KR20180118599A - Semiconductor processing sheet - Google Patents

Abstract

A semiconductor processed sheet comprising a base film and a pressure-sensitive adhesive layer laminated on at least one side of the base film, wherein the base film contains a vinyl chloride resin, an adipate ester plasticizer and a terephthalate ester plasticizer as plasticizers , And the mass ratio of the content of the adipate ester plasticizer to the total content of the adipic ester plasticizer and the terephthalate ester plasticizer in the base film is 50 to 80 mass%. According to such a semiconductor processed sheet, sufficient flexibility is exhibited while using a substitute material of a phthalic acid alkyl ester as a plasticizer, and generation of a residue when peeling from an adherend can be suppressed.

Description

Semiconductor processing sheet

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor processing sheet to which a workpiece such as a semiconductor wafer is to be attached when the workpiece is processed.

For example, semiconductor wafers such as silicon and gallium arsenide, and various package types (hereinafter collectively referred to as " workpieces ") may be manufactured in a large diameter state, (Dicing), and is individually peeled (picked up) and transferred to the mounting process, which is the next step. At this time, a workpiece such as a semiconductor wafer is provided in each step of dicing, cleaning, drying, exposing, picking up, and mounting in a state of being adhered to a semiconductor processing sheet having a base film and a pressure-sensitive adhesive layer.

In the expansion, in order to facilitate picking up of the chips, the semiconductor processing sheet is extended to separate the chip intervals, and after the pickup, the semiconductor processing sheet is returned to its original state. Therefore, a base film of a semiconductor-processed sheet, particularly a semiconductor-processed sheet, is required to be stretchable (expandable) capable of expansion and restoration. Therefore, a polyvinyl chloride film containing a plasticizer is often used as the substrate film (Patent Documents 1 and 2).

As plasticizers incorporated in polyvinyl chloride, alkyl esters of phthalic acid, typically dioctyl phthalate (DOP) or dibutyl phthalate (DBP), are used. A flexible polyvinyl chloride (PVC) film containing a plasticizer such as DOP or DBP has been extensively used as a base material for a semiconductor processing sheet because it has rigidity possessed by its excellent mechanical properties (PVC) and flexibility by a plasticizer .

However, phthalate alkyl esters, such as DOP and DBP, are candidates to be regulated under the Restriction of Hazardous Substances Directive (RoHS) in Europe and are also subject to REACH (Europe for the protection of human health and the environment in the European Union) Parliament and the Council of Europe Rules), SVHC (High Concern substance). For this reason, the use of phthalic acid alkyl esters in the future is highly likely to be limited, and search for alternative substances has been made.

As an alternative to the phthalate alkyl ester, there has been proposed a pressure-sensitive adhesive sheet using di (2-ethylhexyl) terephthalate or adipic acid polyester as a vinyl chloride based plasticizer (Patent Documents 3 and 4).

Japanese Laid-Open Patent Publication No. 2001-207140 Japanese Laid-Open Patent Publication No. 2010-260893 Japanese Laid-Open Patent Publication No. 2012-184369 Japanese Laid-Open Patent Publication No. 2015-187245

In the case of a semiconductor processed sheet having a pressure-sensitive adhesive layer formed on one side of a vinyl chloride base material, the plasticizer in the base material is transferred into the pressure-sensitive adhesive layer and flows into the pressure-sensitive adhesive layer have. In such a case, depending on the choice of the plasticizer, the problem that the plasticizer itself remains as a residue on the semiconductor when peeling the semiconductor-processed sheet from the semiconductor or remains in the semiconductor as a mixture with the component of the adhesive (hereinafter, There may be a case where a " residual object "

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a semiconductor processing sheet capable of exhibiting sufficient flexibility while using a substitute material of phthalic acid alkyl ester as a plasticizer, And to provide the above-mentioned objects.

The present inventors have found that residues are generated when a terephthalate ester plasticizer is used as a plasticizer based on a vinyl chloride base material or when an adipate ester plasticizer is used but when a terephthalate ester plasticizer and an adipate ester plasticizer are mixed at a predetermined ratio The inventors of the present invention have completed the present invention.

That is, first, the present invention provides a semiconductor processed sheet comprising a base film and a pressure-sensitive adhesive layer laminated on at least one side of the base film, wherein the base film comprises a vinyl chloride resin and an adipic ester- Wherein the mass ratio of the content of the adipic ester-based plasticizer to the total content of the adipic ester plasticizer and the terephthalate ester plasticizer in the base film is 50% And 80% by mass, based on the total weight of the composition. (Invention 1)

The base film of the semiconductor processed sheet related to the invention (Invention 1) exhibits sufficient flexibility while using a substitute material of a phthalic acid alkyl ester as a plasticizer. The base film of the semiconductor processed sheet according to the invention (Invention 1) contains an adipate ester plasticizer and a terephthalate ester plasticizer at a predetermined ratio, and therefore, The occurrence of the residue is suppressed when peeling from the adherend.

In the above invention (Invention 1), the 25% stress in the MD direction in the tensile test according to JIS K7161-1: 2014 of the base film is preferably 5 to 16 MPa (Invention 2).

In the invention (Invention 1 or 2), it is preferable that the total content of the plasticizer in the base film is 18 to 65 parts by mass relative to 100 parts by mass of the vinyl chloride resin (Invention 3).

In the invention (Inventions 1 to 3), it is preferable that the adipic acid ester plasticizer contains adipic acid polyester (Invention 4), and the adipic acid polyester has a number average molecular weight of 400 to 1500 (Invention 5).

In the above inventions (Invention 1 to 5), it is preferable that the adipic acid ester plasticizer contains an adipic ester monomer (invention 6).

In the above invention (Invention 6), the adipic ester monomer may be at least one selected from the group consisting of di (2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate and di (2-butoxyethyl adipate) (Invention 7). ≪ tb > < TABLE >

In the above invention (inventions 1 to 7), it is preferable that the terephthalate ester plasticizer is di (2-ethylhexyl) terephthalate (invention 8).

The semiconductor processed sheet according to the above invention (inventions 1 to 8) is characterized in that the content of the di (2-ethylhexyl) phthalate, dibutyl phthalate, benzyl butyl phthalate and diisobutyl phthalate is 0.001% (Invention 9).

In the above invention (Invention 1 to 9), it is preferable that the pressure-sensitive adhesive layer is formed of an energy ray-curable pressure-sensitive adhesive composition (invention 10).

According to the present invention, there is provided a semiconductor processed sheet which exhibits sufficient flexibility while using a substitute material of a phthalic acid alkyl ester as a plasticizer and can suppress the generation of a residue when peeling off from an adherend.

A semiconductor processed sheet according to one embodiment of the present invention will be described below.

[Base film]

The base film included in the semiconductor processed sheet according to the present embodiment contains a vinyl chloride resin and also contains an adipate ester plasticizer and a terephthalate ester plasticizer as plasticizers at a predetermined ratio.

1. Vinyl chloride resin

The base film used in the present embodiment contains a vinyl chloride resin. The vinyl chloride resin means all of the polymers having a repeating unit represented by -CH ₂ -CHCl-, and includes a copolymer of vinyl chloride and a polymerizable monomer such as a homopolymer of vinyl chloride, an ethylene-vinyl chloride copolymer, Vinyl copolymers and the like, and further chlorinated polyolefins which are similar to structural vinyl chloride resins such as chlorinated polyethylene. These vinyl chloride resins may be used singly or in combination of two or more.

The lower limit of the average degree of polymerization of the vinyl chloride resin is preferably 300 or more, more preferably 800 or more. The upper limit of the average degree of polymerization of the vinyl chloride resin is preferably 2500 or less, and more preferably 2000 or less. When the average degree of polymerization is in the above range, moldability and workability are excellent and it is possible to process the film into a uniform thin film. Here, the average polymerization degree of the vinyl chloride resin is a value measured in accordance with JIS K6720-2: 1999.

2. Plasticizer

The base film used in the present embodiment contains an adipic acid ester plasticizer and a terephthalic acid ester plasticizer, and the content of adipic ester plasticizer with respect to the total content of adipic acid ester plasticizer and terephthalic acid ester plasticizer Is 50 to 80% by mass.

By using an adipate ester plasticizer and a terephthalate ester plasticizer as a plasticizer, a base material containing a vinyl chloride resin as a main component can be plasticized, and a semiconductor processed sheet using such a base film exhibits good expandability. In the present embodiment, there is no need to use a phthalic acid alkyl ester, the possibility of containing phthalic acid as an impurity is reduced, and there is no fear of environmental load and toxicity. Further, as shown in Examples described later, when di (2-ethylhexyl) terephthalate or adipic acid polyester is used alone as a vinyl chloride based plasticizer, the semiconductor processing sheet can be used as a workpiece such as a semiconductor wafer , The generation of such residues can be suppressed by adding the adipic acid ester plasticizer and the terephthalate ester plasticizer in the above mass ratio.

