensitive adhesive sheets for dicing obtained in Examples and Comparative Examples was polished (# 2000) in an atmosphere of 23 ° C. (room temperature) and 70 ° C., and was 6 inches thick. After mounting the wafer, dicing was performed at 23 ° C. (room temperature) under the following conditions. After dicing, irradiate ultraviolet rays from the back surface of the sheet (500 mJ
/ Cm ² ) and then picking up (peeling) 50 arbitrary semiconductor chips, observing the depth in the chip thickness direction of the chipping on the side surface of the semiconductor chip with an optical microscope (200 times), and chipping for each size The number (number) was counted. The results are shown in Table 1.

(Yield) Chipping size 5 is set for 50 arbitrary semiconductor chips evaluated for chipping.
The yield (%) was defined as the ratio of those not exceeding 0 μm.

<Dicing conditions> Dicer: DISCO, DFD-651 Blade: DISCO, 27HECC Blade rotation speed: 40,000 rpm Dicing speed: 120 mm / sec Dicing depth: 25 μm Cut mode: Down cut Dicing size: 2.5 × 2.5mm

[0050]

[Table 1] From Table 1, in the pressure-sensitive adhesive sheet for dicing of Example 1, although the pressure-sensitive adhesive layer was thin, the bonding temperature was room temperature (23 ° C.).
Since the peeling adhesive force to the silicon wafer is 10 N / 25 mm or more at both the high temperature (70 ° C.) and the chipping size of 50 μm or more, the yield is good. Further, in Example 2, when the bonding temperature is room temperature (23 ° C.), the peeling adhesive force to the silicon wafer is less than 10 N / 25 mm, and the occurrence of chipping size of 50 μm or more is slightly recognized, but high temperature (70
(° C), the peeling adhesive force to the silicon wafer is as high as 10 N / 25 mm or more, and the chipping size of 50 μm or more does not occur, and the yield is good. On the other hand, in Comparative Example 1, the peeling adhesive force to the silicon wafer was less than 10 N / 25 mm at both the sticking temperature of room temperature (23 ° C.) and the high temperature (70 ° C.),
The chipping size is 50 μm or more and the yield is not good. Further, in Comparative Example 2, the peeling adhesive force to the silicon wafer was 10 N / 25 mm at both the room temperature (23 ° C.) and the high temperature (70 ° C.).
As described above, since the thickness of the pressure-sensitive adhesive layer exceeds 10 μm, chipping size of 50 μm or more occurs, and the yield is not good.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a pressure-sensitive adhesive sheet for dicing.

FIG. 2 is an explanatory diagram of a chipping occurrence mechanism.

[Explanation of symbols]

1 Adhesive sheet for dicing 11 Base film 12 Adhesive layer 13 separator 2 Semiconductor wafer 3 Round blade (dicing blade)

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Claims (4)

[Claims] 1. A pressure-sensitive adhesive sheet for dicing in which a pressure-sensitive adhesive layer is provided on a substrate film, wherein the pressure-sensitive adhesive layer has a thickness of 1 to 10 μm, and after the pressure-sensitive adhesive sheet for dicing is attached to a silicon mirror wafer. 180 at 23 ° C
A pressure-sensitive adhesive sheet for dicing, which has a bonding temperature at which an adhesive force when peeled off (pulling speed: 300 mm / min) is 10 N / 25 mm or more. 2. The pressure-sensitive adhesive sheet for dicing according to claim 1, wherein the pressure-sensitive adhesive sheet for dicing is attached to the silicon mirror wafer at a temperature of 20 to 80 ° C. 3. The pressure-sensitive adhesive sheet for dicing according to claim 1, wherein the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet for dicing is formed of a radiation-curable pressure-sensitive adhesive. 4. The dicing pressure-sensitive adhesive sheet according to claim 1, after being adhered to a silicon mirror wafer on a body to be cut, peeled off by 180 ° at 23 ° C. (pulling speed 300 mm / min). The adhesive strength when performing
After pasting at a pasting temperature of N / 25 mm or more,
A dicing method, which comprises dicing a body to be cut.