TWI688633B - Work fixing sheet having resin layer - Google Patents

Abstract

The present invention relates to a work fixing sheet having a resin layerincluding an adhesive layer on a substrate film, and a curable resin layer on the adhesive layer, wherein the adhesive layer includes a (meth)acrylic acid alkyl ester polymer in which a monomer including a (meth)acrylic acid alkyl ester containing an alkyl group having 10 to 18 carbon atoms is copolymerized, the curable resin layer includes a polymer component (a) and a curable component (b), and the total amount of the polymer component (a) and the curable component (b) in the curable resin layer with respect to the total amount of the curable resin layer is 95% by mass or more.

Description

Workpiece fixing piece with resin layer

The present invention relates to a work fixing sheet having a resin layer formed by providing an adhesive layer on a base film and a curable resin layer on the adhesive layer.

This application claims priority based on Japanese Patent Application No. 2014-192505 filed in Japan on September 22, 2014, and the contents thereof are incorporated herein.

A workpiece fixing sheet with a resin layer, which is provided with an adhesive layer on the base film and a hardening resin layer on the adhesive layer, is suitable for, for example, cutting a semiconductor wafer and going through the steps of picking up the semiconductor wafer. The picked semiconductor wafer is then subjected to the step of die bonding of the substrate, lead frame, or other semiconductor wafer. For example, in the manufacture of a semiconductor device, the curable resin layer of the workpiece fixing sheet with a resin layer functions as a bonding film for die bonding, and the workpiece fixing sheet with a resin layer is attached with the curable resin When dicing in the state of a semiconductor wafer, the workpiece fixing sheet having a resin layer is used as a die-bonding wafer.

In addition to the aforementioned application, the workpiece fixing sheet having a resin layer can also be used as, for example, a protective film and a diced wafer of a semiconductor wafer or a semiconductor wafer (flip chip), or when a flip chip is attached to a wafer mounting portion Then the film and back grinding sheet.

In any application, the workpiece fixing sheet having a resin layer is attached to a semiconductor wafer with a curable resin layer, and the adhesive layer and the base film are further peeled off from the curable resin layer. At this time, if necessary, a polymerization reaction is performed on the adhesive layer in advance, thereby reducing the adhesiveness of the adhesive layer.

On the other hand, the curable resin layer of the work fixing sheet having a resin layer contains fillers to increase the strength. In this regard, the filler may be difficult to uniformly disperse in the curable resin layer. In addition, there is a possibility that the filler may come off the cured film after curing the curable resin layer containing the filler. Therefore, a workpiece fixing sheet having a resin layer having a curable resin layer that does not substantially contain a filler material is desired. In addition, there is known an adhesive sheet that directly adheres an adhesive layer to a semiconductor wafer without passing through a curable resin layer and a work fixing sheet having a resin layer. As such an adhesive sheet, for example, there is disclosed an adhesive layer using a base polymer having a methacrylate monomer derived from an alkyl group having 10 to 17 carbon atoms and other specific Structural units of two kinds of monomers (refer to Patent Document 1).

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2012-136678

However, Patent Document 1 does not describe or suggest the constituents of providing a curable resin layer and a curable resin layer on the adhesive layer of the adhesive sheet. In addition, when a workpiece fixing sheet having a resin layer having a hardenable resin layer that does not substantially contain a filler material is used, there is usually a problem that the so-called easy pick-up property that can easily pick up a semiconductor wafer without applying a large external force is reduced .

The present invention has been completed in view of the foregoing circumstances, and the object is to provide a workpiece fixing sheet having a resin layer provided with an adhesive layer on a base film and a curable resin layer containing substantially no filler material on the adhesive layer It is easy to pick up the semiconductor wafer.

In order to solve the aforementioned problems, the present invention provides a work fixing sheet having a resin layer, which is formed by providing an adhesive layer on a base film and a curable resin layer on the adhesive layer, the adhesive layer containing an alkyl group An alkyl (meth)acrylate polymer obtained by polymerizing monomers of alkyl (meth)acrylate having a carbon number of 10 to 18, and the curable resin layer contains a polymer component (a) and a curable component (b) , And the foregoing of the curable resin layer The total content of the polymer component (a) and the curable component (b) is 95% by mass or more relative to the total amount of the curable resin layer.

In the work fixing sheet having a resin layer of the present invention, it is preferable that the curable resin layer contains an acrylic resin as the polymer component (a), and the content of the acrylic resin relative to the solid content of the curable resin layer The total amount is more than 50% by mass.

In the work fixing sheet having a resin layer of the present invention, it is preferable that the content of the curable component (b) of the curable resin layer is 100 parts by mass to 1 part by mass to 100 parts by mass with respect to the content of the polymer component (a) Minute.

According to the present invention, there is provided a workpiece fixing sheet having a resin layer provided with an adhesive layer on a base film and a curable resin layer containing substantially no filler material on the adhesive layer, that is, containing no filler material at all Or it may be made of a curable resin layer containing a filler to such an extent that the effect produced by using the filler can be ignored, and has easy pick-up of the semiconductor wafer.

1‧‧‧Workpiece fixing piece

10‧‧‧Work piece with resin layer

11‧‧‧ Base film

11a‧‧‧Surface of substrate film

12‧‧‧Adhesive layer

12a‧‧‧Surface of adhesive layer

13‧‧‧curable resin layer

13a‧‧‧The surface of the hardening resin layer

14‧‧‧ peeling film

FIG. 1 is a cross-sectional view schematically showing a work fixing sheet having a resin layer of the present invention.

<Workpiece fixing sheet with resin layer>

The workpiece fixing sheet having a resin layer of the present invention is provided on a base film The adhesive layer is formed by having a hardening resin layer on the adhesive layer. The adhesive layer contains a (meth)acrylic acid monomer containing alkyl (meth)acrylate having an alkyl carbon number of 10 to 18. ) An alkyl acrylate polymer, the curable resin layer containing the polymer component (a) and the curable component (b), and the total of the polymer component (a) and the curable component (b) of the curable resin layer The content is 95% by mass or more with respect to the total amount of the curable resin layer.

In this specification, the laminated structure of the base film and the adhesive layer is referred to as a workpiece fixing sheet.

In this specification, "polymerization" includes both homopolymerization of a single monomer (also called monomer) and copolymerization of plural monomers. Therefore, in this specification, the "polymer" includes both a homopolymer homopolymerized by a single monomer and a copolymer copolymerized by a plurality of monomers.

The aforementioned workpiece fixing sheet having a resin layer is suitable for, for example, cutting a semiconductor wafer, passing through a step of picking up a semiconductor wafer, and then bonding the picked up semiconductor wafer to a substrate, a lead frame, or other semiconductor wafers, etc. At this time, the curable resin layer (resin layer) functions as a bonding film for bonding crystal grains, and when the workpiece fixing sheet having the resin layer is diced with the curable resin layer attached to a semiconductor wafer, The aforementioned work fixing sheet having a resin layer is used as a die-bonding wafer.

The aforementioned workpiece fixing piece having a resin layer has a low external force It is easy to pick up the workpiece (semiconductor wafer) with sufficient ease of picking up. Therefore, it is possible to suppress breakage and the like when picking up a thin semiconductor wafer. When the adhesive layer contains a compound capable of undergoing a polymerization reaction, the adhesiveness of the adhesive layer after the polymerization reaction decreases, which further improves such easy pick-up.

In a work fixing sheet having a resin layer, when the curable resin layer does not substantially contain a filler, the aforementioned easy pick-up property will be reduced. In this regard, the workpiece fixing sheet having a resin layer of the present invention is obtained by polymerizing a monomer containing an alkyl (meth)acrylate having an alkyl carbon number of 10 to 18 by an adhesive layer containing an alkyl (meth)acrylate The ester polymer, even if the curable resin layer does not substantially contain a filler, also has good easy pick-up. If the alkyl carbon number of the alkyl (meth)acrylate used in the adhesive layer is 9 or less, when the curable resin layer does not substantially contain a filler, the workpiece fixing sheet with the resin layer does not have easy pick-up of the semiconductor wafer Sex. On the other hand, alkyl (meth)acrylate used in the adhesive layer having an alkyl carbon number of 19 or more is difficult to handle due to its low solubility.

Generally, when a workpiece fixing sheet provided with an adhesive layer on a base film is used and a semiconductor wafer is directly fixed on the adhesive layer, the semiconductor wafer is peeled (picked up) from the adhesive layer after dicing. When the adhesive layer contains a component that is polymerized by irradiation with energy rays, the adhesive layer can be irradiated with energy rays to reduce the adhesiveness of the adhesive layer and then be picked up.

