KR101967455B1 - Sheet for semiconductor wafer processing - Google Patents

Abstract

assignment
The present invention provides a sheet for processing a semiconductor wafer which exhibits sufficient exponential properties and which exhibits little change with time in adhesive properties even though the substrate does not contain DOP.
Solution
The sheet for processing a semiconductor wafer according to the present invention is characterized by having an adhesive resin layer on at least one side of a substrate made of vinyl chloride containing an alicyclic ester compound as a plasticizer.

Description

TECHNICAL FIELD [0001] The present invention relates to a sheet for processing semiconductor wafers (SHEET FOR SEMICONDUCTOR WAFER PROCESSING)

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet for processing a semiconductor wafer, and more particularly to a sheet used for fixing a semiconductor wafer when a semiconductor wafer is subjected to processing such as dicing. Another aspect of the present invention relates to a dicing die-bonding sheet having the functions of a dicing sheet and a film-like adhesive.

BACKGROUND ART In a series of steps of die-bonding a chip obtained by dicing a semiconductor wafer, various pressure-sensitive adhesive sheets and film adhesives are used.

For example, the pressure-sensitive adhesive sheet used in the dicing process is composed of a substrate and a pressure-sensitive adhesive layer, and is used to fix the semiconductor wafer when dicing the semiconductor wafer and to retain the chip after dicing. There is also a case where the chips diced on the pressure sensitive adhesive sheet are picked up directly from the pressure sensitive adhesive sheet or after the chips are transferred onto the pressure sensitive adhesive sheet for semiconductor pickup.

After completion of the dicing process, die bonding of the chip is performed. At this time, although a liquid type adhesive may be used, a film type adhesive has recently been used. The film-shaped adhesive is adhered to one side of the semiconductor wafer, cut along with the wafer in the dicing step, and then picked up with a chip of the adhesive layer portion, and the chip is adhered to a predetermined portion with the adhesive layer interposed therebetween. Such a film-like adhesive can be obtained by providing a base film or a pressure-sensitive adhesive sheet on which an adhesive such as epoxy or polyimide is formed and semi-solidified.

A dicing die-bonding sheet having both a wafer fixing function at the time of dicing and a die bonding function at the time of die bonding has also been proposed. The dicing die-bonding sheet is composed of a point-adhesive layer and a substrate. The point-adhesive layer has a semiconductor wafer or a chip in the dicing step, and functions as an adhesive for sticking the chip at the time of die bonding. At the time of dicing, the point-adhesive layer is cut together with the wafer, and a point-adhesive layer having the same shape as the cut chip is formed. After the completion of dicing, when the chip is picked up, the point-adhesive layer is peeled off together with the chip. The chip carrying the point adhesive layer is placed on the substrate and the chip and the substrate are bonded to each other through the adhesive layer by heating or the like. In such a dicing die-bonding sheet, a point-adhesive layer having a wafer-fixing function and a die-bonding function is formed on a substrate.

In order to form a protective film on the surface of the chip, a semiconductor wafer is attached to a curable resin layer to cure the resin layer, and then the semiconductor wafer and the resin layer are diced to form a chip having a cured resin layer Is also proposed. Such a sheet for forming a protective film has an adhesive resin layer made of a protective film on a peelable substrate.

In wafer processing using these semiconductor wafer processing sheets, the semiconductor wafer is expanded after dicing, and the chips are spaced apart to facilitate picking up of chips. For this reason, the wafer processing sheet may be required to have flexibility enough to allow expansion. Thus, polyvinyl chloride films containing a plasticizer are often used as the base material for the semiconductor wafer processing sheet (Patent Documents 1 and 2).

As plasticizers incorporated in polyvinyl chloride, alkyl esters of aromatic dicarboxylic acids, typically dioctyl phthalate (DOP), have been used. A flexible polyvinyl chloride (PVC) film containing a plasticizer such as DOP has excellent mechanical properties (stiffness of PVC) and flexibility due to a plasticizer, and is widely used as a substrate for various pressure sensitive adhesive sheets.

However, the DOP is a candidate substance for the Restriction of Hazardous Substances (RoHS) Directive in Europe and is also a REACH Regulation (Registration, Evaluation, Authorization and Restriction of Chemicals: The European Parliament for Protection and the Council of Europe Rules), for example, SVHC (Substance of Very High Concern). For this reason, the use of DOPs is very likely to be limited in the future and searches for alternative substances are being conducted.

