JP2015073056A - Sheet for semiconductor processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet for semiconductor processing which has resistance against a low-polarity organic solvent, and has the easiness of embedding a fine protruding object.SOLUTION: A sheet 1 for semiconductor processing comprises a base 2; and an adhesive layer 3 laminated on at least one surface. The base is composed of a material including a polyester-based resin as a primary component. The adhesive layer is made of an adhesive formed from an adhesive composition including (meta)acrylic ester copolymer (A) with an energy ray-curable group introduced in its side chain. The (meta)acrylic ester copolymer (A) is produced by the reaction between: an acrylic copolymer (AP) produced by the copolymerization of at least a (meta)methyl acrylate (A1) and a functional group-containing monomer (A2) having a reactive functional group; and an energy ray-curable group-containing compound (A3). The percentage of the mass of a structural part originating from the (meta)methyl acrylate (A1) is 8-40 mass% to the total mass of the acrylic copolymer (AP). The product of the percentage of the mass of the (meta)methyl acrylate (A1) in the acrylic copolymer(AP), and the gel fraction of the adhesive is 100-1800.

Description

  The present invention relates to a semiconductor processing sheet, and more particularly to a semiconductor processing sheet using a semiconductor wafer having a through electrode as a suitable workpiece.

  In the manufacture of a semiconductor device, generally, after forming a circuit on the surface of the semiconductor wafer, grinding the back surface of the semiconductor wafer, adjusting the thickness of the semiconductor wafer, and dicing the semiconductor wafer, A dicing process for dividing the chip into pieces is performed.

  Incidentally, in response to the recent increase in capacity and functionality of electronic circuits, development of a laminated circuit in which a plurality of semiconductor chips are three-dimensionally laminated has been progressing. In such a laminated circuit, conventionally, conductive connection of a semiconductor chip is generally performed by wire bonding. However, due to the need for miniaturization and high functionality, a circuit forming surface can be used without wire bonding. An effective method has been developed in which a TSV chip having a through-hole electrode (TSV) penetrating the opposite surface is manufactured and the upper and lower TSV chips are directly conductively connected.

  To manufacture a TSV chip, a TSV wafer is used in which a through electrode penetrating from a circuit forming surface to the opposite surface is provided on a semiconductor wafer. Such TSV wafers are very fragile and may be damaged in the back grinding process, dicing process, transfer process, and the like. For this reason, during these steps, the TSV wafer may be held on a hard support such as glass via an adhesive layer.

  For example, in Patent Document 1, a rigid support plate is attached to the surface of a substrate (semiconductor wafer) on which a circuit is formed with an adhesive, and in this state, the back surface of the substrate is ground and thinned, and then thinned. A method is disclosed in which a through electrode is formed on the back surface of a substrate, and then dicing into individual elements.

  In the method of Patent Document 1, a dicing tape is bonded to the through electrode side of a small element, the dicing tape is irradiated with UV, and then supplied to a large number of through holes formed in the thickness direction of the support plate. Is brought into contact with the adhesive between the support plate and the substrate to melt the adhesive and peel the support plate from the substrate.

  On the other hand, in Non-Patent Document 1, instead of supplying the solvent to the through-hole as described above, the support plate and the semiconductor wafer bonded with an adhesive are immersed in the solvent, and the adhesive is dissolved or swollen to support The plate is peeled from the semiconductor wafer. In this case, when the method is applied to the method of Patent Document 1, the dicing tape is also immersed in the solvent.

JP 2009-177033 A

Magazine "Electronic Materials", Industrial Research Society Publishing, May 2009, pp. 68-69

  As the solvent for dissolving or swelling the adhesive, a low polarity organic solvent is preferably used. However, since the conventional dicing tape has no resistance to low-polar organic solvents, when immersed in a low-polar organic solvent, the adhesive layer of the dicing tape dissolves or swells, or wrinkles occur in the base material. It will not be able to fulfill the exact function as a dicing tape.

  On the other hand, the above-mentioned dicing tape is attached to a surface on which a through electrode protruding from a planar portion is present on a semiconductor wafer or a semiconductor chip. Therefore, the dicing tape needs to have a physical property that allows projections such as through electrodes to be embedded.

  The present invention has been made in view of the above situation, and an object thereof is to provide a semiconductor processing sheet having resistance to a low-polar organic solvent and embedding of minute protrusions. To do.

  In order to achieve the above object, first, the present invention is a semiconductor processing sheet comprising a base material and an adhesive layer laminated on at least one surface of the base material, wherein the base material is And a pressure-sensitive adhesive composition comprising a (meth) acrylic acid ester copolymer (A) made of a material mainly composed of a polyester-based resin, wherein the pressure-sensitive adhesive layer has an energy ray-curable group introduced in the side chain. The (meth) acrylate copolymer (A) comprises a functional group-containing monomer (A2) having at least methyl (meth) acrylate (A1) and a reactive functional group. A curable group-containing compound having a copolymerizable acrylic copolymer (AP), a substituent capable of reacting with the functional group of the functional group-containing monomer (A2), and an energy ray-curable carbon-carbon double bond ( A3) The ratio of the mass of the structural part derived from the methyl (meth) acrylate (A1) in the total mass of the acrylic copolymer (AP) is 8 to 40% by mass, The product of the ratio of the mass of the structural part derived from the methyl (meth) acrylate (A1) to the total mass of the acrylic copolymer (AP) and the gel fraction of the adhesive is 100 to 1800. There is provided a sheet for semiconductor processing characterized in that (Invention 1).

  Examples of the semiconductor processing sheet according to the present invention include, but are not limited to, a dicing sheet used in a dicing process for a TSV wafer, a pick-up sheet used for a TSV chip pick-up process after dicing, and the like. It is not a thing.

  In the said invention (invention 1), when the ratio of the mass of the structure part derived from the methyl (meth) acrylate (A1) to the mass of the whole acrylic copolymer (AP) is 8 to 40% by mass, The sheet for semiconductor processing has resistance to the low polarity organic solvent. Moreover, the product of the ratio of the mass of the structural part derived from methyl (meth) acrylate (A1) to the total mass of the acrylic copolymer (AP) and the gel fraction of the adhesive is 100 to 1800. As a result, the semiconductor processing sheet has an embedding property of minute protrusions.

  In the said invention (invention 1), it is preferable that the gel fraction of the said adhesive is 12.5-100% (invention 2).

