WO2014061774A1

WO2014061774A1 - Adhesive sheet for processing electronic component and method for manufacturing semiconductor device

Info

Publication number: WO2014061774A1
Application number: PCT/JP2013/078285
Authority: WO
Inventors: 朋治宮永; 陽輔佐藤; 明徳佐藤
Original assignee: リンテック株式会社
Priority date: 2012-10-19
Filing date: 2013-10-18
Publication date: 2014-04-24
Also published as: JP6195839B2; TW201435033A; TWI582208B; JPWO2014061774A1

Abstract

Provided is an adhesive sheet for processing an electronic component, the adhesive sheet being able to prevent a reduction in adhesive strength due to the low solvent resistance of a base material even when coming in contact with an organic solvent, and having excellent aptitude for chip pickup. This adhesive sheet for processing an electronic component is configured from a base material film, an adhesive layer provided on one surface of the base material film, and a base material protection film peelably provided on the other surface of the base material film, the bending resistance of the base material film is 105 mm or more, and the base material protection film is one type alone or a combination of two or more types selected from a polyester-based film or a polyolefin film.

Description

Adhesive sheet for processing electronic parts and method for manufacturing semiconductor device

The present invention divides a semiconductor wafer for each circuit, and when a semiconductor chip is formed, a dicing sheet used for fixing the semiconductor wafer or a chip separated is transferred and then picked up. In particular, the present invention relates to an adhesive sheet for processing electronic parts that is excellent in resistance to organic solvents. The present invention also relates to a method for manufacturing a semiconductor device using the pressure-sensitive adhesive sheet for processing electronic parts. In particular, the pressure-sensitive adhesive sheet for processing electronic parts of the present invention fixes a semiconductor wafer or chip having a protruding electrode on its surface, for example, a semiconductor wafer or chip having a so-called through electrode (TSV / Through Silicon Via), and contacts an organic solvent. It is preferably used in a method for manufacturing a semiconductor device including a process.

After a circuit is formed on the surface of a semiconductor wafer, grinding is performed on the back side of the wafer, the back grinding process for adjusting the thickness of the wafer, and the wafer is fixed on a dicing sheet, and separated into a predetermined chip size. A dicing process is performed. The semiconductor chips separated into chips are picked up from the dicing sheet and transferred to the next process.

Developed multilayer circuits in which a plurality of semiconductor chips are three-dimensionally stacked in response to the increase in capacity and functionality of electronic circuits. Conventionally, in such a laminated circuit, the conductive connection of the semiconductor chip is generally performed by wire bonding. However, due to the recent need for miniaturization and high functionality, the semiconductor chip can be connected without wire bonding. An effective method has been developed in which a chip is provided with an electrode (TSV) penetrating from the circuit formation surface to the back surface to directly conduct conductive connection between the upper and lower chips. As a method for manufacturing a chip with a through electrode, for example, a through hole is formed in a predetermined position of a semiconductor wafer by plasma or the like, a conductor such as copper is poured into the through hole, etching is performed, and then the surface of the semiconductor wafer And a method of providing a circuit and a through electrode.

Such ultra-thin wafers and TSV wafers are extremely fragile and may be damaged in the back grinding process, the subsequent processing process, and the transfer process. Therefore, during these steps, the wafer is held on a hard support such as glass via an adhesive. As this adhesive, general-purpose adhesives such as acrylic, epoxy, and inorganic may be used. When the wafer is exposed to a high temperature during the processing step, the wafer and the hard support are bonded with an adhesive having high heat resistance, for example, a polyimide adhesive.

After finishing the backside grinding and processing of the wafer, the wafer is transferred from a hard support onto an adhesive sheet called a dicing sheet, the outer periphery of the dicing sheet is fixed by a ring frame, and then the wafer is cut for each circuit. Chips are then picked up from the dicing sheet. When transferring the wafer to the dicing sheet, the wafer-side surface of the hard support to which the wafer is fixed is stuck on the dicing sheet, the hard support is peeled off from the wafer, and the wafer is transferred to the dicing sheet. To wear. When the hard support is peeled off, the hard support is peeled off by heating and softening the adhesive to dissociate the adhesive by laser beam irradiation. However, an adhesive or a decomposition product thereof may remain on the wafer surface after the hard support is peeled off.

Also, it has been proposed to hold a wafer on a hard support, divide it into chips and transfer them onto an adhesive sheet called a pickup sheet to pick up the chips. Since it is difficult to directly pick up the chip from the hard support, the chip can be easily picked up by transferring the chip onto a soft pickup sheet. However, the adhesive and its decomposition products may remain on the chip transferred onto the pickup sheet in the same manner as described above.

Wafers and chips (hereinafter collectively referred to as adherends) fixed on a dicing sheet or pickup sheet (hereinafter collectively referred to as an adhesive sheet) are washed with an organic solvent in order to wash away and remove the adhesive residue remaining. Sometimes. For this cleaning, for example, a laminate of the adhesive sheet and the adherend is immersed in an organic solvent, or a frame slightly larger than the adherend is placed on the adhesive sheet so as to surround the adherend, An organic solvent is added to the substrate to clean the adherend. When the adherend is a chip, a frame slightly larger than the outer diameter of the chip group is used.
Further, when the adherend such as a wafer is peeled from the hard support, in addition to the above method, the adherend and the hard support are also immersed in an organic solvent.

When immersing the adherend and the hard support in the organic solvent, the organic solvent contacts not only the adherend but also the adhesive sheet. At this time, the base material of the pressure-sensitive adhesive sheet was swollen or dissolved by the organic solvent, and wrinkles were sometimes generated on the base material. With the generation of wrinkles in the substrate, the pressure-sensitive adhesive layer may also be deformed. Due to the deformation of the pressure-sensitive adhesive layer, voids are generated at the interface between the adherend and the ring frame and the pressure-sensitive adhesive layer, and the organic solvent soaks into the voids, and the pressure-sensitive adhesive at the interface between the adherend and the ring frame. The layer swells or dissolves, and the adhesion to the adherend and the ring frame is lost. As a result, the adherend and the ring frame may fall off the adhesive sheet. Further, the wrinkles generated on the base material may make subsequent processing steps (dicing and pickup) difficult. Further, even when the problem that such a base material does not have solvent resistance is solved, depending on the properties of the base material, the chip pick-up suitability may be inferior.

Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-73798) describes a method of peeling an adherend and a support so that an organic solvent does not come into contact with an adhesive sheet, and cleaning and removing an adhesive residue. Yes.

JP 2007-73798 A

However, in Patent Document 1, equipment for preventing the organic solvent from coming into contact with the pressure-sensitive adhesive sheet is required, and the process of cleaning and removing the adhesive residue is complicated.

The present invention is intended to solve the problems associated with the prior art as described above. That is, the present invention provides an adhesive sheet for processing an electronic component that can prevent a decrease in adhesive force due to the low solvent resistance of a substrate even when in contact with an organic solvent and is excellent in chip pick-up suitability. It is aimed.

The gist of the present invention aimed at solving such problems is as follows.
[1] A base film, a pressure-sensitive adhesive layer provided on one surface of the base film, and a base material protective film provided in a peelable manner on the other surface of the base film,
The bending resistance of the base film is 105 mm or more,
The pressure-sensitive adhesive sheet for processing electronic parts, wherein the substrate protective film is a single type or a combination of two or more types selected from a polyester film or a polyolefin film.

[2] The pressure-sensitive adhesive sheet for electronic component processing according to [1], wherein the polyester film is selected from the group consisting of a polyethylene terephthalate film, a polyethylene naphthalate film, a polybutylene terephthalate film, and a polybutylene naphthalate film.

[3] The electronic component processing pressure-sensitive adhesive sheet according to [1], wherein the polyolefin film is selected from the group consisting of a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polystyrene film, and a cycloolefin film.

[4] The pressure-sensitive adhesive sheet for processing electronic parts according to any one of [1] to [3], wherein the thickness of the base material protective film is less than 300 μm.

[5] Used in a step of contacting a laminate of the pressure-sensitive adhesive sheet and the wafer or chip with an organic solvent while holding the semiconductor wafer or chip on the pressure-sensitive adhesive sheet for electronic component processing The adhesive sheet for electronic component processing in any one.

[6] (i) SP value is 9 (cal / cm ³ ) ^1/2 or more, and the change rate of Young's modulus of the base material protective film after being immersed in an organic solvent at 80 ° C. for 1 minute is 8% or less. Or (ii) the SP value is less than 9 (cal / cm ³ ) ^1/2 , and the rate of change in Young's modulus of the base material protective film after being immersed in an organic solvent at 25 ° C. for 24 hours is 8 % Of the pressure-sensitive adhesive sheet for processing electronic parts according to [5].