Adipic acid ester has been noted as a substitute for DOP, but sufficient characteristics are not obtained due to its chemical structure. For example, adipic acid when hayeoteul using the ester as a substrate for electronic components for processing a pressure-sensitive adhesive sheet, there is no problem immediately after the formation of the pressure-sensitive adhesive on a base material, after a period of time, keep the components of the pressure-sensitive adhesive to an adherend to be electroplated (轉着) There was a case. The electronic member to which the pressure-sensitive adhesive is electrodeposited may cause various problems after the subsequent process or mounting. Further, even a compound, such as trimellitic acid ester, which is difficult to generate phthalic acid as a derivative, may contain phthalic acid as an impurity because it has an aromatic ring.

Patent Document 1: JP-A-2001-207140 Patent Document 2: JP-A-2010-260893

Disclosure of the Invention The present invention has been made in view of the above-mentioned prior art, and it is an object of the present invention to provide a sheet for processing a semiconductor wafer, which exhibits sufficient expansibility despite the fact that the substrate contains no DOP, .

The gist of the present invention to solve the above problems is as follows.

(1) A sheet for processing a semiconductor wafer having an adhesive resin layer on at least one side of a vinyl chloride base material containing an alicyclic ester compound as a plasticizer.

(2) The sheet for semiconductor wafer processing according to (1), wherein the alicyclic ester compound is a diester of cyclohexanedicarboxylic acid and an alcohol having 6 to 12 carbon atoms.

(3) The sheet for semiconductor wafer processing according to (2), wherein the cyclohexanedicarboxylic acid is 1,2-cyclohexanedicarboxylic acid and the alcohol is isononyl alcohol.

(4) The sheet for semiconductor wafer processing according to any one of (1) to (3), wherein the content of the aliphatic ester compound in the vinyl chloride base material is 5 to 100 parts by mass relative to 100 parts by mass of vinyl chloride.

(5) The sheet for semiconductor wafer processing according to any one of (1) to (4), wherein the adhesive resin layer has a pressure-sensitive adhesive property.

(6) The sheet for semiconductor wafer processing according to (5), wherein the adhesive resin layer comprises an energy radiation curable pressure sensitive adhesive.

(7) The sheet for semiconductor wafer processing according to (5) or (6), wherein the adhesive resin layer comprises an acrylic pressure-sensitive adhesive.

(8) The sheet for semiconductor wafer processing according to (7), wherein the (meth) acrylic acid ester copolymer contained in the acrylic pressure-sensitive adhesive has a glass transition temperature of -50 to 30 占 폚.

(9) The semiconductor wafer processing sheet according to any one of (1) to (8), which is used for holding a semiconductor wafer and a chip after dicing when dicing the semiconductor wafer.

(10) The sheet for semiconductor wafer processing according to any one of (1) to (9), wherein the adhesive resin layer contains an epoxy adhesive or a polyimide adhesive.

(11) The semiconductor wafer processing sheet according to (9) or (10) for transferring the adhesive resin layer onto a semiconductor wafer and a chip after dicing.

In the present invention, a vinyl chloride substrate containing an alicyclic ester compound as a plasticizer is used for a substrate of a semiconductor wafer processing sheet to obtain a sheet for processing a semiconductor wafer which exhibits sufficient expandability and little change with time. That is, the performance equal to or higher than that of the DOP product can be achieved without using the DOP. For this reason, it is expected to develop as a substitute for DOP products scheduled to be regulated in the future.

Hereinafter, the semiconductor wafer processing sheet according to the present invention will be described in more detail.

The semiconductor wafer processing sheet according to the present invention has a substrate and an adhesive resin layer formed on at least one side thereof.

(materials)

The base material is composed of a vinyl chloride resin containing an alicyclic ester compound as a plasticizer.

The vinyl chloride-based resin used in the present invention refers to the whole polymer having a repeating unit represented by -CH ₂ -CHCl-, and is a copolymer of a vinyl chloride homopolymer and vinyl chloride such as an ethylene-vinyl chloride copolymer and a polymerizable monomer Copolymers and chlorinated vinyl chloride copolymers, and chlorinated polyethylene similar to a structural vinyl chloride resin such as chlorinated polyethylene. These vinyl chloride resins preferably have a number average degree of polymerization of 300 to 3000, more preferably 1000 to 2500. These vinyl chloride resins may be used alone or in combination of two or more thereof to form a vinyl chloride resin component constituting the substrate.

The alicyclic ester used as the plasticizer is an ester of an alicyclic dicarboxylic acid and an alcohol. Examples of the alicyclic ester include aliphatic carboxylic acids such as an ester of cyclobutanedicarboxylic acid, cyclopentanecarboxylic acid, and cyclohexanedicarboxylic acid and alcohols such as methanol, ethanol, propanol, n-butanol, n-pentanol, n- Esters with alcohols such as heptanol, n-octanol, 2-ethylhexanol, n-nonanol, isononanol, n-decanol, n-dodecanol and n-tetradecanol .

