TWI794450B - Adhesive tape and method for manufacturing semiconductor device - Google Patents

Abstract

An object of the present invention is to provide an adhesive tape capable of stably holding a wafer even when dry grinding is performed by a so-called pre-dicing method. The solution of the present invention is to provide an adhesive tape comprising a base material and an adhesive layer provided on one side of the base material, wherein the absolute value of the 60°C TMA value of the base material is 30 μm or less.

Description

Adhesive tape and method for manufacturing semiconductor device

The present invention relates to an adhesive tape, and more specifically, relates to an adhesive tape suitable for temporarily fixing semiconductor wafers and chips when manufacturing semiconductor devices by a so-called predicing method, and using The manufacturing method of the semiconductor device of this adhesive tape.

As the miniaturization and multifunctionalization of various electronic devices progress, semiconductor chips mounted on the electronic devices are also required to be smaller and thinner. In order to reduce the thickness of the wafer, back grinding of the semiconductor wafer is generally performed to adjust the thickness. In addition, there is also a technique called a pre-dicing method, which is to form a groove with a predetermined depth from the surface side of the wafer, and then grind it from the back side of the wafer, and remove the bottom of the groove by grinding to separate the wafer. The circle is singulated and wafers are obtained. In the pre-dicing method, since the backside grinding of the wafer and the singulation of the wafer can be performed simultaneously, thin wafers can be efficiently produced.

Previously, in order to protect the circuit on the surface of the wafer and fix the semiconductor wafer and the semiconductor chip in advance when the backside of the semiconductor wafer is ground and the wafer is manufactured by the pre-dicing method, an adhesive tape called a backside grinding sheet is usually attached. attached to the wafer surface.

As the back grinding sheet used in the pre-cut method, an adhesive tape including a substrate and an adhesive layer provided on one side of the substrate is used. As an example of such an adhesive tape, JP-A-2008-251934 (Patent Document 1) proposes an adhesive tape for semiconductor wafer processing in which a radiation-curable adhesive layer is provided on a base film.

When the wafer is separated into pieces by the above-mentioned pre-dicing method, the back grinding is performed while supplying water to the grinding surface in order to remove heat and grinding dust generated during the grinding during back grinding. However, in such conventional back grinding, grinding traces remain on the back surface of the wafer, and micro chips (fragments) are generated at the edge of the wafer, and this is clearly a factor that impairs the bending strength of the wafer. In particular, as a result of the thinning of the wafer, the wafer is easily damaged and the bending strength is reduced. prior art literature patent documents

[Patent Document 1] Japanese Patent Laid-Open No. 2008-251934

The problem to be solved by the invention

In order to remove the above-mentioned grinding traces, micro-defects of the wafer (hereinafter collectively referred to as "damaged parts"), etc., it has been studied that after the backside grinding using water, the dry grinding (dry grinding) without using water is carried out at the end. Polishing) removes the damaged part and improves the bending strength of the wafer. But because no water is used in dry grinding, the wafer gets hot. The heat of the die is transferred to the adhesive tape. As a result, the base material temperature of the adhesive tape may become 60° C. or higher during dry grinding.

Since the base material of the adhesive tape is formed of a resin film, it is easily deformed by heat. At the time of back grinding, suction is performed from the base material side of the adhesive tape to fix the adhesive tape, but the suction force may be insufficient at the end of the adhesive tape. At this time, when the base material of the adhesive tape is slightly deformed by heat, the fixing of the adhesive tape at the end becomes insufficient, and the end of the adhesive tape may curl. As a result, the wafer on the adhesive tape was peeled off. The peeling of the wafer not only causes a decrease in productivity, but also causes damage to the grinding device or failure of the transfer to the next step due to the contact of the peeled wafer with other wafers and damage to the other wafers.

Therefore, an object of the present invention is to provide an adhesive tape capable of stably holding wafers, wafers, etc. during processing of semiconductor wafers, etc. In particular, an object of the present invention is to provide an adhesive tape capable of stably holding a wafer even when dry grinding is performed by a so-called pre-dicing method. means to solve problems

The object of this invention is to solve such a subject, and the summary is as follows. (1) An adhesive tape comprising a base material and an adhesive layer provided on one side of the base material, wherein the base material has an absolute value of 60°C TMA value of 30 μm or less. (2) The adhesive tape according to (1), wherein the absolute value of the rate of dimensional change after the base material is held at 60° C. for 3 minutes is 0.8% or less. (3) The adhesive tape as described in (1) or (2), wherein the tensile modulus of elasticity (E ₂₃ ) at 23°C and the tensile modulus of elasticity at 60°C (E _{60 )} of the aforementioned substrate are ) The elastic modulus change rate E _(23-60) obtained is below 30%. (4) The adhesive tape according to any one of items (1) to (3), wherein the back surface of the semiconductor wafer having grooves formed on the surface of the semiconductor wafer is ground and the semiconductor wafer is ground by the grinding. It is used to attach to the surface of the semiconductor wafer during the process of wafer singulation into semiconductor wafers. (5) The adhesive tape as described in (4), which includes the step of performing dry grinding after singulating the aforementioned semiconductor wafer into semiconductor wafers. (6) A method of manufacturing a semiconductor device, comprising the steps of: forming a groove from the surface side of a semiconductor wafer; attaching the adhesive tape described in any one of items (1) to (4) above to The step of the surface of the aforementioned semiconductor wafer; the step of grinding the semiconductor wafer with the aforementioned adhesive tape on the surface and the aforementioned groove formed thereon, grinding from the back side, removing the bottom of the aforementioned groove, and singulating into a plurality of wafers ; and the step of peeling off the adhesive tape from the aforementioned plurality of chips. (7) The method for manufacturing a semiconductor device as described in (6), including the step of performing dry grinding after singulating the semiconductor wafer into semiconductor wafers. Invention effect

The adhesive tape of the present invention can suppress the deformation of the base material caused by heat to a very low level and prevent curling during dry grinding. Therefore, even a pre-dicing method including a dry grinding step can manufacture semiconductor wafers with a high yield. In addition, since the adhesive tape of the present invention can suppress thermal deformation to a very low level, it can also be used in a general back grinding step.

form for carrying out the invention

Hereinafter, the adhesive tape of this invention is demonstrated concretely. First, main terms used in this specification will be described. In this specification, for example, the term "(meth)acrylate" is used to represent both "acrylate" and "methacrylate", and the same applies to other similar terms.

The adhesive tape means a laminate including a substrate and an adhesive layer provided on one side of the substrate, and does not exclude the inclusion of other constituent layers. For example, for the purpose of improving the adhesion between the surface of the substrate and the interface of the adhesive layer, preventing the migration of low molecular weight components, etc., a primer layer can also be formed on the surface of the substrate on the side of the adhesive layer, in order to protect the adhesive layer to When used, a release sheet may be laminated on the surface of the adhesive layer. In addition, the substrate may be a single layer or a multilayer. The same applies to the adhesive layer. The "surface" of a semiconductor wafer refers to the side on which circuits are formed, and the "back side" refers to the side on which no circuits are formed. Singulation of a semiconductor wafer refers to dividing a semiconductor wafer into individual circuits to obtain a semiconductor wafer.

Dry grinding means a process of grinding using a buff wheel without using water, slurry of abrasive grains, or the like. As the polishing wheel, various general-purpose polishing wheels can be used, and as a commercially available product, the polishing wheel "Gettering DP" and "DP08 SERIES" of DISCO Corporation can be used, but not limited thereto. The damaged parts of the wafer, that is, grinding traces, micro chips (fragments) of the wafer, etc. are removed by dry grinding. The pre-dicing method refers to a method in which grooves of a predetermined depth are formed from the front side of the wafer, and then ground from the back side of the wafer, and the wafer is divided into individual pieces by grinding.

Next, the structure of each member of the adhesive tape of this invention is demonstrated in detail. [Substrate] (substrate physical properties) As the base material of the adhesive tape, a film or sheet with an absolute value of 60°C TMA value of 30 μm or less can be used. The absolute value of the TMA value at 60°C refers to the use of a film for measurement of 15mm (width) x 10mm (length) made of the same material as the film or sheet constituting the base material, with 4000SA manufactured by BRUKER under a load of 2g, The elongation or contraction (TMA value) of the film for measurement is measured under the condition of a heating rate of 5°C/min, and is the absolute value of the value at 60°C. Measurement conditions other than the above are set in accordance with the operation manual of the measurement device. When the film for measurement is elongated, the TMA value is positive, and when it is shortened, it is negative. In this specification, the measurement is performed on 10 or more samples, and the obtained TMA values are averaged and evaluated as absolute values.

The absolute value of the 60°C TMA value is one of the indicators of the deformability of the substrate at 60°C, and means that the lower the value, the better the deformation can be suppressed. Therefore, the absolute value of the TMA value at 60°C is less than 30 μm, and the thermal deformation at 60°C is very small. Polyvinyl chloride, which is commonly used as the base material of adhesive tape, is about 40 μm, and ethylene/methacrylic acid copolymer is about 220 μm.