[7] A step of bringing a laminate of the pressure-sensitive adhesive sheet and the wafer into contact with an organic solvent in a state where the semiconductor wafer is held on the pressure-sensitive adhesive sheet for processing electronic parts according to any one of [1] to [6]. A method for manufacturing a semiconductor device.

[8] The semiconductor device according to [7], wherein the SP value of the organic solvent is 7 to 12 (cal / cm ³ ) ^1/2 and the contact step is a step of removing the adhesive or the adhesive and the support. Production method.

[9] The method for manufacturing a semiconductor device according to [7] or [8], wherein the semiconductor wafer is a wafer provided with a protruding electrode.

[10] A step of bringing a laminate of the pressure-sensitive adhesive sheet and the chip into contact with an organic solvent in a state where the semiconductor chip is held on the pressure-sensitive adhesive sheet for electronic component processing according to any one of [1] to [6]. A method for manufacturing a semiconductor device.

[11] The semiconductor device according to [10], wherein the SP value of the organic solvent is 7 to 12 (cal / cm ³ ) ^1/2 and the contact step is a step of removing the adhesive or the adhesive and the support. Production method.

[12] The method for manufacturing a semiconductor device according to [10] or [11], wherein the semiconductor chip is a chip provided with a protruding electrode.

The pressure-sensitive adhesive sheet for processing electronic parts according to the present invention exhibits excellent resistance to various organic solvents. For this reason, even when the adherend (wafer, chip, etc.) is peeled off from the hard support, or even if the adhesive sheet for processing electronic parts comes into contact with an organic solvent in the subsequent cleaning process, generation of wrinkles or adhesion on the substrate Deformation of the agent layer is suppressed. As a result, the adherend and the ring frame can be favorably held in the adhesive layer. Therefore, it is possible to prevent the adherend and the ring frame from falling off from the electronic component processing pressure-sensitive adhesive sheet in the peeling step and the cleaning step. In the subsequent processes, the dicing process and the pick-up process can be performed satisfactorily, which can contribute to the improvement of the production efficiency of the semiconductor device. In addition, the chip pick-up property is excellent, and the possibility of pick-up failure and chip breakage in the chip pick-up process can be reduced.

Hereinafter, the adhesive sheet for processing electronic parts according to the present invention will be specifically described. The pressure-sensitive adhesive sheet for processing electronic parts according to the present invention (hereinafter also simply referred to as “pressure-sensitive adhesive sheet”) includes a pressure-sensitive adhesive layer, a base film, and a base material protective film, which are laminated in this order.

(Adhesive layer)
The pressure-sensitive adhesive layer in the present invention is laminated on one surface of the base film and can be formed by various conventionally known pressure-sensitive adhesives. Such an adhesive is not limited at all, but an adhesive such as rubber-based, acrylic-based, silicone-based, or polyvinyl ether is used. In addition, an energy ray curable adhesive, a heat-foaming adhesive, or a water swelling adhesive can be used. As the energy ray curable (ultraviolet ray curable, electron beam curable) pressure-sensitive adhesive, it is particularly preferable to use an ultraviolet curable pressure-sensitive adhesive.

Some of the pressure-sensitive adhesive layers formed by the above pressure-sensitive adhesives dissolve and swell when contacted with an organic solvent. However, in the pressure-sensitive adhesive sheet for processing electronic parts of the present invention, by laminating a base material protective film resistant to an organic solvent on the base material film, the swelling and dissolution of the base material film due to the organic solvent is suppressed, Generation of wrinkles on the base film can be prevented. Therefore, deformation of the pressure-sensitive adhesive layer due to generation of wrinkles in the base film is prevented, and no voids are generated at the interface between the adherend and the pressure-sensitive adhesive layer, and the organic solvent is bonded to the adherend and the pressure-sensitive adhesive layer. Hardly penetrates the interface. As a result, swelling or dissolution of the pressure-sensitive adhesive layer at the interface between the adherend and the pressure-sensitive adhesive layer is suppressed, and sufficient adhesion to the adherend can be maintained, so that the adherend falls off from the pressure-sensitive adhesive sheet. Can be prevented. Therefore, conventionally well-known various adhesives can be used for the adhesive which forms the adhesive layer in this invention.

The thickness of the pressure-sensitive adhesive layer is preferably 5 to 100 μm, more preferably 8 to 50 μm, and particularly preferably 10 to 30 μm. When the thickness of the pressure-sensitive adhesive layer exceeds 100 μm, it takes a very long time (specifically, a time for applying and drying the pressure-sensitive adhesive composition in which the pressure-sensitive adhesive is mixed in a solvent) to form the pressure-sensitive adhesive layer. And it is economically useless.

(Base film)
The base film has a bending resistance of 105 mm or more, preferably 110 mm or more. The pick-up property of a to-be-adhered body (especially TSV wafer or TSV chip) falls that the bending resistance in a base film is less than 105 mm. By setting the bending resistance of the base film within the above range, the pickup property of the adherend is excellent. The upper limit of the bending resistance is preferably 150 mm, more preferably 130 mm. In addition, the bending resistance of the base film is measured by matching the longitudinal direction of the base film (the direction in which the long film manufactured during film formation is sent) with the vertical direction of the test piece.

The base film is not particularly limited as long as the above physical properties are satisfied. For example, a polyethylene film such as a low density polyethylene (LDPE) film, a linear low density polyethylene (LLDPE) film, and a high density polyethylene (HDPE) film, polychlorinated Vinyl film, vinyl chloride copolymer film, polyethylene terephthalate film, polyurethane film, polyimide film, ethylene vinyl acetate copolymer film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic An acid ester copolymer film and a film made of a water additive or a modified product thereof are used. These crosslinked films are also used. The above base film may be a single type, or may be a laminated film in which two or more of these are combined.

Among these, as the base film, specifically, an ethylene / (meth) acrylic acid copolymer film and an ethylene vinyl acetate copolymer film are preferable.

The thickness of the base film is preferably 20 to 200 μm, more preferably 25 to 150 μm, and particularly preferably 50 to 130 μm. When the thickness of the base film is small, film formation may be difficult depending on the material.

Also, the elongation at break of the base film is preferably 300% or more, more preferably 400 to 500%. By setting the breaking elongation of the base film in the above range, the base film is difficult to break during the expansion performed in the manufacturing process of the semiconductor device described later, and the adherends are easily separated from each other. The elongation at break of the base film was determined by using a universal testing machine (Tensilon RTA-T-2M manufactured by Orientec Co., Ltd.) in an environment of 23 ° C. and 50% relative humidity in accordance with JIS K7161: 1994. It can be measured at a speed of 200 mm / min.

Further, a corona treatment or a primer layer may be provided on the upper surface of the base film, that is, the base film surface on the side where the pressure-sensitive adhesive layer is provided, in order to improve the adhesion with the pressure-sensitive adhesive layer. Moreover, you may apply various coating films to the opposite surface (base film surface opposite to the side in which an adhesive layer is provided).

(Base material protective film)
The base material protective film is detachably laminated on the surface (the other surface) opposite to the surface (one surface) of the base film on which the pressure-sensitive adhesive layer is formed. In addition, the base material protective film may be laminated | stacked with a base film through the adhesive bond layer mentioned later, and may be laminated | stacked without passing through an adhesive bond layer by heating lamination etc.

The base material protective film is a single type selected from a polyester film or a polyolefin film, or a combination of two or more types. The substrate protective film as described above has resistance to any of low polar solvents such as d-limonene, 1-dodecene and menthane and high polar solvents such as N-methylpyrrolidone. Difficult to swell, swell or deform even when in contact with polar solvents. Therefore, the deformation of the base film and the pressure-sensitive adhesive layer caused by the deformation of the base material protective film can be suppressed, and the adherend such as the wafer and the chip and the ring frame can be prevented from falling off.

Specifically, the polyester film is preferably selected from the group consisting of a polyethylene terephthalate film, a polyethylene naphthalate film, a polybutylene terephthalate film, and a polybutylene naphthalate film.
Specifically, the polyolefin film is preferably selected from the group consisting of a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polystyrene film, and a cycloolefin film.

(I) The SP value is 9 (cal / cm ³ ) ^1/2 or more, and the change rate of the Young's modulus of the base material protective film after being immersed in an organic solvent at 80 ° C. for 1 minute is 8% or less. Or (ii) the SP value is less than 9 (cal / cm ³ ) ^1/2 and the rate of change in the Young's modulus of the base material protective film after being immersed in an organic solvent at 25 ° C. for 24 hours is 8% The following is preferable. In any of the characteristics (i) and (ii), the change rate of the Young's modulus of the base material protective film after being immersed in an organic solvent is preferably 8% or less, more preferably 6% or less, and still more preferably 0.8. 1 to 3.5%. The rate of change of the Young's modulus of the base material protective film after being immersed in the organic solvent is based on the Young's modulus A of the base material protective film before being immersed in the organic solvent and the Young's modulus B of the base material protective film after being immersed in the organic solvent. Can be calculated by the following equation. The Young's modulus of the protective film for the base material is 23 ° C. and 50% relative humidity in accordance with JIS K7161: 1994, using a universal tensile tester (Tensilon RTA-T-2M manufactured by Orientec). Can be measured at a tensile speed of 200 mm / min.
Change rate of Young's modulus (%) = (AB) / A × 100
An organic solvent having an SP value of 9 (cal / cm ³ ) ^1/2 or more and an organic solvent having an SP value of less than 9 (cal / cm ³ ) ^1/2 are exemplified in the semiconductor device manufacturing method described later. The same as what you do.

