KR20180132813A - Pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer and method for processing the semiconductor wafer - Google Patents

Abstract

A pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer, which is applied to a surface of a semiconductor wafer having a concavo-convex car with a thickness of 20 m or more under a condition of 40 占 폚 to 90 占 폚, Wherein a thickness of the intermediate resin layer is not less than the irregularities and a melting point or a Vicat softening point of the resin constituting the intermediate resin layer is 40 to 90 DEG C , And the melt mass flow rate of the resin constituting the intermediate resin layer is 10 g / min to 100 g / min, and a method of processing a semiconductor wafer using the adhesive tape.

Description

Pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer and method for processing the semiconductor wafer

The present invention relates to a pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer and a method of processing the semiconductor wafer.

The semiconductor package is manufactured by slicing a high-purity silicon single crystal or the like into a semiconductor wafer, forming an integrated circuit on the wafer surface by ion implantation, etching, or the like. By grinding or polishing the back surface of a semiconductor wafer on which an integrated circuit is formed, the semiconductor wafer is processed to a desired thickness. At this time, in order to protect the integrated circuit formed on the surface of the semiconductor wafer, a pressure sensitive adhesive tape for protecting the surface of the semiconductor wafer (hereinafter, simply referred to as "surface protective tape") is used.

The back side semiconductor wafer is housed in a wafer cassette after the back side grinding is finished, is carried in the dicing step, and is processed into a semiconductor chip.

Conventionally, it has been required to reduce the thickness of a semiconductor wafer to about 200 to 400 mu m by back grinding or the like. However, with the recent advances in high-density mounting technology, there is a need to downsize the semiconductor chip, and along with this, the thinning of the semiconductor wafer is progressing. It has become necessary to reduce the thickness of the semiconductor wafer to about 100 mu m depending on the type of the semiconductor chip. On the other hand, in order to increase the number of semiconductor chips that can be manufactured by a single process, the original semiconductor wafer tends to be large-sized. Until now, semiconductor wafers having diameters of 5 inches or 6 inches were mainstream, but in recent years, machining of semiconductor wafers having diameters of 8 to 12 inches into semiconductor chips has become mainstream.

The flow of thinning and curing the semiconductor wafer at the same time is particularly remarkable in the field of flash memory in which NAND type or NOR type exists and in the field of DRAM which is a volatile memory. For example, it is not uncommon to grind a semiconductor wafer having a diameter of 12 inches to a thickness of 150 m or less.

In addition to this, particularly in wafers used for flip chip mounting using an electrode portion with an electrode portion taking account of impact resistance and the like, along with the popularization of smart phones, the improvement of the performance of cellular phones, the miniaturization of music players, and the improvement of performance, Is increasing. In addition, it is necessary to perform thin film grinding of a semiconductor wafer portion with a bump portion of 100 占 퐉 or less even for a semiconductor wafer. The bumps to be flip-chip bonded have been densified to improve the transfer speed, and the height of the bumps (protruding height from the surface of the semiconductor wafer) is lowered, and the distance between the bumps is shortened accordingly. In addition, since flip-chip connection is recently made in DRAM, wafer thinning is also accelerated.

Flip chip mounting has attracted attention as a method capable of mounting a semiconductor device with a minimum area for the recent miniaturization and high density of electronic devices. The bumps are formed on the electrodes of the semiconductor element used in the flip chip mounting, and the bumps and the wiring on the circuit board are electrically connected. As the composition of these bumps, mainly solder or gold is used. This solder bump or gold bump is formed on an exposed aluminum terminal or the like which is connected to the internal wiring of the chip by vapor deposition or plating.

However, since the bump-part semiconductor wafer has large irregularities on the surface thereof, it is difficult to form a thin film, and if the back side grinding is performed using a normal surface protection tape, cracks occur in the semiconductor wafer or the thickness precision of the semiconductor wafer deteriorates do. For this reason, the grinding of the semiconductor wafer in the bump portion is performed by using a specially designed surface protective tape (see, for example, Patent Document 1).

However, in these surface protective tapes, since the bumps are sufficiently absorbed to secure the grinding property, the peeling performance is very difficult to be compatible with each other. The finished thickness of the flip-chip mounted chips so far has been 200 μm or more in thickness, has a certain thickness, and can maintain the rigidity, so that it can somehow be peeled off. However, in recent years, since the finished thickness of the semiconductor wafer has become thinner and the bump density has become higher, the surface protection tape is not easy to peel off and causes a problem of adhesive material remaining. On the other hand, if the peelability is ensured, the adhesion becomes insufficient and seepage (for example, invasion of dust or grinding water) is caused at the time of grinding the back surface.

On the other hand, the bump portion used in the wafer level package still has a high bump height, and a bump having a height of 250 탆 or more is also mounted. In the wafer level package, since it is not necessary to stack the chips, it is hardly grinded to a thickness of 50 mu m or less like a memory semiconductor wafer. However, since it is provided with a high bump, The problem of cracking of the semiconductor wafer easily occurs at the grinding thickness below.

A dedicated surface protection tape for such semiconductor wafers has been proposed (see Patent Documents 2 to 4). Patent document 2 discloses a pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer which is firmly adhered to a semiconductor wafer at the time of processing a semiconductor wafer and can peel off without peeling the semiconductor wafer or leaving a sticky substance at the time of peeling. The surface protective tape has a radiation curing type pressure-sensitive adhesive layer on the base film with the layer thickness and shrinkage value within a specific range. Patent Document 3 discloses a surface protecting adhesive tape used for back grinding of a bump wafer having a high bump height. In the case of grinding a wafer, it is possible to prevent damage to the wafer and to prevent wafer seepage, A pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer is disclosed. The surface protective tape has a specific tacking force and a layer thickness. Patent Document 4 discloses a method of grinding the back surface of a wafer up to a height difference between concavities and convexities formed on the surface of the wafer to prevent unevenness on the surface of the wafer and to prevent intrusion of grinding chips or grinding water onto the surface of the wafer, A method of attaching a pressure-sensitive adhesive sheet for protecting a semiconductor wafer capable of preventing breakage of a semiconductor wafer is disclosed. The surface protective sheet used in this method has an intermediate layer and a pressure-sensitive adhesive layer having a loss tangent in a specific range at 50 ° C to 100 ° C.

Japanese Laid-Open Patent Publication No. 2001-203255 Japanese Patent Publication No. 5242830 Japanese Patent Publication No. 5117630 Japanese Patent Application Laid-Open No. 2010-258426

In the surface protective tape described in Patent Document 2, breakage of the semiconductor wafer and residual adhesive material can be suppressed to a certain extent. In addition, the surface protective tape described in Patent Document 3 has good releasability. However, in order to apply the present invention to a semiconductor wafer having a higher bump at a narrower pitch, the surface protective tape described in Patent Document 2 has a room for further improvement in peelability and residual adhesive. In addition, the surface protective tape described in Patent Document 3 has a possibility to further improve the adhesion, suppress the seed papers, and improve the residual adhesive material.

The surface protective tape used in the method described in Patent Document 4 has extremely good followability. Therefore, when the bump with a height of 250 탆 or more is followed, the tape is deformed into the concavo-convex shape, The wafer may fall and be damaged.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a method of manufacturing a semiconductor wafer which firmly adheres to a semiconductor wafer during processing of a semiconductor wafer to suppress seepage and conveying errors in the processing apparatus and semiconductor wafer breakage, Sensitive adhesive tape for protecting a surface of a semiconductor wafer which can be peeled off without peeling off the surface of the semiconductor wafer.

In order to solve the above problems, the inventors of the present invention have conducted intensive studies. As a result, the present inventors have found that, in a pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer having a base film, an intermediate resin layer and a pressure- The Vicat softening point and the melt mass flow rate (MFR) are each set within a specific range and the surface protection tape is heated and bonded to the surface of the semiconductor wafer having a specific roughness at a specific temperature It is possible to firmly adhere the surface protection tape to the circuit surface of the semiconductor wafer. When the semiconductor wafer is processed, it is possible to suppress the transfer error in the semiconductor wafer, the semiconductor wafer breakage in the processing apparatus, It is possible to peel off the adhesive material without remaining, and to suppress the warping in the state of being adhered to the surface of the semiconductor wafer I found something I could do. The present invention has been successful on the basis of this finding.

That is, the above problem has been solved by the following means.

<1>

A pressure-sensitive adhesive tape for surface protection of a semiconductor wafer, which is applied to the surface of a semiconductor wafer having a concavo-convex car of 20 占 퐉 or more by heating under a condition of 40 占 폚 to 90 占 폚,

Wherein the pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer has a base film, a pressure-sensitive adhesive layer, and an intermediate resin layer between the base film and the pressure-

Wherein the thickness of the intermediate resin layer is not less than the irregularities and the melting point or the Vicat softening point of the resin constituting the intermediate resin layer is from 40 to 90 DEG C and the melt mass flow rate of the resin constituting the intermediate resin layer is , And 10 g / min to 100 g / min.