When the absolute value of the 60°C TMA value is 30 μm or less, deformation of the adhesive tape can be suppressed even when the adhesive tape is heated to about 60°C during dry grinding, and the peeling of the wafer at the end of the adhesive tape can be reduced. Without being bound by any theory, the mechanism by which this effect occurs is speculated as follows. The diameter of the semiconductor wafer is 6 inches or 8 inches, and the diameter is further gradually increased to 12 inches. Furthermore, a surplus area where no circuit is formed is formed on the outer peripheral portion of the wafer. During back grinding or pre-cutting, the size of the adhesive tape attached to the circuit surface of the wafer is roughly the same as that of the semiconductor wafer. As long as the absolute value of the 60°C TMA value is within the above range and the area of the adhesive tape is large, the influence of thermal deformation of the base material is slight as a whole, so even if the end of the adhesive tape is slightly curled, the effect Stay in the remaining area without causing peeling and falling off of the product wafer. Moreover, the deformation of the adhesive tape in the remaining area is also less, and the falling off of the discarded wafers in the remaining area can also be reduced. On the other hand, when the absolute value of the TMA value at 60°C exceeds 30 μm, since the curl of the adhesive tape caused by thermal deformation of the base material also extends to the circuit formation area, many peeling and falling off of the product wafer and the wafer in the remaining area occur. Not only does it lead to a decrease in productivity, but the peeled wafer contacts other wafers and damages other wafers, damages the grinding device, and causes poor transfer to the next step.

The absolute value of the 60°C TMA value of the substrate is preferably 5-25 μm. More preferably, it is 10 to 20 μm.

The lower the absolute value of the 60°C TMA value, the better, but a substrate that is too low may lack flexibility, so it is preferable to set it within the above-mentioned range. When the base material is too hard, the adhesion is poor, and the circuit surface may be put under pressure during back grinding, resulting in tiny defects (fragments) on the chip, resulting in damage to the circuit, bump electrodes, etc. However, when the film is sufficiently soft, the absolute value of the 60°C TMA value can be below 5 μm, or below 7 μm.

Also, the absolute value of the rate of dimensional change after the base material is held at 60°C for 3 minutes is preferably 0.8% or less. The measurement of the dimensional change rate is based on JIS C2151 and ASTM D1204, and the measurement temperature is set to 60°C and the retention time is 3 minutes.

The rate of dimensional change is measured using a 10 cm x 10 cm thin film made of the same material as the film or sheet constituting the substrate. The dimensions of the film for measurement are values measured at 23°C. The sample for measurement is left to stand at a predetermined temperature for a predetermined time in a hot air circulation constant temperature bath. Then, after cooling to room temperature (23°C), according to the following formula, the length of one side at 23°C before heating (10cm: L ₀ ), and the length of the same side at 23°C after heating (L ₁ ) to obtain the dimensional change rate. In this specification, measurement is performed on 10 or more samples, and the obtained dimensional change rates are averaged and evaluated as absolute values. In addition, the measured value uses the measured value of MD direction. Dimensional change rate (%)=100×(L ₀ -L ₁ )/L ₀

The absolute value of the dimensional change rate at 60°C for 3 minutes is one of the indicators of the deformability of the base material at 60°C, which means that the lower the value, the better the deformation can be suppressed. Therefore, the absolute value of the dimensional change rate at 60°C for 3 minutes is less than 0.8%, and the thermal deformation at 60°C is very small. The polyvinyl chloride, which is commonly used as the substrate of adhesive tape, is about 0.9%, and the ethylene/methacrylic acid copolymer is about 1%.

When the absolute value of the dimensional change rate at 60°C for 3 minutes is 0.8% or less, even when the adhesive tape is heated to about 60°C during dry grinding, deformation can be suppressed, and the generation of chips at the end of the adhesive tape can be reduced peel off. Without being bound by any theory, the mechanism for this effect is the same as the above TMA value. Overall, the effect of thermal deformation of the base material is slight, even if the end of the adhesive tape is slightly curled, the effect remains in the The remaining area will not cause peeling and falling off of the product wafer. In addition, the adhesive tape in the remaining area is less deformed, and it is also possible to reduce the falling off of the chip in the remaining area. On the other hand, when the absolute value of the dimensional change rate at 60°C for 3 minutes exceeds 0.8%, the curl of the adhesive tape due to the thermal deformation of the base material also extends to the circuit formation area, resulting in a large number of product wafers, wafers in the remaining area, etc. Peeling and detachment not only lead to a decrease in yield, but also cause damage to the grinding device by contacting and damaging other wafers after peeling, and may cause poor transfer to the next step.

The lower the absolute value of the dimensional change rate at 60°C for 3 minutes, the better the effect, more preferably 0 to 0.5%. Also, in another aspect of the present invention, it may be 0.5 to 0.8%. The absolute value of the dimensional change rate of the substrate at 60°C for 3 minutes is preferably 0-0.2%, and most preferably 0%.

In addition, the heat deformability of the base material can also be evaluated according to the rate of change of the tensile modulus of elasticity at a predetermined temperature with respect to the tensile modulus of elasticity at normal temperature. From the tensile modulus (E ₂₃ ) at room temperature (23°C) to the tensile modulus (E _n ) at a predetermined temperature (n°C), the temperature change from 23°C to n°C The elastic modulus change rate E _(23-n) (%) can be obtained by 100×(E ₂₃ -E _n )/E ₂₃ .

In addition, the tensile modulus refers to the use of a film for measurement of 15 mm (width) × 10 mm (length) formed of the same material as the film or sheet constituting the substrate, Rheovibron DDV-II-EP1 manufactured by ORIENTEC, and Value measured at a measurement frequency of 11 Hz. In this specification, the measurement is performed on 10 or more samples, and the evaluation is performed based on the average value of the obtained tensile elastic modulus.

The substrate of the present invention, the elastic modulus change rate E _(23-60) obtained from the tensile elastic modulus (E ₂₃ ) at 23°C and the tensile elastic modulus (E ₆₀ ) at 60°C , preferably below 30%.

The elastic modulus change rate E _(23-60) is one of the indicators of the deformability of the substrate at 60°C, which means that the lower the value, the better the deformation can be suppressed. Therefore, the base material whose elastic modulus change rate E _(23-60) is less than 30% has very little thermal deformation at 60°C. In polyvinyl chloride, which is commonly used as the substrate of adhesive tape, the change rate of elastic modulus E _(23-60) is about 95%, and in ethylene/methacrylic acid copolymer, it is about 70%.

When the elastic modulus change rate E _(23-60) is 30% or less, even when the adhesive tape is heated to about 60°C during dry grinding, the deformation can be suppressed, and the peeling of the wafer at the end of the adhesive tape can be reduced . Without being bound by any theory, the mechanism by which this effect occurs is postulated as follows. During dry grinding, the base material is deformed due to the heating of the base material and the shear force exerted on the wafer during grinding. In particular, when the modulus of elasticity of the substrate is lowered by heating, deformation is likely to occur and unpredictable deformation may occur. However, when the rate of change in elastic modulus E _(23-60) is 30% or less, the properties at room temperature can be substantially maintained, and deformation due to temperature changes can also be suppressed. On the other hand, when the elastic modulus change rate E _(23-60) exceeds 30%, the heating of the base material greatly changes the characteristics from normal temperature, and unexpected deformation may occur. As a result, thermal deformation causes the adhesive tape to curl, and many product wafers, wafers in the remaining area, etc. are peeled off and fall off, which not only causes a decrease in productivity, but also causes damage to other wafers by contacting the peeled wafers with other wafers, and damages the grinding equipment. When it causes damage and becomes the cause of poor transportation to the next step.

The lower the elastic modulus change rate E _(23-60), the better the effect, preferably less than 25%, more preferably less than 20%. In addition, the lower limit is not particularly limited, but is 3% or more from the viewpoint of material acquisition and the like.

Moreover, the tensile elastic modulus (E ₂₃ ) of the substrate at 23°C is preferably 200-2000 MPa, more preferably 350-1500 MPa. The tensile elastic modulus (E ₂₃ ) of polyvinyl chloride, which is commonly used as the base material of adhesive tape, is about 450 MPa, and that of ethylene/methacrylic acid copolymer is about 110 MPa.

Moreover, the tensile elastic modulus (E ₆₀ ) of the substrate at 60°C is preferably 150-1400 MPa, more preferably 300-1200 MPa. The tensile elastic modulus (E ₆₀ ) of polyvinyl chloride, which is commonly used as the base material of adhesive tape, is about 22MPa, and that of ethylene/methacrylic acid copolymer is about 34MPa.

(non-limiting specific example) The base material of the present invention is not particularly limited as long as it satisfies the above physical properties, and may be a resin film or a resin sheet of various materials. Such a substrate can easily select a sheet with desired characteristics by measuring TMA of various resin sheets, and also measuring the dimensional change rate and modulus of elasticity if necessary. An example of the base material of the present invention will be described in detail below, but this example is only described because the base material is easy to obtain and should not be limitedly interpreted.

The substrate of the present invention may be, for example, a laminate of a first substrate composed of a relatively hard resin film and a second substrate composed of a relatively soft resin film. By using a laminate of resin films having different properties, the properties can be easily controlled and a substrate having desired properties can be easily obtained. Also, the base material of the present invention may be a laminate composed of two layers of the first base material and the second base material, and may also be formed by laminating the same or different second base materials on both sides of the first base material. A laminated body with a 3-layer structure.

(1st substrate) The first substrate is preferably a rigid film with a Young's modulus of 1000 MPa or more, more preferably 1800-30000 MPa, more preferably 2500-6000 MPa. When a rigid film with a high Young's modulus is used as the constituent layer of the base material, it is easy to prevent chipping, damage, etc. . In addition, when the Young's modulus is in the above-mentioned range, the stress when the adhesive tape is peeled from the semiconductor wafer can be reduced, and it is easy to prevent wafer chipping, damage, etc. that occur when the tape is peeled off. In addition, it is possible to improve the workability when the adhesive tape is attached to the semiconductor wafer.