On the other hand, when a work fixing sheet having a resin layer is used and a semiconductor wafer is fixed on the curable resin layer, the semiconductor wafer is cut after dicing Peel off from the adhesive layer while remaining integrated with the curable resin layer, or peel (pick up) from the adhesive layer after irradiation with energy rays as appropriate.

In addition, in general, the work fixing sheet having a resin layer is less likely to be peeled off than the work fixing sheet having no curable resin layer, and tends to be inferior in peelability (easy pickup property).

In contrast, the work fixing sheet having a resin layer of the present invention is excellent in peelability (easy pick-up) by adopting the aforementioned configuration.

In addition, the workpiece fixing sheet having a resin layer of the present invention is also suitable as a sheet for forming a protective film for protecting the back surface of a flip chip. At this time, the curable resin layer (resin layer) functions as a film for forming a protective film of a flip chip, and when the work fixing sheet having a resin layer is diced with the curable resin layer attached to a semiconductor wafer, It is also used as a protective wafer and diced wafer of semiconductor wafers or semiconductor chips (flip chip).

In addition, the workpiece fixing sheet having a resin layer of the present invention can also be used in a case where the curable resin layer is attached to the electrode forming surface of a semiconductor wafer for flip-chip wafer, and is opposite to the electrode forming surface in the semiconductor wafer After grinding the side surface, the hardening resin layer remains on the electrode forming surface and the work fixing sheet is peeled off. In this case, the curable resin layer (resin layer) thereafter functions as an adhesive film when adhering the flip chip to the wafer mounting portion, and the work fixing sheet having the resin layer serves as both the adhesive film and the back polishing sheet.

FIG. 1 schematically shows a workpiece fixing sheet having a resin layer of the present invention Of the cross-sectional view.

The workpiece fixing sheet 10 having a resin layer shown in FIG. 1 is formed by providing an adhesive layer 12 on the base film 11 and a curable resin layer 13 on the adhesive layer 12, and is configured to adhere to the workpiece fixing sheet 1 The agent layer 12 is provided with a curable resin layer 13. In addition, the work fixing sheet 10 having a resin layer further includes a peeling film 14 on the curable resin layer 13.

In the work fixing sheet 10, the adhesive layer 12 is laminated on the surface 11 a of the base film 11, and the curable resin layer 13 is laminated on a part of the surface 12 a of the adhesive layer 12. In addition, the exposed surface of the curable resin layer 13 is not laminated on the surface 12 a of the adhesive layer 12, and the release film 14 is laminated on the surface 13 a (upper surface and side surface) of the curable resin layer 13.

However, the work fixing sheet having a resin layer of the present invention is not limited to those shown in FIG. 1.

[Base film]

The material of the substrate film is preferably various resins, and specific examples include polyethylene (Low-Density Polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density High-density polyethylene (HDPE), etc.), polypropylene, polybutene, polybutadiene, polymethylpentene, polyvinyl chloride, vinyl chloride polymer, polyethylene terephthalate, Polybutylene terephthalate, polyurethane, polyacrylate urethane, polyimide, ethylene/vinyl acetate polymer, ionic polymer resin, ethylene/(meth)acrylic acid polymerization , Ethylene/(meth)acrylate polymer, Polystyrene, polycarbonate, fluororesin, hydride, modified, cross-linked or polymer of any of these resins.

In addition, in this specification, the term "(meth)acrylic acid" includes both "acrylic acid" and "methacrylic acid".

The base film may be formed by one layer (single layer), or may include more than two plural layers. When plural layers are included, the materials of each layer may be all the same, all may be different, or only a part may be the same.

The thickness of the base film can be appropriately selected according to the purpose, preferably 50 μm to 300 μm, more preferably 60 μm to 100 μm.

The aforementioned "thickness of the base film" is a value measured at an arbitrary 5 places using a contact thickness gauge and expressed as an average.

The base film can also be surface roughened by sandblasting, solvent treatment, corona discharge treatment, electron beam irradiation treatment, plasma treatment, ozone/ultraviolet irradiation treatment, flame treatment, chromic acid treatment, hot air treatment Waiting for oxidation treatment, etc., to improve the adhesion with the adhesive layer provided on it. In addition, the base film may be one whose surface is subjected to primer coating treatment.

Among these, in terms of suppressing the breakage of the base film due to the friction of the blade during cutting, the base film is particularly preferably a surface treated with electron beam irradiation.

[Adhesive layer]

The adhesive layer contains the alkyl (meth)acrylate polymer.

The adhesive layer can be formed using an adhesive composition containing the above-mentioned target component such as alkyl (meth)acrylate polymer. In addition, the content ratio of the non-volatile components in the adhesive composition also becomes the same ratio in the adhesive layer.

The thickness of the adhesive layer can be appropriately selected according to the purpose, preferably 1 μm to 100 μm, more preferably 1 μm to 60 μm, and particularly preferably 1 μm to 30 μm.

The aforementioned "thickness of the adhesive layer" is a value measured at an arbitrary 5 places using a contact thickness meter and expressed as an average. In addition, when it is difficult to directly apply contact thickness timing to the adhesive layer, it can also be calculated by measuring the overall thickness in the same manner as described above with other films such as a base material film, a peeling material described later, and the The difference in the thickness of the superimposed other films (measured by the same method as described above).

(Alkyl (meth)acrylate polymer)

The aforementioned alkyl (meth)acrylate polymer is formed by polymerizing a monomer comprising an alkyl (meth)acrylate having 10 to 18 alkyl carbon atoms constituting the alkyl ester. In addition, in this specification, unless otherwise specified, only "alkyl (meth)acrylate" means the said "alkyl (meth)acrylate with an alkyl carbon number of 10-18).

The alkyl group having a carbon number of 10 to 18 may be linear, branched, or cyclic. When cyclic, it may be monocyclic or polycyclic. One kind, but preferably linear or branched.

Preferred examples of alkyl (meth)acrylates having an alkyl carbon number of 10 to 18 are: decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (Lauryl (meth)acrylate), tridecyl (meth)acrylate, myristyl (meth)acrylate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, Cetyl (meth)acrylate (palmityl (meth)acrylate), heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate), ( Isooctadecyl methacrylate (isostearyl (meth) acrylate) and other alkyl groups are chain alkyl (meth) acrylates; isomethan (meth) acrylate, and (meth) acrylic acid Cycloalkyl (meth)acrylates such as dicyclopentyl ester. In addition, as the alkyl (meth)acrylate having an alkyl carbon number of 10 to 18, in terms of the effect of improving the ease of picking up the workpiece, the dodecyl (meth)acrylate (( (Lauryl meth)acrylate, or isooctadecyl (meth)acrylate (isostearyl (meth)acrylate).

The aforementioned alkyl (meth)acrylate polymer may also be one that is polymerizable by energy rays polymerized by irradiation of energy rays, and as a preferred one of such polymers, it may be exemplified by having a hydroxyl group and further passing through amino acid The ester bond has a polymerizable group in the side chain. Such an alkyl (meth)acrylate polymer is crosslinked by, for example, reacting a hydroxyl group possessed with an isocyanate group in an isocyanate-based crosslinking agent described later. Moreover, compared with, for example, a case where a low molecular weight energy ray polymerizable compound is additionally used and the polymerization reaction is performed by irradiation of the energy ray, this acrylate polymer has a polymerizable group in the side chain The adhesiveness of the adhesive layer after the polymerization reaction is reduced, thereby improving the peelability from the adherend and obtaining the effect of improving the ease of picking up the workpiece. In addition, since it is not necessary to separately use a low molecular weight energy ray polymerizable compound, when a curable resin layer is formed on the adhesive layer as described later, such a low molecular weight energy ray polymerizable compound can be suppressed from the adhesive layer to the curability The resin layer migrates to suppress the characteristic change of the curable resin layer.

The above-mentioned preferred alkyl (meth)acrylate polymer is usually obtained by polymerizing the composition obtained by blending the foregoing alkyl (meth)acrylate and hydroxyl group-containing monomer to obtain a polymer, The hydroxyl group of the polymer reacts with the isocyanate group of the compound having the isocyanate group and the polymerizable group. Here, in order to react the hydroxyl group with the isocyanate group (form a urethane bond), a catalyst such as an organotin compound must be further used. The catalyst remains in the reaction system after the reaction is completed, but it is difficult to completely remove the alkyl (meth)acrylate polymer obtained, or even if it can be removed, a removal step is added, so the operation becomes complicated and productive Will also decline. Therefore, a method in which the catalyst is not removed from the reaction system after the completion of the reaction is generally adopted, and therefore the catalyst remains in the obtained (meth)acrylic acid alkyl polymer.