The SP value is 9 (cal / cm ³ ) ^1/2 or more, and the change rate of the Young's modulus of the base material protective film after being immersed in an organic solvent at 80 ° C. for 1 minute is within the above range. Resistance to polar solvents is improved. In addition, the SP value is less than 9 (cal / cm ³ ) ^1/2 , and the change rate of the Young's modulus of the base material protective film after being immersed in an organic solvent at 25 ° C. for 24 hours is within the above range. , Resistance to low polar solvents is improved. By improving the resistance of the base material protective film to the organic solvent, it is difficult to be dissolved, swelled or deformed even in contact with the organic solvent. As a result, the deformation of the base film and the pressure-sensitive adhesive layer due to the deformation of the base material protective film, and the invasion of the organic solvent at the interface between the adherend and the ring frame and the pressure-sensitive adhesive layer such as a wafer and a chip are suppressed, It is possible to prevent the adherend and the ring frame from falling off the adhesive sheet. About the characteristic of (i) and (ii), a base material protective film may be provided with any one of these, and may be provided with all. When the substrate protective film has any of these characteristics, the resistance is improved with respect to both the low polarity solvent and the high polarity solvent.

The thickness of the substrate protective film is preferably less than 300 μm, and when the substrate protective film is a polyester film or a laminated film, the thickness is preferably 20 to 200 μm, more preferably 25 to 110 μm, and particularly preferably It is in the range of 50 to 90 μm. When the substrate protective film is a polypropylene single layer film, it is preferably in the range of 30 to 200 μm, more preferably 50 to 150 μm.

(Adhesive layer)
The adhesive layer can be used for laminating the substrate film and the substrate protective film, and preferably has resistance to an organic solvent. Examples of the organic solvent include low polar solvents such as d-limonene, 1-dodecene, menthane, isododecane, and mesitylene, and high polar solvents such as ethyl acetate, acetone, methyl ethyl ketone, and N-methylpyrrolidone.

The adhesive layer can be formed by various conventionally known adhesives. Such an adhesive is not limited in any way, but for example, an adhesive such as rubber, acrylic, silicone, polyvinyl ether or the like is used. Moreover, as an adhesive agent, it is preferable to use an energy beam curable adhesive having energy beam curability.

The adhesive layer having resistance to a low polarity solvent has a swelling degree of the adhesive layer with respect to d-limonene of preferably 125% or less, more preferably 110% or less, and further preferably 95 to 105%. By setting the degree of swelling of the adhesive layer in the above range, the laminated structure of the base material protective film and the base material film can be maintained without being dissolved or swollen even when contacted with a low polarity solvent.

It is preferable that the adhesive layer which has tolerance with respect to a low polarity solvent and is formed from an energy beam curable adhesive contains an energy beam curable polymer (A). The energy ray curable polymer (A) is a polymer in which an energy ray polymerizable group is bonded to a main chain or a side chain, and itself has adhesiveness and energy ray irradiation (for example, ultraviolet ray irradiation, electron beam irradiation). ). Since the energy ray curable polymer (A) is a high molecular weight substance, it is difficult to elute into the low polarity solvent even if the low polarity solvent and the adhesive layer are in contact with each other. For this reason, the resistance of the adhesive layer to the low-polarity solvent due to the blending hardly occurs.
The energy ray-curable polymer (A) preferably contains 50 to 95% by mass, more preferably 60 to 90% by mass, of structural units derived from (meth) acrylic acid alkyl ester. In addition, in 100 parts by mass of the (meth) acrylic acid alkyl ester, the (meth) acrylic acid alkyl ester having 1 to 4 carbon atoms in the alkyl group is usually 80 parts by mass or more, preferably 90 parts by mass or more, more preferably 95 parts. Occupies ~ 100 parts by mass. In addition, in (meth) acrylic acid alkyl ester, in 100 parts by mass, (meth) acrylic acid alkyl ester having 1 or 2 carbon atoms in the alkyl group preferably occupies 10 parts by mass or more, and 15 to 40 parts by mass Preferably. Thereby, the polarity of the adhesive layer becomes high, resistance to a low polarity solvent is improved, and sufficient adhesive force is imparted to the adhesive layer. In addition, in this specification, (meth) acryl is used in the meaning including both acryl and methacryl.

Examples of (meth) acrylic acid alkyl esters include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, octyl acrylate, octyl Examples include methacrylate, isooctyl acrylate, isooctyl methacrylate, nonyl acrylate, nonyl methacrylate, decyl acrylate, decyl methacrylate, undecyl acrylate, undecyl methacrylate, dodecyl acrylate, dodecyl methacrylate, lauryl acrylate, lauryl methacrylate, and the like. The degree of swelling of the adhesive layer with respect to d-limonene is determined based on the structural unit derived from a (meth) acrylic acid alkyl ester having 1 to 4 carbon atoms in the alkyl group or (meth) acrylic acid having 1 or 2 carbon atoms in the alkyl group. A structural unit derived from an alkyl ester can be used and adjusted by the content ratio.

In addition, the energy ray curable polymer (A) has a structural unit derived from a polymerizable monomer (other polymerizable monomer) other than (meth) acrylic acid alkyl ester, usually 5 to 40% by mass, preferably 10 to Contains 30% by mass.

Examples of such other polymerizable monomers include functional group-containing monomers introduced in advance into the polymer in order to bind the energy ray polymerizable group to the polymer (polymer containing the functional group) described later. . The functional group-containing monomer is a monomer having a polymerizable double bond and a functional group such as hydroxyl group, carboxyl group, amino group, substituted amino group, and epoxy group in the molecule, preferably a hydroxyl group-containing unsaturated compound A carboxyl group-containing unsaturated compound is used.

More specific examples of such functional group-containing monomers include 2-hydroxymethyl acrylate, 2-hydroxymethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl. Examples thereof include hydroxyl group-containing (meth) acrylates such as methacrylate, 2-hydroxybutyl acrylate and 2-hydroxybutyl methacrylate, and carboxyl group-containing compounds such as acrylic acid, methacrylic acid and itaconic acid. The above functional group-containing monomers may be used alone or in combination of two or more.

In a polymer containing a functional group, a structural unit derived from the functional group-containing monomer (hereinafter sometimes simply referred to as “functional group-containing monomer unit”) is usually 5 to 40% by mass, preferably It is contained at a ratio of 10 to 30% by mass. An energy ray curable polymer (A) is obtained by introducing an energy ray polymerizable group into a polymer containing a functional group. At this time, a functional group of the functional group-containing monomer unit and a polymerizable group-containing compound having a substituent that reacts with the functional group react to introduce an energy beam polymerizable group. During this reaction, a part of the functional group of the functional group-containing monomer unit reacts with the polymerizable group-containing compound and is substituted. In the obtained energy ray-curable polymer (A), it is preferable to leave a small amount of unreacted functional group-containing monomer units in order to obtain a reaction point with a crosslinking agent described later. That is, the functional group-containing monomer unit of the energy ray-curable polymer (A) is usually 50 to 100 mol, preferably 60 to 95 mol, particularly preferably 70 to 95 mol of the structural unit derived from the functional group-containing monomer. It is substituted at a rate of 90 moles. The molecular structure in which the hydroxy group-containing (meth) acrylate and / or carboxyl group-containing compound itself has reacted with the polymerizable group-containing compound generally tends to increase the polarity of the energy ray-curable polymer. Therefore, when the mass ratio of the structural unit derived from the functional group-containing monomer in the polymer containing the functional group is in the above range, there is an effect of increasing the resistance of the adhesive layer to the low polarity solvent.

In addition to these monomers, the energy beam curable polymer (A) contains (meth) acrylic acid alkyl ester and (meth) acrylic acid ester other than functional group-containing monomers, vinyl formate, vinyl acetate, styrene, etc. It may be included as a body. As (meth) acrylic acid esters other than (meth) acrylic acid alkyl esters and functional group-containing monomers, from the viewpoint of increasing the polarity of the adhesive layer, (meth) acrylic acid alkoxyalkyl esters, (meth) acrylic acid Nonylphenoxypolyethylene glycol, tetrahydrofuran furfuryl acrylate, diacrylates which are esters of polyether and acrylic acid, and the like may be used.