  In the said invention (invention 1 and 2), it is preferable that the said adhesive composition contains a crosslinking agent (B) further (invention 3).

  In the said invention (invention 1-3), it is preferable that the said polyester-type resin of the said base material is a polybutylene terephthalate (invention 4).

  In the said invention (invention 1-4), it is preferable to use the semiconductor wafer which has a penetration electrode as a workpiece | work (invention 5).

  The semiconductor processing sheet according to the present invention has resistance to a low-polar organic solvent and has the ability to embed minute protrusions.

It is sectional drawing of the sheet | seat for semiconductor processing which concerns on one Embodiment of this invention. It is explanatory drawing which shows an example of the semiconductor processing method using the sheet | seat for semiconductor processing which concerns on one Embodiment of this invention. It is explanatory drawing which shows the other example of the semiconductor processing method using the sheet | seat for semiconductor processing concerning one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a cross-sectional view of a semiconductor processing sheet according to an embodiment of the present invention. The semiconductor processing sheet 1 according to this embodiment includes a base material 2 and an adhesive layer 3 laminated on one surface of the base material 2 (the upper surface in FIG. 1). As an example, the semiconductor processing sheet 1 according to the present embodiment is preferably a TSV wafer or TSV chip as a work, and is preferably used as a dicing sheet or a pickup sheet using a TSV wafer or a TSV chip as a work.

1. Base Material As the base material 2 of the semiconductor processing sheet 1 according to the present embodiment, a material composed mainly of a polyester-based resin is used, and it is usually in the form of a sheet (film). The base material 2 made of such a material has resistance to a low-polar organic solvent used in association with a dicing process, a pick-up process, or the like (hereinafter sometimes simply referred to as “solvent resistance”). Therefore, even when the base material 2 in the present embodiment is immersed in the low-polar organic solvent, the base material 2 is not wrinkled or the base material 2 is not softened. The base material 2 maintains the initial shape, hardness, and the like.

  Here, the low polar organic solvent has a solubility parameter (SP value) of 7 or more and less than 10, preferably 7.5 or more and 9.5 or less. For example, d-limonene, mesitylene, menthane, 1-dodecene. Etc. In the test examples described later, the solvent resistance against d-limonene is tested, but when it has solvent resistance against d-limonene, it also has solvent resistance against other low-polar organic solvents. It can be said.

  Examples of the polyester-based resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and the like. Among these, polyethylene terephthalate and polybutylene terephthalate are preferable, and polybutylene terephthalate is particularly preferable. That is, as the base material 2, a polyethylene terephthalate film and a polybutylene terephthalate film are preferable, and a polybutylene terephthalate film is particularly preferable. Since polybutylene terephthalate (film) is more flexible than other polyester resins, it tends to have good process suitability in the process of picking up a chip as an adherend.

  In the base material 2 used in the present embodiment, the above-described polyester-based resin as a main component may contain various additives such as pigments, flame retardants, plasticizers, antistatic agents, lubricants, and fillers. Good. Examples of the pigment include titanium dioxide and carbon black. Examples of the filler include organic materials such as melamine resin, inorganic materials such as fumed silica, and metal materials such as nickel particles. The content of these additives is not particularly limited, but it is preferable that the base material 2 exhibits a desired function and does not lose smoothness and flexibility.

  In the case where ultraviolet rays are used as the energy rays to be irradiated for curing the pressure-sensitive adhesive layer 3, it is preferable that the base material 2 has transparency to the ultraviolet rays. In addition, when using an electron beam as an energy beam, it is preferable that the base material 2 has the transparency of an electron beam.

  The surface of the substrate 2 on the side of the pressure-sensitive adhesive layer 3 (hereinafter also referred to as “substrate-coated surface”) is a surface such as a primer treatment, a corona treatment, or a plasma treatment in order to improve the adhesion with the pressure-sensitive adhesive layer 3. Processing may be performed. Various coating films may be provided on the surface of the substrate 2 opposite to the substrate-coated surface.

  The thickness of the base material 2 is not limited as long as the base material 2 maintains solvent resistance and does not inhibit the embedding property of the pressure-sensitive adhesive layer 3. Specifically, the thickness of the substrate 2 is preferably 20 to 450 μm, particularly preferably 25 to 300 μm, and more preferably 50 to 200 μm.

2. Adhesive Layer The adhesive layer 3 provided in the semiconductor processing sheet 1 according to the present embodiment is a (meth) acrylic acid ester copolymer (A) in which an energy ray curable group is introduced into the side chain, preferably further crosslinked. It consists of the adhesive formed from the adhesive composition containing an agent (B). In addition, “(meth) acrylic acid” in the present specification means both acrylic acid and methacrylic acid. The same applies to other similar terms.

  The (meth) acrylic acid ester copolymer (A) may be contained as it is in the pressure-sensitive adhesive layer 3, or may be contained as a crosslinked product by performing a crosslinking reaction with the crosslinking agent (B).

  As described above, the pressure-sensitive adhesive layer 3 composed of a pressure-sensitive adhesive composition containing a (meth) acrylic acid ester copolymer (A) having an energy ray-curable group introduced in the side chain is energy. Predetermined adhesive strength is exhibited before the irradiation with the radiation, and after the irradiation with the energy rays, the adhesive is hardened to reduce the adhesive strength, and can be easily separated from the adherend.

(1) (Meth) acrylic acid ester copolymer (A)
The (meth) acrylic acid ester copolymer (A) is an acrylic copolymer (AP) obtained by copolymerizing at least methyl (meth) acrylate (A1) and a functional group-containing monomer (A2) having a reactive functional group. ), A substituent capable of reacting with the functional group of the functional group-containing monomer (A2) and a curable group-containing compound (A3) having an energy ray-curable carbon-carbon double bond. is there.

  The ratio of the mass of the structural portion derived from methyl (meth) acrylate (A1) to the total mass of the acrylic copolymer (AP) is 8 to 40% by mass (parameter P1), and the acrylic copolymer weight The product of the ratio of the mass of the structural part derived from methyl (meth) acrylate (A1) to the total mass of the combined (AP) and the gel fraction of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 3 is 100 to 1800. Yes (parameter P2). In addition, the measuring method of the gel fraction of an adhesive is as showing to the test example mentioned later.