&Lt; 2 &

The adhesive strength of the pressure-sensitive adhesive layer after ultraviolet irradiation to the SUS 280 polished surface at 23 캜 was 0.5 N / 25 mm or more and 5.0 N / 25 mm or less, and the adhesive strength to the SUS 280 polished surface at 50 캜 was 0.3 N / A pressure-sensitive adhesive tape for surface protection of a semiconductor wafer according to < 1 >

&Lt; 3 &

Wherein the ratio of the thickness of the base film to the thickness of the intermediate resin layer is from 0.5 to 9.5 to 7: 3, .

&Lt; 4 &

The resin composition according to any one of <1> to <3>, wherein the resin constituting the intermediate resin layer is at least one of ethylene-methyl acrylate copolymer resin, ethylene-ethyl acrylate copolymer resin and ethylene-acrylic acid butyl copolymer resin Sensitive adhesive tape for protecting a surface of a semiconductor wafer.

&Lt; 5 &

The pressure-sensitive adhesive tape for surface protection of a semiconductor wafer according to any one of <1> to <4>, wherein the constituent material of the base film has a melting point of 90 ° C to 150 ° C.

&Lt; 6 &

The pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer according to any one of <1> to <5>, wherein the thickness of the intermediate resin layer is 100 μm to 400 μm.

&Lt; 7 &

The pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer according to any one of <1> to <6>, wherein the thickness of the pressure-sensitive adhesive layer is 5 μm to 40 μm.

&Lt; 8 &

The pressure-sensitive adhesive tape for surface protection of a semiconductor wafer according to any one of < 1 > to < 7 >, wherein the base film has a thickness of 25 mu m to 100 mu m.

&Lt; 9 &

A method of processing a semiconductor wafer including a step of heating and bonding a pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer to a surface of a semiconductor wafer having a concavo-convex car having a thickness of 20 탆 or more at 40 캜 to 90 캜,

Wherein the pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer has a base film, a pressure-sensitive adhesive layer, and an intermediate resin layer between the base film and the pressure-

Wherein the thickness of the intermediate resin layer is not less than the irregularities and the melting point or the Vicat softening point of the resin constituting the intermediate resin layer is from 40 to 90 DEG C and the melt mass flow rate of the resin constituting the intermediate resin layer is , And 10 g / min to 100 g / min.

In the description of the present invention, the surface of the semiconductor wafer means a surface having irregularities of the semiconductor wafer, that is, the surface on which the integrated circuit is formed. The surface on the opposite side of the surface is referred to as the back surface.

In the description of the present invention, the irregularity means the distance from the highest portion of the convex portion to the wafer surface or the distance from the deepest portion of the concave portion to the surface of the semiconductor wafer. For example, when a metal electrode (bump) is formed on a semiconductor wafer, the highest part is the top part of the highest bump, and the distance from the surface to the surface of the semiconductor wafer, that is, the height of the bump is irregular. Alternatively, in the case where a scribe line (dicing line) is formed on a semiconductor wafer, the deepest portion is the deepest position among the scribe lines, and the distance from the scribe line to the surface of the semiconductor wafer is called a concavo-convex difference.

In the description of the present invention, the numerical value range indicated by "~" means a range including numerical values before and after "~" as a lower limit value and an upper limit value.

INDUSTRIAL APPLICABILITY The adhesive tape for protecting a surface of a semiconductor wafer of the present invention can firmly adhere to a semiconductor wafer when the semiconductor wafer is processed, thereby reducing the generation of seed papers and suppressing a conveying error or semiconductor wafer breakage in the processing apparatus , It is difficult for the adhesive material to remain when peeling off. Further, the pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer of the present invention can suppress warping in a state of being adhered to a surface of a semiconductor wafer. Further, according to the method for processing a semiconductor wafer of the present invention, it is possible to obtain a semiconductor wafer in a thin film state having a high bump at a narrow pitch by using the adhesive tape for protecting the surface of the semiconductor wafer.

1 is a schematic cross-sectional view schematically showing a pressure-sensitive adhesive tape for wafer surface protection of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail.

[Adhesive tape for protecting the surface of a semiconductor wafer]

A pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer according to the present invention is a pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer, which is applied to a surface of a semiconductor wafer having a concavo- A base film and a pressure-sensitive adhesive layer, and at least an intermediate resin layer between the base film and the pressure-sensitive adhesive layer. The thickness of the intermediate resin layer is not less than the irregularities. The melting point or the Vicat softening point of the resin constituting the intermediate resin layer is 40 to 90 占 폚 and the melt mass flow rate of the intermediate resin layer is 10 g / min to 100 g / min.

The pressure-sensitive adhesive layer is not particularly limited, but a radiation-curing pressure-sensitive adhesive layer is preferable. The radiation-curable pressure-sensitive adhesive layer is a layer in which radiation is radiated (for example, ] Of the pressure-sensitive adhesive layer. The radiation to be irradiated is preferably ultraviolet radiation.

<Base film>

The base film used in the pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer of the present invention is not particularly limited. In the pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer of the present invention, the melting point of the material constituting the base film is preferably in the range of 90 占 폚 to 150 占 폚, more preferably in the range of 100 占 폚 to 140 占 폚, Range is more preferable. Since the melting point of the base film is in the above-mentioned range, fusion bonding to the fusing roller or the chuck table is prevented in the step of bonding the surface protective tape, and it is possible to sufficiently bond the semiconductor wafer to the semiconductor wafer having unevenness of 20 占 퐉 or more. Further, even when the dicing die-bonding integrated film (DDF) is bonded, adhesion of DDF to the chuck table can be prevented. The pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer of the present invention is characterized in that the flowability of the intermediate resin layer is improved by applying heat to the intermediate resin layer, and a sufficient temperature for a semiconductor wafer having a concavo- Deg.] C to 90 [deg.] C. Accordingly, if the melting point of the material constituting the base film is too low, the back surface of the base film may melt, and the base film may be fused to the kneading roller or the chuck table. In the case where the base film is made of an amorphous resin such as styrene, for example, since the melting point is not present, the Vicat softening point is the index. That is, it is preferable that the Vicat softening point lies within the melting point range. If the Vicat softening point is too high, fluidity may occur in the back side of the substrate (the side opposite to the side in contact with the intermediate resin layer), which may enter the porous portion of the chuck table.

The base film used in the pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer of the present invention is preferably made of a resin, and plastic, rubber and the like which are usually used in the technical field to which the present invention belongs can be used. For example, a polyolefin resin (for example, polyethylene, polypropylene, an ethylene-propylene copolymer, polybutene-1, poly-4-methylpentene-1, ethylene-vinyl acetate copolymer, , A homopolymer or a copolymer of a monomer containing an ethylenic unsaturated group such as an ethylene-methyl acrylate copolymer, an ethylene-acrylic acid copolymer or an ionomer), a polyester resin (for example, polyethylene terephthalate or polyethylene naphthalate (For example, styrene-ethylene-butene or pentene-based copolymer), a thermoplastic elastomer (for example, a thermoplastic elastomer), a polycarbonate resin, a polyurethane resin, an engineering plastic (e.g., polymethylmethacrylate) For example, a polyamide-polyol copolymer). The base film used in the surface protective tape of the present invention may be a film composed of one kind of the resin alone or a film composed of a combination of two or more kinds. Further, the base film used for the surface protective tape of the present invention may be a single layer or a multi-layered base film. In the multi-layered base film, it is preferable that the melting point of the material constituting the outermost layer on the opposite side of the intermediate resin layer is in the above range.

In the surface protective tape of the present invention, the base film is preferably a film made of a polyester resin or a polyolefin-based resin.

The thickness of the base film is preferably 25 占 퐉 or more, more preferably 50 占 퐉 or more, in view of the balance between the warp correcting force of the semiconductor wafer and the peelability of the surface protective tape, cost, The upper limit is preferably 200 占 퐉 or less, more preferably 150 占 퐉 or less, and particularly preferably 100 占 퐉 or less. When the thickness of the base film is in the above range, even when the semiconductor wafer is thin-film-ground to a thickness of 50 탆 or less, grinding can be performed while suppressing transfer errors, and the peelability of the surface protective tape can be improved. In the case of &quot; thin film grinding of a semiconductor wafer at a thickness of 50 m or less &quot; in the case of a semiconductor wafer having bumps, the back side grinding is performed until the thickness of the semiconductor wafer itself is reduced to 50 탆 or less. In the case of a semiconductor wafer on which a scribe line is formed, it means the distance from the deepest portion to the back surface.