Here, examples of rigid films having a Young's modulus of 1000 MPa or more include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and wholly aromatic polyesters. Films of polyester, polyimide, polyamide, polycarbonate, polyacetal, modified polyphenylene ether, polyphenylene sulfide, polysulfide, polyether ketone, biaxially stretched polypropylene, etc. . Among these resin films, it is preferable to include one or more films selected from polyester films, polyamide films, polyimide films, and biaxially stretched polypropylene films, preferably polyester films, and More preferably, a polyethylene terephthalate film is included.

The thickness (D1) of the first base material is preferably not more than 500 μm, more preferably 15-350 μm, more preferably 20-160 μm. By making the thickness of the 1st base material into 500 micrometers or less, it becomes easy to adjust the peeling force of an adhesive tape to the said predetermined value. Moreover, by setting it as 15 micrometers or more, a base material becomes easy to function as the support body of an adhesive tape.

In addition, the first base material may contain plasticizers, slip agents, infrared absorbers, ultraviolet absorbers, fillers, colorants, antistatic agents, antioxidants, catalysts, etc. within the range that does not impair the effects of the present invention. In addition, the first base material may be transparent or opaque, and may be colored or vapor-deposited as necessary. In addition, an adhesive treatment such as corona treatment may be performed on at least one surface of the first base material to improve the adhesiveness with at least one of the second base material and the adhesive layer. Moreover, the 1st base material may have the above-mentioned resin film and the easy-adhesion layer of a coating film on at least one surface of a resin film.

The easily-adhesive layer-forming composition for forming the easily-adhesive layer is not particularly limited, and examples thereof include combinations containing polyester-based resins, urethane-based resins, polyester-urethane-based resins, and acrylic resins. things. The composition for easily-adhesive layer formation may contain a crosslinking agent, a photoinitiator, an antioxidant, a softener (plasticizer), a filler, an antirust agent, a pigment, a dye, etc. as needed. The thickness of the easily-adhesive layer is preferably from 0.01 to 10 μm, more preferably from 0.03 to 5 μm. Also, because the thickness of the easy-adhesive layer is smaller than that of the first base material, and the material is softer, it has little influence on the Young's modulus. Even with the easy-adhesive layer, the Young's modulus of the first base material It is substantially the same as the Young's modulus of the resin film.

(2nd substrate) The second base material is made of a relatively soft resin film, which can moderate vibration caused by grinding of the semiconductor wafer and prevent cracks and chipping of the semiconductor wafer. In addition, during back grinding, semiconductor wafers with adhesive tape attached thereto are arranged on the suction machine, and the adhesive tape can provide back grinding while improving the retention of the suction machine by setting the second base material on the adhesive tape. Afterwards, it can be detached from the adsorption machine. The storage elastic modulus of the second substrate at 23°C is preferably 100-1500 MPa, more preferably 200-1200 MPa. Also, the stress relaxation rate of the second base material is preferably 70 to 100%, more preferably 78 to 98%.

Since the second base material has the modulus of elasticity and stress relaxation rate within the above range, the second base material can be used for the unevenness and back grinding of the fine foreign matter caught between the adhesive tape and the adsorption machine. The effect of absorbing vibrations and shocks of stones becomes higher. The ratio (D2/D1) of the thickness (D2) of the second base material to the thickness (D1) of the first base material is preferably 0.7 or less. When the thickness ratio (D2/D1) is greater than 0.7, since the ratio of the highly rigid portion of the adhesive tape decreases, it is difficult for the substrate to properly hold the semiconductor wafer, semiconductor wafer, etc., and it is difficult to reduce the vibration during grinding. Therefore, in the case of individualizing small and thin semiconductor wafers by pre-dicing, even if an appropriate material for the second base material is selected, it is difficult to prevent the occurrence of the chip when individualizing by back grinding. semiconductor wafer defects. While reducing chip defects, the second base material has an appropriate thickness to improve the cushioning performance of the adhesive tape, and the thickness ratio (D2/D1) is preferably 0.10-0.70.

The maximum value of tanδ of the dynamic viscoelasticity of the second substrate at -5 to 120°C (hereinafter also referred to simply as "maximum value of tanδ") is preferably 0.7 or higher, preferably 0.8 or higher, more preferably 1.0 or higher . Also, the upper limit of the maximum value of tan δ is not particularly limited, and is usually 2.0. When the maximum value of tan δ of the second base material is 0.7 or more, the effect of the second base material absorbing vibration, impact, etc. of the grinding stone generated during back grinding becomes high. Therefore, even if the semiconductor wafer or the singulated semiconductor wafer is ground to an extremely thin state by the pre-dicing method, it is easy to prevent chipping at the corners of the wafer or the like. In addition, tanδ is called loss tangent and is defined as "loss elastic modulus/storage elastic modulus", which is measured by a dynamic viscoelasticity measurement device to respond to stresses such as tensile stress and torsional stress applied to the object. value.

The thickness (D2) of the second base material is preferably from 8 to 80 μm, more preferably from 10 to 60 μm. By setting the thickness of the second base material to be 8 μm or more, the second base material can appropriately absorb vibration during back grinding. Moreover, it becomes easy to adjust thickness ratio (D2/D1) to the above-mentioned value by being 80 micrometers or less. Also, when the substrate is a laminate of a three-layer structure formed by laminating the same or different second substrates on both sides of the first substrate, the thickness (D2) of the second substrate is preferably 35 μm or less. More preferably, it is 30 μm or less. In a laminate with a three-layer structure, the physical properties of the relatively soft second base material may be important. By setting the thickness of the second base material within the above range, it is easy to adjust to the desired 60°C TMA value and size. rate of change, etc.

The second base material may also be formed of a soft film such as low-density polyethylene, preferably a layer formed of a composition for forming a second base material containing an energy ray polymerizable compound. Since the second base material contains an energy ray polymerizable compound, it can be cured by irradiating energy rays. In addition, the "energy ray" refers to ultraviolet rays, electron beams, etc., and it is preferable to use ultraviolet rays. Also, more specifically, the second substrate-forming composition is a polymerizable compound containing urethane (meth)acrylate (a1) and an alicyclic or heterocyclic group having 6 to 20 ring-forming atoms. (a2) is preferred. When the second base material-forming composition contains these two components, the elastic modulus of the second base material, the stress relaxation rate of the second base material, and the maximum value of tan δ are easily set within the above ranges. Moreover, from these viewpoints, it is preferable that the composition for 2nd base material formation also contains the polymeric compound (a3) which has a functional group in addition to said (a1) and (a2) component. Furthermore, the composition for forming the second substrate preferably contains a photopolymerization initiator in addition to the above-mentioned components (a1) and (a2) or (a1) to (a3), as long as the effects of the present invention are not impaired. It may also contain other additives, resin components, etc. Hereinafter, each component contained in the composition for 2nd base material formation is demonstrated in detail.

(Urethane (meth)acrylate (a1)) The urethane (meth)acrylate (a1) is a compound having at least a (meth)acryl group and a urethane bond, and has a property of being polymerized and hardened by energy ray irradiation. Urethane (meth)acrylate (a1) is an oligomer or a polymer.

The mass average molecular weight (Mw) of the component (a1) is preferably 1,000 to 100,000, preferably 2,000 to 60,000, more preferably 3,000 to 20,000. Moreover, mass average molecular weight (Mw) is the value of the polystyrene conversion measured using the gel permeation chromatography (GPC) method, and can measure on the following conditions specifically,. (measurement conditions) ‧Column: "TSK guard column HXL-H", "TSK gel GMHXL(×2)" and "TSK gel G2000HXL" (both are manufactured by TOSOH Co., Ltd.) ‧Column temperature: 40°C ‧Developing solvent: tetrahydrofuran ‧Flow rate: 1.0mL/min Also, the number of (meth)acryl groups in component (a1) (hereinafter also referred to as "functional group") may be monofunctional, difunctional, or trifunctional or more, preferably monofunctional or difunctional. The component (a1) can be obtained, for example, by reacting a (meth)acrylate having a hydroxyl group with a terminal isocyanate urethane prepolymer obtained by reacting a polyol compound and a polyvalent isocyanate compound. Moreover, a component (a1) may be used individually or in combination of 2 or more types.

The polyol compound used as a raw material of the component (a1) is not particularly limited as long as it has two or more hydroxyl groups. As a specific polyol compound, an alkanediol, a polyether polyol, a polyester polyol, a polycarbonate polyol, etc. are mentioned, for example. Among them, polyester polyol is preferable. In addition, as the polyol compound, it can be any one of dihydric alcohol, trihydric alcohol, and polyhydric alcohol with more than 4 functions, preferably dihydric alcohol with bifunctionality, and polyester type dihydric alcohol. Alcohol is preferred.

Examples of polyvalent isocyanate compounds include aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate; Alicyclic diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, ω,ω'-diisocyanate dimethylcyclohexane, etc. Isocyanates; 4,4'-diphenylmethane diisocyanate, toluene diisocyanate, xylylene diisocyanate, benzylidine diisocyanate, tetramethylene xylylene diisocyanate, naphthalene-1,5-diisocyanate Aromatic diisocyanates such as isocyanate, etc. Among these, isophorone diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate are preferable.