The adipic acid ester plasticizer is composed of an ester of adipic acid and an alcohol. In the present embodiment, adipic acid polyester may be used as the adipic ester-based plasticizer, adipic ester monomer may be used, or both may be used in combination.

In the present specification, "adipic acid polyester" refers to an ester of adipic acid and a polyol. The polyol constituting the adipic acid and the polyester is preferably a divalent alcohol. Examples of the divalent alcohol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methyl 1,5-pentanediol, neopentyl glycol, 1,4-dihydroxymethylcyclohexane, and the like. These polyols may be used singly or in combination of two or more.

As the polyol, the lower limit value of the number of carbon atoms is preferably 2 or more, more preferably 3 or more. The upper limit value is preferably 10 or less, more preferably 8 or less.

The lower limit of the number average molecular weight of the adipic acid polyester is preferably 400 or more, more preferably 600 or more. The number average molecular weight of the adipic acid polyester preferably has an upper limit value of 1,500 or less, and more preferably 1,200 or less. When the number average molecular weight of the adipic acid polyester is in the above range, when an energy ray curable pressure-sensitive adhesive which will be described later is used as the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, the adhesive force is sufficiently lowered So that the adherend can be easily peeled off.

In the present specification, "adipic ester monomer" refers to an ester of adipic acid and monoalcohol. The adipic ester monomer includes a monoester composed of one molecule of adipic acid and one molecule of monoalcohol, and also includes a diester composed of one molecule of adipic acid and two molecules of monoalcohol, and is preferably a diester.

Here, the transition from the base material of the plasticizer to the pressure-sensitive adhesive layer requires a long period of time (in some cases, half a month) from the production of the semiconductor processed sheet, during which the adhesive force changes (in the present specification, this phenomenon is referred to as " Change "). However, when an adipic acid ester monomer is used as a plasticizer, it is possible to suppress the deterioration of the adhesive strength with time. The reason for this is believed to be that the adhesive force of the pressure-sensitive adhesive layer is stabilized early because the speed of transition from the substrate to the pressure-sensitive adhesive layer of the adipic ester monomer is high. In addition, since the deterioration of the adhesive force due to the aging change is suppressed, the storage period until the semiconductor processed sheet is used after production can be shortened.

Examples of the monoalcohol constituting the adipic acid ester monomer include alcohols such as methanol, ethanol, propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, -Nonanol, isonanoanol, n-decanol, isodecanol, n-dodecanol, and n-tetradecanol. As the above-mentioned monoalcohol, those having an ether bond in the molecule, for example, 1-butoxyethanol, 2-butoxyethanol and the like may be used. These monoalcohols may be used singly or in combination of two or more.

As the monoalcohol, the lower limit value of the carbon number is preferably 4 or more, more preferably 6 or more. The upper limit value is preferably 16 or less, more preferably 12 or less. When the number of carbon atoms of the monoalcohol constituting the adipic acid ester monomer is within the above range, the moldability and processability of the substrate are excellent, and the speed of transition from the substrate to the pressure-sensitive adhesive layer of the adipic ester monomer can be increased .

From the above, as the monoalcohol constituting the adipic ester monomer, 2-ethylhexanol, isononanol, isodecanol and 2-butoxyethanol are preferable, and 2-ethylhexanol and isononanol are particularly preferable desirable. As the adipic ester monomer, di (2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate and di (2-butoxyethyl) adipate are preferable, and adipic acid di 2-ethylhexyl) and diisononyl adipate are particularly preferable.

When adipic acid polyester and adipic ester monomer are used in combination as an adipic acid ester plasticizer, the mass ratio of the adipic acid polyester and the adipic ester monomer is preferably 1 part by mass or more per 100 parts by mass of the adipic acid ester monomer More preferably 2 parts by mass or more, and particularly preferably 3 parts by mass or more. The mass ratio of the adipic acid polyester and the adipic acid ester monomer is preferably 12 parts by mass or less, more preferably 10 parts by mass or less, and most preferably 8 parts by mass or less, based on 20 parts by mass of the adipic acid polyester Particularly preferred. When the mass ratio of the adipic acid polyester and the adipic acid ester monomer is within the above range, the deterioration of the adhesive force due to the change over time is more effectively suppressed.

The terephthalic acid ester plasticizer is composed of an ester of terephthalic acid and alcohol, preferably a diester of terephthalic acid and alcohol. The alcohols constituting the terephthalic acid and the ester include alcohols such as methanol, ethanol, propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, , Isonanoanol, n-decanol, n-dodecanol, n-tetradecanol, and the like. These alcohols may be used singly or in combination of two or more.

As the alcohol, an alcohol having 6 to 12 carbon atoms is preferable, an alcohol having 8 to 10 carbon atoms is more preferable, and 2-ethylhexanol is particularly preferable. That is, the terephthalate ester plasticizer particularly preferably used in the present embodiment is di (2-ethylhexyl) terephthalate.

In the base film of the present embodiment, the mass ratio of the content of the adipic ester plasticizer to the total content of the adipic ester plasticizer and the terephthalic ester plasticizer is preferably 50% by mass or more and 60% Or more, more preferably 70 mass% or more. In the base film of the present embodiment, the upper limit of the mass ratio of the content of the adipic ester plasticizer to the total content is preferably 80 mass% or less and 75 mass% or less.

When the mass ratio is less than 50 mass% (the content ratio of the adipic ester plasticizer is small), the plasticizer is transferred to the pressure-sensitive adhesive layer, so that the cohesive force of the pressure-sensitive adhesive is insufficient and the plasticizer itself is transferred to the adherend , A residue is formed on the adherend. On the other hand, when the mass ratio exceeds 80 mass% (the content ratio of the adipic ester plasticizer is large), the adhesive strength of the pressure-sensitive adhesive layer is excessively increased when the plasticizer is transferred to the pressure-sensitive adhesive layer, And it becomes difficult for the adherend to peel off, so that the pickup tends to be defective.

The base film of the present embodiment is a plasticizer other than the adipic acid ester plasticizer and terephthalic acid ester plasticizer as far as it does not impair the effect of the present embodiment and is not a candidate for regulating the RoHS Directive, A plasticizer may be used in combination with a plasticizer that is not a substance to be applied. Examples of such plasticizers include trimellitic acid ester plasticizers such as trimellitic acid-tri-2-ethylhexyl, alicyclic ester plasticizers such as diisononylcyclohexanedicarbonate, and the like, Phosphate ester plasticizers such as bacic ester plasticizers and tricresyl phosphate; Epoxy-based plasticizers such as epoxidized soybean oil, and the like. When the plasticizer other than the adipic acid ester plasticizer and the terephthalic acid ester plasticizer is contained, the content thereof is not particularly limited, but is preferably 25 mass% or less, more preferably 15 mass% or less, based on the total amount of the plasticizer More preferable.

Further, the base film of the present embodiment does not exclude those containing a phthalic acid alkyl ester-based plasticizer. For example, in the process of producing a base film, the possibility of occurrence of contamination of a phthalic acid alkyl ester plasticizer can be considered. However, since the phthalate alkyl ester plasticizer is a candidate substance to be regulated as the above-mentioned RoHS Directive and is a substance to be applied to SVHC (high concern substance) of the REACH regulation, the base film of the present embodiment is a phthalic acid alkyl ester plasticizer , In particular, the content of di (2-ethylhexyl) phthalate, dibutyl phthalate, benzyl butyl phthalate and diisobutyl phthalate is preferably 0.001% by mass or less, and it is particularly preferable that no compound is contained.

The total content of the plasticizer in the base film is preferably 18 parts by mass or more, more preferably 22 parts by mass or more, and more preferably 25 parts by mass or more, based on 100 parts by mass of the vinyl chloride resin constituting the substrate Particularly preferred. The upper limit of the total content of the plasticizer is preferably 65 parts by mass or less, more preferably 60 parts by mass or less, and particularly preferably 55 parts by mass or less, based on 100 parts by mass of the vinyl chloride resin.