  The pressure-sensitive adhesive layer 3 satisfying the parameter P1 has a high polarity of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 3 and has resistance to a low-polar organic solvent. That is, even when the semiconductor processing sheet 1 provided with the pressure-sensitive adhesive layer 3 (and the base material 2) in this embodiment is immersed in a low-polarity organic solvent, the pressure-sensitive adhesive layer 3 is dissolved, swollen, or the like. hard. Therefore, it is suppressed that the low polar organic solvent permeates into the interface between the pressure-sensitive adhesive layer 3 and the adherend, and the adhesion state with the adherend is favorably maintained.

  In addition, the pressure-sensitive adhesive layer 3 satisfying the parameter P2 has the ability to embed minute protrusions. Here, the fine protrusions are, for example, a height of 5 to 50 μm, a width or a diameter of 100 to 450 μm, and a pitch (a distance between an end of one protrusion and an end of another adjacent protrusion) 200. This refers to a protrusion of ˜2000 μm, and in a TSV wafer or TSV chip, a protruding portion of a through electrode protruding from a planar portion thereof can correspond. Therefore, even when the semiconductor processing sheet 1 according to the present embodiment is affixed to a TSV wafer or TSV chip, the protruding portion of the through electrode is satisfactorily embedded in the adhesive layer 3, and the TSV wafer, TSV chip, and adhesive layer 3. And fits closely. As a result, voids are less likely to occur around the protruding portion of the through electrode, and even when cleaning with liquid, the liquid penetrates into the voids and the circuit surface of the TSV wafer or TSV chip is contaminated. Is suppressed.

  The acrylic copolymer (AP) is obtained by copolymerizing at least methyl (meth) acrylate (A1) and a functional group-containing monomer (A2) having a reactive functional group. The methyl (meth) acrylate (A1) is methyl acrylate or methyl methacrylate, preferably methyl methacrylate. The (meth) acrylic acid ester copolymer obtained when the proportion of the mass of the structural portion derived from methyl (meth) acrylate (A1) in the total mass of the acrylic copolymer (AP) is 8 to 40% by mass. The polarity of a polymer (A) becomes high and the tolerance with respect to the low polarity organic solvent of the adhesive layer 3 will become high. From this point of view, the proportion of the mass of the structural portion derived from methyl (meth) acrylate (A1) in the total mass of the acrylic copolymer (AP) is preferably 8 to 35 mass%, particularly 10 to 10 mass%. It is preferably 30% by mass, and more preferably 15-30% by mass.

  The reactive functional group of the functional group-containing monomer (A2) having a reactive functional group reacts with the substituent of the curable group-containing compound (A3). Moreover, when using a crosslinking agent (B), it can also react with the said crosslinking agent (B). Examples of such a functional group include a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, and an epoxy group. Among them, a hydroxyl group and a carboxyl group are preferable, and a hydroxyl group is particularly preferable.

  Examples of the monomer having a hydroxyl group (hydroxyl group-containing monomer) include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and (meth) acrylic acid 2. -Hydroxybutyl, (meth) acrylic acid 3-hydroxybutyl, (meth) acrylic acid 4-hydroxybutyl and other (meth) acrylic acid hydroxyalkyl esters, among others, hydroxyl group reactivity and copolymerization Therefore, 2-hydroxyethyl (meth) acrylate is preferable. These may be used alone or in combination of two or more.

  Examples of the monomer having a carboxyl group (carboxyl group-containing monomer) include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. Acrylic acid is preferred from the standpoints of compatibility and copolymerization. These may be used alone or in combination of two or more.

  The acrylic copolymer (AP) may be a copolymer of different types of functional group-containing monomers (A2), such as hydroxyl group-containing monomers and carboxyl group-containing monomers.

  The ratio of the mass of the structural portion derived from the functional group-containing monomer (A2) to the total mass of the acrylic copolymer (AP) is preferably 8 to 40% by mass, particularly 8 to 35% by mass. Is more preferable, and it is preferable that it is 15-30 mass%. When the proportion of the mass of the structural portion derived from the functional group-containing monomer (A2) is in the above range, the amount of energy ray curable groups introduced into the (meth) acrylic acid ester copolymer (A) is in a suitable range. can do. Moreover, when using a crosslinking agent (B), the grade of the bridge | crosslinking by the said crosslinking agent (B), ie, a gel fraction, can be made into a suitable range.

  The acrylic copolymer (AP) includes (meth) acrylic acid alkyl ester having 2 to 20 carbon atoms in addition to the methyl (meth) acrylate (A1) and the functional group-containing monomer (A2). It is preferable that it is copolymerized. Thereby, (meth) acrylic acid ester copolymer (A) can express preferable adhesiveness.

  Examples of the (meth) acrylic acid alkyl ester having 2 to 20 carbon atoms in the alkyl group include, for example, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, and (meth) acrylic acid. n-pentyl, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, (meth) Examples include myristyl acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and the like. Among these, from the viewpoint of further improving the tackiness, a (meth) acrylic acid ester having 2 to 4 carbon atoms in the alkyl group is preferable, and n-butyl (meth) acrylate is particularly preferable. In addition, these may be used independently and may be used in combination of 2 or more type.

  The proportion of the mass of the structural portion derived from the above (meth) acrylic acid alkyl ester in the total mass of the acrylic copolymer (AP) is preferably 20 to 84 mass%, particularly 40 to 80 mass%. It is preferable that it is 50 to 75 mass%.

  The acrylic copolymer (AP) is, in addition to the methyl (meth) acrylate (A1), the functional group-containing monomer (A2), and the alkyl group (meth) acrylic acid alkyl ester having 2 to 20 carbon atoms, What copolymerized other monomers may be used.

  Examples of the other monomer include alkoxyalkyl group-containing (meth) acrylic such as methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, and ethoxyethyl (meth) acrylate. Acid esters, (meth) acrylic acid esters having an aliphatic ring such as cyclohexyl (meth) acrylate, (meth) acrylic acid esters having an aromatic ring such as phenyl (meth) acrylate, acrylamide, methacrylamide, etc. (Meth) acrylic acid ester having non-crosslinking tertiary amino group such as crosslinkable acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, acetic acid Examples include vinyl and styrene. These may be used alone or in combination of two or more.

  The polymerization mode of the acrylic copolymer (AP) may be a random copolymer or a block copolymer.