The aforementioned catalyst remaining in the alkyl (meth)acrylate polymer undergoes an unintended cross-linking reaction when the aforementioned adhesive composition using such a polymer is stored. In addition, when the mole of hydroxyl group in the alkyl (meth)acrylate polymer is 1 mole, the isocyanate group in the isocyanate-based crosslinking agent has This tendency is particularly strong when the Mohr number is large.

In contrast, in the present invention, even when the mole number of the aforementioned isocyanate group is large, by using a reaction retarder described later, the progress of the above-mentioned non-target crosslinking reaction is suppressed. In addition, in terms of higher suppression effect, the residual amount (content) of the catalyst of the alkyl (meth)acrylate polymer is preferably 2% by mass or less, more preferably 1% by mass or less, and still more preferably 0.5 mass% or less.

As a more preferable polymer among the aforementioned (meth)acrylic acid ester polymers, the aforementioned (meth)acrylic acid alkyl esters and hydroxyl-containing (meth)acrylates as essential monomers can be exemplified The copolymer reacts with a compound having an isocyanate group and a polymerizable group. The reactant is formed by combining a hydroxyl group of the copolymer with an isocyanate group of the compound having an isocyanate group and a polymerizable group.

Examples of the hydroxyl-containing (meth)acrylates include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate.

Examples of the compound having an isocyanate group and a polymerizable group include isocyanate group-containing alkyl (meth)acrylates such as 2-methacryloxyethyl isocyanate.

The aforementioned preferred alkyl (meth)acrylate polymer may be It is necessary to react any compound other than the monomer and the compound, or it may be a polymer obtained by polymerizing the monomer as the aforementioned arbitrary compound.

As any of the aforementioned monomers, there may be exemplified non-hydroxyl-containing (meth)acrylates, (meth)acrylic acid, itaconic acid, and non-(meth)acrylic monomers that do not correspond to the aforementioned alkyl (meth)acrylate Body etc.

Examples of the aforementioned (meth)acrylates that do not contain hydroxyl groups include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and (meth) Group) amyl acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate Ester, n-nonyl (meth)acrylate, isononyl (meth)acrylate, etc. The alkyl group constituting the alkyl ester is linear or branched and the carbon number is 1-9 alkyl alkyl (meth)acrylate; (Meth)acrylic acid aryl alkyl esters such as benzyl (meth)acrylate; (meth)acrylic acid cycloalkenyl esters such as (meth)acrylic acid dicyclopentenyl ester; (meth)acrylic acid dicyclopentenyloxyethyl (Meth)acrylic acid cycloalkenyloxyalkyl ester; amide imine (meth)acrylate; glycidyl (meth)acrylate and other glycidyl group-containing (meth)acrylate and the like.

Examples of the non-(meth)acrylic monomers include vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide.

The aforementioned alkyl (meth)acrylate, hydroxyl-containing (meth)acrylate, compounds having isocyanate groups and polymerizable groups, and any of the foregoing The components used for the preparation of the aforementioned alkyl (meth)acrylate polymer (components of the aforementioned polymer) such as compounds may be only one kind, or may be two or more kinds.

The aforementioned alkyl (meth)acrylate polymer (not limited to the above-mentioned alkyl methacrylate having a hydroxyl group and a preferred form having a polymerizable group in the side chain via an urethane bond Polymer), the ratio of the alkyl (meth)acrylate having an alkyl carbon number of 10 to 18 relative to the total mass of all monomers used for polymerization is preferably 60% by mass or more, more preferably 70% by mass More than 75%, particularly preferably more than 75% by mass In addition, the ratio of the alkyl (meth)acrylate having an alkyl carbon number of 10 to 18 in the alkyl (meth)acrylate polymer relative to the total mass of all monomers used for polymerization is 100% by mass or less .

The aforementioned alkyl (meth)acrylate polymer contained in the adhesive layer may be only one kind or two or more kinds.

In addition, there are no particular limitations on other monomers contained in the monomers containing alkyl (meth)acrylates having an alkyl group of 10 to 18 carbon atoms. For example, the monomers not equivalent to the aforementioned alkyl (meth)acrylates can be exemplified. Hydroxyl (meth)acrylate, non-hydroxyl (meth)acrylate, (meth)acrylic acid, itaconic acid, non-(meth)acrylic monomers, etc., hydroxyl-containing (meth)acrylic acid Specific examples of esters, (meth)acrylates that do not contain hydroxyl groups, and non-(meth)acrylic monomers are the same as described above.

In the adhesive layer, the content of the alkyl (meth)acrylate polymer is preferably 75% by mass or more, and more preferably 80% by mass or more. In order to form such an adhesive layer, the content of the alkyl (meth)acrylate polymer in the adhesive composition is preferably 75% by mass relative to the total amount of all components except the solvent in the adhesive composition. Above, more preferably 80% by mass or more. Moreover, the content of the alkyl (meth)acrylate polymer of the adhesive composition may be 100% by mass.

As a preferable one of the above-mentioned adhesive composition, there can be exemplified those which further contain an isocyanate-based crosslinking agent and a reaction retardant in addition to the above-mentioned alkyl (meth)acrylate polymer. This kind of adhesive composition can prevent the non-target cross-linking reaction from progressing during storage, so that changes in characteristics such as viscosity during storage can be suppressed, and the storage property is high.

(Isocyanate-based crosslinking agent)

The isocyanate-based cross-linking agent is not particularly limited as long as it has an isocyanate group (-N=C=O), and preferred examples include: 2,4-toluene diisocyanate; 2,6-toluene diisocyanate ; 1,3-xylene diisocyanate; 1,4-xylene diisocyanate; diphenylmethane-4,4'-diisocyanate; diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane Diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; trimethylolpropane, etc. All or part of the hydroxyl groups of the polyol Addition of either or both of toluene diisocyanate and hexamethylene diisocyanate; amine acid diisocyanate, etc.

The isocyanate-based crosslinking agent contained in the aforementioned adhesive composition may be only one kind, or two or more kinds.

The number of moles of isocyanate groups possessed by the isocyanate-based crosslinking agent in the adhesive composition is preferably relative to the number of hydroxyl groups possessed by the alkyl (meth)acrylate polymer in the adhesive composition Ear count is more than 0.2 times. With such a configuration, after the adhesive layer is hardened by UV (ultraviolet, ultraviolet) irradiation or the like, the adhesion to the workpiece (curable resin layer, etc.) becomes smaller, thereby improving the ease of picking-up of the workpiece fixing sheet.

On the other hand, in the present invention, the number of moles of isocyanate groups in the isocyanate-based crosslinking agent in the adhesive composition is preferably relative to the alkyl (meth)acrylate in the adhesive composition The number of moles of hydroxyl groups possessed by the polymer is 3 times or less. With such a configuration, the effect of suppressing the generation of by-products between the isocyanate-based crosslinking agents becomes higher.

That is, the number of moles of isocyanate groups possessed by the isocyanate-based crosslinking agent in the adhesive composition is preferably relative to the number of hydroxyl groups possessed by the alkyl (meth)acrylate polymer in the adhesive composition The ears range from 0.2 times to 3 times.

The content of the isocyanate-based crosslinking agent in the adhesive composition as long as The molar number of the isocyanate group may be appropriately adjusted in such a manner as described above. On the basis of satisfying such conditions, the content of the alkyl (meth)acrylate polymer is 100 parts by mass, preferably 3 parts by mass. ~20 mass points, more preferably 5 to 15 mass points.

(Reaction delay agent)

The aforementioned reaction delay agent inhibits the progress of unintended crosslinking reaction in the aforementioned adhesive composition during storage.

The aforementioned alkyl (meth)acrylate polymer usually contains a catalyst for its preparation as described above. As the reaction delay agent, those that hinder the action of the catalyst in the adhesive composition can be exemplified, and preferably, those that form a chelate complex by chelating the aforementioned catalyst can be exemplified. For example, when the catalyst is an organotin compound, as a reaction retarder, a chelate complex with tin can be exemplified.

As a preferred reaction delay agent, more specifically, there may be exemplified those having two or more carbonyl groups (-C(=O)-) in the molecule, and if there are two carbonyl groups in the molecule, then dicarboxylic acid or keto acid may be exemplified. And dione.