The content of the plasticizer in the base film may be specified by the conversion efficiency value obtained by multiplying the plasticizing efficiency value of each plasticizer by the content of each plasticizer. Here, the plasticizing efficiency value is a value obtained by mixing 50 parts by mass of di (n-octyl) phthalate (n-DOP) as a plasticizer with respect to 100 parts by mass of a vinyl chloride homopolymer having a degree of polymerization of 1450 and melt- The test piece of the No. 2 dumbbell was pierced through the sheet and the test piece was subjected to tensile elongation at a rate of 200 mm / min at 20 캜. The stress at the elongation of 100% was used as a reference value, The amount of plasticizer required to achieve this stress is defined as a value divided by 50 parts by mass of the amount of n-DOP, and is a value inherent in each plasticizer. The plasticizer having a small plasticizing efficiency value achieves the same stress as that obtained when 50 parts by weight of n-DOP is blended at a small blending amount, so that the plasticizing efficiency is good.

The plasticization efficiency conversion value is defined as a value obtained by multiplying the plasticizing efficiency value of each plasticizer by the content of each plasticizer, and means a value obtained by converting the content of each plasticizer into n-DOP. In the present embodiment, the sum of the conversion efficiencies of the plasticizers in the plasticizer is preferably 25 parts by mass or more, more preferably 28 parts by mass or more, based on 100 parts by mass of the vinyl chloride resin constituting the substrate , And particularly preferably 30 parts by mass or more. The upper limit of the content of the plasticizer is preferably 50 parts by mass or less, more preferably 48 parts by mass or less, and particularly preferably 45 parts by mass or less, based on 100 parts by mass of the vinyl chloride resin.

When the total content of the plasticizer in the base film or the sum of the conversion efficiencies in terms of plasticization is in the above range, appropriate flexibility is imparted to the base film, and for example, the expandability of the semiconductor processing sheet can be made sufficient On the other hand, the base material is not excessively softened, and the handling property is excellent. When the content of the plasticizer in the base material is within the above range, the performance of the pressure-sensitive adhesive layer due to migration of the plasticizer from the base material to the pressure-sensitive adhesive layer can be suppressed from changing over time.

3. Other components in the base film

The base film used in the present embodiment may contain a resin other than a vinyl chloride resin within a range not to impair the effect of the present embodiment. As the resin other than the vinyl chloride resin, for example, an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid ester copolymer and the like may be cited, and one kind thereof may be used alone, You can. When a resin other than a vinyl chloride resin is contained, its content is not particularly limited, but is preferably 0 to 20% by mass, more preferably 0 to 10% by mass, based on the base film.

The base film used in the present embodiment may contain various additives such as heat stabilizers, stabilization aids, lubricants, ultraviolet absorbers, flame retardants, antistatic agents and colorants. The content of these various additives is not particularly limited as far as the effect of the present embodiment (in particular, the suppression of the generation of residues) is not inhibited (small amount). For example, for 100 parts by mass of vinyl chloride resin, 10 parts by mass or less, 1 part by mass or less, 0.1 parts by mass or less, and more preferably 0.05 parts by mass or less. The lower limit of the content of the various additives may be, for example, 0.01 part by mass or more.

Examples of the thermal stabilizer include metal soap such as calcium stearate, barium stearate, magnesium stearate, lead dibasic stearate; Basic stabilizers such as basic sulfite lead and dibasic lead sulfate; Tin stabilizers such as dibutyltin dilaurate, dibutyltin maleate, and dibutyltin mercaptide; Calcium stabilizer; Zinc-based stabilizers; Magnesium stabilizers; Barium stabilizers, and the like, and one type may be used alone, or two or more types may be used in combination.

Examples of the lubricant include a fatty acid lubricant, a fatty acid amide lubricant, an ester lubricant, a polyethylene wax, and liquid paraffin. One type of lubricant may be used alone, or two or more types may be used in combination.

Examples of the ultraviolet absorber include benzophenone-based, benzotriazole-based, cyanoacrylate-based, salicylic ester-based, and the like, and one type may be used alone, or two or more types may be used in combination.

Examples of the antistatic agent include polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene alkyl ether, glycerin fatty acid ester, and sorbitan fatty acid ester. One type may be used alone, or two or more types .

Examples of the colorant include phthalocyanine-based coloring agents, quinacridone-based coloring agents, hansa yellow, alizarin lake, titanium oxide, zincation, permanent red and carbon black, and one kind of them may be used singly or two kinds Or more may be used in combination.

4. Physical properties of base film

The thickness of the base film is not particularly limited as long as it can perform a desired operation on a work (a semiconductor wafer or the like) to which the semiconductor processing sheet is attached. Specifically, the thickness of the substrate is preferably 25 占 퐉 or more, and more preferably 50 占 퐉 or more. The thickness is preferably 200 占 퐉 or less, and more preferably 150 占 퐉 or less.

In the base film of the present embodiment, the lower limit of the 25% stress in the MD direction in the tensile test is preferably 5 MPa or higher, more preferably 7 MPa or higher, and particularly preferably 9 MPa or higher. The upper limit of the 25% stress in the MD direction is preferably 16 MPa or less, more preferably 15 MPa or less, particularly preferably 14 MPa or less. Here, the 25% stress in the MD direction in the tensile test is a value measured in accordance with JIS K7161-1: 2014, and a specific measuring method is shown in the following examples.

In the base film of the present embodiment, the lower limit value of the breaking point stress in the tensile test is preferably 14 MPa or more, more preferably 18 MPa or more, and particularly preferably 22 MPa or more. The upper limit of the breaking point stress is preferably 48 MPa or less, more preferably 44 MPa or less, particularly preferably 38 MPa or less. Here, the breaking point stress in the tensile test is a value measured in accordance with JIS K7161-1: 2014.

In the base film of the present embodiment, the stiffness of the base film is appropriate because the 25% stress or the breaking point stress in the MD direction in the tensile test is in the above range, and for example, It is possible to obtain a sufficient amount of the carrier, while the handling property is excellent and the supportability of the adherend during transportation is excellent.

5. Manufacturing Method of Base Film

The base film of the present embodiment is not particularly limited as long as it contains a vinyl chloride resin and contains an adipic acid ester plasticizer and a terephthalic acid ester plasticizer in a predetermined mass ratio. For example, a mixture obtained by mixing a vinyl chloride resin, an adipate ester plasticizer and a terephthalate ester plasticizer, preferably a stabilizer, and other additives may be obtained by forming a mixture.

As for the mixing of the components, a single-screw extruder, a twin-screw extruder, a Henschel mixer, a Banbury mixer, various kneaders, a Brabender, and a calender roll are generally used according to a mechanical melt-kneading method. At this time, the order of addition of the respective components is not particularly limited. The temperature at which the melt-kneading is carried out can be suitably selected from 140 to 220 占 폚. The resulting mixture is processed into a film to obtain the base film. Film processing may be carried out by a general molding process such as extrusion molding, calender molding, and inflation molding.

The film-forming method may be carried out by putting the above-mentioned mixture into a solution or a molten state, and applying the coating by a coating means such as calender roll.

The base film may be subjected to surface treatment or primer treatment on the one surface or both surfaces by an oxidation method, an unevenness method or the like in accordance with the purpose as desired for the purpose of improving adhesion with the pressure-sensitive adhesive layer laminated on one surface of the base film. Examples of the oxidation method include a corona discharge treatment, a plasma discharge treatment, a chromium oxidation treatment (wet type), a flame treatment, a hot air treatment, an ozone, an ultraviolet ray irradiation treatment and the like. Sand blast method, spray treatment method, and the like.

The surface of the base film on which the pressure-sensitive adhesive layer is not laminated may be peeled off with a release agent. As a result, even when the semiconductor processing sheet is used as the winding body without using the release film, the feeding can be satisfactorily performed.

[Semiconductor processing sheet]

The semiconductor processed sheet according to the present embodiment comprises the base film and a pressure-sensitive adhesive layer laminated on at least one side of the base film. A release film may be laminated on the surface of the pressure-sensitive adhesive layer opposite to the base film. This peeling film is peeled off at the time of using the semiconductor processed sheet, and protects the pressure sensitive adhesive layer until that time.

1. Adhesive layer

As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, the pressure-sensitive adhesive used in the semiconductor processing sheet can be used as it is as the semiconductor-processed sheet according to the present embodiment. Particularly, when an additive such as a tackifier, a pick-up property improving aid, or an antistatic agent is added, the balance of compatibility in the pressure-sensitive adhesive layer due to the migration of the plasticizer is broken and problems such as change in adhesive force and occurrence of residues However, according to the present embodiment, since the base film containing the plasticizer is used, it is not necessary to review the composition of the pressure-sensitive adhesive, and it is possible to replace the conventional vinyl chloride base material containing dioctyl phthalate (DOP) It is possible.