  On the other hand, the curable group-containing compound (A3) is a compound having a substituent capable of reacting with a functional group of the functional group-containing monomer (A2) and an energy ray-curable carbon-carbon double bond. Examples of the substituent capable of reacting with the functional group of the functional group-containing monomer (A2) include an isocyanate group and an epoxy group, and among them, an isocyanate group having high reactivity with a hydroxyl group is preferable. The curable group-containing compound (A3) preferably has 1 to 5 energy beam-curable carbon-carbon double bonds in one molecule, and more preferably 1 to 2 in particular. As the curable group having an energy ray curable carbon-carbon double bond (energy ray curable group), a (meth) acryloyl group or the like is preferable.

  Examples of the curable group-containing compound (A3) include 2-methacryloyloxyethyl isocyanate, meta-isopropenyl-α, α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate, 1,1- (bisacryloyl). Oxymethyl) ethyl isocyanate; acryloyl monoisocyanate compound obtained by reaction of diisocyanate compound or polyisocyanate compound with hydroxyethyl (meth) acrylate; diisocyanate compound or polyisocyanate compound, polyol compound, hydroxyethyl (meth) acrylate, And an acryloyl monoisocyanate compound obtained by the above reaction. Among these, 2-methacryloyloxyethyl isocyanate is particularly preferable. In addition, a sclerosing | hardenable group containing compound (A3) may be used independently, and may be used in combination of 2 or more type.

  The reaction between the acrylic copolymer (AP) and the curable group-containing compound (A3) may be performed by a conventional method. Through this reaction step, the functional group in the acrylic copolymer (AP) and the substituent in the curable group-containing compound (A3) react to introduce an energy ray-curable group into the side chain ( A (meth) acrylic acid ester copolymer (A) is obtained.

  Here, when the curable group-containing compound (A3) is a compound having only one energy ray-curable group in the molecule, the (meth) acrylic acid ester copolymer (A) is a curable group. The energy ray-curable group derived from the containing compound (A3) with respect to the functional group (the functional group with which the curable group-containing compound (A3) reacts) of the (meth) acrylic acid ester copolymer (A). It is preferable to contain 20-100 mol%, It is preferable to contain 30-95 mol% especially, Furthermore, it is preferable to contain 40-90 mol%. When the content of the energy ray curable group is in the above range, the (meth) acrylic acid ester copolymer (A) exhibits good energy ray curability.

  The weight average molecular weight (Mw) of the (meth) acrylic acid ester copolymer (A) is preferably 100,000 to 2,500,000, particularly preferably 150,000 to 2,000,000, and more preferably 200,000 to 150. It is preferable to be 10,000. In addition, the weight average molecular weight in this specification is the value of standard polystyrene conversion measured by the gel permeation chromatography (GPC) method. When the weight average molecular weight (Mw) of the (meth) acrylic acid ester copolymer (A) is in the above range, the coating property of the pressure-sensitive adhesive composition is ensured and the cohesiveness of the pressure-sensitive adhesive layer 3 is ensured. It will be good.

(2) Crosslinking agent (B)
It is preferable that the adhesive composition which forms the adhesive layer 3 in this embodiment contains the crosslinking agent (B) which can bridge | crosslink a (meth) acrylic acid ester copolymer (A). In this case, the pressure-sensitive adhesive layer 3 in the present embodiment contains a cross-linked product obtained by a cross-linking reaction between the (meth) acrylic acid ester copolymer (A) and the cross-linking agent (B). By using this crosslinking agent (B), it becomes easy to adjust the gel fraction of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 3 to a suitable range.

  Examples of the crosslinking agent (B) include, for example, epoxy compounds, polyisocyanate compounds, metal chelate compounds, polyazimine compounds such as aziridine compounds, melamine resins, urea resins, dialdehydes, methylol polymers, metal alkoxides, A metal salt etc. are mentioned. Among these, an epoxy compound or a polyisocyanate compound is preferable, and a polyisocyanate compound is particularly preferable because the crosslinking reaction is easily controlled.

  Examples of the epoxy compound include 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, and ethylene glycol diglycidyl ether. 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidylaniline, diglycidylamine and the like.

  A polyisocyanate compound is a compound having two or more isocyanate groups per molecule. Specifically, aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like Biuret bodies, isocyanurate bodies, and adduct bodies that are a reaction product with a low molecular active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor oil, and the like.

  A crosslinking agent (B) can also be used individually by 1 type, and can also be used in combination of 2 or more type.

  Content of the crosslinking agent (B) of the adhesive composition which forms the adhesive layer 3 shall be 0.05-15 mass parts with respect to 100 mass parts of (meth) acrylic acid ester copolymers (A). Is preferably 0.1 to 8 parts by mass, more preferably 0.2 to 3 parts by mass. When the content of the crosslinking agent (B) is in such a range, the adhesiveness between the pressure-sensitive adhesive layer 3 and the base material 2 made of a material mainly composed of a polyester resin tends to be good, After the production of the semiconductor processing sheet 1, the adhesive properties are stabilized without requiring an excessively long curing period.

  When the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer 3 in this embodiment contains a crosslinking agent (B), it contains an appropriate crosslinking accelerator depending on the type of the crosslinking agent (B). Is preferred. For example, when the crosslinking agent (B) is a polyisocyanate compound, the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer 3 preferably contains an organic metal compound-based crosslinking accelerator such as an organic tin compound.

(3) Other components In addition to the above components, the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer 3 in the present embodiment is a variety of materials such as photopolymerization initiators, coloring materials such as dyes and pigments, flame retardants, and fillers. An additive may be contained.

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

(4) Irradiation of energy rays Examples of energy rays for curing the (meth) acrylic acid ester copolymer (A) include ionizing radiation, that is, ultraviolet rays, electron beams, X-rays, and the like. Among these, ultraviolet rays that are relatively easy to introduce irradiation equipment are preferable.

When ultraviolet rays are used as the ionizing radiation, it is preferable to use near ultraviolet rays including ultraviolet rays having a wavelength of about 200 to 380 nm for ease of handling. What is necessary is just to select suitably according to the kind of energy-beam curable group which (meth) acrylic acid ester copolymer (A) has, and the thickness of the adhesive layer 3 as a light quantity, Usually, about 50-500 mJ / cm < ² >. 100 to 450 mJ / cm ² is preferable, and 200 to 400 mJ / cm ² is more preferable. Moreover, ultraviolet illuminance is about 50-500 mW / cm < ² > normally, 100-450 mW / cm < ² > is preferable and 200-400 mW / cm < ² > is more preferable. There is no restriction | limiting in particular as an ultraviolet-ray source, For example, a high pressure mercury lamp, a metal halide lamp, UV-LED etc. are used.