The alicyclic dicarboxylic acid is preferably cyclohexanedicarboxylic acid from the viewpoint of steric stability, and the substitution degree of the carboxyl group is not particularly limited, but 1,2-cyclohexanedicarboxylic acid is preferable. 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 isononanol is particularly preferable. Therefore, the plasticizer that is particularly preferably used in the present invention is 1,2-cyclohexanedicarboxylic diisononyl ester.

By using an alicyclic ester, it is inevitable that the phthalic acid diester, which is an aromatic ester, is excluded, the possibility of containing phthalic acid as an impurity is reduced, and there is no fear of environmental load and toxicity, and a substrate containing a vinyl chloride resin as a main component Can be plasticized. When the sheet for processing a semiconductor wafer of the present invention is a pressure-sensitive adhesive sheet having a releasable pressure-sensitive adhesive layer on a substrate, the plasticizer inside the substrate is transferred into the pressure-sensitive adhesive layer during storage after the production of the sheet, It can be injected into the pressure-sensitive adhesive layer. In such a case, although the principle thereof is not clear, depending on the selection of the esters, when the semiconductor wafer processing sheet is peeled from the semiconductor wafer, the component of the pressure-sensitive adhesive layer remains in the semiconductor Residual) may occur. Such occurrence of the residual phenomenon tends to become prominent over time after the production of the semiconductor wafer processing sheet. When alicyclic esters are used, the generation of residues on the semiconductor wafer can be suppressed.

The content of the aliphatic ester compound in the base material is preferably 5 to 100 parts by mass, more preferably 10 to 50 parts by mass, particularly preferably 20 to 50 parts by mass, relative to 100 parts by mass of the vinyl chloride resin constituting the substrate. 40 parts by mass. If the content of the aliphatic ester compound in the substrate is too small, the flexibility of the substrate is lost and the expandability of the semiconductor wafer processing sheet becomes insufficient. If the content of the aliphatic ester compound in the base material is too large, the base material becomes excessively soft and the handling property is lowered, or the plasticizer of the base material is transferred to the adhesive resin layer, and the performance of the adhesive resin layer may be changed over time . When the content of the aliphatic ester in the base material is in this range, as described later, in the pressure-sensitive adhesive sheet provided with a releasable pressure-sensitive adhesive layer on the substrate, the plasticizer inside the pressure- Is likely to occur. Even in such a case, the problem of residual residual of the pressure-sensitive adhesive can be prevented by using the alicyclic ester as the plasticizer of the substrate.

The base material may further contain a filler for improving the strength. Further, barium-zinc-based stabilizers, calcium-zinc-based stabilizers, and the like may be blended for imparting chemical stability. Such a stabilizer may be contained in an amount of about 1.5 to 3.5 parts by mass based on 100 parts by mass of the vinyl chloride resin. In addition to these, additives such as a colorant, an antistatic agent, an antioxidant, an organic lubricant, an ultraviolet absorber, and a light stabilizer may be included. These fillers, stabilizers, additives and the like may be contained in a proportion of about 1.0 to 8.0 parts by mass based on 100 parts by mass of the vinyl chloride resin. In addition, plasticizers other than the alicyclic ester compounds may be included within the scope of the present invention.

The thickness of the base material is not particularly limited and may vary depending on the use of the semiconductor wafer processing sheet, but is generally 10 to 300 占 퐉, preferably 40 to 120 占 퐉. If the thickness of the base material is too thin, when the base material is cut by the dicing blade when the sheet is used for fixing to the workpiece in the dicing step, the thickness of the base material becomes extremely thin, There is a concern. If it is too thick, the force on the tension can be amplified and the expansion ability can be deteriorated. The surface of the base material in contact with the adhesive resin layer may be subjected to a corona treatment or another layer such as a primer in order to improve adhesion with the adhesive resin layer. Further, when the adhesive resin layer is transferred from a substrate to an adhesive resin layer by peeling off the adhesive resin layer, the surface of the substrate may be peeled off to facilitate peeling between the adhesive resin layer and the substrate. In this case, the surface tension of the substrate is preferably 40 mN / m or less, more preferably 37 mN / m or less, particularly preferably 35 mN / m or less. As the releasing agent used in the peeling treatment, an alkyd type, a silicone type, a fluorine type, an unsaturated polyester type, a polyolefin type, a wax type, or the like is used, but an alkyd type, a silicone type and a fluorine type releasing agent are preferable because they have heat resistance.