It is preferable that the adhesive layer which has tolerance with respect to a highly polar solvent and is formed from an energy-beam curable adhesive contains an energy-beam curable polymer (B). The energy ray-curable polymer (B) has a property that an energy ray-polymerizable group is bonded to the main chain or side chain, and itself has a property of being cured by adhesion and energy ray irradiation.
The energy ray curable polymer (B) preferably contains 50 to 90% by mass, more preferably 65 to 90% by mass, and further preferably 75 to 90% by mass of a structural unit derived from an alkyl (meth) acrylate. contains. Further, in 100 parts by mass of the (meth) acrylic acid alkyl ester, the (meth) acrylic acid alkyl ester having 8 to 12 carbon atoms in the alkyl group is usually 95 parts by mass or more, preferably 96 parts by mass or more, more preferably 97 parts by mass. Occupies more than part by mass.

Examples of the (meth) acrylic acid alkyl ester include those exemplified for the (meth) acrylic acid alkyl ester in the energy ray-curable polymer (A). If the content of the structural unit derived from a (meth) acrylic acid alkyl ester having 8 to 12 carbon atoms in the alkyl group is too small, the resistance of the adhesive layer to the high-polarity solvent may decrease, while if it is too large, Although resistance to highly polar organic solvents is improved, sufficient adhesive strength may not be obtained. In the (meth) acrylic acid alkyl ester, it is preferable that isooctyl (meth) acrylate or lauryl (meth) acrylate accounts for more than 50 parts by mass in 100 parts by mass. When isooctyl (meth) acrylate is used, compared to 2-ethylhexyl (meth) acrylate having the same carbon number, a long hydrocarbon chain is present in the adhesive layer at a high density. Easy to improve. Moreover, since lauryl (meth) acrylate has an appropriate number of carbon atoms, it is easy to improve resistance to highly polar solvents. In 100 parts by mass of the (meth) acrylic acid alkyl ester, isooctyl (meth) acrylate or lauryl (meth) acrylate is preferably 65 parts by mass or more, and more preferably 80 parts by mass or more.

Further, examples of (meth) acrylic acid alkyl esters other than the above include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate and the like. When there is too much content of these (meth) acrylic-acid alkylesters, although adhesive force will increase, the tolerance with respect to the highly polar solvent of an adhesive bond layer may fall.

In addition, the energy ray curable polymer (B) contains a structural unit derived from a polymerizable monomer (other polymerizable monomer) other than (meth) acrylic acid alkyl ester, usually 15 to 50% by mass, preferably 15 to The content is 35% by mass, more preferably 15 to 25% by mass.

More specific examples of such a functional group-containing monomer include those exemplified for the functional group-containing monomer in the energy ray-curable polymer (A). You may use a functional group containing monomer individually by 1 type or in combination of 2 or more types.

In the polymer containing a functional group, the structural unit derived from the functional group-containing monomer is usually contained in a proportion of 15 to 50% by mass, preferably 15 to 35% by weight, particularly preferably 15 to 25% by weight. . An energy beam curable polymer (B) is obtained by introducing an energy beam polymerizable group into a polymer containing a functional group. At this time, a functional group of the functional group-containing monomer unit and a polymerizable group-containing compound having a substituent that reacts with the functional group react to introduce an energy beam polymerizable group. During this reaction, a part of the functional group of the functional group-containing monomer unit reacts with the polymerizable group-containing compound and is substituted. In the obtained energy beam curable polymer (B), it is preferable to leave a small amount of unreacted functional group-containing monomer units so as to be a reaction point with a crosslinking agent described later. That is, the functional group-containing monomer unit of the energy ray-curable polymer (B) is usually 50 to 100 mol, preferably 60 to 95 mol, particularly preferably 70 to 95 mol of the structural unit derived from the functional group-containing monomer. It is substituted at a rate of 90 moles.

The energy ray curable polymer (B) contains vinyl formate, vinyl acetate, styrene, vinyl acetate, dialkyl (meth) acrylamide, etc. as structural units in addition to (meth) acrylic acid alkyl ester and functional group-containing monomer. You may do it.

In the energy beam curable polymer (A) or (B), the energy beam polymerizable group bonded to the main chain or side chain of the polymer is, for example, a group containing an energy beam polymerizable carbon-carbon double bond. Specifically, a (meth) acryloyl group and the like can be exemplified. The energy beam polymerizable group may be bonded to the polymer via an alkylene group, an alkyleneoxy group, or a polyalkyleneoxy group.

The weight average molecular weight of the energy ray-curable polymer (A) or (B) is preferably 100,000 or more, preferably 100,000 to 1,500,000, particularly preferably 150,000 to 1 , 000,000. The glass transition temperature of the energy ray curable polymers (A) and (B) is usually about −70 to 30 ° C.

Specific examples of such energy beam curable polymers (A) and (B) will be further clarified from the process for producing energy beam curable polymers described below.

The energy ray-curable polymer is obtained by reacting a polymer (a1) containing a functional group with a polymerizable group-containing compound (a2) having a substituent that reacts with the functional group.

Hereinafter, although the manufacturing method of an energy beam curable polymer is explained in full detail, the energy beam curable polymer preferably used in this invention is not limited to what is obtained by the following manufacturing method.

The polymer (a1) containing a functional group is obtained by copolymerizing the above (meth) acrylic acid alkyl ester monomer, a functional group-containing monomer, and other monomers copolymerized as necessary. It is done. Under the present circumstances, it is preferable to adjust the compounding quantity of a monomer so that the above-mentioned predetermined composition may be satisfied as an essential or preferable aspect about energy-beam curable polymer (A) or (B).

The production method of the polymer (a1) is not particularly limited, and for example, a solution polymerization method in the presence of a solvent, a chain transfer agent, a polymerization initiator, etc., an emulsifier, a chain transfer agent, a polymerization initiator, It is produced by a method of emulsion polymerization in an aqueous system in the presence of a dispersant or the like.

An energy ray-curable polymer having a polymerizable group bonded thereto by reacting the polymer (a1) containing the functional group with a polymerizable group-containing compound (a2) having a substituent that reacts with the functional group. Is obtained.

The polymerizable group-containing compound (a2) contains a substituent capable of reacting with the functional group in the polymer (a1). This substituent varies depending on the type of the functional group. For example, when the functional group is a hydroxyl group or a carboxyl group, the substituent is preferably an isocyanate group or an epoxy group. When the functional group is a carboxyl group, the substituent is preferably an isocyanate group or an epoxy group, and the functional group is In the case of an amino group or a substituted amino group, the substituent is preferably an isocyanate group or the like, and when the functional group is an epoxy group, the substituent is preferably a carboxyl group. One such substituent is included for each molecule of the polymerizable group-containing compound (a2).

The polymerizable group-containing compound (a2) contains 1 to 5, preferably 1 to 2, energy beam polymerizable carbon-carbon double bonds per molecule. Specific examples of the polymerizable group-containing compound (a2) include methacryloyloxyethyl isocyanate, meta-isopropenyl-α, α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, glycidyl (meth) acrylate; (meth) Acrylic acid etc. are mentioned. Also, an acryloyl monoisocyanate compound obtained by reaction of a diisocyanate compound or polyisocyanate compound with hydroxyethyl (meth) acrylate; obtained by reaction of a diisocyanate compound or polyisocyanate compound, a polyol compound and hydroxyethyl (meth) acrylate. And acryloyl monoisocyanate compounds.

As the polymerizable group-containing compound (a2), a polymerizable group-containing polyalkyleneoxy compound represented by the following formula (1) can also be used. When such a polymerizable group-containing polyalkyleneoxy compound is used, the resistance of the adhesive layer to the low polarity solvent is improved, while the resistance of the adhesive layer to the high polarity solvent is inferior.

In the formula, R ¹ is hydrogen or a methyl group, preferably a methyl group, R ² to R ⁵ are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms, preferably hydrogen, and n is 2 It is an integer above, preferably 2-4. A plurality of R ² to R ⁵ may be the same as or different from each other. That is, since n is 2 or more, the polymerizable group-containing polyalkyleneoxy group represented by the formula (1) contains 2 or more R ² . In this case, two or more R ^{2 s} may be the same or different. The same applies to R ³ to R ⁵ . NCO represents an isocyanate group.

The polymerizable group-containing compound (a2) is usually used in a proportion of 50 to 100 mol, preferably 60 to 95 mol, particularly preferably 70 to 90 mol, per 100 mol of the functional group-containing monomer of the polymer (a1). . By leaving a part of the functional group in the polymer in an unreacted state, an adhesive force may be developed. Therefore, by adjusting the amount of the polymerizable group-containing compound (a2) introduced, Adhesive strength can be controlled.