  When an electron beam is used as the ionizing radiation, the accelerating voltage is appropriately determined according to the type of energy ray-curable group of the (meth) acrylic acid ester copolymer (A) and the thickness of the pressure-sensitive adhesive layer 3. What is necessary is just to select and it is preferable that it is normally about 10-1000 kV of acceleration voltage. Moreover, what is necessary is just to set an irradiation dose to the range which (meth) acrylic acid ester copolymer (A) hardens | cures appropriately, and is normally selected in the range of 10-1000 krad. The electron beam source is not particularly limited, and for example, various electron beam accelerators such as a Cockloft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type are used. be able to.

(5) Thickness The thickness of the pressure-sensitive adhesive layer 3 in the present embodiment needs to be at least larger than the height of minute protrusions present on the adherend, and is usually preferably 10 μm or more, particularly 20 μm. It is preferable that it is above, and it is more preferable that it is 35 micrometers or more. On the other hand, if the thickness of the pressure-sensitive adhesive layer 3 is too thick, the pressure-sensitive adhesive layer 3 may adhere to a chip or the like during dicing or wastefully increase the cost. Therefore, the thickness of the pressure-sensitive adhesive layer 3 is 100 μm or less. In particular, it is preferably 80 μm or less, and more preferably 65 μm or less.

(6) Physical Properties The gel fraction of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 3 is preferably 12.5 to 100%, particularly preferably 37.5 to 100%, and more preferably 50 to 95%. It is preferable that When the gel fraction of the pressure-sensitive adhesive is within the above range, the gel fraction and the mass of the structural portion derived from methyl (meth) acrylate (A1) in the total mass of the acrylic copolymer (AP). The product with the ratio easily satisfies the range of 100 to 1800. Moreover, when the gel fraction of the pressure-sensitive adhesive is 12.5% or more, the cohesive force of the pressure-sensitive adhesive becomes good, and the durability of the pressure-sensitive adhesive layer 3 is maintained. In addition, when content of the crosslinking agent (B) in the adhesive composition which forms the adhesive layer 3 is made into the above-mentioned preferable range, the gel fraction of the adhesive which comprises the adhesive layer 3 is 50%. There is a tendency to be above.

  As described above, the proportion of the mass of the structural portion derived from methyl (meth) acrylate (A1) in the total mass of the acrylic copolymer (AP), and the gel fraction of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 3 Product of 100-1800, preferably 300-1500, particularly preferably 400-1500. The pressure-sensitive adhesive layer 3 that satisfies this parameter has the ability to embed minute protrusions. Therefore, even when the semiconductor processing sheet 1 according to the present embodiment is affixed to a TSV wafer or TSV chip, the protruding portion of the through electrode is satisfactorily embedded in the adhesive layer 3, and the TSV wafer, TSV chip, and adhesive layer 3. And fits closely.

3. Release Sheet The semiconductor processing sheet 1 according to this embodiment is a surface of the pressure-sensitive adhesive layer 3 on the substrate 2 side for the purpose of protecting the pressure-sensitive adhesive layer 3 until the pressure-sensitive adhesive layer 3 is applied to the adherend. A release sheet may be laminated on the opposite surface. The configuration of the release sheet is arbitrary, and examples include a release film of a plastic film with a release agent or the like. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, silicone-based, fluorine-based, long-chain alkyl-based, and the like can be used, and among these, a silicone-based material that is inexpensive and provides stable performance is preferable. Although there is no restriction | limiting in particular about the thickness of a peeling sheet, Usually, it is about 20-250 micrometers.

4). Manufacturing method of semiconductor processing sheet The manufacturing method of the semiconductor processing sheet 1 is not particularly limited as long as the pressure-sensitive adhesive layer 3 formed from the above-described pressure-sensitive adhesive composition can be laminated on one surface of the substrate 2. . For example, a coating composition containing the aforementioned pressure-sensitive adhesive composition and, if desired, further containing a solvent or a dispersion medium is prepared, and a die coater, curtain coater, spray coater is formed on one surface of the substrate 2. The pressure-sensitive adhesive layer 3 can be formed by applying the coating composition with a slit coater, knife coater or the like to form a coating film and drying the coating film. The properties of the coating composition are not particularly limited as long as it can be applied. The composition for forming the pressure-sensitive adhesive layer 3 may be contained as a solute, or may be contained as a dispersoid. There is also.

  When the coating composition contains a crosslinking agent (B), the (meth) acrylic acid ester co-polymer can be prepared by changing the drying conditions (temperature, time, etc.) or by separately providing a heat treatment. What is necessary is just to advance the crosslinking reaction of a polymer (A) and a crosslinking agent (B), and to form a crosslinked structure in the adhesive layer 3 with desired presence density. In order to sufficiently advance the crosslinking reaction, usually, after the pressure-sensitive adhesive layer 3 is laminated on the base material 2 by the above-described method or the like, the obtained semiconductor processing sheet 1 is, for example, 23 ° C. and relative humidity 50%. Carry out curing such as leaving it in the environment for several days.

  As another example of the manufacturing method of the semiconductor processing sheet 1, the coating composition is applied on the release-treated surface of the above-described release sheet to form a coating film, which is dried to release from the pressure-sensitive adhesive layer 3. A laminate composed of a sheet is formed, and a surface opposite to the surface on the side of the release sheet in the pressure-sensitive adhesive layer 3 of this laminate is attached to the substrate 2, and the laminate of the semiconductor processing sheet 1 and the release sheet You may get The release sheet in this laminate may be peeled off as a process material, or the adhesive layer 3 may be protected until being attached to an adherend such as a TSV wafer or a TSV chip.

5. Method for Using Semiconductor Processing Sheet (1) Use as Pickup Sheet An example of using the semiconductor processing sheet 1 according to the present embodiment as a TSV chip pickup sheet will be described below with reference to FIG.

  First, as shown in FIG. 2A to FIG. 2B, a dicing process is performed on the TSV wafer 4W fixed on the hard support 7 by the adhesive 71, and a plurality of the TSV wafers 4W are separated from each other. A TSV chip 4C is obtained. In addition to the dicing process, a wafer back grinding process, a process of forming a through hole and a bump in the wafer, a process of transferring between these processes, and the like may be performed on the hard support 7.