Among them, as the better reaction delay agent, those having a carbonylmethylcarbonyl group (-C(=O)-CH ₂ -C(=O)-) can be exemplified, and more specifically, malonic acid and acetic acid can be exemplified. Etc. β-ketoacid; methyl acetoacetate, ethyl acetate, n-propyl acetoacetate, isopropyl acetoacetate, n-butyl acetoacetate, isobutyl acetoacetate, acetoacetate Tributyl ester, methyl propyl acetate, ethyl propyl acetate, n-propyl propyl acetate, isopropyl propyl acetate, n-butyl propyl acetate, third butyl propyl acetate, methyl butyl acetate , Ethyl butyl acetate, n-propyl butyl acetate, isopropyl butyl acetate, n-butyl butyl acetate, third butyl butyl acetate, methyl isobutyl acetate, ethyl isobutyl acetate, N-propyl isobutyl acetate, isopropyl isobutyl acetate, n-butyl isobutyl acetate, tertiary butyl isobutyl acetate, methyl 3-oxo-heptanoate, 3-oxo-heptanoic acid Ethyl ester, n-propyl 3-oxo-heptanoate, isopropyl 3-oxo-heptanoate, n-butyl 3-oxo-heptanoate, third butyl 3-oxo-heptanoate, 5- Methyl-3-oxo hexanoate, 5-methyl-3-oxo hexanoate, 5-methyl-3-oxo hexanoate, 5-methyl-3 -Isopropyl oxohexanoate, n-butyl 5-methyl-3-oxohexanoate, tert-butyl 5-methyl-3-oxohexanoate, 4,4-dimethyl Methyl-3-oxopentanoate, 4,4-dimethyl-3-oxopentanoate, 4,4-dimethyl-3-oxopentanoate, 4, 4-Dimethyl-3-pentoxypentanoic acid isopropyl ester, 4,4-dimethyl-3-pentoxypentanoic acid n-butyl ester, 4,4-dimethyl-3-pentoxypentanoic acid Third butyl acid, methyl benzoyl acetate, dimethyl malonate, diethyl malonate, methyl ethyl malonate, di-n-propyl malonate, diisopropyl malonate , Β-ketoesters such as di-n-butyl malonate, di-tert-butyl malonate, methyl-tert-butyl malonate, etc.; β-diketones such as acetone, dibenzoylmethane (1 , 3-dione), etc.

The reaction retarder contained in the adhesive composition may be only one kind, or two or more kinds.

The aforementioned adhesive composition is preferably a reaction retarder containing 0.01% by mass to 2% by mass relative to the total amount of all components. By delaying the reaction The aforementioned content of the latex is equal to or higher than the aforementioned lower limit, and the effect of suppressing the progress of unintended crosslinking reaction during the storage of the adhesive composition becomes higher. Also, by setting the content of the reaction retarder to be below the upper limit, when the adhesive layer is provided by coating and drying the adhesive composition, the reaction retardant can be volatilized by drying to prevent Excess reaction delay agent remains in the adhesive layer.

The content of the reaction retarder in the aforementioned adhesive composition may be appropriately adjusted so that the mass ratio in the total amount of all components of the adhesive composition becomes the above range. On the basis of satisfying such conditions, the relative The content of the aforementioned alkyl (meth)acrylate polymer is 100 parts by mass, preferably 0.01 to 10 parts by mass, and more preferably 0.05 to 5 parts by mass.

(Photopolymerization initiator)

The adhesive composition preferably further includes a photopolymerization initiator in addition to the alkyl (meth)acrylate polymer, isocyanate-based crosslinking agent, and reaction retarder.

The aforementioned photopolymerization initiator may be a well-known one, and specific examples include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl) ketone, α-hydroxy-α,α'- Α-ketoalcohol compounds such as dimethylacetophenone, 2-methyl-2-hydroxyphenylacetone, 1-hydroxycyclohexylphenylketone; methoxyacetophenone, 2,2-dimethoxy- 2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1 and other benzenes Acetone compounds; benzoin ether, Benzoin ether compounds such as benzoin isopropyl ether and anisin methyl ether; ketal compounds such as diphenylethanedione dimethyl ketal; 2-aromatic sulfonyl chloride compounds such as naphthalene sulfonyl chloride; 1- Photoactive oxime compounds such as benzophenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methyl Benzophenone compounds such as oxybenzophenone; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropyl Thioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone and other thioxanthone compounds; camphorquinone; halogenated ketone; Acyl phosphine oxide; acetyl phosphonate and so on.

The content of the photopolymerization initiator of the adhesive composition relative to the content of the alkyl (meth)acrylate polymer is 100 parts by mass, preferably 0.05 to 20 parts by mass.

(Solvent)

It is more preferable that the adhesive composition further contains a solvent in addition to the alkyl (meth)acrylate polymer.

The aforementioned solvent is not particularly limited, and preferably, examples include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutanol (2-methylpropane-1-ol), and 1-butanol; Esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; amides (compounds with amide bonds) such as dimethylformamide and N-methylpyrrolidone.

The solvent contained in the adhesive composition may be only one kind, or two or more kinds.

When the aforementioned adhesive composition contains a solvent, the solvent content is preferably 40% by mass to 90% by mass, and more preferably 50% by mass to 80% by mass relative to the total mass of the adhesive composition.

(Other ingredients)

In addition to the alkyl (meth)acrylate polymer, the adhesive composition may contain the isocyanate-based crosslinking agent, the reaction retarder, the photopolymerization initiator, and the solvent within a range that does not impair the effects of the present invention Other ingredients.

The aforementioned other components may be known and can be arbitrarily selected according to the purpose, and are not particularly limited, and preferably include dyes, pigments, anti-deterioration agents, antistatic agents, flame retardants, polysiloxane compounds, chain transfer agents, etc. Various additives.

The adhesive composition is obtained by blending the alkyl (meth)acrylate polymer and components other than the polymer.

The order of addition of each of the aforementioned components is not particularly limited, and two or more components may be added simultaneously.

The method of mixing the components at the time of preparation is not particularly limited. For example, a method of mixing by rotating a stirring element or a stirring wing, etc.; a method of mixing using a mixer; a method of mixing by applying ultrasonic waves may be appropriately selected from known methods.

The temperature and time at the time of addition and mixing of each component are not particularly limited as long as they do not deteriorate each formulated component, and may be adjusted appropriately, but the temperature It is preferably 15°C to 30°C.

[Curable resin layer]

The curable resin layer contains a polymer component (a) and a curable component (b), and the total content of the polymer component (a) and curable component (b) of the curable resin layer relative to the curable resin The total amount of layers is 95% by mass or more, preferably 97% by mass or more, more preferably 98% by mass or more, and may be 100% by mass. Such a curable resin layer contains substantially no filler (filler (c) described later). In addition, even if such a curable resin layer is provided in the present invention, the work fixing sheet having the resin layer has easy pick-up properties as described above. In addition, by making the curable resin layer substantially not contain a filler, the workpiece fixing sheet having a resin layer of the present invention does not have the following problem: the filler unique to the case where the filler is contained contains unevenly in the curable resin layer In the dispersed state, the filling material will come off from the cured film after curing the curable resin layer.

In addition, in this specification, "curable resin layer does not substantially contain a filler" means that the curable resin layer does not contain a filler at all, or the curable resin layer contains only a small amount to the extent that the effect of using a filler can be ignored Filler. Specifically, it refers to the case where the total amount of the filler contained in the curable resin layer with respect to the solid content of the curable resin composition forming the curable resin layer is less than 5% by mass, preferably less than 3% by mass %, more preferably less than 1% by mass.

For the curable resin layer, the above-mentioned polymer component (a) and curing The curable resin composition of the target component such as the sexual component (b) is formed. In addition, the content ratio of the nonvolatile components in the curable resin composition to the curable resin layer also becomes the same.

In the present invention, the polymer component (a) can be regarded as a component formed by a polymerization reaction of a polymerizable compound. In addition, the curable component (b) is a component that can undergo a curing (polymerization) reaction. Furthermore, in the present invention, the polymerization reaction also includes polycondensation reaction.

The polymer component (a) and the curable component (b) are the main constituent components of the curable resin layer required for the curable resin layer to exert its effect. In addition, although there are components corresponding to both the polymer component (a) and the curable component (b), this component is used as the polymer component (a) instead of the curable component (b) in the present invention. ).

The thickness of the curable resin layer can be appropriately selected according to the purpose, preferably 1 μm to 100 μm, more preferably 5 μm to 75 μm, and particularly preferably 5 μm to 50 μm. The average thickness of the curable resin layer can be obtained by the same measurement method as the average thickness of the adhesive layer.

The aforementioned "thickness of the curable resin layer" is a value measured at an arbitrary 5 points using a contact thickness meter and expressed as an average. In addition, when it is difficult to directly apply the contact thickness measurement to the curable resin layer, it can also be calculated as follows: in the state where the base material film, the adhesive layer, and other layers such as the release material described later are superimposed, the same as above Measure the thickness of the whole, take the thickness of the other layers that are overlapped (use the same method as above to measure or before using Measure the difference of the adhesive layer measurement method).