The reaction between the polymer (a1) and the polymerizable group-containing compound (a2) is usually performed at a temperature of about room temperature and at normal pressure for about 24 hours. This reaction is preferably performed using a catalyst such as dibutyltin laurate in a solution such as ethyl acetate.

As a result, the functional group present in the side chain in the polymer (a1) reacts with the substituent in the polymerizable group-containing compound (a2), and the polymerizable group becomes a side chain in the polymer (a1). When introduced, an energy ray curable polymer is obtained.

In addition, when a polymerizable group-containing polyalkyleneoxy compound is used, an energy beam curable polymer in which the polymerizable group is bonded via the polyalkyleneoxy group is obtained. By introducing a polyalkyleneoxy group into the energy beam curable polymer, the elongation at break after energy beam curing of the energy beam curable polymer is improved.

The adhesive layer may have a crosslinked structure in which the energy beam curable polymer is crosslinked. By making the energy ray-curable polymer a crosslinked structure, resistance to a high polarity solvent or a low polarity solvent is improved. Moreover, it is possible to control the adhesive force between the base material protective film and the base material film. In the case of the energy ray curable polymer (B), when the adhesive layer does not contain a crosslinked structure, the adhesive strength in the adhesive layer of the pressure-sensitive adhesive sheet for electronic component processing before the adhesive layer is cured by irradiation with energy rays. Is excessively high, and there is a concern that the adhesive force in the adhesive layer of the pressure-sensitive adhesive sheet for electronic component processing after irradiation with energy rays cannot be sufficiently reduced. When the adhesive layer contains a cross-linked structure, the cross-link density of the energy ray curable polymer is controlled to an appropriate range by adjusting the amount of the cross-linking agent used to a range described later, thereby allowing electronic components to be controlled. The adhesive force in the adhesive layer of the processing pressure-sensitive adhesive sheet is not excessively lowered, and the resistance of the adhesive layer to the organic solvent tends to be maintained.

Examples of the crosslinking agent include organic polyvalent isocyanate compounds, organic polyvalent epoxy compounds, organic polyvalent imine compounds, and the like, and organic polyvalent isocyanate compounds are preferable.

Examples of organic polyvalent isocyanate compounds include aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, alicyclic polyvalent isocyanate compounds, trimers of these organic polyvalent isocyanate compounds, and these organic polyvalent isocyanate compounds. Examples thereof include terminal isocyanate urethane prepolymers obtained by reacting with a polyol compound.

More specific examples of the organic polyvalent isocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane-4,4. '-Diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, trimethylolpropane adduct Examples include tolylene diisocyanate and lysine isocyanate.

Specific examples of the organic polyvalent epoxy compound include 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, Examples include ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl aniline, and diglycidyl amine.

Specific examples of the organic polyvalent imine compound include N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, tetra Mention may be made of methylolmethane-tri-β-aziridinylpropionate and N, N′-toluene-2,4-bis (1-aziridinecarboxyamide) triethylenemelamine.

The amount of the crosslinking agent used for the energy ray-curable polymer (A) is the above-mentioned (meth) acrylic acid alkyl ester having 1 to 4 carbon atoms in the alkyl group, or (meta) having 1 or 2 carbon atoms in the alkyl group. ) Is appropriately set according to the content of the structural unit derived from the alkyl acrylate ester, but is generally preferably 0.01 to 100 parts by mass with respect to 100 parts by mass of the energy ray-curable polymer (A). It is used at a ratio of 10 parts by mass, more preferably 0.1 to 5 parts by mass, particularly preferably 0.5 to 3 parts by mass. If the amount of the crosslinking agent used is excessive, the adhesive layer will be excessively cured and sufficient adhesive strength may not be obtained. If the crosslinking is insufficient, the solvent resistance of the adhesive layer will be reduced. There are things to do.

The amount of the crosslinking agent used for the energy ray curable polymer (B) is appropriately determined according to the content of the structural unit derived from the alkyl group (meth) acrylic acid alkyl ester having 8 to 12 carbon atoms as described above. Set to In the adhesive layer, preferably 100 parts by mass of the energy ray curable polymer (B) does not contain a crosslinking agent, or 0.8 parts by mass with respect to 100 parts by mass of the energy ray curable polymer (B). It is contained in an amount of not more than mass parts, more preferably 0.005 to 0.3 parts by mass, particularly preferably 0.01 to 0.3 parts by mass. By adjusting the use amount of the crosslinking agent within such a range, an effect that the crosslinking density can be controlled within an appropriate range can be obtained.

The adhesive layer is formed using an adhesive composition in which an energy beam curable polymer and a photopolymerization initiator as necessary are blended. Furthermore, in order to improve various physical properties, the above-mentioned adhesive composition may contain other components (for example, the above-described crosslinking agent) as necessary. When the energy ray curable polymer is irradiated with energy rays in the presence of a photopolymerization initiator, it is cured and the adhesive strength is reduced. Specifically, ultraviolet rays, electron beams, etc. are used as the energy rays.

Examples of the photopolymerization initiator include photoinitiators such as benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, thioxanthone compounds and peroxide compounds, and photosensitizers such as amines and quinones. Include α-hydroxycyclohexyl phenyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, β-chloranthraquinone Examples include 2,4,6-trimethylbenzoyldiphenylphosphine oxide. When ultraviolet rays are used as energy rays, the irradiation time and irradiation amount can be reduced by adding a photopolymerization initiator.

The content of the photopolymerization initiator is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass with respect to 100 parts by mass of the energy ray curable polymer. When the content of the photopolymerization initiator is within such a range, the photopolymerization starts after curing of the energy beam curable polymer while obtaining the effect that the curing of the energy beam curable polymer proceeds efficiently. It can be avoided that the agent remains and causes trouble.

Further, instead of the photopolymerization initiator, a radical generating group may be introduced into the main chain or side chain of the energy beam curable polymer. Specifically, a radical generating group-containing monomer having a polymerizable double bond and a group (radical generating group) that generates a free radical (radical) that initiates a polymerization reaction under excitation by energy rays is converted into the above-mentioned acrylic. By copolymerizing with an acid alkyl ester or the like, a radical generating group can be introduced into the energy ray-curable polymer. Details of such a radical generating group-containing monomer are described, for example, in JP-A No. 2010-215769.

Furthermore, the adhesive layer has a polymer, energy beam polymerizable compound, dye, pigment, anti-degradation agent, antistatic agent, flame retardant, silicone compound other than the above as long as the resistance to the organic solvent is not excessively impaired. A chain transfer agent or the like may be added.

The thickness of the adhesive layer composed of the above components is not particularly limited, and is preferably 3 to 50 μm, more preferably 5 to 20 μm. When the thickness of the adhesive layer is within the above range, the adhesion between the base film and the base protective film is increased, and the space between the base film and the base protective film is sealed. Even when washed with a polar solvent or a highly polar solvent), the organic solvent does not enter between the base film and the base protective film, and the swelling and dissolution of the base film by the organic solvent is suppressed. It is possible to prevent wrinkles from occurring on the base film. Therefore, deformation of the pressure-sensitive adhesive layer due to generation of wrinkles in the base film is prevented, and voids are not generated at the interface between the adherend and the ring frame and the pressure-sensitive adhesive layer. It hardly penetrates into the interface between the frame and the adhesive layer. As a result, swelling or dissolution of the pressure-sensitive adhesive layer at the interface between the adherend and the ring frame and the pressure-sensitive adhesive layer is suppressed, and sufficient adhesion can be maintained for the adherend and the ring frame. The ring frame can be prevented from falling off the adhesive sheet.

(Manufacturing method of pressure-sensitive adhesive sheet for processing electronic parts)
The manufacturing method of the adhesive sheet for electronic component processing of this invention is not specifically limited.
For example, the following method is mentioned as a method of laminating | stacking a base film and a base material protective film through an adhesive bond layer.
In the first method, the adhesive is diluted with an appropriate solvent as necessary to obtain an adhesive composition, which is applied onto the release sheet so as to have a predetermined dry film thickness and dried to form an adhesive layer. To do. And an adhesive bond layer is transcribe | transferred on the surface of a base film or a base-material protective film. Then, it is the method of laminating | stacking the base material protective film in which the adhesive bond layer is not formed, or a base film on said adhesive bond layer.
In the second method, the adhesive composition is directly applied to the surface of the base film or the base material protective film and dried to form an adhesive layer. Then, it is the method of laminating | stacking the base material protective film in which the adhesive bond layer is not formed, or a base film on said adhesive bond layer.

Examples of the method for providing the pressure-sensitive adhesive layer on the surface of the base film include the following methods.
In the first method, the pressure-sensitive adhesive is diluted with an appropriate solvent as necessary to form a pressure-sensitive adhesive composition, and applied to the release sheet so as to have a predetermined dry film thickness and dried to form a pressure-sensitive adhesive layer. To do. And it is the method of transferring an adhesive layer on the surface of a base film.
The second method is a method in which the pressure-sensitive adhesive composition is directly applied to the surface of the base film and dried to form a pressure-sensitive adhesive layer.