In order to peel the surface of the substrate using the above releasing agent, the releasing agent may be directly applied as a solvent or by solvent dilution or emulsification and then applied by a gravure coater, a Meyer bar coater, an air knife coater, a roll coater, The laminate may be formed by electron beam hardening, wet lamination, dry lamination, heat dissolution lamination, melt extrusion lamination, coextrusion, or the like.

In addition, the vinyl chloride resin generally has a low heat resistance and may not be able to use the above peeling treatment means. In such a case, it is also possible to form the film by applying a releasing agent to the vinyl chloride resin film for substrate using energy ray curable resin as a releasing agent, and curing the film by energy ray irradiation.

The production method of the base material is not particularly limited, but can be obtained by forming a mixture obtained by mixing the vinyl chloride resin, the alicyclic ester compound as the plasticizer, the stabilizer, and other additives.

As for the mixing of the components, a single-screw extruder, a twin-screw extruder, a Banbury mixer, various kneaders, a bravender, calender rolls and the like are generally used by a mechanical melting kneading method. At this time, there is no restriction on the order of addition of each component. The melting and kneading temperature may be suitably selected from 140 to 220 占 폚.

The obtained mixture is processed into a sheet shape to obtain a substrate. The sheet processing may be carried out according to a general molding process such as extrusion molding, calender molding, and inflation molding.

The film-forming method may be a method in which the above-mentioned mixture is put in a solution or a dissolved state, and the coating is performed by a coating means such as a knife coater.

(Adhesive resin layer)

The adhesive resin layer in the semiconductor wafer processing sheet is appropriately selected among resins having various functions depending on the use of the sheet.

(Pressure-sensitive adhesive resin layer)

Among them, it is particularly preferable that the sheet for processing a semiconductor wafer be a pressure-sensitive adhesive sheet composed of a pressure-sensitive adhesive layer (pressure-sensitive adhesive layer) having an adhesive resin layer having re-releasability and that the sheet for semiconductor wafer processing is used as a dicing sheet desirable. Since the substrate for semiconductor wafer processing is composed of a flexible vinyl chloride resin containing a plasticizer, the expandability of the substrate is excellent, and the chip spacing is likely to expand isotropically. Further, it is difficult for the cutting blade to occur due to sliding of the dicing blade at the contact portion with the base material. In addition, it is difficult for the chip to be pulled out or cracked due to the impact at the time of cutting. Further, the application of the pressure-sensitive adhesive sheet is not limited to the dicing sheet. For example, the pressure-sensitive adhesive sheet may be a sheet for transferring chips from one sheet to another sheet, Sheets and the like, the applications involving expansion are very suitable from the same viewpoint.

In the case of a sheet for processing a semiconductor wafer having a pressure-sensitive adhesive layer on a substrate made of a vinyl chloride resin containing a plasticizer, a plasticizer present in the substrate during storage may be transferred into the pressure-sensitive adhesive layer. This is caused by the diffusion phenomenon caused by the concentration gradient of the plasticizer in the inside of the substrate and the pressure-sensitive adhesive layer, and the higher the concentration of the plasticizer in the substrate, the more likely it is to occur. Even in the case where the plasticizer is transferred to the pressure-sensitive adhesive layer as described above, the use of the alicyclic ester as the plasticizer of the substrate as described above can be used to suppress the residue of the residue. The dicing sheet is used to hold a semiconductor wafer and a chip produced by dicing when dicing a semiconductor wafer into chips. Therefore, it is required to have an appropriate re-peeling property to such an extent that the chip can be peeled off after dicing. Such a pressure-sensitive adhesive layer can be formed by various conventionally known pressure-sensitive adhesives (pressure-sensitive adhesives). The pressure-sensitive adhesive is not limited, and for example, a pressure-sensitive adhesive such as rubber, acrylic, silicone, or polyvinyl ether is used. Among them, an acrylic pressure-sensitive adhesive which is easy to control the adhesive force is particularly preferable.

The acrylic pressure-sensitive adhesive contains a (meth) acrylic acid ester copolymer as a main agent. Examples of the (meth) acrylic acid ester copolymer include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, dodecyl acrylate, lauryl acrylate, myristyl acrylate, One or more monomers of (meth) acrylic acid esters in which only hydrocarbons are added to an ester structure such as ethyl, ethyl methacrylate, propyl methacrylate, butyl methacrylate, benzyl acrylate, cyclohexyl acrylate and isobornyl acrylate, 2-hydroxyethyl, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 3-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, (Meth) acrylate such as 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 3-hydroxybutyl methacrylate and 4-hydroxybutyl methacrylate ) Acrylic acid alkyl ester, carboxyl group-containing compounds such as acrylic acid, methacrylic acid, maleic acid, and fumaric acid, vinyl esters such as vinyl acetate and vinyl propionate, cyano group-containing compounds such as acrylonitrile and methacrylonitrile, , And copolymers of at least one monomer selected from polymerizable monomers such as aromatic compounds such as styrene and vinyl pyridine. In the case where the polymerizable monomer is one type, it is not a narrow copolymer, but is collectively referred to as a copolymer including such a case.