Urethane (meth)acrylate can be obtained by reacting a (meth)acrylate having a hydroxyl group with an isocyanate-terminated urethane prepolymer obtained by reacting the above-mentioned polyol compound and a polyisocyanate compound. (a1). It will not specifically limit if it is a compound which has a hydroxyl group and a (meth)acryl group in at least 1 molecule as (meth)acrylate which has a hydroxyl group.

Specific (meth)acrylates having a hydroxyl group include, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 4-Hydroxyhexyl (meth)acrylate, 5-Hydroxyoctyl (meth)acrylate, 2-Hydroxy-3-phenoxypropyl (meth)acrylate, Neopentylthritol tri(meth)acrylate , Polyethylene glycol one (meth)acrylate, polypropylene glycol one (meth)acrylate and other hydroxyalkyl (meth)acrylates; N-methylol (meth)acrylamide and other hydroxyl-containing ( Meth)acrylamide; a reactant obtained by reacting (meth)acrylic acid with vinyl alcohol, vinylphenol, or bisphenol-A diglycidyl ester, and the like. Among them, hydroxyalkyl (meth)acrylate is preferable, and 2-hydroxyethyl (meth)acrylate is more preferable.

As a condition for reacting the terminal isocyanate urethane prepolymer with a (meth)acrylate having a hydroxyl group, in the presence of a solvent catalyst added as needed, the reaction is carried out at 60 to 100°C for 1 to 4 The condition of the hour is better. The content of the component (a1) in the second base material forming composition is preferably 10 to 70% by mass, preferably 20 to 60% by mass based on the total amount (100% by mass) of the second base material forming composition. % by mass, more preferably 25 to 55% by mass, more preferably 30 to 50% by mass.

(Polymerizable compound (a2) having an alicyclic or heterocyclic group having 6 to 20 ring-forming atoms) Component (a2) is a polymerizable compound having an alicyclic or heterocyclic group having 6 to 20 ring-forming atoms, preferably a compound having at least one (meth)acryl group. By using this component (a2), the film-forming property of the obtained 2nd base material forming composition can be improved.

The number of ring-forming atoms of the alicyclic group or heterocyclic group contained in the component (a2) is preferably 6-20, preferably 6-18, more preferably 6-16, particularly preferably 7-12. Examples of atoms forming the ring structure of the heterocyclic group include carbon atoms, nitrogen atoms, oxygen atoms, sulfur atoms and the like. In addition, the number of ring-forming atoms indicates the number of atoms constituting the ring itself in a compound having a structure in which atoms are bonded in a ring, and the number of ring-forming atoms does not include atoms that do not constitute the ring (for example, hydrogen bonded to atoms constituting the ring) atom), the ring is an atom contained in the substituent when the ring is substituted by a substituent, etc.

Specific examples of the component (a2) include isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentyl (meth)acrylate, and dicyclopentanyl (meth)acrylate. Alicyclic group-containing (meth)acrylates such as alkenyloxyester, cyclohexyl (meth)acrylate, and adamantyl (meth)acrylate; tetrahydrofurfuryl (meth)acrylate, (meth)acrylic acid Heterocyclic group-containing (meth)acrylates such as morpholino esters, etc. Moreover, a component (a2) may be used individually or in combination of 2 or more types. Among them, alicyclic group-containing (meth)acrylate is preferable, and isobornyl (meth)acrylate is preferable.

The content of the component (a2) in the second substrate-forming composition is preferably 10 to 70% by mass, preferably 20 to 60% by mass relative to the total amount (100% by mass) of the second substrate-forming composition. % by mass, more preferably 25 to 55% by mass, particularly preferably 30 to 50% by mass.

(polymerizable compound (a3) having a functional group) Component (a3) is a polymerizable compound containing functional groups such as hydroxyl group, epoxy group, amido group, amino group, etc., and is preferably a compound having at least one (meth)acryl group. The compatibility of component (a3) and component (a1) is good, and it is easy to adjust the viscosity of the composition for 2nd base material formation to an appropriate range. In addition, when the component (a3) is contained, the elastic modulus and the value of tan δ of the second base material formed from the composition can be easily brought into the above-mentioned ranges, and the cushioning performance is good even if the second base material is thin. As a component (a3), a hydroxyl group containing (meth)acrylate, an epoxy group containing compound, an amide group containing compound, an amino group containing (meth)acrylate etc. are mentioned, for example.

Examples of hydroxyl-containing (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, (meth)acrylate Base) 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, phenylhydroxypropyl (meth)acrylate, etc. Examples of epoxy group-containing compounds include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, allyl glycidyl ether, and the like. Epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate and methylglycidyl (meth)acrylate are preferred. Examples of compounds containing amide groups include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hydroxyl Methyl(meth)acrylamide, N-methylolpropane(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(methyl) Acrylamide etc. Examples of amino group-containing (meth)acrylates include (meth)acrylates containing a primary amino group, (meth)acrylates containing a secondary amino group, and (meth)acrylates containing a secondary amino group. (meth)acrylates, etc.

Among them, hydroxyl-containing (meth)acrylates are preferable, and hydroxyl-containing (meth)acrylates having an aromatic ring such as phenylhydroxypropyl (meth)acrylate are preferable. Moreover, a component (a3) may be used individually or in combination of 2 or more types.

In order to easily make the elastic modulus and stress relaxation rate of the second base material fall within the above-mentioned ranges, and to improve the film-forming properties of the second base material-forming composition, the component (a3) in the second base material-forming composition The content is preferably 5 to 40 mass %, preferably 7 to 35 mass %, more preferably 10 to 30 mass %, particularly preferably 10 to 30 mass %, relative to the total amount (100 mass %) of the second base material forming composition 13 to 25% by mass. Also, the content ratio [(a2)/(a3)] of the component (a2) to the component (a3) in the composition for forming the second base material is preferably 0.5 to 3.0, preferably 1.0 to 3.0, more preferably 1.3-3.0, especially 1.5-2.8.

(polymerizable compounds other than components (a1) to (a3)) The second composition for base material formation may contain other polymerizable compounds other than the above-mentioned components (a1) to (a3) within the range that does not impair the effect of the present invention. Examples of other polymerizable compounds include alkyl (meth)acrylates having an alkyl group having 1 to 20 carbon atoms; styrene, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, and N-vinylformamide. Vinyl compounds such as N-vinylpyrrolidone and N-vinylcaprolactam, etc. Moreover, these other polymeric compounds may be used individually or in combination of 2 or more types.

The content of other polymerizable compounds in the second base material forming composition is preferably 0 to 20% by mass, preferably 0 to 10% by mass, more preferably 0 to 5% by mass, most preferably 0 to 2% by mass %.

(thioxanthone)化合物、過氧化化合物、以及胺、苯醌等的光敏化劑等，更具體地，例如可舉出1-羥基環己基苯基酮、2-羥基-2-甲基-1-苯基-丙烷-1-酮、苯偶姻、苯偶姻甲醚、苯偶姻乙醚、苯偶姻異丙醚、苄基苯基硫醚、四甲基秋蘭姆一硫醚、偶氮雙異丁腈、聯苄(dibenzyl)、聯乙醯、8-氯蒽醌、雙(2,4,6-三甲基苯甲醯基)苯基氧化膦等。 該等光聚合起始劑能夠單獨或組合2種以上而使用。 第2基材形成用組合物中的光聚合起始劑含量，相對於能量線聚合性化合物的總量100質量份，良好為0.05～15質量份，較佳為0.1～10質量份，更佳為0.3～5質量份。(Photopolymerization initiator) When forming the second substrate, the polymerization time is shortened by light irradiation, and from the viewpoint of reducing the amount of light irradiation, the composition for forming the second substrate further contains a photopolymerization initiator. good. Examples of photopolymerization initiators include benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, 9-oxythiol

Photosensitizers such as (thioxanthone) compounds, peroxide compounds, amines and benzoquinones, etc., more specifically, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-benzene Base-propan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl phenyl sulfide, tetramethylthiuram monosulfide, azobis Isobutyronitrile, dibenzyl, diacetyl, 8-chloroanthraquinone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, etc. These photoinitiators can be used individually or in combination of 2 or more types. The content of the photopolymerization initiator in the second substrate-forming composition is preferably 0.05 to 15 parts by mass, preferably 0.1 to 10 parts by mass, more preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the total amount of the energy ray polymerizable compound. It is 0.3-5 mass parts.

(other additives) The second substrate-forming composition may contain other additives within the range not impairing the effect of the present invention. Examples of other additives include antistatic agents, antioxidants, softeners (plasticizers), fillers, antirust agents, pigments, dyes, and the like. When preparing these additives, the content of each additive in the second base material forming composition is preferably 0.01 to 6 parts by mass, preferably 0.1 to 3 parts by mass, based on 100 parts by mass of the total amount of the energy ray polymerizable compound.

(resin component) The second composition for base material formation may also contain a resin component within the range that does not impair the effect of the present invention. Examples of the resin component include polyene-thiol-based resins, polyolefin-based resins such as polybutene, polybutadiene, and polymethylpentene, and thermoplastic resins such as styrene-based copolymers. The content of the resin components in the second base material forming composition is preferably 0 to 20% by mass, preferably 0 to 10% by mass, more preferably 0 to 5% by mass, most preferably 0 to 2% by mass . (preparation of base material) A non-limiting example of the base material of the adhesive tape of the present invention is a laminate of the above-mentioned first base material and second base material. It does not specifically limit as a manufacturing method, It can manufacture using a well-known method. For example, a laminated base material can be obtained by applying the second base material-forming composition on a release sheet and setting the second base material after curing, directly bonding the first base material and removing the release sheet. As a method of forming the second base material on the release sheet, a coating film can be formed by directly coating the composition for forming the second base material on the release sheet using a known coating method, and irradiating the coating film energy lines to form the second base material. In addition, the second base material can also be formed by directly coating the second base material forming composition on one side of the first base material, and heating and drying or irradiating the coating film with energy rays.