Specifically, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer may be a non-curable pressure-sensitive adhesive or a curable pressure-sensitive adhesive. The curable pressure sensitive adhesive may be in a state before curing or after curing. When the pressure-sensitive adhesive layer is composed of multiple layers, a combination of a non-curable pressure-sensitive adhesive and a curable pressure-sensitive adhesive may be used. Examples of the noncurable adhesive include acrylic pressure sensitive adhesives, rubber pressure sensitive adhesives, silicone pressure sensitive adhesives, urethane pressure sensitive adhesives, polyester pressure sensitive adhesives, polyvinyl ether pressure sensitive adhesives, phenoxy pressure sensitive adhesives and acrylic urethane pressure sensitive adhesives. Examples of the curable pressure-sensitive adhesive include energy ray-curable pressure-sensitive adhesives, thermosetting pressure-sensitive adhesives, and the like. Hereinafter, the energy radiation curable pressure sensitive adhesive will be described in some detail.

(1) Energy ray hardenable adhesive theme

In the case where the pressure-sensitive adhesive layer of the present embodiment is formed of an energy ray-curable pressure-sensitive adhesive, the energy ray curable pressure-sensitive adhesive may include an energy ray-curable monomer and / or an oligomer, May contain a curable monomer and / or an oligomer, may contain an energy ray curable polymer, may contain an energy ray curable polymer and an energy ray curable monomer and / or an oligomer, Ray-curable polymer, an energy ray-non-curable polymer, and an energy ray-curable monomer and / or an oligomer. Among them, an energy ray non-curable polymer which can easily increase the adhesive force before the energy ray curing and can increase the difference from the adhesive force after the energy ray curing and an energy ray containing an energy ray curable monomer and / Ray-curable pressure-sensitive adhesive is preferable. The energy ray-curable pressure-sensitive adhesive may further contain a crosslinking agent. Among these components, energy ray-curable monomers and / or oligomers and energy ray-curable polymers are energy ray-curable components.

(1-1) Energy ray non-hardening polymer

When the energy ray-curable pressure-sensitive adhesive contains an energy ray non-curable polymer, the energy ray non-curable polymer may be contained intact in the pressure-sensitive adhesive layer, or at least a part thereof may be subjected to a cross- . Examples of the energy ray non-curable polymer include an acrylic polymer, a phenoxy resin, a urethane resin, a polyester resin, a rubber resin, an acryl urethane resin, and a silicone resin. Among them, Acrylic polymers are preferred. Hereinafter, the case of using an acrylic polymer will be described in detail.

As the acrylic polymer, conventionally known acrylic polymers may be used. The acrylic polymer may be a homopolymer formed of one kind of acrylic monomer, a copolymer formed of plural kinds of acrylic monomers, or a copolymer formed of one kind or plural kinds of acrylic monomers and monomers other than acrylic monomers. The specific kind of the compound to be an acrylic monomer is not particularly limited and specific examples include (meth) acrylic acid, (meth) acrylic acid ester and derivatives thereof (acrylonitrile, itaconic acid, etc.). In the present specification, (meth) acrylic acid means both acrylic acid and methacrylic acid. The same is true of other similar terms. The term " polymer " in this specification includes the concept of " copolymer ".

(Meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, n-butyl (meth) acrylate (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (Meth) acrylate having a skeletal skeleton such as acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate and the like; (Meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, tetrahydrofurfuryl (Meth) acrylate having a phenolic skeleton; (Meth) acrylate having a hydroxy group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 4-hydroxybutyl acrylate; (Meth) acrylate having a reactive functional group other than a hydroxyl group such as glycidyl (meth) acrylate and N-methylaminoethyl (meth) acrylate. Examples of monomers other than the acrylic monomer include olefins such as ethylene and norbornene, vinyl acetate, and styrene. When the acrylic monomer is alkyl (meth) acrylate, the number of carbon atoms of the alkyl group is preferably in the range of 1 to 18. [

When the energy ray-curable pressure-sensitive adhesive in the present embodiment contains a crosslinking agent, it is preferable that the acrylic polymer has a reactive functional group that reacts with the crosslinking agent. The kind of the reactive functional group is not particularly limited and may be suitably determined based on the kind of the cross-linking agent and the like.

For example, when the crosslinking agent is a polyisocyanate compound, examples of the reactive functional group contained in the acrylic polymer include a hydroxyl group, a carboxyl group, and an amino group. When the crosslinking agent is an epoxy compound, examples of the reactive functional group of the acrylic polymer include a carboxyl group, an amino group, and an amide group. When the crosslinking agent is a chelate compound, examples of the reactive functional group contained in the acrylic polymer include hydroxyl group, A carboxyl group, an epoxy group and the like.

A method for introducing a reactive functional group into an acrylic polymer is not particularly limited and examples thereof include a method in which an acrylic polymer is formed using a monomer having a reactive functional group and a structural unit based on a monomer having a reactive functional group is contained in the backbone of the polymer . For example, when introducing a hydroxy group into an acrylic polymer, an acrylic polymer may be formed using a monomer having a hydroxy group such as 2-hydroxyethyl acrylate. When a carboxyl group is introduced into the acrylic polymer, an acrylic polymer may be formed using a monomer having a carboxyl group such as acrylic acid.

When the acrylic polymer has a reactive functional group, the ratio of the mass of the structural part derived from the monomer having a reactive functional group in the total mass of the acrylic polymer is preferably 1% by mass or more, particularly preferably 2% by mass or more. The proportion is preferably 30 mass% or less, particularly preferably 20 mass% or less. When the ratio is in the above range, the degree of crosslinking can be improved.

The acrylic polymer is obtained by copolymerizing the respective monomers by a conventional method. The polymerization of the acrylic polymer may be a random copolymer or a block copolymer.

The weight average molecular weight (Mw) of the acrylic polymer is preferably 10,000 or more, more preferably 100,000 or more. The weight average molecular weight of the acrylic polymer is preferably 2,000,000 or less, and particularly preferably 1,500,000 or less. When the weight average molecular weight is in the above range, good stickiness can be exhibited and film-forming property at the time of coating can be satisfactorily secured. The weight average molecular weight in the present specification is a standard polystyrene conversion value measured under the following conditions (GPC measurement) using a gel permeation chromatograph apparatus (product name: " HLC-8020 "

≪ GPC measurement condition >

Column: "TSK gel column G2000HXL", "TSK gel G1000HXL" (all manufactured by Toso Co., Ltd.) were sequentially connected with "TSK guard column HXL-L", "TSK gel G2500HXL"

Column temperature: 40 ° C

· Developing solvent: tetrahydrofuran

Flow rate: 1.0 mL / min

· Detector: Differential refractometer

· Standard sample: Polystyrene

(1-2) Energy ray-curable monomers and / or oligomers

The energy ray curable monomer and / or oligomer (hereinafter referred to as " energy ray curable compound ") has an energy ray curable group and is polymerized when irradiated with an energy ray and has a molecular weight lower than that of an energy ray curable polymer .

The energy ray-curable group possessed by the energy ray-curable compound includes, for example, a group containing an energy ray-curable carbon-carbon double bond, specifically, a (meth) acryloyl group, a vinyl group, and the like.

The energy ray curable compound may be monofunctional or multifunctional, but is preferably multifunctional. In this case, the energy ray-curable compound is preferably two or more functional, more preferably three or more, and more preferably four or more. The energy radiation curable compound is preferably 15 or less, more preferably 12 or less, and more preferably 10 or less. If the energy ray-curable compound has such a multifunctionality as described above, it is difficult to control the adhesive force by the ultraviolet curing and easily cause poor volume adhesion to the substrate due to volume shrinkage caused by curing.

Specific examples of the energy ray curable compound include trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) , Dipentaerythritol hexa (meth) acrylate, dipentaerythritol poly (meth) acrylate, or 1,4-butylene glycol di (meth) acrylate, dipentaerythritol poly Acrylate, cyclic aliphatic skeleton-containing acrylates such as 1,6-hexanediol di (meth) acrylate, dicyclopentadiene dimethoxydi (meth) acrylate and isobornyl (meth) acrylate, polyethylene glycol di (Meth) acrylate oligomer, epoxy-modified (meth) acrylate, polyether (meth) acrylate, Acrylate-based compounds such as other acid oligomer. These may be used singly or in combination of two or more kinds.

The molecular weight of the energy ray-curable compound is preferably 100 or more, more preferably 300 or more. The molecular weight of the energy ray-curable compound is preferably 30,000 or less, more preferably 10,000 or less. When the molecular weight of the energy ray-curable compound is within the above range, the effect of volatilization of the material during coating and drying can be suppressed while ensuring the film-forming property.