The content ratio of the unit derived from the (meth) acrylic acid ester to which only the hydrocarbon is added to the ester structure in the (meth) acrylic acid ester copolymer is preferably from 10 to 98 mass%, more preferably from 20 to 95 mass% And more preferably 50 to 93 mass%. The weight average molecular weight of the (meth) acrylic acid ester copolymer is preferably 100,000 to 250,000, more preferably 200,000 to 1,500,000, and particularly preferably 300,000 to 1,000,000. In the present specification, the weight average molecular weight is a value in terms of standard polystyrene measured by a gel permeation chromatography (GPC) method.

These pressure-sensitive adhesives may be used alone or in combination of two or more. Among these pressure-sensitive adhesives, an acrylic pressure-sensitive adhesive is preferably used. In particular, an acrylic pressure-sensitive adhesive obtained by crosslinking an acrylic copolymer with at least one crosslinking agent such as a polyisocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, or a chelate crosslinking agent is preferable.

Examples of the epoxy cross-linking agent include (1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N'-tetraglycidyl- N, N'-tetraglycidylaminophenylmethane, triglycidylisocyanate, m-N, N-diglycidylaminophenylglycidylateur, N, N-diglycidyltoluidine, N, N -Diglycidyl aniline, pentaerythritol polyglycidyl ether, 1,6-hexanediol diglycidyl ether, and the like.

Examples of the polyisocyanate cross-linking agent include toluene diisocyanate (TDI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), xylene diisocyanate (XDI), hydrogenated tolylene diisocyanate, diphenylmethane diisocyanate, An additive, polymethylene polyphenyl polyisocyanate, naphthylene-1,5-diisocyanate, polyisocyanate free polymer, polymethylol propane-modified TDI, and the like.

The crosslinking agent may be used alone or in combination of two or more. The amount of the crosslinking agent to be used is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the acrylic copolymer.

When the sheet for processing a semiconductor wafer is used as a dicing sheet, the pressure-sensitive adhesive layer may be a pressure-sensitive adhesive capable of controlling the adhesive force by energy ray curing, heated foaming, water swelling and the like. The energy ray curable pressure sensitive adhesive layer can be formed by various energy ray curable pressure sensitive adhesives which are conventionally cured by irradiation of energy rays such as gamma rays, electron rays, ultraviolet rays, and visible rays, but it is particularly preferable to use an ultraviolet ray curable pressure sensitive adhesive.

Examples of the energy ray curable pressure sensitive adhesive include pressure sensitive adhesives obtained by mixing a polyfunctional energy ray curable resin with an acrylic pressure sensitive adhesive. Examples of the polyfunctional energy ray curable resin include a low molecular compound having a plurality of energy ray polymerizable functional groups, urethane acrylate oligomer, and the like. Further, a pressure-sensitive adhesive containing an acrylic copolymer having an energy ray-polymerizable functional group in its side chain can also be used. As such an energy ray polymerizable functional group, a (meth) acryloyl group is preferable.

In the present invention, the pressure-sensitive adhesive layer preferably has a glass transition temperature (Tg) of -50 ° C to 30 ° C, more preferably -25 ° C to 30 ° C. When the content of the alicyclic ester in the substrate is large, the pressure-sensitive adhesive layer preferably has a glass transition temperature (Tg) of 0 to 30 캜, more preferably 5 to 25 캜. Here, the Tg of the pressure-sensitive adhesive layer is the temperature at which the loss tangent (tan?) Shows the maximum value in the range of -50 to 50 占 폚 in the dynamic viscoelasticity measurement of the sample having the pressure-sensitive adhesive layer laminated at a frequency of 11 Hz. When the pressure-sensitive adhesive layer is an energy ray-curable pressure-sensitive adhesive, it indicates the glass transition temperature before curing the pressure-sensitive adhesive layer by energy ray irradiation. When the pressure-sensitive adhesive layer is made of the above-mentioned acrylic pressure-sensitive adhesive, the glass transition temperature of the pressure-sensitive adhesive layer regulates the type and the polymerization ratio of the monomers constituting the acrylic pressure-sensitive adhesive, and presumably affects the influence of the ultraviolet- .