When the adhesive layer is provided directly on the surface of the base film, or when the base film is laminated on the adhesive layer provided on the surface of another sheet, the base film is in a state where the adhesive layer is provided. Even before, a state before an adhesive layer is provided may be sufficient.

Further, a release sheet may be laminated on the pressure-sensitive adhesive layer in order to protect the pressure-sensitive adhesive layer before use. The release sheet is not particularly limited. For example, a film made of a resin such as polyethylene terephthalate, polypropylene, or polyethylene or a foamed film thereof, paper such as glassine paper, coated paper, laminated paper, silicone-based, fluorine A system and a release agent such as a long chain alkyl group-containing carbamate can be used.

The adhesive force with the silicon mirror wafer as an adherend of the adhesive sheet for processing electronic parts from which the base material protective film has been removed before irradiation of energy rays to the adhesive layer is preferably 500 mN / 25 mm or more, more preferably 1000 to 30000 mN / 25 mm, particularly preferably 2000 to 30000 mN / 25 mm. Adhesive strength before irradiation with energy rays is in such a range, so that the adhesiveness at the interface between the adhesive layer and the adherend surface becomes high, and the adhesive sheet for processing electronic components has resistance to organic solvents. It becomes possible to raise more. The adhesive strength before energy ray irradiation can be adjusted by the type and blending ratio of the (meth) acrylic acid alkyl ester and the amount of the crosslinking agent used.

The adhesive strength of the adhesive sheet for processing an electronic component from which the base material protective film has been removed after irradiation of the adhesive layer with energy rays is preferably 10 to 500 mN / 25 mm, more preferably 10 to 300 mN / 25 mm. is there. By setting the adhesive strength of the pressure-sensitive adhesive layer within the above range, the dicing property and the pickup property are excellent. The adhesive strength after energy beam irradiation can be controlled by the amount of energy beam polymerizable groups introduced into the energy beam curable polymer of the energy beam curable adhesive.

(Method for manufacturing semiconductor device)
The pressure-sensitive adhesive sheet for processing electronic parts according to the present invention has a dicing sheet used for holding the wafer and the chip to be generated when the wafer is singulated or a group of singulated chips transferred to the chip. It is preferably used as a pickup sheet used for picking up the material. After the chip is peeled off from the dicing sheet or the pickup sheet, it is incorporated into a circuit board or the like according to a conventional method to obtain a semiconductor device.

In particular, the pressure-sensitive adhesive sheet of the present invention is preferably applied to a semiconductor device manufacturing process including a step in which an adherend (wafer, chip) held on a sheet comes into contact with an organic solvent. This contact step is not particularly limited as long as it is a step of bringing the laminate of the pressure-sensitive adhesive sheet and the adherend into contact with an organic solvent while holding the adherend on the pressure-sensitive adhesive sheet. For example, on the adherend Examples include a cleaning process of the remaining adhesive (adhesive removal process) and peeling of the adherend from the support on which the adherend is fixed by the adhesive (adhesive and support removal process).

Since ultra-thin wafers and TSV wafers are extremely fragile, they may be damaged in the back grinding process, the subsequent processing process, and the transfer process. Therefore, during these steps, the wafer is held on a hard support such as glass via an adhesive (for example, an adhesive composed of an acrylic or polyimide adhesive).

The pressure-sensitive adhesive sheet of the present invention can be used as a dicing sheet for transferring a wafer on which a predetermined process has been completed. When the pressure-sensitive adhesive sheet of the present invention is used as a dicing sheet, for example, after fixing the outer periphery of the dicing sheet with a ring frame, the wafer is cut into circuits to form chips, and then the substrate protective film is formed from the dicing sheet. The chip is picked up from the laminate of the remaining base film and the pressure-sensitive adhesive layer after being peeled and removed. When transferring a wafer from a hard support to a dicing sheet, for example, a laminate of a dicing sheet, an adherend (wafer), and a hard support is immersed in an organic solvent, or a frame slightly larger than the adherend. Is placed so as to surround the adherend, and the organic solvent is brought into contact with the adhesive by introducing an organic solvent into the frame, and the adhesive is dissolved or swollen to be peeled off from the hard support. At this time, since the laminate of the dicing sheet (adhesive sheet) and the wafer comes into contact with the organic solvent, the adhesive sheet of the present invention can be preferably used. As another method, the wafer-side surface of the hard support to which the wafer is fixed is stuck on the dicing sheet, the hard support is peeled off from the wafer, and the wafer is transferred to the dicing sheet. When the hard support is peeled off, the hard support may be peeled off by heating to soften the adhesive to slide the hard support or by decomposing the adhesive by laser light irradiation. In this case, the laminate of the adhesive sheet and the wafer does not come into contact with the organic solvent when the adherend is peeled from the support. However, the adhesive and its decomposition products may remain on the wafer surface after the hard support is peeled off.

The pressure-sensitive adhesive sheet of the present invention can also be preferably used in a semiconductor device manufacturing process including a step of washing a wafer with the adhesive adhered as described above with an organic solvent. The wafer is cleaned with an organic solvent while being held on the pressure-sensitive adhesive sheet of the present invention. Also in this cleaning, cleaning is performed by bringing an organic solvent into contact with the laminate of the pressure-sensitive adhesive sheet and the wafer by the same method as that for peeling the hard support described above. At this time, a ring frame may be attached to the outer peripheral portion of the adhesive sheet.

In addition, the pressure-sensitive adhesive sheet of the present invention is a pickup sheet for holding a wafer on a hard support, and after grinding the back surface and processing steps, separating the wafer into chips and transferring the chips to pick them up. Can also be used. Since it is difficult to directly pick up the chip from the hard support, the chip can be easily picked up by transferring the chip onto a soft pickup sheet. In this process as well as the process using the dicing sheet described above, there is a case where the pickup sheet (adhesive sheet) and the adherend (chip) come into contact with an organic solvent when the hard support is peeled off. In addition, the adhesive or its decomposition product may remain on the chip transferred onto the pickup sheet as well, and a cleaning process may be performed. As the pickup sheet in the production method including these steps, the pressure-sensitive adhesive sheet of the present invention is preferably used.

The organic solvent used for cleaning varies depending on the composition of the adhesive used to fix the wafer on the hard support, and the SP value is 9 (cal / cm ³ ) ^1/2 as a low polarity organic solvent. Less than 6 (cal / cm ³ ) ^1/2 or more and less than 9 (cal / cm ³ ) ^1/2 or even 7 (cal / cm ³ ) ^1/2 or more but less than 9 (cal / cm ³ ) ^1/2 It is preferable to use an organic solvent, particularly d-limonene (SP value: 8.2 (cal / cm ³ ) ^1/2 ) or 1-dodecene (SP value: 7.9 (cal / cm ³ ) ^1/2 ). ) Is preferably used. Further, as a highly polar organic solvent, the SP value is 9 (cal / cm ³ ) ^1/2 or more, 9 to 12 (cal / cm ³ ) ^1/2 , and further 10 to 12 (cal / cm ³ ) ^1/2. It is preferable to use N-methylpyrrolidone (NMP) (SP value: 11 (cal / cm ³ ) ^1/2 ).

In addition, SP value (solubility parameter value) in this specification is a characteristic value about the compatibility of an organic substance, The details are described in the solvent handbook (Matsuda Tanemitsu 1962 Sangyo Tosho Co., Ltd.), for example. .

Such a pressure-sensitive adhesive sheet and method of the present invention can be preferably applied particularly to a wafer or a chip provided with a protruding electrode on which an adhesive easily adheres. Examples of the protruding electrode include a cylindrical electrode and a spherical electrode. In particular, it can be suitably used for a wafer chip having a penetrating electrode that has been increasingly used in recent years.

When dicing the wafer affixed to the pressure-sensitive adhesive sheet or picking up chips from the pressure-sensitive adhesive sheet, it is preferable to peel off the substrate protective film of the pressure-sensitive adhesive sheet according to the present invention as necessary. By peeling the base material protective film, the chip can be easily picked up due to the characteristics of the base film having high flexibility and high flexibility. Thereafter, the adhesive sheet is expanded to separate the intervals between the semiconductor chips, and then the semiconductor chips are picked up by a general-purpose means such as a suction collet. Further, the adhesive layer may be irradiated with energy rays to reduce the adhesive strength, and then expanded and picked up.

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to these examples. In the following examples and comparative examples, “flexibility of base film”, “change rate of Young's modulus of base material protective film”, and “RF dropout, wafer dropout, wrinkle, penetration amount, pickup appropriateness” are Evaluation was performed as follows.