The curable resin layer preferably has pressure-sensitive adhesiveness, and preferably has heat-curing properties, and more preferably has both pressure-sensitive adhesiveness and heat-curing properties. The curable resin layer, which has both pressure-sensitive adhesive properties and heat-curing properties, can be attached to various adherends by light pressing in an uncured state. In addition, the curable resin layer can be softened by heating and attached to various adherends. The thermosetting resin layer undergoes thermal curing and finally becomes a hardened product with high impact resistance. The hardened product also has excellent shear strength, and can maintain sufficient adhesive properties under strict high temperature and high humidity conditions.

(Polymer component (a))

The polymer component (a) is a polymer compound used to impart film-forming properties, flexibility, etc. to the curable resin layer. The polymer component (a) may also correspond to the curable component (b). For example, a phenoxy resin or an acrylic resin having an epoxy group in the side chain corresponds to the polymer component (a) and also corresponds to the curable component (b). Such a component is used as the polymer component (a).

The polymer component (a) may be used alone or in combination of two or more.

As the polymer component (a), acrylic resins, polyester resins, urethane resins, acrylic urethane resins, polysiloxane resins, rubber-based polymers, phenoxy resins, etc. are preferred It is acrylic resin.

As the acrylic resin, a known acrylic polymer can be used.

The weight average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2 million, and more preferably 100,000 to 1.5 million. If the weight-average molecular weight of the acrylic resin is too small, the adhesive force between the curable resin layer and the adhesive layer may become high, which may cause poor pickup of the semiconductor wafer. In addition, if the weight average molecular weight of the acrylic resin is too large, the curable resin layer may not be able to follow the uneven surface of the adherend, and it may become a factor for voids and the like.

In addition, in this specification, the weight average molecular weight is the polystyrene conversion value measured by the gel permeation chromatography (GPC) method unless there is particular notice.

The glass transition temperature (Tg) of the acrylic resin is preferably -60°C to 70°C, more preferably -30°C to 50°C. If the Tg of the acrylic resin is too low, the peeling force of the curable resin layer and the adhesive layer may increase, which may cause poor pickup of the semiconductor wafer. In addition, if the Tg of the acrylic resin is too high, there is a possibility that the adhesive force for fixing the semiconductor wafer becomes insufficient.

Examples of monomers constituting the acrylic resin include: methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethyl (meth)acrylate Hexyl ester, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, (meth) Group) undecyl acrylate, dodecyl (meth) acrylate (lauryl (meth) acrylate), tridecyl (meth) acrylate, (meth) propyl Myristyl enoate (myristyl (meth)acrylate), pentadecyl (meth)acrylate, cetyl (meth)acrylate (palmityl (meth)acrylate), (meth) Heptadecyl acrylate, octadecyl (meth) acrylate (stearyl (meth) acrylate) and other alkyl groups are chain-shaped and have 1 to 18 carbon atoms; ) Cycloalkyl acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentyl (meth) acrylate, dicyclopentenyl (meth) acrylate, di(meth) acrylate (Meth)acrylates with a cyclic skeleton such as cyclopentenyloxyethyl, amide imide (meth)acrylate; hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate , (Meth)acrylic acid 2-hydroxypropyl and other hydroxyl-containing (meth)acrylate; (meth)acrylic acid and other glycidyl-containing (meth)acrylate and other (meth)acrylate.

In addition, the acrylic resin may be monomers such as polymerized acrylic acid, methacrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, or N-methylolacrylamide.

The monomer constituting the acrylic resin may be only one kind, or two or more kinds.

In this specification, the terms "polymer" or "resin" used for substances polymerized by monomers are "polymers" or "resins" that include structural units (also called repeating units) derived from the aforementioned monomers Wait. In addition, in this specification, when the above-mentioned "polymer" or "resin", etc., are used to describe the amount of monomers used in the manufacture in terms of mass, molar number, etc., the ratio can be understood as The constituent units derived from the body are polymerized relative to the aforementioned monomers The ratio of the total amount of the resulting "polymer" or "resin". That is, for example, when it is described that 20% by mass and 80% by mass of monomers X and Y are used and these are polymerized to obtain a polymer Z, it can be understood that the constituent unit derived from the monomer X in the polymer Z The ratio of the structural unit derived from the monomer Y to the total mass of the polymer Z is 20% by mass and 80% by mass, respectively.

The acrylic resin may also have functional groups capable of bonding with other compounds, such as vinyl groups, (meth)acryloyl groups, amine groups, hydroxyl groups, carboxyl groups, and isocyanate groups. The bonding with other compounds may be performed via a crosslinking agent (f) described below, or the aforementioned functional groups may be directly bonded to other compounds without passing through the crosslinking agent (f). By bonding the acrylic resin with these functional groups, there is a tendency to improve the packaging reliability of the semiconductor device using the workpiece fixing sheet having a resin layer.

When the curable resin composition contains an acrylic resin as the polymer component (a), the content of the acrylic resin in the curable resin composition is preferably 50% by mass relative to the total solid content of the curable resin composition the above. By setting to such a range, when the curable resin layer is used in the blanket curing process in the resin sealing of the semiconductor wafer, the curable resin layer becomes a preferable characteristic. The reason is that in this process, the wafer is wire-bonded before the resin sealing of the semiconductor wafer, but even when the curable resin layer before curing is exposed to high temperature, it can be carried out while maintaining a certain degree of hardness Hit the line. That is, if the content of the acrylic resin in the curable resin composition is relatively large, it can be cured even before thermal curing The storage modulus of the resin layer is higher. Therefore, even in a state where the curable resin layer is not cured or semi-cured, wafer vibration and displacement during wire bonding are suppressed, and wire bonding can be performed stably.

In addition, when the curable resin composition contains an acrylic resin as the polymer component (a), the content of the acrylic resin in the curable resin composition is more preferably the total amount relative to the solid content of the curable resin composition as 50% by mass to 90% by mass. When the content of the acrylic resin is relatively large as described above, the adhesiveness between the adhesive layer and the curable resin layer becomes higher, and the adhesive force tends to be higher, but by using the adhesive layer of the present invention, the adhesion can be reduced The adhesive force between the agent layer and the curable resin layer improves the ease of pickup of the semiconductor wafer.

As described above, when the curable resin layer contains an acrylic resin as the polymer component (a), the content of the acrylic resin in the curable resin layer is preferably 50% by mass or more, more preferably 50% by mass to 90% by mass %.

In the present invention, in order to improve the peelability of the work fixing sheet (adhesive layer) from the hardenable resin layer and improve the ease of pick-up, or to suppress voids by the hardenable resin layer following the uneven surface of the adherend As a result, for the polymer component (a), thermoplastic resins other than acrylic resins (hereinafter simply referred to as "thermoplastic resins") may be used alone or in combination with acrylic resins.

The weight average molecular weight of the aforementioned thermoplastic resin is preferably 1,000 to 100,000, more preferably 3,000 to 80,000.

The glass transition temperature (Tg) of the aforementioned thermoplastic resin is preferably -30°C~ 150 ℃, more preferably -20 ℃ ~ 120 ℃.

Examples of the aforementioned thermoplastic resins include polyester resins, urethane resins, phenoxy resins, polybutene, polybutadiene, and polystyrene.

The thermoplastic resin may be used alone or in combination of two or more.

The aforementioned effects are obtained by using the aforementioned thermoplastic resins. On the other hand, the hardness of the curable resin layer before curing decreases when exposed to high temperature, and the flexibility of the curable resin layer in the uncured or semi-cured state Falling fears. Therefore, the content of the thermoplastic resin of the curable resin composition is preferably set in consideration of such influence.

In the present invention, it is preferable to use the aforementioned thermoplastic resin in combination with acrylic resin.

(Hardening component (b))

The curable component (b) can be exemplified by epoxy-based thermosetting resins, thermosetting polyimide resins, urethane resins, unsaturated polyester resins, polysiloxane resins, etc., among these, preferably Epoxy thermosetting resin. The curable component (b) may also correspond to the polymer component (a), but such a component is used as the polymer component (a).

‧Epoxy thermosetting resin

The epoxy-based thermosetting resin includes an epoxy resin and a thermosetting agent.

Epoxy thermosetting resins can be used alone or in combination. the above.

The aforementioned epoxy resins may be publicly known ones, and specific examples thereof include polyfunctional epoxy resins, biphenyl compounds, bisphenol A diglycidyl ether and its hydrogenated products, o-cresol novolac epoxy resins, and bicyclic Two or more functional epoxy compounds such as pentadiene type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenylene skeleton type epoxy resin.