When the content of the aliphatic ester in the substrate is large, the preferable range of the glass transition temperature of the pressure-sensitive adhesive layer is generally higher than the range that is considered preferable for the pressure-sensitive adhesive. The reasons for this range are as follows. As described above, in the case of the pressure-sensitive adhesive sheet as one form of the present invention, the plasticizer in the substrate may be transferred to the pressure-sensitive adhesive layer. Then, the pressure-sensitive adhesive layer contains the plasticizer by the transition, and the pressure-sensitive adhesive layer tends to be softened. Even in this case, if the glass transition temperature is within the above range, the cohesive force of the pressure-sensitive adhesive layer is not excessively lowered, and the effect of preventing the residual paste is hardly impaired.

The dicing sheet is commonly used for semiconductor processing. The dicing sheet fixes the wafer at the time of dicing, and has an adhesive force such that chips generated by dicing do not scatter. After completion of the dicing process, the chip is picked up. At this time, the chip is picked up from the dicing sheet by using an extrusion pin or a suction collet. When the pressure-sensitive adhesive layer has energy ray curability, the pressure sensitive adhesive layer is irradiated with an energy ray to lower the adhesive force, thereby making it easier to pick up the chip. When picking up the chips, it is preferable to expand the dicing sheet in a state where the chips are fixed on the dicing sheet in order to separate the chips from each other. The chip spacing is spaced apart by expansion, so that the chip is easily recognized, and breakage due to contact between the chips is also reduced, thereby improving the yield.

(Film-shaped adhesive)

The adhesive resin layer may be a film-like adhesive. Such a film-shaped adhesive has recently been widely used in the die bonding process of a chip. Such a film-like adhesive is preferably formed by forming and semi-curing an epoxy-based adhesive or a polyimide-based adhesive, and is peelable on a substrate or on the above-mentioned pressure-sensitive adhesive sheet to obtain a sheet for processing a semiconductor wafer of the present invention .

The film-form adhesive layer is pasted on the semiconductor wafer. The semiconductor wafer and the film-shaped adhesive layer are diced into a chip size to obtain a chip of the adhesive layer portion, picked up from the base material or the adhesive sheet, and fixed to the predetermined position through the adhesive layer. When picking up the adhesive layer chips, it is preferable to perform expansion in the same manner as described above.

The sheet for processing a semiconductor wafer of the present invention may be a dicing die-bonding sheet having both a wafer fixing function at the time of dicing and a die bonding function at the time of die bonding. In this case, the adhesive resin layer may have a sticky property or softened by heating so as to be attached to an adherend, so that a semiconductor wafer or chip can be held in the dicing step. In die bonding, it functions as an adhesive for bonding chips. The adhesive layer is cut along with the wafer at the time of dicing to form an adhesive layer having the same shape as the chips cut. After the completion of the dicing, if the chip is picked up, the adhesive layer is peeled from the substrate together with the chips. A chip accompanied by an adhesive layer is placed on a substrate and subjected to heating or the like, and an adherend such as a chip and a substrate or another chip is bonded through an adhesive layer. Such a dicing die-bonding sheet is formed by forming an adhesive layer having a wafer fixing function and a die bonding function on a substrate. The adhesives having the wafer fixing function and the die bonding function include, for example, the above acrylic pressure-sensitive adhesives and epoxy adhesives, and if necessary, energy ray curable compounds and curing aids. In order to facilitate the transfer of the adhesive resin layer to the chip, it is preferable that the substrate in the dicing / die bonding sheet is peeled. In picking up the point-adhesive-layer chip, it is preferable to perform expansion in the same manner as described above.

(Sheet for forming a protective film)

The sheet for processing a semiconductor wafer may be a sheet for forming a protective film for forming a protective film on the back surface of the chip. In this case, the semiconductor wafer is attached to the adhesive resin layer to cure the adhesive resin layer, and then the semiconductor wafer and the resin layer are diced to obtain a cured resin layer (protective film). Such a sheet for forming a protective film has an adhesive resin layer which becomes a protective film on a peelable substrate. The adhesive resin layer to be a protective film includes the acrylic adhesive, the epoxy adhesive, and the curing aid, and may further include a filler or the like if necessary.

The thickness of the adhesive resin layer in the sheet for processing a semiconductor wafer of the present invention varies depending on the use thereof, and is about 30 to 200 mu m when used as a dicing sheet. When the sheet is used as a dicing / die bonding sheet About 50 to 300 mu m.