<Flexibility of base film>
In accordance with the 45 ° cantilever method described in JIS L1086; 2007, the longitudinal direction of the base film was measured in accordance with the vertical direction of the test piece.

<Change rate of Young's modulus of substrate protective film>
The rate of change of the Young's modulus of the base material protective film after being immersed in the organic solvent is based on the Young's modulus A of the base material protective film before being immersed in the organic solvent and the Young's modulus B of the base material protective film after being immersed in the organic solvent. , Calculated by the following formula.
The Young's modulus of the base material protective film is determined by using a universal tensile tester (Tensilon RTA-T-2M manufactured by Orientec Co., Ltd.) in accordance with JIS K7161: 1994 under an environment of 23 ° C. and 50% humidity. It was measured at 200 mm / min. For Comparative Examples 1 to 6 having no base material protective film, the Young's modulus of the base film was measured and the rate of change was calculated. The types of organic solvents and the immersion conditions are as shown in Table 1.
Change rate of Young's modulus (%) = (AB) / A × 100

<RF dropout, wafer dropout, wrinkles, penetration amount, pick-up suitability>
A mirror surface of a silicon wafer (diameter 8 inches, thickness 50 μm) whose one side is mirror-polished (# 2000) is pasted on the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet prepared in Examples and Comparative Examples (23 ° C., pressure of 0.3 MPa). The sticking speed was 5 mm / second). A ring frame (RF) was attached to the outer periphery of the adhesive sheet under the same conditions. The laminate of RF, silicon wafer, and adhesive sheet was immersed in the organic solvent described in Table 1 under the immersion conditions described in Table 1. The SP value of N-methylpyrrolidone is 11.2 (cal / cm ³ ) ^1/2 , the SP value of d-limonene is 8.2 (cal / cm ³ ) ^1/2 and the SP value of 1-dodecene. Is 7.9 (cal / cm ³ ) ^1/2 .

After completion of immersion, the presence or absence of RF and wafer removal was confirmed. Regarding the omission of RF, in the table, “◯” indicates that there is no omission and “x” indicates that it has omission. Regarding the wafer drop-off, “◯” in the table indicates that no peeling occurred, and “△” indicates that peeling occurred in an area of less than 50% of the area of the adhesive sheet attached to the wafer. “X” indicates that peeling occurred in an area of 50% or more of the area of the adhesive sheet attached to the wafer.

Also, the presence or absence of “wrinkles” generated on the base film of the pressure-sensitive adhesive sheet was visually confirmed.

Further, the penetration of the organic solvent at the interface between the wafer and the pressure-sensitive adhesive layer was visually observed, and the penetration distance of the organic solvent that had penetrated between the wafer and the pressure-sensitive adhesive layer was measured. When peeling of the pressure-sensitive adhesive sheet from the wafer occurred, that is, when it was “Δ” or “x” in the evaluation of the removal of the wafer, measurement was impossible.

After that, for the pressure-sensitive adhesive sheet from which the pressure-sensitive adhesive sheet peeled off from the wafer, that is, the pressure-sensitive adhesive sheet excluding the pressure-sensitive adhesive sheet that was evaluated as “△” or “×” in the evaluation of the removal of the wafer, Dicing was performed under the conditions of a blade feed rate of 50 mm / sec, a blade rotation speed of 30000 rpm, and a base film with a cutting depth of 20 μm to obtain a 10 mm × 10 mm chip group. Next, the adhesive sheet was irradiated with ultraviolet rays under a nitrogen atmosphere (illuminance 230 mW / cm ² , light quantity 190 mJ / cm ² ) using an ultraviolet irradiation device (RAD-2000m / 12 manufactured by Lintec Corporation), and the adhesive layer of the adhesive sheet After reducing the tackiness of both the adhesive layer and the adhesive layer, the base material protective film was removed when the pressure sensitive adhesive sheet had a base material protective film. These chips were pushed up by 4 pins attached to the pickup device under the conditions of a push-up amount of 1000 μm and a push-up speed of 1 mm / second, and picked up by a collet. The case where pick-up was possible was designated as “A”, and the case where chip cracking occurred was designated as “B”. When the wafer dropout was evaluated as “Δ” or “×”, dicing could not be performed, so this evaluation was not performed, and “measurement impossible” was described in Table 1.

(Example 1)
[Preparation of pressure-sensitive adhesive composition (1)]
Acrylic polymer obtained by reacting 2-ethylhexyl acrylate / 2-hydroxyethyl acrylate = 80/20 (mass ratio), and 21.4 g per 100 g of the acrylic polymer (2-hydroxyethyl acrylate unit of acrylic polymer) 100 parts by mass of an energy ray-curable polymer (weight average molecular weight: 600,000) obtained by reacting with 80 mol of methacryloyloxyethyl isocyanate (MOI) per 100 mol, a photopolymerization initiator (α-hydroxycyclohexylphenyl) 3 parts by weight of ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) and 1 part by weight of a crosslinking agent (addition product of TDI-TMP toluene diisocyanate and trimethylolpropane triacrylate) are mixed in a solvent Agent composition (1) was obtained. . The weight average molecular weight is measured using a commercially available molecular weight measuring instrument (main product name “HLC-8220GPC”, manufactured by Tosoh Corporation; column product name “TSKGel SuperHZM-M”, manufactured by Tosoh Corporation; developing solvent tetrahydrofuran). (The same applies hereinafter). Moreover, even if a mass part is a thing of the packing form diluted with a solvent, all are values of solid content conversion (hereinafter, the same).

[Production of Adhesive Composition (1)]
An acrylic polymer obtained by reacting lauryl acrylate / 2-hydroxyethyl acrylate = 80/20 (mass ratio) and 21.4 g per 100 g of the acrylic polymer (100 mol of 2-hydroxyethyl acrylate units of the acrylic polymer) 100 parts by mass of an energy ray-curable polymer (weight average molecular weight: 600,000) obtained by reacting with 80 mol of methacryloyloxyethyl isocyanate (MOI), a photopolymerization initiator (α-hydroxycyclohexyl phenyl ketone ( Ciba Specialty Chemicals Co., Ltd. Irgacure 184)) 3 parts by mass, and 0.1 parts by mass of a cross-linking agent (addition product of TDI-TMP toluene diisocyanate and trimethylolpropane triacrylate) are mixed in a solvent and bonded. An agent composition (1) was obtained.

[Preparation of adhesive sheet]
The pressure-sensitive adhesive composition (1) is applied to a release film (SP-PET3811 manufactured by Lintec Corporation) so that the thickness after drying is 10 μm (drying conditions: 100 ° C., 1 minute), and then the release film The pressure-sensitive adhesive layer formed above was obtained. Next, the pressure-sensitive adhesive layer and the base film (ethylene vinyl acetate copolymer film, 120 μm thickness, bending resistance: 125 mm) were bonded together to obtain a laminate A of the pressure-sensitive adhesive layer and the base film.
Further, the adhesive composition (1) was applied to a release film (SP-PET 3811 manufactured by Lintec Corporation) and dried (drying conditions: 100 ° C., 1 minute) so that the thickness after drying was 10 μm. An adhesive layer formed on the release film was obtained. Next, the adhesive layer and the base material protective film (polyethylene terephthalate film, 50 μm thickness, bending resistance: 101 mm) were bonded together to obtain a laminate B of the adhesive layer and the base material protective film.
The release film on the adhesive layer of the laminate B was removed, and the adhesive layer of the laminate B was bonded to the base film side of the laminate A to obtain an adhesive sheet. Then, each evaluation was performed by removing the release film on the pressure-sensitive adhesive layer. The results are shown in Table 1.

(Example 2)
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the base film was replaced with an ethylene / (meth) acrylic acid copolymer film (80 μm thickness, bending resistance: 110 mm). The results are shown in Table 1.

(Example 3)
The following pressure-sensitive adhesive composition (2) was used as the pressure-sensitive adhesive composition. Further, the base film was replaced with an ethylene / (meth) acrylic acid copolymer film (80 μm thickness, bending resistance: 110 mm), and the base protective film was replaced with a polypropylene film (140 μm). Except for the above, a pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1. The results are shown in Table 1.

[Preparation of pressure-sensitive adhesive composition (2)]
Acrylic polymer obtained by reacting 2-ethylhexyl acrylate / 2-hydroxyethyl acrylate = 80/20 (mass ratio), and 21.4 g per 100 g of the acrylic polymer (2-hydroxyethyl acrylate unit of acrylic polymer) 100 parts by mass of an energy ray-curable polymer (weight average molecular weight: 600,000) obtained by reacting with 80 mol of methacryloyloxyethyl isocyanate (MOI) per 100 mol, a photopolymerization initiator (α-hydroxycyclohexylphenyl) 3 parts by weight of ketone (Irgacure 184 manufactured by Ciba Specialty Chemicals Co., Ltd.) and 0.3 part by weight of a crosslinking agent (addition product of TDI-TMP toluene diisocyanate and trimethylolpropane triacrylate) are mixed in a solvent. The pressure-sensitive adhesive composition (2) Obtained.