<Intermediate resin layer>

In the pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer of the present invention, an intermediate resin layer is essential. The surface protection tape is heated and bonded to the surface of the semiconductor wafer at a temperature of 40 to 90 DEG C to melt the intermediate resin layer and the surface of the semiconductor wafer having the irregularities of 20 mu m or more, The shape follows. Further, since the surface protection tape is fixed in a state in which the pressure-sensitive adhesive layer is in close contact with the surface of the semiconductor wafer, the penetration of dust and the like can be suppressed. The melting point or the Vicat softening point of the resin constituting the intermediate resin layer used in the surface protective tape of the present invention is in the range of 40 캜 to 90 캜 and more preferably in the range of 60 캜 to 80 캜. The tensile modulus of elasticity of the intermediate resin layer needs to be largely changed in this temperature range because it is necessary to heat-adhere the surface protective tape to the surface of the semiconductor wafer in a temperature range of 40 to 90 占 폚 and to adhere the pressure sensitive adhesive layer to the surface of the semiconductor wafer. That is, it is a normal temperature at the time of grinding a semiconductor wafer, and when the resin flows at this temperature, the thickness accuracy at the time of grinding is extremely deteriorated, so that it is preferable that the resin is highly elastic. On the other hand, in order to sufficiently follow the surface of the semiconductor wafer when heating and coalescing, it is necessary to be low-carbon, and therefore, the intermediate resin layer is required to have an opposite performance. In order to realize this opposite performance, it is necessary that the melting point or Vicat softening point, which greatly affects the tensile modulus and fluidity, is 40 to 90 ° C. The melting point and Vicat softening point are measured by the method described in the examples. In the present invention, it is also preferable that both the melting point and the Vicat softening point of the intermediate resin layer are 40 to 90 占 폚.

When the melting point of the resin and the Vicat softening point of the resin constituting the intermediate resin layer are less than 40 占 폚, it is difficult to mold and the thickness precision also deteriorates. That is, the thickness of the intermediate resin layer becomes uneven. On the other hand, when the melting point of the resin and the Vicat softening point of the resin constituting the intermediate resin layer exceed 90 DEG C, the surface of the semiconductor wafer can not sufficiently follow the shape of the surface of the semiconductor wafer even when heated to 40 to 90 DEG C, Wafer cracks are likely to occur.

The resin constituting the intermediate resin layer used in the surface protective tape of the present invention has a melting point or a Vicat softening point of 40 to 90 DEG C and a melt mass flow rate (MFR) of 10 g / min to 100 g / min. The intermediate resin layer having the melting point or the Vicat softening point within the above range can be obtained by bonding the surface protective tape to the semiconductor wafer under the condition of 40 to 90 DEG C as described above to form the intermediate resin layer and the pressure- The shape of the layer follows. As a result, the pressure-sensitive adhesive layer sufficiently adheres to the surface of the semiconductor wafer. However, only when the melting point of the resin or the Vicat softening point of the resin constituting the intermediate resin layer is within the above range, the surface protective tape itself is deformed into a concavo-convex shape if the irregularity difference of the semiconductor wafer is 250 탆 or more, causing conveyance errors. By setting the MFR in the range of 10 g / min to 100 g / min, an appropriate fluidity is generated in the intermediate resin layer at the time of heat application, and the surface protection tape deformed following the unevenness can be returned to a flat state. This makes it possible to prevent a conveying error and breakage due to the falling of the semiconductor wafer. If the melt mass flow rate (MFR) of the intermediate resin layer is less than 10 g / min, fluidity is insufficient and the surface protective tape itself is processed in a deformed state, so that conveyance errors and breakage of the semiconductor wafer occur. On the other hand, when the melt mass flow rate (MFR) of the resin constituting the intermediate resin layer exceeds 100 g / min, film formation (film formation) while maintaining the thickness precision (uniformity of thickness) as a substrate becomes difficult. In addition, the thickness precision of the semiconductor wafer after grinding is deteriorated. In the surface protective tape of the present invention, the melting point or the Vicat softening point of the resin constituting the intermediate resin layer is within the above range, and the MFR is in the range of 10 g / min to 100 g / min. It can be applied to the processing of semiconductor wafers of 250 μm or more. The upper limit of the irregularities of the semiconductor wafer to which the surface protection tape of the present invention can be applied is practically 300 μm or less.

Further, the MFR is measured by the method described in the examples.

Since the intermediate resin layer is not intended to be adhered, non-adhesive property is preferable. Non-tackiness refers to a state without stickiness at room temperature.

As the resin constituting the resin layer or resin film, at least one comonomer selected from, for example, a radical polymerizable acid comonomer, an acrylic acid ester comonomer, a methacrylic acid ester comonomer and a carboxylic acid vinyl ester comonomer, A resin comprising an ethylenic copolymer as a copolymer with ethylene, a resin comprising a homopolymer or a copolymer of a monomer containing an ethylenic unsaturated group such as an ionomer, and a resin comprising polyethylene (for example, low density polyethylene). In the intermediate resin layer used for the surface protective tape of the present invention, these resins may be used singly or in combination of two or more kinds. The intermediate resin layer may have two or more layers.

Specific examples of the radically polymerizable comonomer include?,? - unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid and itaconic acid, or anhydrides thereof, acrylic acid, methacrylic acid, crotonic acid, And unsaturated monocarboxylic acids such as pentenoic acid. Of these, maleic anhydride, acrylic acid and methacrylic acid are preferable.

Specific examples of the acrylic acid ester comonomer include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate and the like. Of these, methyl acrylate, ethyl acrylate and butyl acrylate are preferable.

Specific examples of the methacrylic acid ester comonomer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate and the like. Of these, methyl methacrylate, ethyl methacrylate, desirable.

Specific examples of the carboxylic acid vinyl ester comonomer include vinyl formate, vinyl acetate, vinyl propionate, and vinyl butyrate, among which vinyl acetate is preferable.

Specific examples of the ethylenic copolymer include ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-maleic anhydride copolymer, ethylene-acrylic acid methyl copolymer, ethylene-acrylic acid copolymer Copolymers, ethylene-methyl methacrylate copolymers, ethylene-ethyl methacrylate copolymers, and ethylene-vinyl acetate copolymers.

Examples of the ternary copolymer include ethylene-acrylic acid-methyl acrylate copolymer, ethylene-acrylic acid-ethyl acrylate copolymer, ethylene-acrylic acid-vinyl acetate copolymer, ethylene-methacrylic acid-methyl methacrylate copolymer, ethylene -Ethyl methacrylate-ethyl acetate copolymer, ethylene-methacrylic acid-vinyl acetate copolymer, ethylene-maleic anhydride-methyl acrylate copolymer, ethylene-maleic anhydride-ethyl acrylate copolymer, ethylene-maleic anhydride -Methyl methacrylate copolymer, ethylene-maleic anhydride-ethyl methacrylate copolymer, and ethylene-maleic anhydride-vinyl acetate copolymer.

Further, a multi-component copolymer obtained by combining the comonomers described above is also exemplified.

Among the above copolymers, particularly preferred are ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-maleic anhydride-methyl acrylate Ethylene-maleic anhydride-ethyl acrylate copolymer, ethylene-maleic anhydride-methyl methacrylate copolymer and ethylene-maleic anhydride-ethyl methacrylate copolymer are preferable, and ethylene-methyl acrylate copolymer, ethylene- Ethylene-ethyl acrylate copolymer and ethylene-butyl acrylate copolymer are preferable.

The content of the comonomer in the total mass of ethylene and the comonomer used in the synthesis of the ethylenic copolymer is preferably 10% by mass to 50% by mass, more preferably 15% by mass to 40% by mass.

The intermediate resin layer may be a single layer or a multiple layer as described above. From the standpoint of manufacturability, the multilayer structure is easier to form than a single layer. In the case of a multi-layered structure, the layer on the substrate film side is preferably a resin layer or a resin film made of low-density polyethylene or ethylene-vinyl acetate copolymer, and the rejection rate can be lowered during the film formation of the double- , And can be produced at low cost. The melting point to the Vicat softening point in the case where the intermediate resin layer is a multiple layer indicates the melting point to the Vicat softening point of the resin constituting the layer or the film in contact with the pressure-sensitive adhesive layer.

The method of laminating the resin layer or the resin film is not particularly limited as long as the thickness of the resin layer or the resin film is sufficient and the resin layer or the resin film does not affect the defect. For example, film forming by coextrusion and sticking by an adhesive can be mentioned.

The ratio of the thickness of the base film to the thickness of the intermediate resin layer is preferably in the range of the thickness of the base film: the thickness of the intermediate resin layer = 0.5: 9.5 to 3: 7, Which is preferable in view of the following. The method of laminating the base film and the intermediate resin layer is not particularly limited as long as it does not affect the defects of the integral film, and it is possible to form the film by co-extrusion or sticking with an adhesive.

The thickness of the intermediate resin layer used in the surface protective tape of the present invention needs to be equal to or larger than the unevenness of the semiconductor wafer, but it is preferably 100 占 퐉 to 400 占 퐉 in terms of production and thickness accuracy. If the thickness of the pressure-sensitive adhesive layer is thinner than that of the semiconductor wafer, the pressure-sensitive adhesive layer is not sufficiently adhered to the semiconductor wafer, thereby causing dust intrusion and wafer cracking. The thickness of the intermediate resin layer used in the surface protective tape of the present invention is preferably 10 to 30 占 퐉 thick than that of the semiconductor wafer. If the intermediate resin layer is too thick, the thickness precision of the semiconductor wafer may deteriorate, and the manufacturing cost also increases. Further, when manufacturing a bump portion of a semiconductor wafer with a bump, an error of about 10 mu m is generated, so that if the thickness is 10 mu m in addition to the average bump height, it is possible to follow with margin.

<Pressure-sensitive adhesive layer>

The pressure-sensitive adhesive used in the pressure-sensitive adhesive layer of the surface protective tape of the present invention is not particularly limited, but a radiation-curable pressure-sensitive adhesive is preferred.