Examples of coating methods for the second substrate-forming composition include spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, and die coating. Cloth method, gravure coating method, etc. Moreover, in order to improve applicability, an organic solvent may be mixed with the composition for 2nd base material formation, and it may apply|coat on a peeling sheet in the form of a solution.

When the second base material forming composition contains an energy ray polymerizable compound, it is preferable to irradiate the coating film of the second base material forming composition with energy rays and harden it to form the second base material. The hardening of the second base material may be performed once, or divided into plural times. For example, the coating film on the release sheet can be completely cured to form the second base material, and then bonded to the first base material, or the coating film can be formed without fully curing the second base material in a semi-cured state. film, and the second base material is formed into a film and bonded to the first base material, and then irradiated with energy rays again to completely harden to form the second base material. Ultraviolet rays are preferable as the energy ray irradiated in the hardening treatment. In addition, during curing, the coating film of the composition for forming the second base material may be exposed, but the coating film may be covered with a release sheet, the first base material, etc., and the coating film may not be exposed. It is better to harden by irradiating energy rays downward.

Furthermore, the base material can also be obtained by bonding the second base material to one or both surfaces of the first base material. In addition, the substrate of the present invention may have other constituent layers as long as it satisfies a predetermined 60°C TMA value in addition to the above-mentioned first substrate and second substrate.

The total thickness of the substrate is the total thickness of the first substrate, the second substrate, and other constituent layers that may be used as needed, and is preferably 23 to 150 μm, more preferably 30 to 140 μm. The above-mentioned laminated base material which is an example of the base material of the present invention is a laminate of a first base material and a second base material, and its physical properties can be controlled by the material and thickness of the first base material and the second base material. Therefore, in order to obtain a base material with desired properties, it is important to balance the properties of the first base material and the second base material according to the guidelines below.

The 60°C TMA value, dimensional change rate, and elastic modulus change rate of the substrate can be controlled by appropriately selecting the film constituting the substrate. For example, these values can be lowered by performing an annealing treatment on a thin film having a relatively high Tg or a base material during film formation as a constituent thin film. Also, when the base material is a laminated base material of the first base material and the second base material, it is also possible to form the first base material or the second base material by using a high Tg film, an annealed film, or the like. material or both, and can control the 60°C TMA value, dimensional change rate, and elastic modulus change rate in a relatively low range. In addition, when laminating substrates, by increasing the relative thickness of high-Tg films and annealed films, the 60°C TMA value, dimensional change rate, and elastic modulus change rate can be kept low. range. In addition, when other constituent layers are used, when a film with high rigidity is used, the 60°C TMA value, dimensional change rate, and elastic modulus change rate can be controlled in a low range.

[adhesive layer] The adhesive is not particularly limited as long as it has appropriate pressure-sensitive adhesiveness at room temperature, and the storage modulus of elasticity at 23°C is preferably 0.05-0.50 MPa. Circuits and the like are formed on the surface of the semiconductor wafer and generally have unevenness. When the adhesive tape has a storage elastic modulus within the above range, when it is attached to the surface of the wafer with unevenness, the unevenness of the wafer surface can be fully contacted with the adhesive layer, and the adhesion of the adhesive layer can be properly maintained. play. Therefore, the adhesive tape can be reliably fixed to the semiconductor wafer and properly protect the wafer surface during back grinding. From these viewpoints, the storage elastic modulus of the adhesive is preferably 0.10-0.35 MPa. Also, the storage elastic modulus of the adhesive means the storage elastic modulus of the hardened surface obtained by irradiating energy rays when the adhesive layer is formed of an energy ray-curable adhesive.

The thickness (D3) of the adhesive layer is preferably less than 200 μm, more preferably 5-55 μm, more preferably 10-50 μm. When the adhesive layer is thinned in this way, since the ratio of the low-rigidity portion in the adhesive tape can be reduced, it becomes easier to further prevent semiconductor wafer chipping during back grinding.

The adhesive layer is formed of, for example, an acrylic adhesive, a urethane adhesive, a rubber adhesive, a silicone adhesive, etc., preferably an acrylic adhesive.

Also, the adhesive layer is preferably formed of an energy ray curable adhesive. By forming the adhesive layer with an energy ray-curable adhesive, the elastic modulus at 23°C is set within the above range before curing by energy ray irradiation, and the peeling force can be easily set after curing. Below 1000mN/50mm.

Hereinafter, specific examples of the adhesive will be described in detail, but these are non-limiting illustrations, and the adhesive layer in the present invention should not be construed as being limited thereto.

As the energy ray-curable adhesive, for example, in addition to the non-energy ray-curable adhesive resin (also referred to as "adhesive resin I"), an energy ray-curable adhesive containing an energy ray-curable compound other than the adhesive resin can also be used. Adhesive composition (hereinafter also referred to as "type X adhesive composition"). In addition, as an energy ray-curable adhesive, an energy ray-curable adhesive resin containing an unsaturated group introduced into a side chain of a non-energy ray-curable adhesive resin (hereinafter also referred to as "adhesive resin II") can also be used. ”) as the main component, and an adhesive composition that does not contain energy ray-curable compounds other than adhesive resins (hereinafter also referred to as “Y-type adhesive composition”).

Furthermore, as an energy ray-curable adhesive, a combination of X-type and Y-type can also be used, that is, an energy ray that contains an energy-ray-curable compound other than the adhesive resin in addition to the energy ray-curable adhesive resin II. Hardening adhesive composition (hereinafter also referred to as "XY type adhesive composition").

Among them, it is preferable to use an XY-type adhesive composition. By using the XY type, it has sufficient adhesive properties before curing, and on the other hand, it can sufficiently reduce the peeling force to the semiconductor wafer after curing.

However, the adhesive may also be formed from a non-energy ray-curable adhesive composition that does not harden when irradiated with energy rays. The non-energy ray-curable adhesive composition contains at least the non-energy ray-curable adhesive resin I, and on the other hand, does not contain the energy ray-curable adhesive resin II and the energy ray-curable compound.

In addition, in the following description, "adhesive resin" is used as a term referring to one or both of the above-mentioned adhesive resin I and adhesive resin II. Specific adhesive resins include, for example, acrylic resins, urethane-based resins, rubber-based resins, and silicone-based resins, among which acrylic resins are preferred. Hereinafter, an acrylic adhesive using an acrylic resin as an adhesive resin will be described in more detail.

As the acrylic resin, an acrylic polymer (b) can be used. The acrylic polymer (b) is obtained by polymerizing a monomer containing at least an alkyl (meth)acrylate, and contains a structural unit derived from an alkyl (meth)acrylate. Examples of the alkyl (meth)acrylate include those having 1 to 20 carbon atoms in the alkyl group, and the alkyl group may be straight or branched. Specific examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-propyl (meth)acrylate, ( n-butyl methacrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, (meth) Decyl acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, etc. Alkyl (meth)acrylate can be used individually or in combination of 2 or more types.

Also, from the viewpoint of improving the adhesive force of the adhesive layer, the acrylic polymer (b) preferably contains a structural unit derived from an alkyl group having a carbon number of 4 or more alkyl (meth)acrylate. As carbon number of this alkyl (meth)acrylate, Preferably it is 4-12, More preferably, it is 4-6. Also, the alkyl (meth)acrylate having an alkyl group having 4 or more carbon atoms is preferably an alkyl acrylate.

In the acrylic polymer (b), the alkyl (meth)acrylate having an alkyl group having 4 or more carbon atoms has a higher ratio than the total amount of monomers constituting the acrylic polymer (b) (hereinafter referred to simply as "monomer"). Total amount"), preferably 40 to 98% by mass, preferably 45 to 95% by mass, more preferably 50 to 90% by mass.

The acrylic polymer (b), in addition to the structural unit derived from an alkyl (meth)acrylate having 4 or more carbon atoms, contains A copolymer of structural units of an alkyl (meth)acrylate having 1 to 3 carbon atoms in the alkyl group is preferable. In addition, the alkyl (meth)acrylate is preferably an alkyl (meth)acrylate having 1 or 2 carbon atoms, more preferably methyl (meth)acrylate, most preferably methyl methacrylate. In the acrylic polymer (b), the alkyl (meth)acrylate having an alkyl group having 1 to 3 carbon atoms is preferably 1 to 30% by mass, more preferably 3 to 26% by mass, based on the total amount of monomers %, more preferably 6 to 22% by mass.

The acrylic polymer (b) preferably has a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from the above-mentioned alkyl (meth)acrylate. Examples of the functional group of the functional group-containing monomer include a hydroxyl group, a carboxyl group, an amino group, an epoxy group, and the like. The functional group-containing monomer can react with a crosslinking agent described later to serve as a crosslinking origin, or react with an unsaturated group-containing compound to introduce an unsaturated group into the side chain of the acrylic polymer (b).

Examples of the functional group-containing monomer include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an amino group-containing monomer, an epoxy group-containing monomer, and the like. These monomers can be used individually or in combination of 2 or more types. Among these, hydroxyl-containing monomers and carboxyl-containing monomers are preferable, and hydroxyl-containing monomers are more preferable.