The typical composition and application of the adhesive resin layer have been described above for the semiconductor wafer processing sheet of the present invention. However, the adhesive resin layer in the semiconductor wafer processing sheet of the present invention is not limited to the above, And its use is not particularly limited.

[Example]

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to these examples. The measurement and evaluation methods employed in the present invention are as follows.

<Adhesive strength measurement>

As a condition simulating long-term aging, the semiconductor wafer processing sheets prepared in Examples and Comparative Examples were placed under accelerated conditions (40 占 폚 for 7 days or 40 占 폚 for 14 days). Thereafter, the sheet was stored for 24 hours under the environment of a relative humidity of 23 캜 and a humidity of 50%, and then the sheet cut to a length of 250 mm with a width of 25 mm was transferred to a mirror-finished silicon wafer (6 inches in diameter, 650 탆 in thickness, After the chemical mechanical polishing, the alkali was removed and then the residue was removed by acid. Specification of warpage: The distance between the edge and the horizontal plane was 100 μm or less when placed on a horizontal plane. : 30 elements or less, elemental abundance of Al, Cr, Cu, Fe, Ni, Zn, and Na: less than 5 x 10 ¹⁰ atoms / cm ² ) and stored at 23 캜 in a 50% relative humidity for 30 minutes The pressure-sensitive adhesive layer was cured by irradiating ultraviolet rays (ultraviolet irradiation apparatus: Adwill (registered trademark) RAD-2000m / 12 (manufactured by LINTEC Co., Ltd., 230 mW / cm ² , 190 mJ / cm ² ) After 10 minutes of storage under the environment, the peeling speed was 300 mm / min and the peeling angle was 180 deg. To measure the force when the stripped. The adhesive strength was also measured in the same manner as for the sheet not irradiated with ultraviolet rays.

<Evaluation of full residue>

In the adhesion measurement, the presence or absence of the adhesive residue on the surface of the silicon wafer at the portion where the sheet was peeled off was confirmed. "A" indicates that the residue of the adhesive is not identified, and "F" indicates that the residue of the adhesive is identified.

<Expendability>

The semiconductor wafer processing sheet of Example 1 and Reference Example 1 was attached to a 6-inch silicon wafer (thickness 350 占 퐉), and a chip of 8 mm 占 8 mm size using a dicing blade 27HECC The chip was spaced 10 mm apart in pulling out, and chip intervals in the horizontal direction (X direction) and the vertical direction (Y direction) were confirmed by a digital microscope.

&Lt; Measurement of Glass Transition Temperature of Pressure-Sensitive Adhesive Layer &gt;

Using a roll knife coater, the energy ray-curable pressure-sensitive adhesive composition of the example diluted with a solvent was applied to a release treatment surface of a polyethylene terephthalate (PET) film (thickness 38 탆) obtained by silicone release treatment so as to have a coating thickness after drying of 10 탆 And dried at 100 占 폚 for 1 minute to bond the exposed PET film to the exposed surface of the pressure-sensitive adhesive layer with a silicone peeling treatment having a different peeling force to obtain a pressure-sensitive adhesive layer sandwiched between two PET films. Subsequently, after storage for 7 days in an environment of 23 ° C and 50% RH, only the pressure sensitive adhesive layer except for the PET film was laminated until the thickness became 1 mm. A pressure sensitive adhesive layer laminated up to a thickness of 1 mm was pulled out from the mold in a cylindrical shape having a diameter of 8 mm and then laminated up to a thickness of 3 mm to obtain a sample for measurement. The tan δ (loss tangent) of the sample measured at a frequency of 11 Hz at -50 ° C to 110 ° C was measured using a viscoelasticity measuring device (DYNAMIC ANALYZER RADII, manufactured by REOMETRIC Co., Ltd.). The temperature at which the maximum value of tan delta in the range of -50 deg. C to 50 deg. C was determined as the glass transition temperature.

Example  One

(materials)

, 100 parts by weight of a polyvinyl chloride resin (average degree of polymerization: 1100), 30 parts by weight of 1,2-cyclohexanedicarboxylic acid diisononyl ester (product name: Hexamoll-DINCH, product of BASF) and 2.8 parts by weight of barium- The mixture was kneaded at 180 DEG C using a Banbury mixer. This mixture was rolled by a calender roll to obtain a substrate made of vinyl chloride resin having a thickness of 80 mu m.