In addition, as the epoxy resin, an epoxy resin having an unsaturated hydrocarbon group may be used. As the epoxy resin having an unsaturated hydrocarbon group, a compound in which a part of the epoxy resin of a multifunctional epoxy resin is converted into a group containing an unsaturated hydrocarbon group can be exemplified. Such a compound can be produced by adding acrylic acid to an epoxy group, for example. The epoxy resin having an unsaturated hydrocarbon group may be exemplified by a compound obtained by directly bonding a group containing an unsaturated hydrocarbon group to an aromatic ring constituting the epoxy resin. The unsaturated hydrocarbon group is a polymerizable unsaturated group, and specific examples include vinyl (ethenyl) (vinyl), 2-propenyl (allyl), propenyl acetyl, methacryl acetyl, The acrylamide group, the methacrylamide group and the like are preferably acrylamide groups.

Compared with epoxy resins without unsaturated hydrocarbon groups, epoxy resins with unsaturated hydrocarbon groups have high compatibility with acrylic resins. Therefore, by using a curable resin composition containing an epoxy resin having an unsaturated hydrocarbon group, the packaging reliability of the semiconductor device is improved.

In terms of improvement in easy pick-up, the epoxy resin is preferably one having a high softening point or a high glass transition temperature.

The number average molecular weight of the aforementioned epoxy resin is not particularly limited. From the viewpoint of the curability of the curable resin layer or the strength and heat resistance after curing, it is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably It is 500~3000.

The epoxy equivalent of the aforementioned epoxy resin is preferably 100 g/eq to 1000 g/eq, more preferably 300 g/eq to 800 g/eq.

One type of the epoxy resin may be used alone, or two or more types may be used in combination.

The aforementioned thermosetting agent functions as a curing agent for epoxy resin.

The thermal hardener can be exemplified by a compound having two or more functional groups reactive with epoxy groups in one molecule. Examples of the aforementioned functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amine groups, carboxyl groups, and acidified anhydride groups, preferably phenolic hydroxyl groups, amine groups, and acidified anhydride groups. The phenolic hydroxyl group and amine group are preferable, and the phenolic hydroxyl group is particularly preferable.

Among the aforementioned thermosetting agents, phenolic hardeners (hardeners with phenolic hydroxyl groups) can be exemplified by multifunctional phenol resins, biphenols, novolac type phenol resins, dicyclopentadiene phenol resins, and aralkyl phenol resins Wait.

Among the aforementioned thermal hardeners, amine-based hardeners (hardeners with amine groups) Examples include DICY (dicyandiamide).

The aforementioned thermosetting agent may have an unsaturated hydrocarbon group.

As the thermosetting agent having an unsaturated hydrocarbon group, a compound in which a part of the hydroxyl group of the phenol resin is substituted with a group containing an unsaturated hydrocarbon group, a compound in which a group containing an unsaturated hydrocarbon group is directly bonded to the aromatic ring of the phenol resin, etc. . The unsaturated hydrocarbon group in the thermal hardener is the same as the unsaturated hydrocarbon group in the aforementioned epoxy resin having an unsaturated hydrocarbon group.

In terms of improvement in easy pick-up, the thermal hardener is preferably one having a high softening point or a high glass transition temperature.

The number average molecular weight of the aforementioned thermosetting agent is preferably 300 to 30,000, more preferably 400 to 10,000, and particularly preferably 500 to 3,000.

The aforementioned thermosetting agent may be used alone or in combination of two or more.

The content of the thermosetting agent of the curable resin composition relative to the content of the epoxy resin is 100 parts by mass, preferably 0.1 to 500 parts by mass, and more preferably 1 to 200 parts by mass. If the content of the thermosetting agent is too small, there may be insufficient curing to obtain adhesiveness. If the content of the thermosetting agent is excessive, the moisture absorption rate of the curable resin layer becomes high, which may reduce the reliability of the package.

The content of the curable component (b) of the curable resin composition (curable resin layer) relative to the content of the polymer component (a) is 100 parts by mass, preferably 1 to 100 parts by mass, and more preferably 1.5 parts by mass Points ~ 75 mass points, especially good for 2 ~ 60 mass points. By setting the content of the curable component (b) to the above-mentioned range, there is a tendency to maintain the hardness of the curable resin layer before curing, while the flexibility of the curable resin layer in the uncured or semi-cured state is improved. . On the other hand, when the content of the curable component (b) is relatively small with respect to the content of the polymer component (a), there may be cases where each component of the curable component (b) is set to the softening point or glass transition If the temperature is high, it is necessary to suppress the adhesive force between the adhesive layer and the curable resin layer from increasing to improve the pick-up property, but it cannot be sufficiently improved. However, by using the adhesive layer of the present invention, the adhesive force between the adhesive layer and the curable resin layer can be reduced, and the ease of pick-up of the semiconductor wafer is improved.

The curable resin layer may be formed using a curable resin composition that contains other components not corresponding to these components in addition to the polymer component (a) and the curable component (b), as necessary, to improve various physical properties.

Examples of other components contained in the curable resin composition include filler (c), curing accelerator (d), coupling agent (e), crosslinking agent (f), and general-purpose additive (g).

(Filling material (c))

The curable resin composition usually contains a filler (c) to facilitate the adjustment of its thermal expansion coefficient. Therefore, by using this hardenability The resin composition optimizes the thermal expansion coefficient of the curable resin layer after curing for semiconductor wafers, metals, or organic substrates, and improves package reliability.

In addition, by generally using the curable resin composition containing the filler (c), the moisture absorption rate of the curable resin layer after curing can also be reduced.

The filler (c) is a component that does not correspond to any of the polymer component (a) and the curable component (b).

However, in the present invention, as described above, the curable resin layer does not contain the filler (c), or the content of the filler (c) is set to more than 0% by mass and less than 5% by mass, so the curable resin The content of the filler (c) of the composition relative to the total solid content of the curable resin composition is less than 5 mass%, preferably less than 3 mass%, and more preferably less than 1 mass%.

The filler material (c) is preferably an inorganic filler material (c), and preferred inorganic filler materials can be exemplified by powders of silicon dioxide, alumina, talc, calcium carbonate, titanium white, iron dan, silicon carbide, boron nitride, etc. ; Beads made of the aforementioned silica, etc.; single crystal fibers of the aforementioned silica; glass fiber, etc.;

Among these, the inorganic filler is preferably silica filler or alumina filler.

The inorganic filler (c) may be used alone or in combination of two or more.

(Hardening accelerator (d))

The curing accelerator (d) is a component for adjusting the curing rate of the curable resin composition and does not correspond to any of the polymer component (a) and the curable component (b).

Preferred hardening accelerators (d) can be exemplified by tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol; 2 -Methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxyl Imidazoles such as methylimidazole (imidazoles in which more than one hydrogen atom is replaced by a group other than hydrogen atoms); organic phosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (more than one hydrogen Phosphine with atoms replaced by organic groups); tetraphenyl boron salts such as tetraphenyl boron tetraphenyl phosphonium, tetraphenyl boric acid triphenyl phosphine, etc.

One type of hardening accelerator (d) may be used alone, or two or more types may be used in combination.

When the curing accelerator (d) is used, the content of the curing accelerator (d) in the curable resin composition is 100 parts by mass relative to the content of the curable component (b), preferably 0.01 to 10 parts by mass, More preferably, it is 0.1 to 1 mass point. By setting the content of the curing accelerator (d) to such a range, the curable resin layer also has excellent adhesion characteristics under high temperature and high humidity conditions, and high packaging reliability can also be achieved when exposed to strict reflow conditions. If the content of the hardening accelerator (d) is too small, the effects of using the hardening accelerator (d) cannot be sufficiently obtained. If the content of the hardening accelerator (d) is excessive, the high-polarity hardening accelerator (d) is at a high temperature 1. Under the condition of high humidity, in the curable resin layer, it will move to the interface side of the adherend and be biased. Analysis, which reduces the reliability of the package.

(Coupling agent (e))

By using a functional group that can react with an inorganic compound and a functional group that can react with an organic functional group as the coupling agent (e), the adhesiveness and adhesiveness of the curable resin layer to the adherend can be improved. In addition, by using the coupling agent (e), the cured product obtained by curing the curable resin layer can improve water resistance without impairing its heat resistance.

The coupling agent (e) is a component that does not correspond to any of the polymer component (a) and the curable component (b).

The coupling agent (e) is preferably a compound having a functional group that reacts with a functional group possessed by the polymer component (a), curable component (b), etc., and more preferably is a silane coupling agent.

Preferred examples of the aforementioned silane coupling agent are: γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl) Ethyltrimethoxysilane, γ-(methacryloxypropyl)trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-amino Propyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ- Ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, Methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and imidazolium Alkane etc.