Examples of hydroxyl-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, -Hydroxyalkyl (meth)acrylates such as hydroxybutyl, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc. Unsaturated alcohols such as vinyl alcohol and allyl alcohol class etc.

Examples of carboxyl group-containing monomers include ethylenically unsaturated monocarboxylic acids such as (meth)acrylic acid and crotonic acid; Ethylenically unsaturated dicarboxylic acid and its anhydride, 2-carboxyethyl methacrylate, etc.

The functional group monomer is preferably 1 to 35% by mass, preferably 3 to 32% by mass, more preferably 6 to 30% by mass based on the total amount of monomers constituting the acrylic polymer (b). In addition, the acrylic polymer (b) may contain, in addition to the above, compounds derived from styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, acrylamide, etc. A structural unit of acrylic monomer copolymerized monomer.

The above-mentioned acrylic polymer (b) can be used as the non-energy ray-curable adhesive resin I (acrylic resin). In addition, examples of energy ray-curable acrylic resins include those obtained by reacting a compound having a photopolymerizable unsaturated group (also referred to as an unsaturated group-containing compound) with the functional group of the above-mentioned acrylic polymer (b). into things.

An unsaturated group-containing compound is a compound which has both the substituent which can bond with the functional group of an acryl-type polymer (b), and a photopolymerizable unsaturated group. Examples of the photopolymerizable unsaturated group include a (meth)acryl group, a vinyl group, an allyl group, and the like, and a (meth)acryl group is preferable. Moreover, an isocyanate group, a glycidyl group, etc. are mentioned as a substituent which the unsaturated group containing compound has and which can bond with a functional group. Therefore, examples of the unsaturated group-containing compound include (meth)acryloxyethyl isocyanate, (meth)acryl isocyanate, glycidyl (meth)acrylate, and the like.

Furthermore, it is preferable that the unsaturated group-containing compound reacts with a part of the functional groups of the acrylic polymer (b). Specifically, the unsaturated group-containing compound reacts with the Preferably, 50-98 mol% of the functional groups are reacted, more preferably 55-93 mol% are reacted. Thus, in the energy ray-curable acrylic resin, since some functional groups remain without reacting with the unsaturated group-containing compound, crosslinking by a crosslinking agent becomes easy. In addition, the weight average molecular weight (Mw) of the acrylic resin is preferably 300,000 to 1,600,000, preferably 400,000 to 1,400,000, more preferably 500,000 to 1,200,000.

(energy ray hardening compound) The energy ray-curable compound contained in the X-type or XY-type adhesive composition is preferably a monomer or oligomer having an unsaturated group in the molecule and capable of being polymerized and hardened by energy ray irradiation. Examples of such energy ray-curable compounds include trimethylolpropane tri(meth)acrylate, neopentylthritol (meth)acrylate, neopentylthritol tetra(meth)acrylate, di Poly(meth)acrylate monomers such as neopentylitol hexa(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol (meth)acrylate, etc. Oligomers of urethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, epoxy (meth)acrylate, etc.

Among them, urethane (meth)acrylate oligomers are preferable from the viewpoint of high molecular weight and low elastic modulus of the pressure-sensitive adhesive layer. The molecular weight (weight average molecular weight in the case of an oligomer) of the energy ray-curable compound is preferably 100-12,000, preferably 200-10,000, more preferably 400-8,000, and most preferably 600-6,000.

The content of the energy ray-curable compound in the type X adhesive composition is preferably 40 to 200 parts by mass, preferably 50 to 150 parts by mass, more preferably 60 to 90 parts by mass relative to 100 parts by mass of the adhesive resin share. On the other hand, the content of the energy ray-curable compound in the XY-type adhesive composition is preferably 1 to 30 parts by mass, preferably 2 to 20 parts by mass, and more preferably 2 to 20 parts by mass relative to 100 parts by mass of the adhesive resin. It is 3-15 mass parts. In the XY type adhesive composition, since the adhesive resin is energy ray curable, even if the content of the energy ray curable compound is small, the release force can be sufficiently reduced after energy ray irradiation.

(crosslinking agent) The adhesive composition preferably further contains a crosslinking agent. A crosslinking agent is what reacts the functional group originating in the functional group monomer which adhesive resin has, and crosslinks adhesive resin, for example. Examples of the crosslinking agent include isocyanate-based crosslinking agents such as toluene diisocyanate, hexamethylene diisocyanate, and their adducts; ethylene glycol glycidyl ether, 1,3-bis (N,N'-diecidylaminomethyl) cyclohexane and other epoxy-based crosslinking agents; Aziridine-based crosslinking agents; chelate-based crosslinking agents such as aluminum chelates, etc. These crosslinking agents may be used alone or in combination of two or more.

Among them, an isocyanate-based crosslinking agent is preferable from the viewpoint of enhancing the cohesive force to enhance the adhesive force, and the viewpoint of easiness of acquisition. From the standpoint of accelerating the crosslinking reaction, the compounded amount of the crosslinking agent is preferably 0.01 to 10 parts by mass, preferably 0.03 to 7 parts by mass, more preferably 0.05 to 4 parts by mass, based on 100 parts by mass of the adhesive resin. .

(photopolymerization initiator) Also, when the adhesive composition is energy ray curable, it is preferable that the adhesive composition further contains a photopolymerization initiator. By containing the photopolymerization initiator, even with low-energy energy rays such as ultraviolet rays, the hardening reaction of the adhesive composition can be sufficiently advanced.

化合物、過氧化物化合物、以及胺、苯醌等的光敏化劑等，更具體地，例如可舉出1-羥基環己基苯基酮、2-羥基-2-甲基-1-苯基-丙烷-1-酮、苯偶姻、苯偶姻甲醚、苯偶姻乙醚、苯偶姻異丙醚、苄基苯基硫醚、四甲基秋蘭姆一硫醚、偶氮雙異丁腈、聯苄、聯乙醯、8-氯蒽醌、雙(2,4,6-三甲基苯甲醯基)苯基氧化膦等。Examples of photopolymerization initiators include benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, 9-oxythiol

Compounds, peroxide compounds, photosensitizers such as amines and benzoquinones, and more specifically, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl- Propan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl phenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyl Nitrile, bibenzyl, diacetyl, 8-chloroanthraquinone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, etc.

These photoinitiators may be used alone or in combination of two or more. The compounding quantity of a photoinitiator is 0.01-10 mass parts with respect to 100 mass parts of adhesive resins, Preferably it is 0.03-5 mass parts, More preferably, it is 0.05-5 mass parts.

(other additives) The adhesive composition may contain other additives within the range that does not impair the effect of the present invention. Examples of other additives include antistatic agents, antioxidants, tackifiers, softeners (plasticizers), fillers, antirust agents, pigments, dyes, and the like. When compounding these additives, the compounded amount of the additives is preferably 0.01 to 6 parts by mass relative to 100 parts by mass of the adhesive resin.

Moreover, from a viewpoint of improving the applicability to a base material, a peeling sheet, etc., the adhesive composition can also use the solution form of the adhesive composition diluted with the organic solvent further. Examples of organic solvents include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, isopropanol and the like. In addition, the organic solvent used in the synthesis of the adhesive resin may be used as it is, and it is also possible to add a solvent other than the organic solvent used in the synthesis so that the solution of the adhesive composition can be uniformly coated. One or more organic solvents.

[Peel off sheet] The release sheet can also be pasted on the surface of the adhesive tape. Specifically, the release sheet is attached to the surface of the adhesive layer of the adhesive tape. By sticking the release sheet on the surface of the adhesive layer, the adhesive layer is protected during transportation and storage. The release sheet is detachably attached to the adhesive tape, and is peeled and removed from the adhesive tape before using the adhesive tape (ie, before wafer backside grinding). As the release sheet, one having at least one surface subjected to a release treatment can be used, and specifically, one in which a release agent is applied to the surface of a base material for a release sheet, and the like can be used.

As the base material for the release sheet, a resin film is preferable, and examples of the resin constituting the resin film include polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, and polyethylene naphthalate resin. Polyester resin films such as diester resins, polyolefin resins such as polypropylene resins and polyethylene resins, and the like. Examples of release agents include rubber-based elastomers such as silicone-based resins, olefin-based resins, isoprene-based resins, and butadiene-based resins, long-chain alkyl-based resins, alkyd-based resins, fluorine-based Department of resin, etc. The thickness of the release sheet is not particularly limited, but is preferably 10 to 200 μm, more preferably 20 to 150 μm.

(Manufacturing method of adhesive tape) It does not specifically limit as a manufacturing method of the adhesive tape of this invention, It can manufacture using a well-known method. For example, an adhesive tape having a release sheet attached to the surface of the adhesive layer can be produced by bonding the adhesive layer provided on the release sheet to one side of the substrate. The release sheet attached to the surface of the adhesive layer may be properly peeled off and removed before using the adhesive tape. As a method of forming the adhesive layer on the release sheet, the adhesive composition can be directly coated on the release sheet using a known coating method, and the adhesive layer can be formed by heating and drying to evaporate the solvent from the coating film.

In addition, an adhesive (adhesive composition) may be directly applied to one side of the substrate to form an adhesive layer. Examples of methods for applying the adhesive include spin coating, spray coating, bar coating, knife coating, roll coating, and blade coating listed in the production method of the second base material. method, die coating method, gravure coating method, etc.