The ratio of the energy ray-curable compound to 100 parts by mass of the total amount of the energy ray-non-curable polymer and the curable polymer is preferably 30 parts by mass or more, more preferably 40 parts by mass or more, further preferably 50 parts by mass or more Do. The ratio is preferably 200 parts by mass or less, more preferably 170 parts by mass or less, further preferably 150 parts by mass or less. When the above ratio is in the above range, a good adhesive force is exerted before curing, and the adhesive force can be sufficiently lowered after curing.

(1-3) Energy ray curable polymer

The energy ray curable polymer is preferably a polymer into which an energy ray curable group is introduced. The polymer into which the energy ray-curable group is introduced may be contained intact in the pressure-sensitive adhesive layer, or at least a part of the polymer may have a crosslinking structure by carrying out a crosslinking reaction with the crosslinking agent.

Examples of the polymer to which the energy ray-curable group is introduced include an acrylic polymer containing a functional group containing a functional group-containing monomer containing a functional group, a substituent reactive with the functional group, and a curing An acrylic polymer obtained by reacting a genital group-containing compound.

The functional group-containing acrylic polymer is preferably one obtained by copolymerizing an acrylic monomer containing a functional group, an acrylic monomer containing no functional group and a monomer other than an acrylic monomer as desired. That is, the functional group-containing monomer is preferably an acrylic monomer containing a functional group.

As the functional group (functional group of the functional group-containing monomer) of the acrylic monomer containing a functional group, those capable of reacting with the substituent of the curable group-containing compound are selected. Examples of such a functional group include a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, and an epoxy group. When the energy ray-curable pressure-sensitive adhesive in the present embodiment contains a crosslinking agent, the functional group-containing acrylic polymer preferably contains a functional group-containing monomer having a functional group which reacts with the crosslinking agent as a constituent component, and the functional group- Containing monomer having a functional group capable of reacting with the substituent group possessed by the curable group-containing compound may serve as the functional group-containing monomer.

The acrylic monomer not containing a functional group preferably contains a (meth) acrylic acid alkyl ester monomer. Examples of the (meth) acrylic acid alkyl ester monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, (Meth) acrylate, lauryl (meth) acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate, n-hexyl , Stearyl (meth) acrylate, and the like. Among the (meth) acrylic acid alkyl ester monomers, the alkyl group preferably has 1 to 18 carbon atoms, particularly preferably 1 to 8 carbon atoms. These may be used alone or in combination of two or more.

The acrylic monomer not containing a functional group may be, for example, methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, (meth) (Meth) acrylic acid esters having aromatic rings such as (meth) acrylic acid esters, (meth) acrylic acid esters having alkoxyalkyl groups such as methoxyethyl acrylate and ethoxyethyl, non-crosslinkable acrylamides such as acrylamide and methacrylamide, (Meth) acrylate ester having a non-cross-linkable tertiary amino group such as N, N-dimethylaminoethyl, (meth) acrylic acid N, N-dimethylaminopropyl and the like.

Examples of the monomer other than the acrylic monomer include olefins such as ethylene and norbornene, vinyl acetate and styrene.

The ratio of the mass of the structural part derived from the functional group-containing monomer in the mass of the entire functional group-containing acrylic polymer in the functional group-containing acrylic polymer is preferably 0.1% by mass or more, more preferably 1% by mass or more, By mass or more. The proportion is preferably 50 mass% or less, more preferably 40 mass% or less, further preferably 30 mass% or less. Thereby, the degree of crosslinking of the obtained pressure-sensitive adhesive layer can be controlled within a preferable range by adjusting the introduction amount of the curable group by the curable group-containing compound (and the amount of reaction with the crosslinking agent) to a desired amount.

The functional group-containing acrylic polymer is obtained by copolymerizing the respective monomers by a conventional method. The polymerization of the functional group-containing acrylic polymer may be a random copolymer or a block copolymer.

The curable group-containing compound has a substituent and an energy ray-curable carbon-carbon double bond which react with the functional group of the functional group-containing acrylic polymer. Examples of the substituent that reacts with the functional group contained in the acrylic polymer containing a functional group include an isocyanate group, an epoxy group, and a carboxyl group, and among these, an isocyanate group having high reactivity with a hydroxy group is preferable.

The curable group-containing compound preferably contains 1 to 5, particularly 1 to 3, energy-ray-curable carbon-carbon double bonds per molecule of the curable group-containing compound.

Examples of such curable group-containing compounds include 2-methacryloyloxyethyl isocyanate, methisopropenyl-alpha, alpha -dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1,1- Bisacryloyloxymethyl) ethyl isocyanate; An acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth) acrylate; Acryloyl monoisocyanate compounds obtained by the reaction of a diisocyanate compound or polyisocyanate compound, a polyol compound and hydroxyethyl (meth) acrylate, and the like. The curing agent group-containing compound may be used singly or in combination of two or more kinds.

The polymer into which the energy ray-curable group is introduced preferably contains a curable group derived from the curable group-containing compound in an amount of 20 mol% or more with respect to the functional group (functional group reactive with the substituent of the curable group-containing compound) , More preferably 35 mol% or more, further preferably 50 mol% or more. Further, it is preferably contained in an amount of 120 mol% or less, particularly preferably 100 mol% or less. When the curable group-containing compound is monofunctional, the upper limit is 100% by mole, but when the curable group-containing compound is polyfunctional, it may exceed 100% by mole. When the ratio of the curable group to the functional group is within the above range, the lowering of the adhesive force by energy ray irradiation becomes better.

The weight average molecular weight (Mw) of the polymer to which the energy ray-curable group is introduced is preferably 100,000 or more, more preferably 300,000 or more. The weight average molecular weight is preferably 2,000,000 or less, more preferably 1,500,000 or less. When the weight average molecular weight is in the above range, good stickiness can be exhibited and film-forming property at the time of coating can be satisfactorily secured.

(1-4) Crosslinking agent

As the crosslinking agent, a polyfunctional compound having reactivity with the above-mentioned acrylic polymer or a functional group contained in the polymer into which the energy ray-curable group is introduced can be used. Examples of such a polyfunctional compound include polyisocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, Phenol resin and the like. These crosslinking agents may be used singly or in combination of two or more kinds.

Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane Alicyclic polyisocyanates such as diisocyanate and the like, and reaction products thereof with low-molecular active hydrogen-containing compounds such as burette, isocyanurate, and furthermore, ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, And duct bodies. Among them, trimethylolpropane-modified aromatic polyisocyanates, particularly trimethylolpropane-modified tolylene diisocyanate, are preferable from the viewpoint of reactivity with functional groups.

The content of the crosslinking agent is preferably 0.01 equivalents or more, particularly preferably 0.02 equivalents or more, as the lower limit of the functional group in the acrylic polymer or the polymer to which the energy ray-curable group is introduced. The upper limit value is preferably 1 equivalent or less, more preferably 0.8 equivalent or less. When the content of the crosslinking agent is in the above range, the degree of crosslinking of the obtained pressure-sensitive adhesive layer can be controlled within a preferable range.

(1-5) Other components

The pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer in the present embodiment may contain various additives such as a photopolymerization initiator, a coloring material such as a dye and a pigment, an antistatic agent, a tackifier, a flame retardant and a filler in addition to the above components .

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 Specific examples thereof include 1-hydroxycyclohexyl phenyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl diphenyl sulfide, tetramethyl thiuram monosulfide, azobisisobutyl Nitrile, dibenzyl, diacetyl,? -Chlorantraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and the like. These photopolymerization initiators may be used singly or in combination of two or more. When ultraviolet rays are used as an energy ray, irradiation time and amount of irradiation can be reduced by blending a photopolymerization initiator.

(1-6) Investigation of energy ray

Examples of the energy ray for curing the above-described energy ray curable pressure-sensitive adhesive include ionizing radiation, that is, X-ray, ultraviolet ray, electron beam and the like. Of these, ultraviolet rays which are relatively easy to introduce irradiation equipment are preferable.

When ultraviolet rays are used as the ionizing radiation, near ultraviolet rays including ultraviolet rays having a wavelength of about 200 to 380 nm may be used for ease of handling. The amount of light is appropriately selected depending on the kind of energy ray curable group and the thickness of the pressure-sensitive adhesive layer of the above-described energy ray-curable compound and energy ray curable polymer, and is usually about 50 to 500 mJ / mJ / cm2 is preferable, and 200 to 400 mJ / cm2 is more preferable. The ultraviolet illuminance is usually about 50 to 500 mW / cm 2, preferably 100 to 450 mW / cm 2, and more preferably 200 to 400 mW / cm 2. The ultraviolet source is not particularly limited, and for example, a high pressure mercury lamp, a metal halide lamp, a UV-LED, or the like is used.