The coupling agent (e) may be used alone or in combination of two or more.

When the coupling agent (e) is used, the content of the coupling agent (e) of the curable resin composition relative to the total content of the polymer component (a) and the curable component (b) is 100 parts by mass, preferably 0.03 parts by mass ~20 mass points, more preferably 0.05 to 10 mass points, particularly preferably 0.1 to 5 mass points. If the content of the coupling agent (e) is too small, the aforementioned effect produced by using the coupling agent (e) may not be obtained. On the other hand, if the content of the coupling agent (e) is too large, there is a possibility of outgassing .

(Crosslinking agent (f))

When using the aforementioned acrylic resin having a functional group such as an isocyanate group which can be bonded to a functional group possessed by another compound as the polymer component (a), in order to crosslink the functional group with another compound, it may be Use crosslinker (f). By crosslinking using the crosslinking agent (f) as described above, the initial adhesive force and cohesive force of the curable resin layer can be adjusted.

Examples of the crosslinking agent (f) include organic polyisocyanate compounds and organic polyimide compounds.

The crosslinking agent (f) is a component that does not correspond to any of the polymer component (a) and the curable component (b).

The aforementioned organic polyisocyanate compound can be exemplified by: aromatic polyisocyanate Cyanate compounds, aliphatic polyisocyanate compounds, cycloaliphatic polyisocyanate compounds and trimers, isocyanurate bodies and adducts of these compounds (with ethylene glycol, propylene glycol, neopentyl glycol, trivalent Reactants of low molecular compounds containing active hydrogen such as methylolpropane or castor oil, such as trimethylolpropane addition xylene diisocyanate, etc.), or terminal isocyanates obtained by reacting organic polyisocyanate compounds with polyol compounds Based on carbamate prepolymer and so on.

The aforementioned organic polyisocyanate compound can be more specifically exemplified: 2,4-toluene diisocyanate; 2,6-toluene diisocyanate; 1,3-xylene diisocyanate; 1,4-xylene diisocyanate; diphenylmethane- 4,4'-diisocyanate; diphenylmethane-2,4'-diisocyanate; 3-methyldiphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4 ,4'-diisocyanate; dicyclohexylmethane-2,4'-diisocyanate; addition of toluene diisocyanate and hexamethylene diisocyanate to all or part of the hydroxyl groups of polyhydric alcohols such as trimethylolpropane Or a compound of both; diisocyanate of amine acid, etc.

The aforementioned organic polyimine compounds can be exemplified by: N,N'-diphenylmethane-4,4'-bis(1-aziridine carboxyamide), trimethylolpropane-tri-β-aziridinyl propane Ester, tetramethylolmethane-tri-β-aziridinyl propionate, N,N'-toluene-2,4-bis(1-aziridine carboxyamide) triethylidene melamine, etc.

When an isocyanate-based crosslinking agent is used as the crosslinking agent (f), the polymer The aforementioned acrylic resin of component (a) is preferably a polymer containing a hydroxyl group. When the crosslinking agent (f) has an isocyanate group and the acrylic resin has a hydroxyl group, the crosslinking structure can be easily introduced into the curable resin layer by the reaction of the crosslinking agent (f) and the acrylic resin.

When the crosslinking agent (f) is used, the content of the crosslinking agent (f) in the curable resin composition is 100 parts by mass relative to the content of the polymer component (a), preferably 0.01 to 20 parts by mass, More preferably, it is 0.1 to 10 mass points, and particularly preferably 0.5 to 5 mass points.

(General additive (g))

The general additive (g) can be exemplified by well-known plasticizers, antistatic agents, antioxidants, pigments, dyes, getters, and the like.

The general additive (g) is a component that does not correspond to any of the polymer component (a) and the curable component (b).

(Solvent)

In order to improve the handleability of the curable resin composition by dilution, it is preferable to further contain a solvent.

The solvent contained in the curable resin composition may be the same as the solvent in the aforementioned adhesive composition.

The solvent contained in the curable resin composition may be only one kind, or two or more kinds.

In order to uniformly mix the components used in the curable resin composition, the solvent contained in the curable resin composition is preferably methyl ethyl ketone or the like.

The solvent system does not correspond to any of the polymer component (a) and the curable component (b).

The total content of the polymer component (a) and the curable component (b) of the curable resin layer is 95% by mass or more, more preferably 97% by mass or more relative to the total amount of the curable resin layer, as described above It is preferably over 98% by mass. In order to form such a curable resin layer, the total content of the aforementioned polymer component (a) and curable component (b) of the curable resin composition relative to the total content of all components other than the solvent in the curable resin composition The amount is 95% by mass or more, more preferably 97% by mass or more, and still more preferably 98% by mass or more.

In addition, the total content of the polymer component (a) and the curable component (b) in the curable resin layer may be 100% by mass relative to the total amount of the curable resin layer.

The curable resin composition is obtained by blending the aforementioned components for constituting the same. For example, except that the blending ingredients are different, the same method as in the case of the aforementioned adhesive composition is obtained.

When a solvent is used, it can be used by mixing the solvent with any formulation components other than the solvent and diluting the formulation component in advance, or by mixing the solvent with these formulation components without diluting any formulation components other than the solvent in advance use.

Furthermore, regarding the ease of picking up the semiconductor wafer described in the workpiece fixing sheet with a resin layer of the present invention, for example, a semiconductor wafer on the surface of the workpiece fixing sheet with a resin layer can be used with a commercially available die bonding machine The jacking speed and jacking height are set to specific conditions, and evaluation is made based on whether the semiconductor wafer can be picked up under these conditions. At this time, for example, when 100 wafers are continuously picked up, when the picking of all wafers is successful, or the picking degree of any one of the second and subsequent wafers after the picking of more than one wafer is successful, it can be determined as Easy to pick up is relatively good.

<Manufacturing method of workpiece fixing sheet with resin layer>

The workpiece fixing sheet having a resin layer of the present invention can be manufactured, for example, by forming an adhesive layer on the base film using the adhesive composition, and using the curable resin composition on the adhesive layer to form and harden Sexual resin layer.

The adhesive layer can be formed by applying and drying an adhesive composition on the surface of the base film (the surface 11a of the base film 11 in FIG. 1). At this time, crosslinking may be performed by heating the applied adhesive composition as necessary. The heating conditions can be, for example, 100 to 130° C. for 1 to 5 minutes, but it is not limited thereto. Furthermore, the adhesive layer formed by applying the adhesive composition on the surface of the peeling layer of the peeling material and drying it is bonded to the surface of the base film, and the peeling material is removed to form an adhesive layer.

The application of the adhesive composition on the surface of the base film or the surface of the release layer of the release material may be performed by a known method, and examples include air knife coater, blade coater, bar coater, and gravure coating. Machine, roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater, wire bar coater, contact coater, etc. The method of cloth machine.

The curable resin layer can be formed using a curable resin composition and in the same manner as when forming the adhesive layer on the base film as described above, but it is usually difficult to apply the curable resin composition directly on the adhesive layer Thing. Therefore, it is preferable to separately form a hardenable resin layer in advance and attach it to the surface of the adhesive layer, for example, a hardener formed by coating a hardenable resin composition on the surface of the release layer of the release material and drying The resin layer is attached to the surface of the adhesive layer, and the peeling material and the like are removed.

Furthermore, in addition to the aforementioned method, the work fixing sheet having a resin layer of the present invention can be manufactured, for example, by forming the adhesive layer using the adhesive composition and forming the curable resin layer using the curable resin composition Thereafter, the adhesive layer and the curable resin layer are superimposed to form a laminate, and the base film is bonded to the surface of the adhesive layer of the laminate.

The conditions for forming the adhesive layer and the curable resin layer at this time are the same as the aforementioned method.

[Example]

The present invention will be described in more detail below using specific examples. However, this post The description is not limited by the examples shown below.

<Manufacture of work piece fixing sheet with resin layer> [Example 1]

A work piece having a resin layer having the structure shown in FIG. 1 is manufactured. More specifically, it is as follows.

(Manufacture of alkyl acrylate polymer)

Add lauryl acrylate (hereinafter referred to as "LA") (80 parts by mass) and 2-hydroxyethyl acrylate (hereinafter referred to as "HEA") to a reaction vessel equipped with a cooling tube, nitrogen introduction tube, thermometer, and stirring device 20 parts by mass), benzoyl peroxide (0.2 parts by mass), ethyl acetate (70 parts by mass), toluene (30 parts by mass), and a polymerization reaction was carried out in a nitrogen stream at 60°C for 8 hours, thereby obtaining an acrylic system Polymer (A). The compounding ratio of each component is shown in Table 1 below.