  Next, as shown in FIG. 2 (c), the TSV chips 4 </ b> C supported by the hard support 7 are turned upside down and the surface of the semiconductor processing sheet 1 on the pressure-sensitive adhesive layer 3 side (that is, Affixed to the surface of the pressure-sensitive adhesive layer 3 opposite to the substrate 2). The peripheral edge portion of the semiconductor processing sheet 1 is usually attached to the ring frame 5 by the adhesive layer 3 provided in that portion. Since the pressure-sensitive adhesive layer 3 of the semiconductor processing sheet 1 has an embedding property of minute protrusions, the protruding portion of the through electrode 42 of the TSV chip 4C is embedded in the pressure-sensitive adhesive layer 3 satisfactorily. As a result, the TSV chip 4C is closely adhered to the adhesive layer 3 of the semiconductor processing sheet 1.

  Next, as shown in FIG. 2D, the cleaning device 6 is used to clean the TSV chip 4C sandwiched between the hard support 7 and the semiconductor processing sheet 1, and the TSV chip 4C is fixed to the hard support 7. The adhesive 71 fixed to the substrate is dissolved or swollen. In the present embodiment, the TSV chip 4C sandwiched between the hard support 7 and the semiconductor processing sheet 1 is immersed in a low polarity organic solvent.

  Since the pressure-sensitive adhesive layer 3 of the semiconductor processing sheet 1 is resistant to a low-polar organic solvent, it is difficult to dissolve or swell even when immersed in a low-polar organic solvent as described above. Therefore, the low polar organic solvent is prevented from entering the interface between the pressure-sensitive adhesive layer 3 and the TSV chip 4C, and the adhesive state between the pressure-sensitive adhesive layer 3 and the TSV chip 4C is maintained well. This also effectively suppresses the low polar organic solvent from entering the TSV chip 4C from between the through electrode 42 of the TSV chip 4C and the substrate 41. When the adhesive force of the adhesive 71 is reduced by dissolving or swelling the adhesive 71 as described above, the TSV chip 4C is used by using the hard support peeling device 8 as shown in FIG. The adhesive 71 and the hard support 7 are peeled off.

  In addition, as shown in FIG. 2D, the TSV chip 4C may be peeled from the hard support 7 using a physical means such as a laser without using the cleaning device 6. In this case, a residue of the adhesive 71 may be attached to the TSV chip 4C.

  In that case, as shown in FIG. 2F, the rinsing apparatus 9 is used to clean the TSV chip 4C on the semiconductor processing sheet 1. At this time, a low-polar organic solvent is usually used as the rinsing liquid. However, the pressure-sensitive adhesive layer 3 of the semiconductor processing sheet 1 is resistant to the low-polar organic solvent, and thus hardly dissolves or swells. . Therefore, the low polar organic solvent is prevented from entering the interface between the pressure-sensitive adhesive layer 3 and the TSV chip 4C, and the adhesive state between the pressure-sensitive adhesive layer 3 and the TSV chip 4C is maintained well.

  Although not shown in the drawings, energy beam irradiation is performed from the substrate 2 side of the semiconductor processing sheet 1 after completion of the dipping process or the rinsing process. As a result, the polymerization reaction of the energy ray curable group of the (meth) acrylic acid ester copolymer (A) contained in the pressure-sensitive adhesive layer 3 proceeds to reduce the pressure-sensitive adhesiveness, and the TSV chip 4C can be picked up. Become.

  As an example, after the energy beam irradiation, an expanding process of extending the semiconductor processing sheet 1 in the planar direction is performed so that the plurality of TSV chips 4C arranged close to the semiconductor processing sheet 1 can be easily picked up. In addition, you may perform an expanding process before energy beam irradiation. After the expanding step, the TSV chip 4C on the pressure-sensitive adhesive layer 3 is picked up. The picked up TSV chip 4C is used for the next process such as a transport process.

(2) Use as a dicing sheet With reference to FIG. 3, the example which uses the sheet | seat 1 for semiconductor processing which concerns on this embodiment as a dicing sheet of a TSV wafer is demonstrated.

  First, a dipping process or a rinsing process is performed in the same manner as the use as the pickup sheet described above except that the dicing process is not performed on the TSV wafer 4W fixed on the hard support 7 with the adhesive 71. As shown in FIG. 3 (a), a TSV wafer 4W is affixed to the surface of the semiconductor processing sheet 1 on the pressure-sensitive adhesive layer 3 side (that is, the surface opposite to the base material 2 of the pressure-sensitive adhesive layer 3). A sheet having a ring frame 5 attached to the periphery of the sheet 1 is obtained. In the dipping process or the rinsing process, the excellent solvent resistance effect of the semiconductor processing sheet 1 according to this embodiment is exhibited.

  Here, the TSV wafer 4 </ b> W includes a substrate 41 and a through electrode 42 that penetrates the substrate 41, and both end portions of the through electrode 42 protrude from the planar portion of the substrate 41. Since the pressure-sensitive adhesive layer 3 of the semiconductor processing sheet 1 has an embedding property of minute protrusions, the protruding portion of the through electrode 42 is well embedded in the pressure-sensitive adhesive layer 3. The agent layer 3 is in close contact with the TSV wafer 4W.

  Next, as shown in FIG. 3B, a dicing process is performed to obtain a plurality of TSV chips 4C from the TSV wafer 4W. At this time, in order to prevent contamination of the TSV chip 4C due to substrate cutting powder or adhesive aggregate generated during dicing, dicing is performed while washing the TSV chip 4C on the semiconductor processing sheet 1 with water or an aqueous solution. There are many cases. However, since the pressure-sensitive adhesive layer 3 of the semiconductor processing sheet 1 follows the protruding portion of the through electrode 42, it is difficult for voids to form around the protruding portion of the through electrode 42, and water or the like enters the void. Thus, it is possible to prevent the occurrence of a situation where the circuit surface of the TSV chip 4C is soiled.

  Although not shown in the drawings, energy rays are irradiated from the substrate 2 side of the semiconductor processing sheet 1 after completion of the above-described cleaning process. As a result, the polymerization reaction of the energy ray curable group of the (meth) acrylic acid ester copolymer (A) contained in the pressure-sensitive adhesive layer 3 proceeds to reduce the pressure-sensitive adhesiveness, and the TSV chip 4C can be picked up. Become.

  As an example, after the energy beam irradiation, an expanding process of extending the semiconductor processing sheet 1 in the planar direction is performed so that the plurality of TSV chips 4C arranged close to the semiconductor processing sheet 1 can be easily picked up. The extent of this extension may be set as appropriate in consideration of the distance that the TSV chips 4C that are arranged in close proximity should have, the tensile strength of the substrate 2, and the like. In addition, you may perform an expanding process before energy beam irradiation.