When an electron beam is used as the ionizing radiation, the acceleration voltage can be suitably selected according to the kind of the energy ray-curable group and the thickness of the pressure-sensitive adhesive layer of the energy ray curable compound and the energy radiation curable polymer described above, The acceleration voltage is preferably about 10 to 1000 kV. The irradiation dose may be set within a range in which the energy ray-curable compound and the energy ray-curable polymer are suitably cured, and is usually selected within the range of 10 to 1000 krad. The electron beam source is not particularly limited and various electron beam accelerators such as a Cockloft Walton type, a Vandegraph type, a resonant transformer type, an insulating core transformer type, a linear type, a dynamictron type, and a high frequency type can be used .

(2) Thickness of the pressure-sensitive adhesive layer

The lower limit value of the thickness of the pressure-sensitive adhesive layer in the present embodiment is preferably 1 占 퐉 or more, particularly preferably 2 占 퐉 or more, further preferably 3 占 퐉 or more. The thickness of the pressure-sensitive adhesive layer in the present embodiment is preferably 50 占 퐉 or less, more preferably 40 占 퐉 or less, further preferably 30 占 퐉 or less. When the thickness of the pressure-sensitive adhesive layer is in the above range, a desired adhesive force can be effectively obtained. When the pressure-sensitive adhesive layer is formed of an energy ray-curable pressure-sensitive adhesive, if the upper limit of the thickness of the pressure-sensitive adhesive layer is less than the above value, the energy ray curable pressure-sensitive adhesive tends to be hardened.

2. Release film

The peeling film protects the pressure-sensitive adhesive layer until the semiconductor processing sheet is used, and may be omitted. The constitution of the release film is arbitrary, and examples thereof include a plastic film in which the film itself has a releasability to the pressure-sensitive adhesive layer, and a plastic film which has been subjected to release treatment with a release agent or the like. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the releasing agent, a silicone system, a fluorine system, a rubber system, a long chain alkyl system, or the like can be used, and among these, a silicone system that can achieve an inexpensive and stable performance is preferable. The thickness of the release film is not particularly limited, but is usually about 20 to 250 占 퐉.

3. Another example of semiconductor processing sheet

The semiconductor processing sheet having the base film and the pressure-sensitive adhesive layer has been described above, but the present invention is not limited thereto.

For example, as another embodiment, the semiconductor processed sheet may be provided with a primer layer or the like between the base film and the pressure-sensitive adhesive layer for improving the adhesion between the base film and the pressure-sensitive adhesive layer. Further, the semiconductor processing sheet may be provided with an intermediate layer between the base film and the pressure-sensitive adhesive layer. Examples of the intermediate layer include those having a function of imparting desired elasticity and followability to protrusions of the semiconductor chip to the semiconductor-processed sheet, for example. Such an intermediate layer is composed of a material containing, for example, urethane acrylate or the like.

In another embodiment, the semiconductor processing sheet may be provided with an adhesive layer located on the outermost layer. The adhesive layer preferably exhibits adhesiveness by a trigger such as heating. Such an adhesive layer can be used, for example, as an adhesive in die bonding.

In another embodiment, the semiconductor processed sheet may be provided with a protective film forming film located on the outermost layer. The protective film forming film can be used as a protective film for protecting the back surface of a semiconductor chip, particularly when a semiconductor device is manufactured by a mounting method called a face down method.

4. Manufacturing Method of Semiconductor Processed Sheet

The semiconductor processed sheet according to the present embodiment can be manufactured in the same manner as the conventional semiconductor processed sheet. In particular, the method for producing a semiconductor processed sheet comprising a substrate and a pressure-sensitive adhesive layer is not particularly limited as long as the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition described above can be laminated on one surface of the substrate. For example, a pressure-sensitive adhesive composition for forming a pressure-sensitive adhesive layer, and a coating solution containing a solvent or a dispersion medium according to the desire, may be prepared, and a coating composition such as a die coater, a curtain coater, a spray coater, A coating liquid is applied by a knife coater or the like to form a coating film, and the coating film is dried to form a pressure-sensitive adhesive layer. The coating liquid is not particularly limited as far as it can be applied, and the component for forming the pressure-sensitive adhesive layer may be contained as a solute or may be contained as a dispersion.

As another example of the method for producing a semiconductor processed sheet, a coating liquid is applied on the release surface of the release sheet described above to form a coating film, and this is dried to form a laminate composed of a pressure-sensitive adhesive layer and a release sheet, The surface of the pressure-sensitive adhesive layer of the laminate opposite to the surface on the release sheet side may be attached to the substrate to obtain a laminated body of the semiconductor processed sheet and the release sheet. The release sheet in this laminate may be peeled off as a process material, or the pressure-sensitive adhesive layer may be protected until it is attached to an adherend such as a semiconductor chip or a semiconductor wafer.

When the coating liquid contains a crosslinking agent, the energy ray non-curable polymer or the crosslinking agent of the energy ray-curable polymer and the crosslinking agent in the coating film may be crosslinked by changing the drying conditions (temperature, time, etc.) The reaction is allowed to proceed to form a crosslinked structure at a desired density present in the pressure-sensitive adhesive layer.

5. Physical properties of semiconductor processed sheet

The thickness of the semiconductor processed sheet according to the present embodiment is not particularly limited, but is preferably 50 占 퐉 or more, and more preferably 80 占 퐉 or more. The thickness is preferably 200 占 퐉 or less, and more preferably 160 占 퐉 or less.

When the pressure-sensitive adhesive layer is formed of an energy ray-curable pressure-sensitive adhesive, the lower limit value of the pressure-sensitive adhesive force before energy ray irradiation (hereinafter also referred to as " , Preferably 100 mN / 25 mm or more, particularly preferably 150 mN / 25 mm or more, further preferably 200 mN / 25 mm or more. As a result, unintended peeling can be suppressed from occurring during operation of the adherend to which the semiconductor processing sheet is adhered. In addition, good adhesion can be exhibited for various materials, and the present invention can be applied to a wide range of adherends. On the other hand, the upper limit of the adhesive strength before irradiation is preferably 20000 mN / 25 mm or less, more preferably 18000 mN / 25 mm or less, and further preferably 16000 mN / 25 mm or less. As a result, the adhesive force after irradiation of the energy ray can be easily lowered to a desirable range. In the present specification, the pre-irradiation adhesive force was measured by a 180-degree peel test according to JIS Z0237: 2000 using a silicon mirror wafer as an adherend.

In the case where the pressure-sensitive adhesive layer is formed of an energy ray-curable pressure-sensitive adhesive, the upper limit of the adhesive strength after irradiation with energy rays (hereinafter also referred to as "adhesion after irradiation") is preferably 800 mN / 25 mm or less, 25 mm or less, and more preferably 500 mN / 25 mm or less. Thereby, the semiconductor-processed sheet can be easily peeled off from the adherend. On the other hand, the lower limit value of the adhesive force after irradiation is not particularly limited, but is preferably 5 mN / 25 mm or more, particularly preferably 10 mN / 25 mm or more, further preferably 20 mN / 25 mm or more. The post-irradiation adhesive force in this specification refers to a silicon mirror wafer as an adherend, which is measured by a 180-degree peel test according to JIS Z0237: 2000, and a specific measuring method is as described in Test Examples same.

The ratio (A) / (B) of the adhesive force (A) measured after storing at 40 占 폚 for 7 days and the adhesive force (B) measured after storing at 40 占 폚 for 14 days is 1.0 or more . The adhesive force ratio (A) / (B) is preferably 1.5 or less, more preferably 1.2 or less. It can be said that the semiconductor processed sheet having the above adhesive strength ratio (A) / (B) in the above range is suppressed from being changed over time. In the present embodiment, it is easy to set the adhesive force ratio (A) / (B) within the above range by using the above plasticizer, particularly using an adipic ester monomer as an adipic ester plasticizer. Here, the adhesive force measured after storage at 40 占 폚 for 7 days and 14 days is the adhesive force before irradiation in the case where the pressure-sensitive adhesive layer is formed of the energy ray-curable pressure-sensitive adhesive, and the specific measuring method is as shown in the following test example.