(Pressure-sensitive adhesive layer)

Acrylic acid ester copolymer (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) 3.2 parts by mass of an organic polyisocyanate compound (TOYOCHEM CO., LTD., Trade name: BHS8515) as a curing agent and 1 part by mass of 1-hydroxycyclohexyl phenyl ketone (trade name: 2.6 parts by mass of Argacure 184) and 85.7 parts by mass of a mixture of a 1: 1 ratio of bifunctional urethane acrylate and 6-functional urethane acrylate as an energy ray curable compound were blended (solid mass ratio) to obtain an energy radiation curable pressure- . The pressure-sensitive adhesive layer obtained by this composition had a glass transition temperature of 17 캜.

(Preparation of a sheet for processing a semiconductor wafer)

The energy ray-curable pressure-sensitive adhesive composition was diluted with a solvent to be applied to a release material (SP-PET381031, manufactured by LINTEC CORPORATION) so as to have a coverage of 10 g / m ² and then dried to laminate the pressure- To prepare a working sheet. In addition, corona treatment was performed on the base material in advance, and a pressure-sensitive adhesive layer was laminated on the corona-treated surface.

Table 1 shows the evaluation results of &quot; full residue &quot; using the obtained sheet for semiconductor wafer processing, and Table 3 shows the measurement results of &quot; Adhesive Force Measurement &quot;

Comparative Example  One

The same procedure as in Example 1 was carried out except that di (2-ethylhexyl) adipate was used as a plasticizer to be mixed with a substrate. The results are shown in Tables 1 and 2.

Comparative Example  2

The procedure of Example 1 was repeated except that di (2-ethylhexyl) terephthalate was used as the plasticizer to be mixed with the base material. The results are shown in Tables 1 and 2.

Comparative Example  3

The procedure of Example 1 was repeated except that di (2-ethylhexyl) phthalate was used as the plasticizer to be mixed with the base material. The results are shown in Tables 1 and 2.

Table 1 Pool remaining evaluation Promote 7 days at 40 ℃ Promote 14 days at 40 ℃ UV cooking dictionary After UV irradiation UV cooking dictionary After UV irradiation Example 1 A A A A Comparative Example 1 F F F F Comparative Example 2 F F F F Comparative Example 3 A A A A

Table 2 Adhesion (mN / 25 mm) Promote 7 days at 40 ℃ Promote 14 days at 40 ℃ UV cooking dictionary After UV irradiation UV cooking dictionary After UV irradiation Example 1 370 50 355 50 Comparative Example 1 350 60 300 60 Comparative Example 2 420 60 430 60 Comparative Example 3 680 60 650 60

Comparative Example  4

The same procedure as in Example 1 was carried out except that an ethylene-methacrylic acid copolymer film having a thickness of 80 占 퐉 was used. Table 3 shows the results of &lt; expansion ability &gt;. When the semiconductor processing sheet of Comparative Example 4 was used, the expansion in the X direction and the Y direction was not uniform and was inferior to the expansion ability.

Table 3 Chip spacing (㎛) X direction Y direction Example 1 135 138 Comparative Example 4 130 101

Claims (23)

delete delete delete delete delete delete delete delete delete delete delete delete delete A sheet for processing a semiconductor wafer having an adhesive resin layer on at least one side of a substrate made of vinyl chloride containing an alicyclic ester compound as a plasticizer,
Wherein the alicyclic ester compound is a diester of 1,2-cyclohexanedicarboxylic acid and isononyl alcohol,
Wherein the adhesive resin layer comprises an acrylic pressure-sensitive adhesive. 15. The method of claim 14,
Wherein the content of the aliphatic ester compound in the vinyl chloride base material is 5 to 100 parts by mass based on 100 parts by mass of vinyl chloride. 15. The method of claim 14,
Wherein the adhesive resin layer has a pressure-sensitive adhesive property. 17. The method of claim 16,
Wherein the adhesive resin layer comprises an energy radiation curable pressure sensitive adhesive. 15. The method of claim 14,
Wherein the (meth) acrylic acid ester copolymer contained in the acrylic pressure-sensitive adhesive has a glass transition temperature of -50 to 30 占 폚. 19. The method according to any one of claims 14 to 18,
A semiconductor wafer processing sheet used for holding a semiconductor wafer and a chip after dicing when dicing a semiconductor wafer. 19. The method according to any one of claims 14 to 18,
Wherein the adhesive resin layer contains an epoxy adhesive or a polyimide adhesive. 20. The method of claim 19,
Wherein the adhesive resin layer contains an epoxy adhesive or a polyimide adhesive. 20. The method of claim 19,
A sheet for processing a semiconductor wafer for transferring an adhesive resin layer onto a semiconductor wafer and a chip after dicing. 21. The method of claim 20,
A sheet for processing a semiconductor wafer for transferring an adhesive resin layer onto a semiconductor wafer and a chip after dicing.