The radiation-curing pressure-sensitive adhesive may be cured by radiation and have three-dimensional reticulation properties. The radiation-curing pressure-sensitive adhesive may be roughly divided into 1) an ethylenically unsaturated group (also referred to as an ethylenic double bond as a radiation- (2) a low molecular weight compound having at least two ethylenically unsaturated groups in the molecule (hereinafter, referred to as &quot; radiation polymerizable compound &quot;) with respect to a rubber or a (meth) Molecular weight compound &quot;) and a pressure-sensitive adhesive compounding a photopolymerization initiator.

In the surface protective tape of the present invention, the above-mentioned 2) is preferable.

1) a pressure-sensitive adhesive comprising a base resin having an ethylenic unsaturated group in its side chain

The pressure sensitive adhesive having an ethylenic unsaturated group in the side chain is preferably a (meth) acrylic pressure sensitive adhesive, and more preferably the base resin contains a (meth) acrylic polymer or a (meth) acrylic polymer as a main component.

The term "(meth) acrylic polymer as a main component" means that the content of the (meth) acrylic polymer in the polymer or resin constituting the base resin is at least 50 mass% or more, preferably 80 mass% or more Mass% or less).

The (meth) acrylic polymer has an ethylenic unsaturated group at least in its side chain and can be cured by irradiation with radiation. The (meth) acrylic polymer may also have a functional group such as an epoxy group or a carboxyl group.

The (meth) acrylic polymer having an ethylenically unsaturated group in the side chain may be produced by any method. For example, a (meth) acrylic polymer having a functional group (?) In the side chain and a (meth) acryloyl group, (?) Having a group having an ethylenic unsaturated group such as an acryloyloxy group and an acryloyloxy group and having a functional group (?) Capable of reacting with the functional group (?) Of the side chain of the (meth) acrylic polymer.

The group having an ethylenic unsaturated group may be any group having a non-aromatic ethylenic double bond, but any group may be used, and examples thereof include a (meth) acryloyl group, a (meth) acryloyloxy group, a (meth) acryloylamino group, (Meth) acryloyl group, and (meth) acryloyloxy group are more preferable.

Examples of the functional groups (?) And (?) Include a carboxyl group, a hydroxyl group, an amino group, a sulfonyl group, a cyclic acid anhydride group, an epoxy group and an isocyanate group (-N═C═O).

Here, when one of the functional group (?) And the functional group (?) Is a carboxyl group, a hydroxyl group, an amino group, a sulfonyl group or a cyclic acid anhydride group, the other functional group may be an epoxy group or an isocyanate group. When one of the functional groups is a cyclic acid anhydride group, the other functional group includes a carboxyl group, a hydroxyl group, an amino group, and a sulfuryl group. When one of the functional groups is an epoxy group, the other functional group may be an epoxy group.

As the functional group (?), A carboxyl group and a hydroxyl group are preferable, and a hydroxyl group is particularly preferable.

The (meth) acrylic polymer having a functional group (?) In the side chain is preferably a (meth) acrylic monomer having a functional group (?), Preferably a (meth) acrylic ester (especially having an alcohol group with a functional group It can be obtained by using it as a monomer component.

The (meth) acrylic polymer having a functional group (?) In the side chain is preferably a copolymer, and the copolymerization component is preferably a (meth) acrylic acid alkyl ester, especially a group having a functional group (?) Or an ethylenic unsaturated group (Meth) acrylic acid alkyl ester which is not substituted is preferable.

Examples of the (meth) acrylic esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) (Meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and dodecyl Hexyl acrylate.

The (meth) acrylic acid esters may be used alone, or two or more of them may be used in combination. It is preferable that the alcohol having 5 or less carbon atoms and 6 to 12 carbon atoms are used in combination.

Further, the more the monomer having a large number of carbon atoms in the alcohol moiety is used, the lower the glass transition point (Tg) is, and hence the desired glass transition point can be obtained. In addition to the glass transition point, it is also preferable to blend low molecular weight compounds having carbon-carbon double bonds such as vinyl acetate, styrene and acrylonitrile for the purpose of improving compatibility and various performances. In this case, The content of the monomer component is preferably in the range of 5% by mass or less.

Examples of the (meth) acrylic monomers having a functional group (?) Include acrylic acid, methacrylic acid, cinnamic acid, itaconic acid, fumaric acid, phthalic acid, 2-hydroxyalkyl acrylates, 2-hydroxyalkyl methacrylates, Acrylate, glycol monomethacrylates, N-methylol acrylamide, N-methylolmethacrylamide, allyl alcohol, N-alkylaminoethyl acrylates, N-alkylaminoethyl methacrylates, A part of the isocyanate group of the polyisocyanate compound is reacted with a polyisocyanate compound in the presence of a catalyst such as a catalyst, Those obtained by urethane-forming a monomer having a hydroxyl group or a carboxyl group and an ethylenic unsaturated group, and the like.

Among these, acrylic acid, methacrylic acid, 2-hydroxyalkyl acrylates, 2-hydroxyalkyl methacrylates, glycidyl acrylate and glycidyl methacrylate are preferable, and acrylic acid, methacrylic acid, 2-hydroxyalkyl acrylates and 2-hydroxyalkyl methacrylates are more preferable, and methacrylic acid, 2-hydroxyalkyl acrylates and 2-hydroxyalkyl methacrylates are more preferable.

As the functional group (?) In the compound having an ethylenic unsaturated group and a functional group (?), An isocyanate group is preferable, and for example, a (meth) acrylic acid ester having an isocyanate (-N═C═O) (Meth) acrylic acid alkyl ester substituted with isocyanate (-N = C = O) group is preferable. Examples of such a monomer include 2-isocyanatethyl methacrylate, 2-isocyanatethyl acrylate, and the like.

Preferred examples of the compound other than the isocyanate group of the functional group (?) Include the compounds exemplified as the (meth) acrylic monomers having the functional group (?).

The compound having an ethylenically unsaturated group and a functional group () reacts with a functional group (?) Of the side chain of the polymer, preferably a hydroxyl group, in addition to the (meth) acrylic polymer having a functional group (?) In the side chain, And it is possible to reduce the adhesive force after irradiation with radiation.

In the synthesis of the (meth) acrylic copolymer, ketones, esters, alcohols and aromatics can be used as the organic solvent in the case of carrying out the reaction by solution polymerization. Among them, toluene, ethyl acetate, isopropyl alcohol (Good solvent) of a (meth) acryl-based polymer such as benzene methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone and the like is preferable. As the polymerization initiator, azo-based systems such as α, α'-azobisisobutyronitrile, and organic peroxide-based radical generators such as benzoyl peroxide are usually used. At this time, a catalyst and a polymerization inhibitor can be used in combination according to need, and the (meth) acrylic copolymer having a desired molecular weight can be obtained by controlling the polymerization temperature and the polymerization time. As for controlling the molecular weight, it is preferable to use a solvent such as mercaptan and carbon tetrachloride. Further, this reaction is not limited to solution polymerization, and other methods such as bulk polymerization, suspension polymerization and the like may be used.

The mass average molecular weight of a base resin having an ethylenic unsaturated group in its side chain (preferably a (meth) acrylic copolymer) is preferably about 200,000 to 1,000,000.

When the mass average molecular weight is too large, the pressure-sensitive adhesive after irradiation with radiation is not flexible and embrittled when irradiated with radiation, so that the adhesive material remains on the semiconductor chip surface at the time of peeling. When the mass average molecular weight is too small, the cohesive force before irradiation with the radiation is small and the adhesive force is weak, so that the semiconductor chip can not be sufficiently retained at the time of dicing, and chip scattering may occur. Further, even after the irradiation with radiation, the curing is insufficient, and adhesive material remains on the semiconductor chip surface at the time of peeling. In order to prevent these as much as possible, it is preferable that the mass average molecular weight is 200,000 or more.

In the description of the present invention, the mass average molecular weight is a mass average molecular weight in terms of polystyrene obtained by a conventional method.

The glass transition point of the base resin having an ethylenically unsaturated group in its side chain is preferably -70 to -10 占 폚, and more preferably -50 to -10 占 폚. If the glass transition point is too low, the viscosity of the pressure-sensitive adhesive becomes high and causes sticky material to remain. If the glass transition point is too high, the fluidity becomes insufficient and is hardly fixed on the back surface of the semiconductor wafer. It becomes a cause.

The acid value of the base resin having an ethylenically unsaturated group in its side chain [the number of mg of potassium hydroxide necessary for neutralizing the free fatty acid present in 1 g of the base resin] is preferably 0.5 to 30, more preferably 1 to 20.

The number of mg of potassium hydroxide required for neutralizing the acetic acid bound to the hydroxyl group when 1 g of the base resin is acetylated is preferably 5 to 100, more preferably 10 to 100, 80 is more preferable.

By doing so, the effect of preventing the adhesive material from remaining at the time of peeling off the adhesive tape for protecting the surface of the semiconductor wafer is more excellent.