In the semiconductor processed sheet according to the present embodiment, the values of the 25% stress and the breaking point stress in the MD direction in the tensile test are substantially equal to the values of the base film described above. This is because the rigidity of the layer (pressure-sensitive adhesive layer or the like) other than the base film in the semiconductor processed sheet is sufficiently small and negligible in comparison with the rigidity of the base film. Here, the 25% stress and the breaking point stress in the MD direction in the tensile test of the semiconductor processed sheet are measured in accordance with JIS K7161-1: 2014 by measuring the force at 25% elongation and breakage in the MD direction of the semiconductor processed sheet And divided by the cross-sectional area of the substrate film. When the pressure-sensitive adhesive layer is formed of an energy ray-curable pressure-sensitive adhesive, the value measured before irradiation of the energy ray is used.

Specifically, in the semiconductor processed sheet according to the present embodiment, the lower limit value of the 25% stress in the MD direction in the tensile test is preferably 5 MPa or more, more preferably 7 MPa or more, and particularly preferably 9 MPa or more. The upper limit of the 25% stress in the MD direction is preferably 24 MPa or less, more preferably 20 MPa or less, and particularly preferably 16 MPa or less.

In the semiconductor processed sheet of the present embodiment, the lower limit value of the breaking point stress in the tensile test is preferably 14 MPa or more, more preferably 18 MPa or more, and particularly preferably 22 MPa or more. The upper limit of the breaking point stress is preferably 48 MPa or less, more preferably 44 MPa or less, particularly preferably 38 MPa or less.

The semiconductor processed sheet of the present embodiment has satisfactory expandability due to the 25% stress and the breaking point stress in the MD direction in the tensile test in the above-described range, while being excellent in handling property, It is excellent in the complex support property.

6. Uses of semiconductor processing sheet

The semiconductor processed sheet according to the present embodiment can be used when supporting a semiconductor wafer, dicing, and picking up a semiconductor chip that has been separated.

For example, the semiconductor processed sheet according to the present embodiment can be used as a dicing sheet. In this case, the back-ground semiconductor wafer is attached to the semiconductor processing sheet and diced on the semiconductor processing sheet, whereby the semiconductor wafer can be divided into semiconductor chips. Thereafter, a plurality of semiconductor chips can be individually picked up from the semiconductor processing sheet.

The semiconductor processed sheet according to the present embodiment can also be used in a pre-dicing method in which a dicing process is performed before grinding the back surface of a semiconductor wafer, or in a stealth dicing method in which a fractured layer is formed by a laser. Here, in the case of the die dicing method, for example, the back side grinding adhesive sheet may be attached to the wafer surface after dicing, and the semiconductor wafer processed sheet according to the present embodiment may be peeled off. On the other hand, in the case of the stealth dicing method, for example, after a backsheet for back grinding is attached to the surface of a semiconductor wafer, the semiconductor wafer processing sheet according to the present embodiment is attached to the back surface of the semiconductor wafer, After the stealth dicing is performed, the semiconductor wafer processing sheet may be peeled off.

The semiconductor processed sheet according to the present embodiment can be used not only for dicing but also for picking up a semiconductor chip after dicing. In this case, after the plurality of semiconductor chips are moved from the dicing sheet to the semiconductor processing sheet, the semiconductor chips can be picked up from the semiconductor processing sheet. Further, the movement from the dicing sheet to the semiconductor processing sheet may be carried out by transfer or by pick-up.

The semiconductor processed sheet according to the present embodiment can also be used as a dicing / die bonding sheet. In this case, the semiconductor processed sheet preferably includes the above-mentioned adhesive layer, and a barrier layer or the like for suppressing the migration of the additive into the adhesive layer is formed between the adhesive layer and the above- . According to the semiconductor processing sheet, the adhesive layer is also cut at the same time when the semiconductor wafer is diced, and the separated semiconductor chips are picked up to obtain a semiconductor chip with an adhesive attached thereto. As the pressure-sensitive adhesive layer in the dicing / die-bonding sheet, a pressure-sensitive adhesive for fixing an adherend such as a semiconductor wafer and a pressure-sensitive adhesive layer for bonding a die bonding adhesive having a die- But the pressure-sensitive adhesive layer in the present embodiment does not have such a function as a point-adhesive layer.

The semiconductor processed sheet according to the present embodiment can also be used as a protective film forming sheet for forming a protective film on a semiconductor wafer. In this case, the semiconductor processing sheet is provided with a protective film forming film in addition to the outermost layer. According to such a semiconductor processing sheet (protective film forming sheet), the protective film forming film is cut simultaneously with the semiconductor wafer during dicing, A semiconductor chip having a protective film on the back surface can be obtained.

7. How to use semiconductor processing sheet

As an example of a method of using the semiconductor processed sheet according to the present embodiment, a method of using the semiconductor processed sheet as a dicing sheet will be described below.

In the semiconductor processed sheet according to the present embodiment, in use, the side of the pressure-sensitive adhesive layer side (that is, the side of the pressure-sensitive adhesive layer opposite to the base film) is affixed to the semiconductor wafer. When the release film is laminated on the pressure-sensitive adhesive layer side of the semiconductor processing sheet, the release film may be peeled off to expose the pressure-sensitive adhesive layer side, and the surface of the pressure sensitive adhesive layer may be attached to the adhesion surface of the semiconductor wafer. The periphery of the semiconductor processing sheet is usually affixed to an annular jig called a ring frame for fixation to a device or to a device by means of a pressure-sensitive adhesive layer formed thereon.

Subsequently, a dicing process is performed to obtain a plurality of chips from the semiconductor wafer. Further, when the pressure-sensitive adhesive layer is formed of an energy ray-curable pressure-sensitive adhesive, energy ray irradiation is performed from the base film side of the semiconductor processing sheet after the completion of the dicing process to lower the adhesiveness of the pressure-sensitive adhesive layer.

Then, in order to facilitate picking up a plurality of chips arranged close to the semiconductor processing sheet, an expanding process of stretching the semiconductor processing sheet in the plane direction is performed. The degree of elongation can be appropriately set in consideration of the interval that the adjacent chips should have, the tensile strength of the base film, and the like. Further, the expanding step may be performed before the energy ray irradiation.

After the expanding process, the chip is picked up on the pressure-sensitive adhesive layer. The pick-up is carried out by a general-purpose means such as a suction collet. At this time, in order to facilitate pick-up, it is preferable to push the object chip from the substrate film side of the semiconductor processing sheet to a pin or needle.

The semiconductor processed sheet according to the present embodiment exhibits sufficient flexibility even when a substitute material of a phthalic acid alkyl ester is used as a plasticizer contained in the base film. Therefore, the processed semiconductor sheet has excellent expandability, It is easy, and the chip can be easily recovered. In addition, since the base film contains the adipic acid ester plasticizer and the terephthalate ester plasticizer at a predetermined ratio, the occurrence of residues on the chip when the chip is peeled is suppressed. Further, the picked-up chip is supplied to a next process such as a transporting process.

The above-described embodiments are described for the purpose of facilitating understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design modifications and equivalents falling within the technical scope of the present invention.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope of the present invention is not limited to these Examples and the like.

[Example 1]

(1) Production of vinyl chloride resin base material

(Terephthalic acid di (2-ethylhexyl), ADEKA Co., Ltd. (trade name), manufactured by TAIYO CHEMICAL INDUSTRIES, LTD., TH-1000, average degree of polymerization: 1000) 10 parts by mass of Adeka Sider D-810, molecular weight: 391), and adipic acid polyester B1 (ADEKA PN-7160, manufactured by ADEKA, average molecular weight: 800, 20 parts by mass of a plasticizer efficiency value: 1.00) and 5 parts by mass of adipic ester monomer C (oxygenase DINA, molecular weight 398, manufactured by Shin-Nippon Rikagaku Co., Ltd.) as a colorant and a phthalocyanine blue- DA EP4610 Blue), 0.03 part by mass of a quinacridone red coloring agent (manufactured by Dainichi Seika Kogyo K.K., DA P4121 Red), and a small amount of a magnesium-based stabilizer as a stabilizer were mixed at 180 ° C using a Banbury mixer And kneaded. The obtained kneaded product was rolled with a calendar roll to obtain a substrate made of vinyl chloride resin having a thickness of 80 mu m.

(2) Preparation of adhesive

20 parts by mass of 2-ethylhexyl acrylate, 78 parts by mass of vinyl acetate, 1 part by mass of acrylic acid and 1 part by mass of 2-hydroxyethyl methacrylate were copolymerized to prepare an acrylic polymer as an energy ray non- Molecular weight: 170,000, glass transition temperature Tg: 5 占 폚).