The adhesive layer can be provided on the surface of the first substrate constituting the substrate, or on the surface of the second substrate. When the substrate is a laminate composed of two layers, it is preferably provided on the surface of the first substrate. When the adhesive layer is provided on the surface of the first base material, the side of the second base material is placed on the adsorption machine used for back grinding. Because the second substrate is relatively soft, it can be easily adhered to the adsorption machine and prevent the adhesive tape from curling.

[Manufacturing method of semiconductor device] The adhesive tape of the present invention is particularly suitable for use when attaching to the surface of a semiconductor wafer in a pre-dicing method and performing back grinding of the wafer. As a non-limiting usage example of the adhesive tape, a method of manufacturing a semiconductor device will be described more specifically below.

Specifically, the method of manufacturing a semiconductor device includes at least the following steps 1 to 4. Step 1: a step of forming trenches from the surface side of the semiconductor wafer; Step 2: a step of attaching the above-mentioned adhesive tape to the surface of the semiconductor wafer; Step 3: Grinding the semiconductor wafer with the adhesive tape attached on the surface and forming the above-mentioned grooves from the back side, removing the bottom of the grooves, and singulating into a plurality of wafers; and Step 4: A step of peeling off the adhesive tape from the singulated semiconductor wafer (that is, a plurality of semiconductor wafers).

Hereinafter, each step of the manufacturing method of the above-mentioned semiconductor device will be described in detail. (step 1) In step 1, trenches are formed from the surface side of the semiconductor wafer. The trench formed in this step is a trench whose depth is shallower than the thickness of the semiconductor wafer. The trenches can be formed by dicing using a conventionally known wafer dicing device or the like. In addition, in step 3 described later, the semiconductor wafer is divided into a plurality of semiconductor wafers along the trench by removing the bottom of the trench. (step 2) In step 2, the adhesive tape of the present invention is pasted on the surface of the semiconductor wafer formed with the groove through the adhesive layer.

The semiconductor wafer used in this manufacturing method may be a silicon wafer, and may also be a gallium-arsenic wafer, a glass wafer, a sapphire wafer, or the like. The thickness of the semiconductor wafer before grinding is not particularly limited, but is usually about 500 to 1000 μm. Also, a semiconductor wafer generally has circuits formed on its surface. Forming circuits on the wafer surface can be performed using various methods including conventional methods such as etching method, lift-off method, doctor blade method and the like.

The semiconductor wafer on which the adhesive tape is attached and the groove is formed is placed on the adsorption machine, and is sucked and held by the adsorption machine. At this time, the surface side of the semiconductor wafer system is placed on the machine side and sucked.

(step 3) After step 1 and step 2, the back surface of the semiconductor wafer on the adsorption machine is ground, and the semiconductor wafer is singulated into a plurality of semiconductor wafers. Here, when the trenches are formed on the semiconductor wafer, the backside grinding is performed so that the semiconductor wafer is thinned to at least the bottom of the trenches. By this back grinding, the trench becomes a kerf penetrating the wafer, and the semiconductor wafer is divided and singulated into individual semiconductor wafers by the kerf.

The shape of the singulated semiconductor wafer may be square or elongated such as a rectangle. Also, the thickness of the singulated semiconductor wafer is not particularly limited, but is preferably about 5 to 100 μm, more preferably 10 to 45 μm. Also, the size of the singulated semiconductor wafer is not particularly limited, and the size of the wafer is preferably less than 50 mm ² , preferably less than 30 mm ² , more preferably less than 10 mm ² .

When the adhesive tape of the present invention is used, even such a thin and/or small semiconductor wafer can be prevented from being chipped during back grinding (step 3) and when the adhesive tape is peeled off (step 4). After the back grinding is completed, dry grinding is preferably performed before picking up the wafer.

In back grinding, grinding traces remain on the back of the wafer, and micro chips (fragments) occur at the edge of the wafer, which are the main causes of damage to the bending strength of the wafer. As a result of the thinning and miniaturization of wafers, the wafers are easily damaged and the bending strength is reduced. In order to remove the above-mentioned grinding traces, micro-defects (damages) of the wafer, etc., after backside grinding, it is preferable to remove the damages and increase the bending strength of the wafer by dry grinding without using water at the end. Because no water is used during dry grinding, the wafers get hot. The heat of the die is transferred to the adhesive tape. As a result, during dry polishing, the temperature of the base material becomes 60° C. or higher, and curling occurs at the end of the adhesive tape, which may cause the wafer to peel off. However, by using the adhesive tape of the present invention, the deformation of the adhesive tape can be suppressed, and peeling of the wafer can be reduced. Thus, the adhesive tape of the present invention is particularly suitable for holding semiconductor wafers, wafers, etc. in a pre-dicing process involving a dry grinding step.

(step 4) Next, the adhesive tape for semiconductor processing is peeled off from the singulated semiconductor wafer (that is, a plurality of semiconductor wafers). This step is performed, for example, using the following method. First, when the adhesive layer of the adhesive tape is formed of an energy ray-curable adhesive, the energy ray is irradiated to harden the adhesive layer. Next, a pick-up tape is attached to the back side of the singulated semiconductor wafer, and the position and direction are aligned so that it can be picked up. At this time, the ring-shaped frame arranged on the outer peripheral side of the wafer is also bonded to the pick-up tape, and the outer peripheral edge portion of the pick-up tape is fixed to the ring-shaped frame. The pick-up tape can be attached to the wafer and the ring frame at the same time, or it can be attached in different timings. Next, the adhesive tape is peeled off from the plurality of semiconductor wafers fixed on the pick-up tape.

Subsequently, a plurality of semiconductor wafers on the pick-up tape are picked up, and the semiconductor wafers are fixed on a substrate or the like to manufacture a semiconductor device. Moreover, the pick-up tape is not specifically limited, For example, it can be comprised with the adhesive sheet provided with the base material and the adhesive agent layer provided in one surface of the base material.

Moreover, it is also possible to use an adhesive tape instead of a pick-up tape. Adhesive tapes include a laminate of a film adhesive and a release sheet, a laminate of a dicing tape and a film adhesive, and one composed of an adhesive layer and a release sheet that have both the functions of a dicing tape and a die bonding tape. Dicing‧Die bonding tape, etc. In addition, before the pick-up tape is attached, a film-like adhesive may be attached to the back side of the singulated semiconductor wafer. When a film adhesive is used, the film adhesive may have the same shape as the wafer.

When using an adhesive tape, before attaching a pick-up tape, etc., when attaching a film-like adhesive to the rear side of a singulated semiconductor wafer, pick up multiple semiconductors on the adhesive tape, pick-up tape, etc. The wafer and the adhesive layer are divided into the same shape as the semiconductor wafer. Then, the semiconductor wafer is fixed on a substrate or the like through an adhesive layer to manufacture a semiconductor device. The division of the adhesive layer can be performed using a laser, an expander, or the like.

Above, the adhesive tape of the present invention has mainly been described as an example in which a semiconductor wafer is separated into pieces using a pre-dicing method. However, the adhesive tape of the present invention can also be used for general back grinding, and can also be used Used to temporarily fix the workpiece during processing of glass, ceramics, etc. Moreover, various re-peelable adhesive tapes can also be used. Example

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

The measurement method and evaluation method in the present invention are as follows. [TMA Value] A film for measurement of 15 mm (width)×10 mm (length) formed of the same material as the film or sheet constituting the substrate was prepared. Using 4000SA manufactured by BRUKER, the elongation or contraction (TMA value) of the film for measurement was measured under the conditions of a load of 2 g and a heating rate of 5° C./min, and the value at 60° C. was set as the 60° C. TMA value. Measurement conditions other than the above are set according to the operation manual of the measurement device. The measurement was performed for 10 samples, and the average value of the obtained TMA values was calculated. [Rate of Dimensional Change] A 10 cm x 10 cm measurement film made of the same material as the film or sheet constituting the substrate was prepared. The dimensions of the film for measurement are values measured at 23°C. The sample for measurement was left to stand at 60° C. for 3 minutes on a heating platform. Then, after cooling to room temperature (23°C), the length of one side at 23°C before heating (10cm: L ₀ ) and the length of the same side at 23°C after heating (L ₁ ) are as follows The formula to obtain the size change rate. The measurement was performed on 10 samples, and the average value of the obtained dimensional change rates was calculated. In addition, the measured value uses the measured value of MD direction. Dimensional change rate (%)=100×(L ₀ -L ₁ )/L ₀

[Tensile elastic modulus] A film for measurement of 15 mm (width)×10 mm (length) made of the same material as the film or sheet constituting the base material was prepared. Using a dynamic viscoelasticity device (manufactured by ORIENTEC, trade name "Rheovibron DDV-II-EP1"), under the conditions of a frequency of 11 Hz and a temperature range of -20 to 150°C, the tensile modulus of the film for measurement was measured for 10 a sample. Set the average value of the tensile modulus at 23°C as E ₂₃ and the average value of the tensile modulus at 60°C as E ₆₀ to obtain the tensile strength from 23°C to 60°C. The rate of change of the modulus of elasticity E _(23-60) (%).

[Young's modulus of the first substrate] The Young's modulus of the first base material was measured in accordance with JIS K-7127 (1999) under the condition of a test speed of 200 mm/min.