The preparation of an acidic or hydroxyl group is preferably carried out by reacting a (meth) acrylic polymer having an ethylenic unsaturated group having a functional group (?) In the side chain and an ethylenically unsaturated group capable of reacting with the functional group (? In the step of reacting the compound having a functional group (?), A desired compound can be prepared by leaving unreacted functional groups.

When a base resin having an ethylenically unsaturated group in its side chain is cured by irradiation, a photopolymerization initiator such as isopropylbenzoin ether, isobutylbenzoin ether, benzophenone, phenyldimethoxyacetylbenzene , Hydroxybutyl ketone, chlorotryoxane, dodecyltoxane, dimethylthioxanthone, diethylthioxanthone, benzyldimethylketal,? -Hydroxycyclohexylphenylketone, 2-hydroxymethylphenylpropane and the like can be used .

The blending amount of these photopolymerization initiators is preferably from 0.01 to 10 parts by mass, more preferably from 0.01 to 5 parts by mass, per 100 parts by mass of the base resin. If the blending amount is too small, the reaction is insufficient, and if the blending amount is too large, the amount of the low molecular component is increased, which affects the staining property.

The pressure-sensitive adhesive comprising a base resin having an ethylenic unsaturated group in its side chain preferably contains a crosslinking agent.

Any such crosslinking agent may be used, but a crosslinking agent selected from the group of polyisocyanates, melamine-formaldehyde resins and epoxy resins is preferable.

Among them, in the surface protective tape of the present invention, polyisocyanates are preferable.

The polyisocyanates are not particularly limited and include, for example, 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, 4,4'-diphenyl ether diisocyanate, Aromatic isocyanates such as [2,2-bis (4-phenoxyphenyl) propane] diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, Dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, lysine diisocyanate, and lysine triisocyanate. Specifically, Colonate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) and the like can be used.

Specific examples of the melamine formaldehyde resin include NIKARAK MX-45 (trade name, manufactured by Sanwa Chemical co., LTD.) And Meran (trade name, manufactured by Hitachi Kasei Kogyo Co., Ltd.) Can be used.

As the epoxy resin, TETRAD-X (trade name, manufactured by Mitsubishi Chemical Corporation) can be used.

The blending amount of the crosslinking agent is preferably 0.1 to 10 parts by mass, more preferably 1 to 10 parts by mass, per 100 parts by mass of the base resin.

After the application of the pressure-sensitive adhesive, the base resin forms a crosslinked structure by the crosslinking agent, and the cohesive force of the pressure-sensitive adhesive can be improved.

If the blending amount of the crosslinking agent is too small, the effect of improving the cohesive force is not sufficient, so that the flowability of the pressure-sensitive adhesive is high and the adhesive material remains. If the blending amount of the crosslinking agent is too large, the elastic modulus of the pressure-sensitive adhesive becomes too high, and the surface of the semiconductor wafer can not be protected.

2) a pressure-sensitive adhesive containing a radiation-polymerizable low molecular weight compound

The main component of the pressure-sensitive adhesive containing the radiation-polymerizable low-molecular weight compound is not particularly limited, and examples thereof include a conventional chlorinated polypropylene resin, an acrylic resin [(meth) acrylic resin], a polyester resin, a polyurethane resin, Resin or the like can be used.

In the surface protective tape of the present invention, as the base resin of the pressure-sensitive adhesive, an acrylic resin [(meth) acrylic resin] is preferable, and a functional group (?) Is added to the side chain which is a raw material in the synthesis of the base resin having an ethylenically unsaturated group in the above- ) Is particularly preferable as the (meth) acrylic polymer.

As the pressure-sensitive adhesive in this case, it is preferable to prepare a pressure-sensitive adhesive by appropriately blending a photopolymerization initiator, a curing agent or a crosslinking agent in addition to an acrylic resin as a base resin and a radiation-polymerizable low molecular weight compound.

The mass average molecular weight of the base resin of the pressure-sensitive adhesive is preferably about 200,000 to 2,000,000.

The pressure-sensitive adhesive preferably contains at least one oligomer having a mass average molecular weight of 1,000 to 20,000 in addition to the base resin. The mass average molecular weight of the oligomer is more preferably 1,100 to 20,000, more preferably 1,300 to 20,000, and particularly preferably 1,500 to 10,000.

The radiation-polymerizable low-molecular weight compound is preferably a compound having at least two ethylenically unsaturated groups (radiation polymerizable carbon-carbon double bonds) in the molecule and capable of being three-dimensionally reticularized by irradiation with radiation, (Preferably a hydroxyl group) is used.

In particular, in the surface protective tape of the present invention, it is preferable that the oligomer is a radiation-polymerizable low molecular weight compound having an ethylenic unsaturated group.

Specific examples of the radiation-polymerizable low molecular weight compound include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol monohydroxy Butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol (meth) acrylate, dipentaerythritol hexa Acrylate and (meth) acrylate compounds such as oligoester (meth) acrylate are applicable.

In addition to the above (meth) acrylate compounds, urethane (meth) acrylate oligomers may also be used as the radiation-polymerizable low molecular weight compounds. The urethane (meth) acrylate oligomer is obtained by reacting a polyol compound such as polyester type or polyether type with a polyisocyanate compound (for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, (Meth) acrylate having a hydroxy group (for example, methyl (meth) acrylate diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4-diisocyanate) (For example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, polyethylene glycol acrylate, polyethylene glycol methacrylate ).

The radiation-polymerizable low molecular weight compounds may be used singly or in combination of two or more.

The radiation-curable pressure-sensitive adhesive may contain a photopolymerization initiator in accordance with necessity. The photopolymerization initiator is not particularly limited as long as it reacts with radiation transmitted through the substrate, and conventional ones can be used. Examples thereof include benzophenones such as benzophenone, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone and 4,4'-dichlorobenzophenone, acetophenone, diethoxyacetophenone, Benzoin ethyl ether, benzoin isopropyl ether, benzyl, 2, 3-diethoxyacetophenone and 2-ethylhexanoic acid; 4,5-triarylimidazole dimer (lopin dimer), acridine-based compound, acylphosphine oxides, and the like. These may be used alone or in combination of two or more.

The amount of the photopolymerization initiator to be added is preferably from 0.1 to 10 parts by mass, more preferably from 0.3 to 7.5 parts by mass, further preferably from 0.5 to 5 parts by mass, per 100 parts by mass of the base resin. If the addition amount of the photopolymerization initiator is too large, radiation curing will occur at multiple points and suddenly occur, so that the radiation curing shrinkage becomes large, so that the amount of the photopolymerization initiator is reduced compared with the conventional radiation curing type surface protecting adhesive tape. It is useful in terms of inhibiting shrinkage.

The pressure-sensitive adhesive preferably contains a curing agent or a crosslinking agent.

Examples of the curing agent or crosslinking agent include polyvalent isocyanate compounds, polyvalent epoxy compounds, polyvalent aziridine compounds, and chelate compounds.

Examples of the polyvalent isocyanate compound include, but are not limited to, 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, 4,4'-diphenyl ether diisocyanate, Aromatic isocyanates such as [2,2-bis (4-phenoxyphenyl) propane] diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, Dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, lysine diisocyanate, and lysine triisocyanate. Specifically, Colonate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) and the like can be used.

Examples of the polyvalent epoxy compound include epoxy resins, and examples thereof include ethylene glycol diglycidyl ether, terephthalic acid diglycidyl ester acrylate, and anilines in which two glycidyl groups are substituted for the N atom have. In addition, TETRAD-X described above can also be used.

Examples of the anilines include N, N'-tetraglycidyl-m-phenylenediamine.

The polyvalent aziridine compound may be at least one compound selected from the group consisting of tris-2,4,6- (1-aziridinyl) -1,3,5-triazine, tris [1- (2-methyl) -aziridinyl] [1- (2-methyl) -aziridinyl] triphospatriazine, and the like. Examples of the chelate compound include ethyl acetoacetate aluminum diisopropylate and aluminum tris (ethyl acetoacetate).

The blending amount of the curing agent or crosslinking agent is preferably 0.1 to 10 parts by mass, more preferably 0.1 to 5.0 parts by mass, and further preferably 0.5 to 4.0 parts by mass with respect to 100 parts by mass of the base resin.

(Thickness of the pressure-sensitive adhesive layer)

The thickness of the pressure-sensitive adhesive layer is preferably 5 占 퐉 or more, more preferably 10 占 퐉 or more, and still more preferably 20 占 퐉 or more from the viewpoint of manufacturability. The upper limit is preferably 75 占 퐉 or less, more preferably 50 占 퐉 or less, and particularly preferably 40 占 퐉 or less. The pressure-sensitive adhesive layer may be a multilayer, and in this case, it is preferable that the pressure-sensitive adhesive in the outermost layer in contact with the surface of the semiconductor wafer is at least a radiation-curable pressure-

(Properties of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive)

[Content of ethylenically unsaturated group in radiation-curable pressure-sensitive adhesive layer]

In the surface protective tape of the present invention, the content of the ethylenic unsaturated group (radiation-polymerizable carbon-carbon double bond) of the radiation-curing pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is preferably 0.2 to 2.0 mmol / g.