  After the expanding step, the TSV chip 4C on the pressure-sensitive adhesive layer 3 is picked up. The pickup is performed by general means such as a suction collet. At this time, in order to facilitate the pickup, the target TSV chip 4C is pushed up from the substrate 2 side of the semiconductor processing sheet 1 with a pin or a needle. Is preferred. The picked up TSV chip 4C is used for the next process such as a transport process.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, another layer may be interposed between the base material 2 and the pressure-sensitive adhesive layer 3 in the semiconductor processing sheet 1.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Example 1]
(1) Preparation of (meth) acrylic acid ester copolymer (A) n-butyl acrylate 69 parts by mass (in terms of solid content; hereinafter the same), 10 parts by mass of methyl methacrylate (A1), acrylic An acrylic copolymer (AP) was obtained by copolymerizing 20 parts by mass of 2-hydroxyethyl acid and 1 part by mass of acrylic acid (A2).

  Subsequently, the obtained acrylic copolymer (AP) and 2-methacryloyloxyethyl isocyanate (MOI; A3) were reacted to introduce an energy ray-curable group (methacryloyl group) into the side chain (meta ) An acrylic ester copolymer (A) was obtained. At this time, the MOI is 21.4 g per 100 g of the acrylic copolymer (AP) (80 mol (80 mol%) per 100 mol of 2-hydroxyethyl acrylate unit of the acrylic copolymer (AP)). Both were reacted. When the molecular weight of the obtained (meth) acrylic acid ester copolymer (A) was measured by the method described later, the weight average molecular weight (Mw) was 600,000. In any of the following examples and comparative examples, the (meth) acrylic acid ester copolymer (A) had a weight average molecular weight (Mw) of 600,000.

(2) Preparation of pressure-sensitive adhesive composition 100 parts by mass of the (meth) acrylic acid ester copolymer (A) obtained in the above step (1) and α-hydroxycyclohexyl phenyl ketone (BASF) as a photopolymerization initiator Product, product name “Irgacure 184”) and 3 parts by weight of trimethylolpropane modified tolylene diisocyanate (product name “BHS-8515” manufactured by Toyo Ink Co., Ltd.) as a crosslinking agent (B) in a solvent. By mixing, a coating solution of the pressure-sensitive adhesive composition was obtained.

(3) Production of sheet for semiconductor processing A release sheet (product name, manufactured by Lintec Co., Ltd.) obtained by peeling off the coating solution of the pressure-sensitive adhesive composition obtained in the above step (2) with a silicone release agent on one side of the polyethylene terephthalate film. “SP-PET381031” (thickness: 38 μm) was coated with a knife coater so that the thickness after drying was 50 μm, and then treated at 100 ° C. for 1 minute to form an adhesive coating film. did. Next, by bonding the obtained coating film and a polybutylene terephthalate (PBT) film (thickness: 80 μm) as a base material, the surface on the side opposite to the base material side in the pressure-sensitive adhesive layer is applied. A semiconductor processing sheet was obtained with the release sheets laminated.

[Example 2]
An acrylic copolymer (AP) was prepared by copolymerizing 52 parts by mass of n-butyl acrylate, 20 parts by mass of methyl methacrylate, and 28 parts by mass of 2-hydroxyethyl acrylate. The resulting acrylic copolymer (AP) and MOI were reacted to obtain a (meth) acrylic acid ester copolymer (A). At this time, MOI is 30.0 g per 100 g of acrylic copolymer (AP) (80 mol (80 mol%) per 100 mol of 2-hydroxyethyl acrylate unit of acrylic copolymer (AP)). Both were reacted.

  While using the said (meth) acrylic acid ester copolymer (A), the compounding quantity of a crosslinking agent (B) is 0.3 mass part with respect to 100 mass parts of (meth) acrylic acid ester copolymer (A). A coating solution for the pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the thickness was changed so as to produce a semiconductor processing sheet.

Example 3
While using the (meth) acrylic acid ester copolymer (A) prepared in the same manner as in Example 1, the blending amount of the crosslinking agent (B) was 100 parts by mass of the (meth) acrylic acid ester copolymer (A). A coating solution of the pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the content was changed to 0.5 parts by mass, and a semiconductor processing sheet was prepared using the same.

Example 4
An acrylic copolymer (AP) was prepared by copolymerizing 52 parts by mass of n-butyl acrylate, 28 parts by mass of methyl methacrylate, and 20 parts by mass of 2-hydroxyethyl acrylate. The obtained acrylic copolymer (AP) and MOI were reacted in the same manner as in Example 2 to obtain a (meth) acrylic acid ester copolymer (A).

  While using the said (meth) acrylic acid ester copolymer (A), the compounding quantity of a crosslinking agent (B) is 0.5 mass part with respect to 100 mass parts of (meth) acrylic acid ester copolymer (A). A coating solution for the pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the thickness was changed so as to produce a semiconductor processing sheet.

Example 5
While using the (meth) acrylic acid ester copolymer (A) prepared in the same manner as in Example 2, the blending amount of the crosslinking agent (B) was changed to 100 parts by weight of the (meth) acrylic acid ester copolymer (A). A coating solution for the pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the content was changed to 0.8 parts by mass, and a semiconductor processing sheet was prepared using the same.

[Comparative Example 1]
A coating solution of the pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the (meth) acrylic acid ester copolymer (A) prepared in the same manner as in Example 2 was used, and semiconductor processing was performed using it. A sheet was prepared.

[Comparative Example 2]
An acrylic copolymer (AP) was prepared by copolymerizing 89 parts by mass of n-butyl acrylate, 5 parts by mass of methyl methacrylate, and 6 parts by mass of 2-hydroxyethyl acrylate. The obtained acrylic copolymer (AP) and MOI are 6.4 g of MOI per 100 g of acrylic copolymer (AP) (2-hydroxyethyl acrylate unit of acrylic copolymer (AP)). It was made to react so that it might become 50 mol (50 mol%) per 100 mol, and the (meth) acrylic acid ester copolymer (A) was obtained.

  While using the said (meth) acrylic acid ester copolymer (A), the compounding quantity of a crosslinking agent (B) is 0.5 mass part with respect to 100 mass parts of (meth) acrylic acid ester copolymer (A). A coating solution for the pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the thickness was changed so as to produce a semiconductor processing sheet.