To this acrylic polymer (A) was added 2-methacryloxyethyl isocyanate (hereinafter referred to as "MOI") (22 parts by mass, about 80 mol% relative to HEA), lauric acid di Butyl tin (hereinafter abbreviated as "DBTL") (0.13 parts by mass) was added in an air stream at 23°C for 12 hours to obtain the target alkyl acrylate polymer (A-1) in the state of a 47% by mass solution ). The compounding ratio of each component is shown in Table 1 below.

(Manufacture of adhesive composition)

For the alkyl acrylate polymer (A-1) obtained above (100 mass Points) Add a photopolymerization initiator (Z-1) ("Irgacure 651" manufactured by Ciba Specialty Chemicals, diphenylethanedione dimethyl ketal) (3 parts by mass), and acetone as a reaction delay agent Acetone (1 part by mass), diluted with methyl ethyl ketone, fully stirred, and further added thereto is toluene diisocyanate trimer of trimethylolpropane as the isocyanate-based crosslinking agent (B-1). The finished product ("Coronate L" manufactured by Nippon Polyurethane) (7.5 parts by mass, with respect to 1 mole of residual hydroxyl groups in the acrylate polymer (A-1), the amount of isocyanate groups it has becomes 1 mole), The mixture was stirred at 23°C to obtain an adhesive composition having a solid content concentration of 25% by mass. In addition, the compounding score in this "manufacture of adhesive composition" is the conversion value of solid content. The compounding ratio of each component is shown in Table 1 below.

(Manufacturing of workpiece fixing piece)

Apply the adhesive composition obtained above to the release surface of polyethylene terephthalate (PET) release liner subjected to polysiloxane treatment, heat-dry at 120°C for 2 minutes to form a thickness of 10 μm Adhesive layer. Then, an ethylene/methacrylic acid polymer film with a thickness of 100 μm as a base film was laminated on the surface of the adhesive layer, and stored at 23° C. for 168 hours, thereby obtaining a workpiece fixing sheet.

(Manufacture of curable resin composition)

Acrylic resin ("SG-P3" manufactured by Nagase Chemtex) (87.8 parts by mass), epoxy resin (Nippon Kayaku Co., Ltd.) Manufactured "NC-3000") (12 parts by mass), phenol resin ("MEH-7851-H" manufactured by Meiwa Chemical Co., Ltd.) (10 parts by mass), and triphenylphosphine (0.2 parts by mass) as a hardening accelerator , And a silane coupling agent ("KBM403" manufactured by Shin-Etsu Silicone, 3-glycidoxypropyltrimethoxysilane) (1 part by mass) dissolved in methyl ethyl ketone to obtain a hardening resin A methyl ethyl ketone solution having a solid content concentration of 20% by mass in the composition.

(Manufacture of work piece fixing sheet with resin layer)

The curable resin composition obtained above was coated on a release liner ("SP-PET381031" manufactured by Lintec), and dried at 100°C for 1 minute to form a 20 μm-thick curable resin layer. In addition, a release liner of the same kind as described above is bonded to the curable resin layer. Furthermore, after cutting the bonded release liner and the curable resin layer in half to form a circle with a diameter of 150 mm, unnecessary portions outside the circle are removed. Then, the release liner is removed from the work fixing sheet obtained previously. In addition, the half-cut release liner is removed from the curable resin layer, and the adhesive layer of the work fixing sheet is bonded to the surface of the hardening resin layer, thereby obtaining a work fixing sheet having a resin layer.

<Evaluation of Workpiece Fixing Sheet with Resin Layer>

For the work fixing sheet having a resin layer obtained as described above, the ease of pick-up was evaluated by the following method.

(Easy to pick up)

Using a laminating machine ("Adwill RAD2500" manufactured by Lintec), the work piece with a resin layer obtained above was attached to the polished surface of silicon wafer (diameter 150mm, thickness 100μm) at 60°C. After fixing it to the ring frame for wafer dicing, the silicon wafer was cut into a size of 10 mm×10 mm using a dicing device (“DFD651” manufactured by DISCO) to obtain a wafer. At the time of this cutting, the base film was cut into 20 μm from the surface. Then ultraviolet irradiation device (manufactured by Lintec Corporation's "Adwill RAD2000") at 220mW / cm ^2, at 190mJ / cm ² of the conditions from the side of the substrate film irradiated with ultraviolet rays for fixing the workpiece sheet with a resin layer. Then, using a die-bonding machine ("BESTEM-D02" manufactured by Canon Machinery Co., Ltd.), it was evaluated whether the wafer could be picked up when the pin-up speed was set to 1 mm/s and the lift height was set to 0.2 mm. The needle system is equipped with four pins at four square corners of 8mm. The evaluation is carried out by continuously picking up 100 wafers, and all wafers are successfully picked up as "A", and after one or more wafers are successfully picked up, any one of the second and subsequent wafers fails to be evaluated. It is "A1", and the case where the initial chip fails is evaluated as "B". The results are shown in Table 1 below.

<Manufacture and Evaluation of Workpiece Fixing Sheet with Resin Layer> [Example 2, Comparative Examples 1-2, Reference Example 1]

The formulation component at the time of manufacture of the alkyl acrylate polymer and the formulation component at the time of manufacture of the curable resin composition were as shown in Table 1 below, except that the workpiece fixing sheet having a resin layer was manufactured and evaluated in the same manner as in Example 1. . The results are shown in Table 1 below.

In addition, the alkyl acrylate polymer obtained here is made into alkyl acrylate polymer (A-2) (Example 2), alkyl acrylate polymer (R-1) (Comparative Example 1), alkyl acrylate Ester polymer (R-2) (Comparative Example 2, Reference Example 1).

In all the examples, comparative examples, and reference examples, the amount of methyl ethyl ketone was adjusted to adjust the solid content concentration of the adhesive composition to 25% by mass.

In addition, in Table 1 below, "2EHA" represents 2-ethylhexyl acrylate, "ISTA" represents isostearyl acrylate, and "MA" represents methyl acrylate.

The "filling material" is "SC2050MA" manufactured by Admatechs.

In addition, "-" in the field of compounding ingredients means that the ingredients are not blended.

As shown in Table 1, the workpiece fixing pieces with resin layers of Examples 1 to 2 For the production of alkyl acrylate polymers (the aforementioned polymers (A-1) and (A-2)), use LA (alkyl carbon number 12) or ISTA (alkyl carbon number 18) as alkyl acrylate And, the total content of the polymer component (a) and the curable component (b) of the curable resin layer is set to 98.9% by mass, and it is easy to pick up.

In this regard, in the manufacture of the workpiece fixing sheet having a resin layer of Comparative Examples 1 to 2 in an alkyl acrylate polymer (the aforementioned polymers (R-1), (R-2)), MA (the alkyl carbon number is 1) or 2EHA (the alkyl carbon number is 8) as an alkyl acrylate, which does not have easy pick-up.

Although the work fixing sheet with a resin layer of Reference Example 1 uses MA as the alkyl acrylate in the production of the alkyl acrylate polymer, the curable resin layer contains a filler and is easy to pick up.

In addition, as shown in Table 1, in the foregoing examples, there is no case where any one of the second and subsequent wafers fails to be picked up after one or more wafers are successfully picked up, that is, an evaluation example where the ease of picking is "A1" .

[Industry availability]

The invention can be used in the manufacture of semiconductor wafers and the like.

1‧‧‧Workpiece fixing piece

10‧‧‧Work piece with resin layer

11‧‧‧ Base film

11a‧‧‧Surface of substrate film

12‧‧‧Adhesive layer

12a‧‧‧Surface of adhesive layer

13‧‧‧curable resin layer

13a‧‧‧The surface of the hardening resin layer

14‧‧‧ peeling film

Claims (3)

A workpiece fixing sheet with a resin layer is provided with an adhesive layer on a base film and a hard resin layer directly laminated on the adhesive layer; the adhesive layer contains an alkyl group containing a carbon number of Alkyl (meth)acrylate polymer formed by polymerizing monomers of alkyl (meth)acrylate of 10 to 18; the curable resin layer contains a polymer component (a) and a curable component (b); The total content of the polymer component (a) and the curable component (b) of the curable resin layer is 95% by mass or more with respect to the total amount of the curable resin layer. The work fixing sheet having a resin layer as described in claim 1, wherein the curable resin layer contains an acrylic resin as the polymer component (a); the content of the acrylic resin relative to the solid of the curable resin layer The total amount of ingredients is 50% by mass or more. The work fixing sheet having a resin layer as described in claim 1 or 2, wherein the content of the curable component (b) of the curable resin layer is 1 mass based on 100 mass of the polymer component (a) Points ~ 100 quality points.

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