The content of the ethylenic unsaturated group in the radiation-curing pressure-sensitive adhesive is the total of all the ethylenic unsaturated groups contained in the compound having an ethylenic unsaturated group contained in the radiation-curable pressure-sensitive adhesive, and the total amount of the ethylenic unsaturated groups per gram of the radiation- It is confiscation. Further, the compound having an ethylenic unsaturated group is, for example, a polymer such as a base resin having an ethylenic unsaturated group in its side chain, and a radiation-polymerizable low molecular weight compound.

The content of the ethylenic unsaturated group in the radiation-curable pressure-sensitive adhesive is preferably 0.2 to 1.8 mmol / g, more preferably 0.2 to 1.5 mmol / g, and still more preferably 0.5 to 1.5 mmol / g.

In the case where the pressure-sensitive adhesive layer is a multilayer, it is preferable that the content of the ethylenic unsaturated group of the radiation-curing pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer satisfies the above range when all of the pressure-sensitive adhesive layers are regarded as one layer, Range is more preferable.

The content of the ethylenic unsaturated group in the radiation-curable pressure-sensitive adhesive can be controlled by the number of the ethylenic unsaturated group of the compound having the functional group (?) And the radiation-polymerizable low molecular weight compound, or the compounding amount thereof.

The content of the ethylenic unsaturated group in the radiation-curable pressure-sensitive adhesive can be determined from the amount of the compound to be used as described above or from the number of the ethylenic unsaturated groups of the compound. Further, the iodine value of the radiation-curable pressure-sensitive adhesive (g number of iodine (I ₂ ) to be added to the total of 100 g of the base resin and the radiation-polymerizable low molecular weight compound) was determined and the molecular weight of I ₂ was 253.8. / g. &lt; / RTI &gt;

[Adhesive strength after UV curing to SUS plate]

The adhesive force of the pressure-sensitive adhesive layer of the present invention after irradiation with ultraviolet rays is preferably 0.5 N / 25 mm or more, and more preferably 0.7 N / 25 mm or more, with respect to the SUS polished surface at 23 占 폚. The upper limit is preferably 5.0 N / 25 mm or less, more preferably 3.0 N / 25 mm or less, and more preferably 1.5 N / 25 mm or less. The adhesive force of the pressure-sensitive adhesive layer after ultraviolet irradiation is preferably 0.3 N / 25 mm or more, and more preferably 0.5 N / 25 mm or more, with respect to the SUS polished surface at 50 占 폚. The upper limit is preferably 7.0 N / 25 mm or less, more preferably 4.0 N / 25 mm or less, and still more preferably 2.5 N / 25 mm or less. This adhesive force is a characteristic of the surface protective tape itself.

After irradiating ultraviolet rays, it means after irradiating the entire pressure-sensitive adhesive layer to cure the ultraviolet rays so that the cumulative irradiation amount becomes 500 mJ / cm ² .

Specifically, it can be obtained as follows.

Three test specimens each having a width of 25 mm and a length of 150 mm are taken from the surface protective tape before irradiation. The test piece is pressed with a 2 kg rubber roller over three rounds on an SUS steel plate having a thickness of 1.5 mm to 2.0 mm specified in JIS G4305 finished with 280 abrasive paper specified in JIS R6253. After standing at room temperature (25 캜) for 1 hour, the pressure sensitive adhesive layer is cured by irradiating ultraviolet rays with a cumulative dose of 500 mJ / cm ² . After the pressure-sensitive adhesive layer is cured, the average value of the three points of adhesion is obtained by using a tensile tester suitable for JIS B7721 in which the measured value falls within a range of 15 to 85% of the capacity. The adhesive force is measured at a room temperature and a humidity of 50% by a 90 deg. Peeling method at a tensile speed of 50 mm / min. In this test, before pressing the test piece on the SUS steel plate, the SUS steel plate is adjusted to a predetermined temperature (23 ° C, 50 ° C) using a hot plate or the like. As the tensile tester, for example, a tensile tester: Twin Column Tablet Model 5567 (trade name) manufactured by INSTRONG CO., LTD may be used.

The adhesive force after ultraviolet curing to the SUS polished surface can be set within a preferable range of the present invention by suitably controlling the kind and amount of the compound used in the pressure-sensitive adhesive, the kind and amount of the additive such as the cross-linking agent, and the thickness of the pressure-sensitive adhesive layer.

If the above adhesive force to the SUS polished surface is too small, the shrinkage due to the crosslinking reaction becomes large, so that the peeling force from the adherend having a large surface unevenness such as a bump wafer increases. If the adhesive strength of the outer surface to the SUS polished surface is too large, the radiation hardening is insufficient, and peeling failure or sticky material remains.

<Peel Liner>

The pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer may have a release liner on the pressure-sensitive adhesive layer. As the release liner, a polyethylene terephthalate film treated with a silicone release treatment or the like is used. In addition, a polypropylene film not subjected to a silicon mold-releasing treatment is also used in accordance with necessity.

<< Processing Method of Semiconductor Wafer >>

The method for processing a semiconductor wafer of the present invention is a method for processing a semiconductor wafer using the adhesive tape for protecting the surface of the semiconductor wafer of the present invention.

The pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer of the present invention may be used in any process as long as it is a process for processing a semiconductor wafer. For example, the back side of the semiconductor wafer is preferably a grinding step, a dicing step, and a dicing die bonding step.

The pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer of the present invention is used by being attached to the surface of a semiconductor wafer having a concavo-convex difference of 20 占 퐉 or more.

More preferably, the irregularities (the height of the bump (electrode) and the depth of the scribe line) are applied to a semiconductor wafer of 20 to 400 mu m, more preferably to a semiconductor wafer of 50 to 250 mu m.

The arrangement density (high density) of the bumps on the surface of the semiconductor wafer is not particularly limited, but may be a pitch (0.5 to 3 times or less, preferably 1 to 2 times or less the pitch of the bumps The distance to the apex of the arranged bumps in the height direction). It is also used for a semiconductor wafer in which bumps are uniformly arranged on the entire surface.

The thickness of the semiconductor wafer is preferably 20 to 500 占 퐉, more preferably 50 to 200 占 퐉, and even more preferably 80 to 200 占 퐉 in the thickness of the back-ground semiconductor wafer by a working method using a pressure-sensitive adhesive tape for protecting the surface of the semiconductor wafer .

By using the adhesive tape for protecting the surface of the semiconductor wafer of the present invention, a thin film semiconductor wafer can be obtained with high yield. This semiconductor wafer processing method is suitable for a method of manufacturing a semiconductor wafer in which an electrode portion thinly ground to 50 탆 or less.

The method for processing a semiconductor wafer of the present invention includes a step of peeling off a pressure sensitive adhesive tape for protecting a surface of a semiconductor wafer by irradiating a pressure sensitive adhesive tape for protecting a surface of a semiconductor wafer of the present invention onto a surface of a semiconductor wafer and irradiating the pressure sensitive adhesive tape with radiation, desirable.

More specifically, first, the pressure-sensitive adhesive tape for protecting the surface of the semiconductor wafer of the present invention is applied to the circuit pattern surface (surface) of the semiconductor wafer so that the pressure-sensitive adhesive layer becomes the coherent surface. Next, the surface side of the semiconductor wafer on which no circuit pattern is formed is ground until the thickness of the semiconductor wafer reaches a predetermined thickness, for example, 10 to 200 mu m. Thereafter, the bonded surface of the adhesive tape for protecting the surface of the semiconductor wafer is placed on the heating adsorption table in the downward direction. In this state, when the dicing / die bonding film is applied to the grinding surface without the circuit pattern of the semiconductor wafer good.

A heat seal type (heat fusion type) or adhesive type peeling tape is adhered to the back surface of the base film of the adhesive tape for protecting the surface of the semiconductor wafer to separate the adhesive tape for protecting the surface of the semiconductor wafer from the semiconductor wafer do.

[Example]

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

(Preparation of pressure-sensitive adhesive composition)

The pressure-sensitive adhesive compositions 1A to 1C were prepared as follows.

1) Preparation of pressure-sensitive adhesive composition 1A

78 parts by mass of 2-ethylhexyl acrylate, 17 parts by mass of 2-hydroxyethyl acrylate and 5 parts by mass of methacrylic acid, a copolymer having a weight average molecular weight of 55,000 was obtained. 100 parts by mass of a urethane acrylate oligomer having a mass average molecular weight of 3,000 and a hydroxy group as a functional group (?) Were mixed with 100 parts by mass of 100 parts by mass of the copolymer, and 100 parts by mass of a polyisocyanate colloquin L [trade name, Nippon Polyurethane High Kyo , 5.0 parts by mass of SPEEDCURE BKL (trade name, manufactured by DKSH Japan) as a photopolymerization initiator were added and mixed to obtain a pressure-sensitive adhesive composition 1A.

2) Preparation of pressure-sensitive adhesive composition 1B

70 parts by mass of 2-ethylhexyl acrylate, 7 parts by mass of 2-hydroxyethyl acrylate and 23 parts by mass of methacrylic acid were polymerized in ethyl acetate to obtain a methacrylic polymer having a mass average molecular weight of 1,000,000. To 100 parts by mass of the methacrylic polymer, 2.0 parts by mass of an epoxy curing agent was mixed to obtain a pressure-sensitive adhesive composition 1B.