Example 4
[Preparation of pressure-sensitive adhesive composition (3)]
An acrylic polymer obtained by reacting 2-ethylhexyl acrylate / vinyl acetate / 2-hydroxyethyl acrylate = 40/40/20 (mass ratio) and 21.4 g (100% of acrylic polymer) per 100 g of the acrylic polymer. -100 parts by mass of an energy ray-curable polymer (weight average molecular weight: 600,000) obtained by reacting methacryloyloxyethyl isocyanate (MOI) of 80 mol per 100 mol of hydroxyethyl acrylate units, a photopolymerization initiator ( 3 parts by mass of α-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) and 1 part by mass of a crosslinking agent (addition product of TDI-TMP toluene diisocyanate and trimethylolpropane triacrylate) in a solvent Mixed with adhesive A composition (3) was obtained.

[Preparation of adhesive composition (2)]
Acrylic polymer obtained by reacting butyl acrylate / methyl methacrylate / 2-hydroxyethyl acrylate = 65/15/20 (mass ratio), and 21.4 g (acrylic polymer 2-hydroxy) per 100 g of the acrylic polymer 100 parts by mass of an energy ray-curable polymer (weight average molecular weight: 600,000) obtained by reacting methacryloyloxyethyl isocyanate (MOI) of 80 mol per 100 mol of ethyl acrylate unit, a photopolymerization initiator (α- 3 parts by weight of hydroxycyclohexyl phenyl ketone (Irgacure 184 manufactured by Ciba Specialty Chemicals Co., Ltd.) and 2 parts by weight of a crosslinking agent (addition product of TDI-TMP toluene diisocyanate and trimethylolpropane triacrylate) are mixed in a solvent. Adhesive group A product (2) was obtained.

[Preparation of adhesive sheet]
The pressure-sensitive adhesive composition (3) is applied to a release film (SP-PET3811 manufactured by Lintec Corporation) and dried (drying conditions: 100 ° C., 1 minute) so that the thickness after drying is 10 μm. The pressure-sensitive adhesive layer formed above was obtained. Next, the pressure-sensitive adhesive layer and the base film (ethylene / (meth) acrylic acid copolymer film, 80 μm thickness, bending resistance: 110 mm) are bonded together, and a laminate A of the pressure-sensitive adhesive layer and the base film is obtained. Obtained.
Further, the adhesive composition (2) was applied to a release film (SP-PET3811 manufactured by Lintec Corporation) and dried (drying conditions: 100 ° C., 1 minute) so that the thickness after drying was 10 μm. An adhesive layer formed on the release film was obtained. Next, the adhesive layer and the base material protective film (polyethylene terephthalate film, 50 μm thickness) were bonded together to obtain a laminate B of the adhesive layer and the base material protective film.
The release film on the adhesive layer of the laminate B was removed, and the adhesive layer of the laminate B was bonded to the base film side of the laminate A to obtain an adhesive sheet. Then, each evaluation was performed by removing the release film on the pressure-sensitive adhesive layer. The results are shown in Table 1.

(Example 5)
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 4 except that the following pressure-sensitive adhesive composition (4) was used as the pressure-sensitive adhesive composition. The results are shown in Table 1.

[Preparation of pressure-sensitive adhesive composition (4)]
Acrylic polymer obtained by reacting butyl acrylate / 2-hydroxyethyl acrylate = 80/20 (mass ratio), and 21.4 g (100 mol of 2-hydroxyethyl acrylate unit of acrylic polymer) per 100 g of the acrylic polymer 100 parts by mass of an energy ray-curable polymer (weight average molecular weight: 600,000) obtained by reacting with 80 mol of methacryloyloxyethyl isocyanate (MOI), a photopolymerization initiator (α-hydroxycyclohexyl phenyl ketone ( Ciba Specialty Chemicals Co., Ltd. Irgacure 184)) 3 parts by mass and cross-linking agent (adduct of TDI-TMP toluene diisocyanate and trimethylolpropane triacrylate) 0.4 parts by mass were mixed in a solvent and adhered. An agent composition (4) was obtained.

(Example 6)
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 5 except that the substrate protective film was replaced with a polypropylene film (140 μm thickness). The results are shown in Table 1.

(Comparative Example 1)
Instead of the pressure-sensitive adhesive sheet for processing electronic parts, a sheet consisting only of the laminate A of the pressure-sensitive adhesive layer and the base film in Example 1 was used for each evaluation. The results are shown in Table 1.

(Comparative Example 2)
A pressure-sensitive adhesive sheet was obtained in the same manner as in Comparative Example 1 except that the base film was replaced with an ethylene / (meth) acrylic acid copolymer film (120 μm thickness). The results are shown in Table 1.

(Comparative Example 3)
Instead of the pressure-sensitive adhesive sheet for processing electronic parts, a sheet consisting only of the laminate A of the pressure-sensitive adhesive layer and the base film in Example 4 was used for each evaluation. The results are shown in Table 1.

(Comparative Example 4)
Instead of the pressure-sensitive adhesive sheet for processing electronic parts, a sheet consisting only of the laminate A of the pressure-sensitive adhesive layer and the base film in Example 5 was used for each evaluation. The results are shown in Table 1.

(Comparative Example 5)
Instead of the electronic component processing pressure-sensitive adhesive sheet, a sheet consisting only of the laminate B of the adhesive layer and the base material protective film in Example 1 was used for each evaluation. The results are shown in Table 1.

(Comparative Example 6)
Instead of the pressure-sensitive adhesive sheet for processing electronic parts, a sheet consisting only of the laminate B of the adhesive layer and the base material protective film in Example 4 was used for each evaluation. The results are shown in Table 1.

Claims

It consists of a base film, a pressure-sensitive adhesive layer provided on one surface of the base film, and a base material protective film provided in a peelable manner on the other surface of the base film,
The bending resistance of the base film is 105 mm or more,
The pressure-sensitive adhesive sheet for processing electronic parts, wherein the substrate protective film is a single type or a combination of two or more types selected from a polyester film or a polyolefin film.
The pressure-sensitive adhesive sheet for processing electronic parts according to claim 1, wherein the polyester film is selected from the group consisting of a polyethylene terephthalate film, a polyethylene naphthalate film, a polybutylene terephthalate film, and a polybutylene naphthalate film.
The pressure-sensitive adhesive sheet for processing electronic parts according to claim 1, wherein the polyolefin film is selected from the group consisting of a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polystyrene film, and a cycloolefin film.
The pressure-sensitive adhesive sheet for processing electronic parts according to any one of claims 1 to 3, wherein the thickness of the substrate protective film is less than 300 µm.
5. The method according to claim 1, which is used in a step of bringing a laminate of the pressure-sensitive adhesive sheet and the wafer or chip into contact with an organic solvent in a state where the semiconductor wafer or chip is held on the pressure-sensitive adhesive sheet for electronic component processing. Adhesive sheet for processing electronic parts.
(I) Whether the SP value is 9 (cal / cm 3 ) 1/2 or more, and the change rate of the Young's modulus of the base material protective film after being immersed in an organic solvent at 80 ° C. for 1 minute is 8% or less. Or (ii) the SP value is less than 9 (cal / cm 3 ) 1/2 and the change rate of the Young's modulus of the base material protective film after being immersed in an organic solvent at 25 ° C. for 24 hours is 8% or less The pressure-sensitive adhesive sheet for processing electronic parts according to claim 5.
A method of manufacturing a semiconductor device, comprising: a step of bringing a laminate of the pressure-sensitive adhesive sheet and the wafer into contact with an organic solvent in a state where the semiconductor wafer is held on the pressure-sensitive adhesive sheet for electronic component processing according to any one of claims 1 to 6. Method.
The method of manufacturing a semiconductor device according to claim 7, wherein the SP value of the organic solvent is 7 to 12 (cal / cm 3 ) 1/2 and the contact step is a step of removing the adhesive or the adhesive and the support.
9. The method for manufacturing a semiconductor device according to claim 7, wherein the semiconductor wafer is a wafer provided with a protruding electrode.
A method for manufacturing a semiconductor device, comprising the step of bringing a laminate of the pressure-sensitive adhesive sheet and the chip into contact with an organic solvent in a state where the semiconductor chip is held on the pressure-sensitive adhesive sheet for processing electronic components according to any one of claims 1 to 6. Method.
11. The method for manufacturing a semiconductor device according to claim 10, wherein the SP value of the organic solvent is 7 to 12 (cal / cm 3 ) 1/2 and the contact step is a step of removing the adhesive or the adhesive and the support.
12. The method of manufacturing a semiconductor device according to claim 10, wherein the semiconductor chip is a chip provided with a protruding electrode.