Here, the glass transition temperature Tg of the acrylic polymer is a theoretical value calculated by the FOX formula using the Tg of the homopolymer of each constituent monomer and the mass ratio of each constituent monomer, and the glass transition temperature Tg of the homopolymer of each constituent monomer Is as follows.

2-ethylhexyl acrylate homopolymer: -70 ° C (203 K)

Vinyl acetate homopolymer: 32 < 0 > C (305 K)

Acrylic acid homopolymer: 103 DEG C (376 K)

Hydroxyethyl methacrylate homopolymer: 55 ° C (328 K)

3.2 parts by mass of a composition containing 100 parts by mass of the acrylic polymer and trimethylolpropane-modified tolylene diisocyanate (TDI-TMP) as a crosslinking agent (Coronate L, manufactured by Tosoh Corporation) and an aliphatic aromatic copolymer petroleum resin 7.1 parts by mass as a photopolymerization initiator and 7.1 parts by mass of a rosin-based polyol (molecular weight: 2700 (liquid phase)) and 2,2-dimethoxy-1,2-diphenylethane- (Mixing mass ratio 1: 1) of 5.1 parts by mass (trade name: IRGACURE 651) and a bifunctional urethane acrylate (weight average molecular weight 11000) and a hexafunctional urethane acrylate (weight average molecular weight 1500) as an energy ray- And the mixture was diluted with toluene to a solid content concentration of 37 mass%, and this was used as a coating liquid for the pressure-sensitive adhesive composition.

(3) Manufacturing of semiconductor processing sheet

On the exfoliated surface of a release film (SP-PET381031, manufactured by Lin Tec Co., Ltd.) in which one main surface of a polyethylene terephthalate film having a thickness of 38 탆 was peeled off with a silicone-based releasing agent, Was coated with a die coater and dried to form a pressure-sensitive adhesive layer having a thickness of 10 占 퐉 to obtain a laminate comprising a release film and a pressure-sensitive adhesive layer. Next, one surface of a substrate made of vinyl chloride resin (thickness: 80 占 퐉) obtained in the above (1) was subjected to corona treatment, and the surface of the laminate with the pressure-sensitive adhesive layer side was stuck to the corona- A semiconductor processing sheet comprising a base material and a pressure-sensitive adhesive layer was obtained in the state that a release film was laminated on the surface of the pressure-sensitive adhesive layer opposite to the base material.

[Examples 2 to 4, Comparative Examples 1 to 4 and Reference Example 1]

A semiconductor processed sheet was obtained in the same manner as in Example 1 except that the kind and blending amount of the plasticizer were changed as shown in Table 1.

Details of the abbreviations and the like in Table 1 are as follows.

Plasticizer A: di (2-ethylhexyl) terephthalate, ADEKA CYZER D-810, manufactured by ADEKA, molecular weight: 391

Plasticizer B1: adipic acid polyester, ADEKA ADEKA CHEMICALS PN-7160, average molecular weight: 800, plasticizing efficiency value: 1.00

Plasticizer B2: adipic acid polyester, manufactured by J · PLUS Co., Ltd., D-643, average molecular weight: 1800, plasticizing efficiency value: 1.16

Plasticizer C: isononyl adipate, manufactured by Shin-Nippon Rika Co., Ltd., oxygenase DINA, molecular weight: 398

[Test Example 1] < Measurement of 25% stress of base material &

The semiconductor processed sheets produced in Examples and Comparative Examples were cut into a rectangular shape of 15 mm x 150 mm so that the MD direction was in the long-side direction, and a measurement sample was obtained. The measurement sample thus obtained was set in a universal tensile tester (Tensilon RTA-T-2M, manufactured by Orientec Co., Ltd.) so that the gap between grippers became 100 mm. Tensile test was carried out at a tensile speed of 200 mm / min. The force measured at 25 mm elongation was divided by the cross-sectional area of the substrate of the measurement sample to yield a 25% stress of the substrate. The results are shown in Table 1.

[Test Example 2] < Measurement of adhesive force after ultraviolet irradiation >

The semiconductor processed sheets prepared in Examples and Comparative Examples were placed under accelerated conditions (40 占 폚, 14 days). Thereafter, the sheet was stored for 24 hours under the environment of a relative humidity of 23% at 50%, and each was cut to obtain an adhesive strength measuring sheet having a length of 250 mm and a width of 25 mm. The pressure-sensitive adhesive layer side of the resulting adhesive force measuring sheet was affixed to a mirror-finished silicon mirror wafer (diameter 6 inches, thickness 650 占 퐉) using a roller of 2 kg to obtain a laminate composed of a sheet for measuring adhesion force and a silicon wafer . The obtained laminate was stored for 20 minutes in an environment of 23 ° C and a relative humidity of 50%, and then irradiated with ultraviolet rays (ultraviolet ray irradiation apparatus: Adwill (registered trademark) RAD-2000 m / 12, manufactured by Lin Tec Co., Ltd., 230 mW / 190 mJ / cm < 2 >) to cure the pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer was stored for 10 minutes under the environment of a relative humidity of 50% at 23 deg.

The evaluation samples were peeled off at a peeling speed of 300 mm / min and a peeling angle of 180 占 according to JIS Z0237: 2000 using a universal tensile tester (TENSILON / UTM-4-100 manufactured by Orientech) (The adhesive force measuring sheet was regarded as the member on the side to be peeled off), and the adhesive force after irradiation was measured (unit: mN / 25 mm). Table 1 shows the measurement results of the adhesion after irradiation.

[Test Example 3] < Evaluation of Residues &

The presence or absence of residues on the surface of the silicon wafer at the peeled portion of the adhesion-force measurement sheet was checked in the measurement of the adhesion after irradiation (promoting condition: 40 占 폚, 14 days) conducted in Test Example 2. &Quot;, and " x ", where the residue was identified, were regarded as " DELTA "

[Test Example 4] < Measurement of adhesive force ratio &

The adhesive strength (A) before irradiation with ultraviolet rays after the promoting condition at 40 占 폚 for 14 days was measured in the same manner as in Test Example 2, except that the ultraviolet irradiation was not performed on the semiconductor processed sheets prepared in Examples and Comparative Examples. The adhesion (B) before irradiation with ultraviolet rays after the promoting condition at 40 占 폚 for 7 days was measured in the same manner as in Test Example 2 except that the promoting condition was 40 占 폚 for 7 days and the ultraviolet irradiation was not performed. From the obtained results, the adhesive force ratio (A) / (B) was calculated. The results are shown in Table 1.

As can be seen from Table 1, in the semiconductor processed sheet produced in the examples, the generation of residues was suppressed.

Industrial availability

The semiconductor processed sheet according to the present invention is preferably used, for example, in a processing step of a semiconductor wafer, particularly a processing step having an expanding step.

Claims (10)

A semiconductor processing sheet comprising a base film and a pressure-sensitive adhesive layer laminated on at least one side of the base film,
Wherein the base film contains a vinyl chloride resin, an adipate ester plasticizer and a terephthalate ester plasticizer as plasticizers,
Wherein the mass ratio of the content of the adipic ester plasticizer to the total content of the adipic ester plasticizer and the terephthalate ester plasticizer in the base film is 50 to 80 mass% Sheet. The method according to claim 1,
Wherein the base film has a 25% stress in the MD direction in a tensile test according to JIS K7161-1: 2014 of 5 to 16 MPa. 3. The method according to claim 1 or 2,
Wherein the total content of the plasticizer in the base film is 18 to 65 parts by mass based on 100 parts by mass of the vinyl chloride resin. 4. The method according to any one of claims 1 to 3,
Wherein the adipic ester plasticizer comprises adipic acid polyester. 5. The method of claim 4,
Wherein the adipic acid polyester has a number average molecular weight of 400 to 1,500. 6. The method according to any one of claims 1 to 5,
Wherein the adipic ester plasticizer comprises an adipic ester monomer. The method according to claim 6,
The adipic ester monomer may be one or two kinds selected from the group consisting of di (2-ethylhexyl) adipate, diisononyl adipate, diisodecyl adipate and di (2-butoxyethyl) adipate Or more. 8. The method according to any one of claims 1 to 7,
Wherein the terephthalate ester plasticizer is di (2-ethylhexyl) terephthalate. 9. The method according to any one of claims 1 to 8,
Wherein the content of the di (2-ethylhexyl) phthalate, dibutyl phthalate, benzyl butyl phthalate and diisobutyl phthalate in the base film is 0.001 mass% or less. 10. The method according to any one of claims 1 to 9,
Wherein the pressure-sensitive adhesive layer is formed of an energy ray-curable pressure-sensitive adhesive composition.