3) Preparation of pressure-sensitive adhesive composition 1C

78 parts by mass of 2-ethylhexyl acrylate, 13 parts by mass of 2-hydroxyethyl acrylate and 9 parts by mass of methacrylic acid, a copolymer having a mass average molecular weight of 600,000 was obtained. 100 parts by mass of a urethane acrylate oligomer having a mass average molecular weight of 1,500 and a hydroxyl group as a functional group (?) And 3.0 parts by mass of a polyisocyanate of Colonate L were mixed with 100 parts by mass of the copolymer, 0.5 part by mass of TETRAD-X (produced by Mitsubishi Gas Chemical Company, Inc.) and 5.0 parts by mass of SPEEDCURE BKL as a photopolymerization initiator were added and mixed to obtain a pressure-sensitive adhesive composition 1C.

(Formation of base film and intermediate resin layer)

The intermediate resin layer and the base films 2A to 2G were formed in the following manner.

1) Production of Film 2A

An ethylene-acrylic acid copolymer (EEA) resin (manufactured by Japan Polyethylene Corporation, trade name: Lekspar ET6200) was used as a resin constituting the intermediate resin layer, and low-density polyethylene (LDPE ) Resin (manufactured by TOSOH CORPORATION, trade name: Petrocene 212) was used. These resins were extruded by an extruder to prepare a base film (film 2A) having an intermediate resin layer. The thickness of the LDPE layer was 12.5 mu m and the thickness of the EEA was 237.5 mu m.

2) Production of film 2B

(EMA) resin (Nippon Polyethylene Shore, trade name: Lekspar EB330H) was used as a resin constituting the intermediate resin layer and a low density polyethylene (LDPE) resin (Tosoh , Trade name: Petrocene 212) was used. These resins were extruded by an extruder to prepare a base film (film 2B) having an intermediate resin layer. The thickness of the LDPE layer was 140.0 mu m and the thickness of the EEA was 210.0 mu m.

3) Production of Film 2C

(Nippon Polyethylene Shoe Co., Ltd., trade name: Lekspar ET720X) was used as a resin constituting the intermediate resin layer, and a low density polyethylene (LDPE) resin (trade name: Petro Sen 212) was used. By extruding these resins by an extruder, a base film (film 2C) having an intermediate resin layer was produced. The thickness of the LDPE layer was 50.0 mu m, and the thickness of the ethylenic special copolymer resin layer was 200.0 mu m.

4) Production of film 2D

(Manufactured by Nippon Polyethylene Industry Co., Ltd., trade name: Kernel KJ640T) was used as the resin constituting the intermediate resin layer and a low density polyethylene (LDPE) resin LLUJ580). These resins were extruded by an extruder to prepare a base film (film 2D) having an intermediate resin layer. The thickness of the LDPE layer was 90.0 mu m, and the thickness of the ethylenic special copolymer resin layer was 210.0 mu m.

5) Production of film 2E

(Nippon Polyethylene Shoe Co., Ltd., trade name: Lekspar ET220X) was used as a resin constituting the intermediate resin layer, and a low density polyethylene (LDPE) resin (Tosoh Corporation, trade name: 212) was used. These resins were extruded by an extruder to prepare a base film (film 2E) having an intermediate resin layer. The thickness of the LDPE layer was 150.0 mu m, and the thickness of the ethylenic special copolymer resin layer was 150.0 mu m.

6) Production of Film 2F

(Trade name: LOTRIL 28BA175) as the resin constituting the intermediate resin layer and a low density polyethylene (LDPE) resin (Nippon Polyethylene SHEET, trade name: Nova Tech LLUJ580). By extruding these resins by an extruder, a base film (film 2F) having an intermediate resin layer was produced. The thickness of the LDPE layer was 90.0 mu m, and the thickness of the ethylene-butyl acrylate copolymer resin layer was 210.0 mu m.

7) Film formation of film 2G

(Nippon Polyethylene Shore, trade name: EB240H) as a resin constituting the intermediate resin layer and a low-density polyethylene (LDPE) resin (Tosoh Corporation, trade name: Petrocene 212) . These resins were extruded by an extruder to prepare a base film (film 2G) having an intermediate resin layer. The thickness of the LDPE layer was 90.0 mu m, and the thickness of the ethylene-acrylic acid copolymer resin layer was 210.0 mu m.

8) Film formation of film 2H

(Petrosen 180) as a resin constituting the intermediate resin layer and a low-density polyethylene (LDPE) resin (Tosoh Corporation, trade name: Petrocene 212) as a resin constituting the base film . These resins were extruded by an extruder to prepare a base film (film 2H) having an intermediate resin layer. The thickness of the LDPE layer used as the intermediate resin layer was 90.0 mu m, and the thickness of the LDPE layer used as the base film was 210.0 mu m.

(Example 1)

The pressure-sensitive adhesive composition 1A was coated on a transparent release liner so as to have a thickness of 30 mu m after drying, and dried. The pressure-sensitive adhesive layer on the release liner and the intermediate resin layer of the film 2A came into contact with each other so that the release liner was removed to obtain a pressure-sensitive adhesive tape for protecting a semiconductor wafer surface shown in Fig.

(Example 2)

A pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer having the structure shown in Fig. 1 was obtained in the same manner as in Example 1, except that the pressure-sensitive adhesive composition 1A was changed to the pressure-sensitive adhesive composition 1B and the film 2A was changed to the film 2B.

(Example 3)

A pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer having the structure shown in Fig. 1 was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive composition 1A was changed to the pressure-sensitive adhesive composition 1C and the film 2A was changed to the film 2C.

(Example 4)

A pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer shown in Fig. 1 was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive composition 1A was changed to the pressure-sensitive adhesive composition 1B and the film 2A was changed to the film 2D.

(Comparative Example 1)

A pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive composition 1A was changed to the pressure-sensitive adhesive composition 1C and the film 2A was changed to the film 2E.

(Comparative Example 2)

A pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive composition 1A was changed to the pressure-sensitive adhesive composition 1B and the film 2A was changed to the film 2F.

(Comparative Example 3)

A pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer was obtained in the same manner as in Example 1 except that the film 2A was changed to the film 2G in Example 1. [

(Comparative Example 4)

A pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer was obtained in the same manner as in Example 1 except that the film 2A was changed to the film 2H in Example 1.

The following tests were conducted on the pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer prepared in the above-mentioned Examples and Comparative Examples, and the performance thereof was evaluated. The evaluation results are shown in Table 1 below. Tests were also conducted on the surface protective tapes produced in Examples 2 to 4 and Comparative Examples 1 to 3 in the same manner as in Example 1.

&Lt; Test Example 1 > Adhesion test

(1) Adhesion to a bump having a height of 50 탆

(Trade name) manufactured by Nitto Seiki Co., Ltd.) was applied to the surface of a silicon wafer (silicon wafer itself, thickness 725 μm) having a diameter of 8 inches and a bump portion having a pillar bump of 50 μm in height and 100 μm in bump pitch The surface protective tape prepared in Example 1 was applied to the wafer under the conditions of a table temperature of 80 캜 and a roller temperature of 60 캜, a bonding pressure of 0.35 MPa, and a bonding speed of a low speed (9 mm / sec). In this way, 25 pieces of the surface protection tape portion wafers (bump height: 50 m) were produced. Under this bonding condition, the intermediate resin layer of the surface protective tape constituting the intermediate resin layer composed of the resin having a melting point of 80 占 폚 or less melted (the same was true for the following Test example 2). The adhesion at that time was visually confirmed, and the presence or absence of air contamination between the surface protective tape and the wafer was examined.

(2) Adhesion to a bump having a height of 200 μm

(Manufactured by Nitto Seikisha Co., Ltd.) at a table temperature of 80 占 폚 and a roller at a table temperature of 80 占 폚 on a surface of a silicon wafer having a diameter of 8 inches and a solder bump having a height of 200 占 퐉 and a bump pitch of 400 占 퐉 The surface protective tape prepared in Example 1 was bonded to the wafer under the conditions of a temperature of 60 캜, a bonding pressure of 0.35 MPa, and a bonding speed of a low speed (9 mm / sec). In this manner, five pieces of the surface protection tape portion wafers (bump height: 200 mu m) were produced. The adhesion at that time was visually confirmed, and the presence or absence of air contamination between the surface protective tape and the wafer was examined. Evaluation criteria are shown below. A and B are passed.

(Evaluation standard)

A: After the bonding, the wafer was allowed to stand at room temperature (25 占 폚), and even if it exceeded 72 hours, no air entrainment was observed in all of the surface protection tape portions.

B: After bonding, the wafer was allowed to stand at room temperature, and within 48 hours and 72 hours, no air entrainment was observed in all of the surface protection tape portions.

C: After the bonding, the wafer was allowed to stand at room temperature, and at least one surface protective tape was observed on the wafer with air within 48 hours after the bonding.