[The modulus of elasticity of the second substrate and the maximum value of tanδ] Except that a release sheet (manufactured by Lintec Co., Ltd., trade name "SP-PET381031", thickness: 38 μm) was used instead of the first base material, and the thickness of the obtained second base material was 200 μm, the following examples, The second base material for the test was produced in the same manner as the second base material of the comparative example. After removing the peeling sheet on the second base material for the test, use a test piece cut into a predetermined size, and use a dynamic viscoelasticity device (manufactured by ORIENTEC, trade name "Rheovibron DDV-II-EP1") in the The loss elastic modulus and storage elastic modulus were measured under the condition of frequency 11Hz and temperature range -20～150°C. Calculate the value of "loss elastic modulus/storage elastic modulus" at each temperature as tan δ at that temperature, and set the maximum value of tan δ in the range of -5 to 120°C as "tan δ of the second base material maximum value".

[Stress Relaxation Ratio of Second Base Material] In the same manner as above, the second base material for the test was prepared on a release sheet and cut into 15 mm×140 mm to form a sample. Using a universal tensile testing machine (AUTOGRAPH AG-10kNIS manufactured by SHIMADZU Co., Ltd.), hold both ends of the sample at 20 mm and stretch it at a speed of 200 mm per minute to measure the stress A (N/m ² ), and the stress B (N/m ² ) after 1 minute from the stop of stretching of the tape. Calculate (A-B)/A×100(%) from the values of these stresses A and B as the stress relaxation rate.

[Peel off evaluation] The adhesive tape with release sheet obtained in Examples and Comparative Examples was installed in a tape lamination machine (manufactured by Lintec Co., Ltd., trade name "RAD-3510") while peeling off the release sheet, and attached under the following conditions: Attached to a 12-inch silicon wafer (thickness 760 μm) with grooves formed on the wafer surface by pre-dicing. Roller height: 0mm Roller temperature: 23°C (room temperature) Machine temperature: 23°C (room temperature) The obtained adhesive tape-attached silicon wafers were singulated into pieces with a thickness of 30 μm and a wafer size of 1 mm square using backside grinding (pre-dicing method). After the back grinding was completed, the ground surface was ground using DPG8760 manufactured by DISCO Corporation. As a grinding wheel, "Gettering DP" manufactured by DISCO was used. Damaged portions (grinding traces, fragments) of the wafer are removed by this polishing. After dry grinding, check whether there is any deformation at the end of the adhesive tape and the number of wafers held at the end of the adhesive tape. The deformation of the end of the adhesive tape was evaluated according to the distance between the adhesive tape and the suction machine, and when there was a space between the adhesive tape and the suction machine, it was evaluated as defective. Furthermore, when the group of wafers held by the adhesive tape was observed and the peeled wafers could be confirmed, it was rated as defective.

In addition, all the parts by mass of the following examples and comparative examples are solid content values.

[Example 1] (1) The first substrate A polyethylene terephthalate film (Young's modulus: 2500 MPa) having a thickness of 50 μm was prepared as a first base material.

(2) Second substrate (Synthesis of urethane acrylate oligomer) The terminal isocyanate urethane prepolymer obtained by reacting polyester diol with isophorone diisocyanate is reacted with 2-hydroxyethyl acrylate to obtain a bifunctional polymer with a mass average molecular weight (Mw) of 5000. Urethane acrylate oligomer (UA-1).

(Preparation of the second substrate-forming composition) 40 parts by mass of the urethane acrylate oligomer (UA-1) synthesized above, 40 parts by mass of isocamphoryl acrylate (IBXA), and 20 parts by mass of phenylhydroxypropyl acrylate (HPPA) were prepared, and A second substrate-forming composition was prepared as 2.0 parts by mass of hydroxycyclohexyl phenyl ketone (manufactured by BASF Corporation, product name "IRGACURE 184"), which is one of the photopolymerization initiators, and 0.2 parts by mass of a phthalocyanine pigment.

(3) Laminated substrate. The composition for forming the second substrate obtained above was coated on one side of the first substrate, and the ultraviolet ray was irradiated under the conditions of an illuminance of 160 mW/cm ² and an irradiation dose of 500 mJ/cm ² . The composition for forming the second base material was cured to obtain a laminated base material having a second base material with a thickness of 30 μm on the first base material.

(4) Preparation of adhesive composition Acrylic polymer (b) obtained by copolymerizing 65 parts by mass of butyl acrylate (BA), 20 parts by mass of methyl methacrylate (MMA), and 15 parts by mass of 2-hydroxyethyl acrylate (2HEA), Energy ray-curable acrylic resin ( Mw: 500,000).

To 100 parts by mass of the energy ray-curable acrylic resin, 6 parts by weight of polyfunctional urethane acrylate (trade name: SHIKOH UT-4332, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), an isocyanate As a cross-linking agent (manufactured by TOSOH Co., Ltd., trade name: CORONATE L), a photonite composed of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide with a solid content of 0.375 parts by mass was used. The coating liquid of the adhesive composition was prepared by diluting 1 weight part of polymerization initiators with a solvent.

(5) Manufacture of adhesive tape The above-obtained adhesive composition coating solution was applied to the release-treated surface of a release sheet (manufactured by Lintec Co., Ltd., trade name: SP-PET381031) so that it would become a thickness of 20 μm after drying, and heated. It dries to form an adhesive layer on the release sheet. The adhesive layer was attached to the surface of the first substrate of the laminated substrate to obtain an adhesive tape with a release sheet. In addition, the storage elastic modulus of the adhesive layer at 23° C. was 0.15 MPa. In addition, the storage elastic modulus at 23°C of the second base material was 250 MPa, the stress relaxation rate was 90%, and the maximum value of tan δ was 1.24.

[Example 2] Except using a composite film (thickness 80 μm) of low-density polyethylene 27.5 μm/polyethylene terephthalate 25 μm/low-density polyethylene 27.5 μm as the substrate instead of the laminated substrate, it was obtained in the same manner as in Example 1. Adhesive tape.

[Comparative example 1] Except having used a commercially available polyvinyl chloride film (thickness 80 micrometers) instead of a laminated base material as a base material, it carried out similarly to Example 1, and obtained the adhesive tape.

[Comparative example 2] An adhesive tape was obtained in the same manner as in Example 1, except that NEWCREL (registered trademark: Mitsui DUPONT FLUOROCHEMICALS) of an ethylene/methacrylic acid copolymer film (thickness 80 μm) was used instead of the laminate base material.

The characteristic evaluation of the base material used in the Example and the comparative example was performed, and peeling evaluation was performed using each adhesive tape. The results are shown in Table 1.

[Table 1]

From the above results, it can be seen that when the absolute value of the 60°C TMA value is 30 μm or less, the adhesive tape can hold the wafer well without deformation even if dry grinding is performed. Furthermore, it was confirmed that good results can be obtained when the absolute value of the TMA value at 60°C is 30 μm or less by tests using the adhesive tapes described in detail in Examples and Comparative Examples, and various adhesive tapes. Similarly, the absolute value of the dimensional change rate at 60°C for 3 minutes and the elastic modulus change rate E _(23-60) (%) can be confirmed to be 0.8% or less and 30% respectively by tests using various adhesive tapes Favorable results can be obtained with the following conditions.

none.

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Claims (7)

An adhesive tape, which is an adhesive tape comprising a base material and an adhesive layer disposed on one side of the base material, the base material is a base body of a first base material and a second base material, and the Young's mold of the first base material is The number is above 1000MPa, and the absolute value of the 60°C TMA (Thermomechanical Analyzer) value of the above-mentioned substrate is 30 μm or less, wherein the above-mentioned 60°C TMA value is 15mm (width)×10mm (length) formed of the same material as the substrate ) measurement film, the elongation or contraction of the measurement film was measured with 4000SA manufactured by BRUKER under the conditions of a load of 2 g and a heating rate of 5 °C/min, and the value at 60 °C was set as the 60 °C TMA value. The adhesive tape described in claim 1 of the patent application, wherein the absolute value of the dimensional change rate is 0.8% or less after the aforementioned base material is kept at 60°C for 3 minutes, wherein the aforementioned dimensional change rate is determined by the same method as that of the base material The measurement value (L ₀ ) of a 10cm×10cm measurement film formed by the material at 23°C is the length of one side in the MD direction. The length of the same side (L ₁ ) up to room temperature (23°C), and the dimensional change rate obtained according to the following formula: dimensional change rate (%)=100×(L ₀ -L ₁ )/L ₀ . The adhesive tape as described in claim 1 or 2, wherein the elasticity obtained from the tensile modulus (E ₂₃ ) and the tensile modulus (E ₆₀ ) of the aforementioned substrate at 23°C Modulus change rate E _(23-60) is 30% or less. Adhesive tape as described in item 1 or 2 of the patent application, wherein the second base material is at 23°C The storage elastic modulus is 100~1500MPa. The adhesive tape as described in item 1 or 2 of the scope of the patent application, wherein the adhesive tape is made of an alicyclic group with urethane (meth)acrylate (a1) and ring-forming atoms of 6-20 or The composition for forming the second base material of the heterocyclic polymerizable compound (a2). A method of manufacturing a semiconductor device, comprising the steps of: forming a groove from the surface side of a semiconductor wafer; attaching the adhesive tape described in any one of items 1 to 4 of the scope of application to the aforementioned semiconductor wafer The step of surface; the step of grinding the semiconductor wafer with the above-mentioned adhesive tape on the surface and forming the above-mentioned groove from the back side, removing the bottom of the above-mentioned groove, and singulating into a plurality of wafers; The step of stripping the adhesive tape from the aforementioned plurality of wafers. The method for manufacturing a semiconductor device as described in claim 6, which includes the step of performing dry grinding after the aforementioned semiconductor wafer is singulated into semiconductor wafers.