&Lt; Test Example 2 >

(1) Dust penetration

The surface protection tape was bonded to the wafer in the same manner as above. Five surface protection tape portions (bump height: 50 μm) of Example 1 and a surface protection tape portion of Example 1 (bump height: 200 μm) I made a hawk. After the surface protective tape was bonded to the wafer, the wafer was allowed to stand for 48 hours, and then the back surface was ground. A grinder (DFG8760 (trade name), manufactured by Disco Corporation) having an inline mechanism was used for the back grinding. Thereafter, the presence or absence of penetration of silicon dust between the wafer and the surface protective tape was visually confirmed with respect to the surface protective tape portion after grinding. Further, for the wafer (bump height: 50 mu m) of the surface protection tape portion of Example 1, backgrinding was performed until the final grinding thickness of the wafer became 50 mu m. On the other hand, for the wafer (bump height: 200 mu m) of the surface protection tape portion of Example 1, backgrinding was performed until the final thickness of silicon became 200 mu m, and evaluation was made according to the following evaluation criteria.

(Evaluation standard)

Pass: No dust penetration was observed in any of the surface protection tape portion wafer (bump height: 50 mu m) and the surface protection tape portion wafer (bump height: 200 mu m).

Failure: Dirt penetration was observed in at least one of the surface protection tape portion wafer (bump height: 50 mu m) and the surface protection tape portion wafer (bump height: 200 mu m).

(2) Return error

Evaluation criteria are shown below. A and B are passed.

A: In the grinding test, no conveying error occurred in the grinding apparatus with all of the wafers.

B: In grinding test, one conveying error occurred in the grinding apparatus.

C: In the grinding test, two or more conveying errors occurred in the grinding apparatus.

The &quot; transport error &quot; means that the base film was deformed and vacuum-adsorbed so that the surface protection tape could not carry the wafer.

(3) Evaluation of wafer breakage

Each of the grinded surface protective tape portions was visually observed over the entire wafer, and the edge of the wafer was observed with an optical microscope to investigate whether the wafer was damaged. Evaluation criteria are shown below. "No (A)" is acceptable.

(Evaluation standard)

None (A): There was no breakage in visual observation and microscopic observation.

B: There was no breakage in the naked eye, but the breakage was confirmed by the microscope.

C: Damage was confirmed visually.

(4) Evaluation of bending

(The surface protection tape portion was placed on a flat plate and the highest point of the wafer bent from the flat plate surface) was measured for five pieces of the wafer (bump height: 50 占 퐉) The height to the lower surface) was measured. Evaluation criteria are shown below. A is accepted.

(Evaluation standard)

A: Average value of bending height is less than 5mm

B: Average value of bending height is 5 mm or more, less than 10 mm

C: Average value of the warp height is 10 mm or more

(5) Evaluation of peelability

Each of the above-prepared pressure sensitive adhesive tapes for protecting the surface of the semiconductor wafer was bonded at a bonding temperature of 90 占 폚 to the surface of a semiconductor wafer of 8 inch diameter having bump (bump pitch of 150 占 퐉) of 75 占 퐉 in height on the surface. Thereafter, the back surface of the semiconductor wafer bonded with the above-mentioned adhesive tape for protecting a semiconductor wafer surface was ground to a thickness of 200 mu m in two pieces by using DFG8760 (trade name) manufactured by Disco Corporation. Adhesive tape portion for protecting the surface of the semiconductor wafer after grinding The semiconductor wafer was irradiated with ultraviolet rays of 500 mJ / cm ² , and the adhesive tape for protecting the surface of the semiconductor wafer was peeled off using a tensile tester (Twin Column Tabletop Model 5567 , And peeling force when the width at the time of peeling reached a maximum (200 mm) was evaluated according to the following criteria. A and B are passed.

In Table 1, the &quot; peelability &quot;

(Evaluation standard)

A: 20N / 200mm or less

B: 20N / 200mm or more and 50N / 200mm or less

C: Greater than 50N / 200mm

(6) Residual evaluation of adhesive substance

Adhered material remnants were observed with an optical microscope (Olympus) for five wafers (bump height: 50 mu m) of the surface protection tape portion of Example 1 used in the peelability evaluation. Evaluation criteria are shown below.

(Evaluation standard)

Pass: All of the surface protection tape portions did not cause adhesive residue on the wafer.

Failure: At least one surface protection tape portion sticking material remained on the wafer.

&Lt; Test Example 3 > Heat resistance test

The surface protective tape of Example 1 was bonded to the mirror wafer. The bonding conditions were the same as those in Test Example 2 in which the surface protective tape was applied to the silicon wafer. Thereafter, the base tape of the surface protective tape was brought into contact with the hot plate on the hot plate heated to 90 占 폚 downward and allowed to stand for 3 minutes, and then the surface of the tape was visually observed.

(Evaluation standard)

Pass: The substrate film did not melt.

Fail: The substrate film melted.

&Lt; Measurement of physical properties &

(Melting point, Vicat softening point, MFR)

The melting point and the Vicat softening point of the resin constituting the intermediate resin layer were measured based on JIS K7206. The melt mass flow rate (MFR) of the resin constituting the intermediate resin layer was measured based on JIS K7210. The melting point of the constituent material of the base film was measured based on JIS K6977-2.

(adhesiveness)

Was measured by the above-mentioned method.

<Notes on the Table>

The parentheses in the line of adhesion indicate the kind of the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer.

As apparent from Table 1, the surface protection tapes of Examples 1 to 4 satisfying the provisions of the present invention were excellent in adhesion, and were able to suppress dust intrusion, transfer error, and wafer breakage. In addition, the surface protection tapes of Examples 1 to 4 were able to suppress warpage in the state of being adhered to the surface of a semiconductor wafer, and were excellent in peelability, residual adhesive material, and heat resistance.

On the other hand, in the surface protective tapes of Comparative Examples 1 to 3, at least two evaluation items failed.

While the present invention has been described in conjunction with the embodiments thereof, it is to be understood that the invention is not limited to any details of the description thereof except as specifically set forth and that the invention is broadly construed broadly I think it is natural to be interpreted.

The present application is based on Japanese Patent Application No. 2017-71346, filed on March 31, 2017, which is hereby incorporated by reference herein in its entirety as part of the description of this specification.

10: Adhesive tape for semiconductor wafer surface protection
1: pressure-sensitive adhesive layer
2: intermediate resin layer
3: base film

Claims (9)

A pressure-sensitive adhesive tape for surface protection of a semiconductor wafer, which is applied to the surface of a semiconductor wafer having a concavo-convex car of 20 占 퐉 or more by heating under a condition of 40 占 폚 to 90 占 폚,
Wherein the pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer has a base film, a pressure-sensitive adhesive layer, and an intermediate resin layer between the base film and the pressure-
Wherein the thickness of the intermediate resin layer is not less than the irregularities and the melting point or the Vicat softening point of the resin constituting the intermediate resin layer is from 40 to 90 DEG C and the melt mass flow rate of the resin constituting the intermediate resin layer is , And 10 g / min to 100 g / min. The method according to claim 1,
The adhesive strength of the pressure-sensitive adhesive layer after ultraviolet irradiation to the SUS 280 polished surface at 23 캜 was 0.5 N / 25 mm or more and 5.0 N / 25 mm or less, and the adhesive strength to the SUS 280 polished surface at 50 캜 was 0.3 N / Wherein the thickness of the adhesive tape is 25 mm or less. 3. The method according to claim 1 or 2,
Wherein the ratio of the thickness of the base film to the thickness of the intermediate resin layer is from 0.5: 9.5 to 7: 3 in terms of the thickness of the base film: the thickness of the intermediate resin layer. 4. The method according to any one of claims 1 to 3,
Wherein the resin constituting the intermediate resin layer is at least one of an ethylene-acrylic acid methyl copolymer resin, an ethylene-acrylic acid ethyl copolymer resin, and an ethylene-acrylic acid butyl copolymer resin. 5. The method according to any one of claims 1 to 4,
Wherein the constituent material of the base film has a melting point of 90 占 폚 to 150 占 폚. 6. The method according to any one of claims 1 to 5,
Wherein the thickness of the intermediate resin layer is 100 占 퐉 to 400 占 퐉. 7. The method according to any one of claims 1 to 6,
Wherein the thickness of the pressure-sensitive adhesive layer is 5 占 퐉 to 40 占 퐉. 8. The method according to any one of claims 1 to 7,
Wherein the base film has a thickness of 25 占 퐉 to 100 占 퐉. A method of processing a semiconductor wafer including a step of heating and bonding a pressure-sensitive adhesive tape for protecting a surface of a semiconductor wafer to a surface of a semiconductor wafer having a concavo-convex car having a thickness of 20 탆 or more at 40 캜 to 90 캜,
Wherein the pressure-sensitive adhesive tape for protecting the surface of a semiconductor wafer has a base film, a pressure-sensitive adhesive layer, and an intermediate resin layer between the base film and the pressure-
Wherein the thickness of the intermediate resin layer is not less than the irregularities and the melting point or the Vicat softening point of the resin constituting the intermediate resin layer is from 40 to 90 DEG C and the melt mass flow rate of the resin constituting the intermediate resin layer is , And 10 g / min to 100 g / min.

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