[Comparative Example 3]
While using the (meth) acrylic acid ester copolymer (A) prepared in the same manner as in Comparative Example 2, the blending amount of the crosslinking agent (B) was 100 parts by mass of the (meth) acrylic acid ester copolymer (A). A coating solution for the pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the content was changed to 7 parts by mass, and a semiconductor processing sheet was prepared using the same.

[Comparative Example 4]
A semiconductor processing sheet was produced in the same manner as in Example 1 except that the base material was changed to a film (thickness: 120 μm) made of an ethylene / vinyl acetate copolymer (EVA).

[Comparative Example 5]
While using the (meth) acrylic acid ester copolymer (A) prepared in the same manner as in Example 4, the blending amount of the crosslinking agent (B) was 100 parts by weight of the (meth) acrylic acid ester copolymer (A). A coating solution for the pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the amount was changed to 1.5 parts by mass, and a semiconductor processing sheet was prepared using the same.

  Here, the above-described weight average molecular weight (Mw) is a weight average molecular weight in terms of standard polystyrene measured (GPC measurement) using gel permeation chromatography (GPC).

In addition, Table 1 shows the composition of the (meth) acrylic acid ester copolymer (A), the blending amount of the crosslinking agent (B), and the type of substrate in each of the examples and comparative examples. Details of abbreviations and the like described in Table 1 are as follows.
BA: n-butyl acrylate MMA: methyl methacrylate HEA: 2-hydroxyethyl acrylate AA: acrylic acid MOI: 2-methacryloyloxyethyl isocyanate

[Test Example 1] (Measurement of gel fraction)
A pressure-sensitive adhesive layer having a thickness of 20 μm produced in the same manner as in each of the examples and comparative examples was cut into a size of 50 mm × 100 mm, and the pressure-sensitive adhesive layer was wrapped in a nylon mesh (mesh size 200) having a size of 100 mm × 150 mm, The mass of the adhesive and the nylon mesh was weighed with a precision balance, and the mass of the nylon mesh measured in advance was subtracted from the weighed mass to obtain the mass of the adhesive alone. The mass at this time is M1.

  Next, the adhesive wrapped in the nylon mesh was immersed in 100 mL of ethyl acetate at 25 ° C. for 24 hours. Thereafter, the pressure-sensitive adhesive was taken out, dried at 120 ° C. for 1 hour, and then allowed to stand for 1 hour under conditions of a temperature of 23 ° C. and a relative humidity of 50% to adjust the humidity. The masses of the subsequent adhesive and nylon mesh were weighed with a precision balance, and the mass of the nylon mesh measured in advance was subtracted from the weighed mass to obtain the mass of only the adhesive. The mass at this time is M2. The gel fraction (%) is represented by (M2 / M1) × 100. The results are shown in Table 1.

  Further, the product of the measured gel fraction of the pressure-sensitive adhesive and the ratio of the mass of the structural portion derived from methyl methacrylate to the total mass of the acrylic copolymer (AP) was calculated. The results are shown in Table 1.

[Test Example 2] (Evaluation of embeddability)
As a TSV wafer, a silicon wafer (diameter 8 inches, thickness 350 μm) having a plurality of square columnar projections having a height of 20 μm, a width of 300 μm, and a pitch of 1 mm was prepared on one side. This silicon wafer was affixed to the semiconductor processing sheet produced in the examples or comparative examples at a laminating pressure of 0.3 MPa and a laminating speed of 10 mm / s.

  Subsequently, it observed using the optical microscope from the surface by the side of the base material of the sheet | seat for semiconductor processing, and measured the width | variety of the air caught from one side of the square columnar projection. If the width of the entrained air is less than 1/5 of the pitch size (less than 200 μm), it is determined that the embedding property is good (O), and the width of the entrained air becomes the pitch size. On the other hand, those with 1/5 or more (200 μm or more) were determined to have poor embeddability (×). The results are shown in Table 1.

[Test Example 3] (Evaluation of solvent resistance)
In the same manner as in Test Example 2, a silicon wafer was affixed to the semiconductor processing sheet produced in the example or comparative example. Moreover, a ring frame was affixed to the peripheral edge of the semiconductor processing sheet under the same affixing conditions, and this was used as an evaluation sample.

  The said evaluation sample was immersed in d-limonene (SP value: 8.2) which is a low polar organic solvent for 10 minutes at room temperature. Thereafter, the appearance of the evaluation sample, the penetration of the solvent between the silicon wafer and the semiconductor processing sheet (adhesive layer), and the like were observed. As a result, there was no problem in all cases where the solvent resistance was good (O), and the silicon wafer and / or the ring frame dropped off, the solvent resistance was poor (X), and the silicon wafer and / or ring frame did not fall off. However, wrinkles were generated in the base material, or the adhesive layer was swollen / dissolved was judged as poor solvent resistance (Δ). The results are shown in Table 1.

  As is clear from Table 1, the semiconductor processing sheets of the examples have good embedding properties with respect to minute protrusions and have good resistance against low-polar organic solvents.

  The semiconductor processing sheet according to the present invention is suitably used as a dicing sheet or a pickup sheet using a TSV wafer or a TSV chip as a workpiece.

DESCRIPTION OF SYMBOLS 1 ... Semiconductor processing sheet 2 ... Base material 3 ... Adhesive layer 4W ... TSV wafer 4C ... TSV chip 41 ... Substrate 42 ... Through electrode 5 ... Ring frame 6 ... Cleaning device 7 ... Hard support 71 ... Adhesive 8 ... Hard Support peeling device 9 ... Rinsing device

Claims (5)

A semiconductor processing sheet comprising a substrate and an adhesive layer laminated on at least one surface of the substrate,
The base material is made of a material mainly composed of a polyester-based resin,
The pressure-sensitive adhesive layer is made of a pressure-sensitive adhesive formed from a pressure-sensitive adhesive composition containing a (meth) acrylic acid ester copolymer (A) having an energy ray curable group introduced in the side chain,
The (meth) acrylic acid ester copolymer (A) is
An acrylic copolymer (AP) obtained by copolymerizing at least methyl (meth) acrylate (A1) and a functional group-containing monomer (A2) having a reactive functional group;
It is obtained by reacting a functional group of the functional group-containing monomer (A2) with a functional group capable of reacting with a functional group and a curable group-containing compound (A3) having an energy ray-curable carbon-carbon double bond,
The ratio of the mass of the structural part derived from the methyl (meth) acrylate (A1) in the total mass of the acrylic copolymer (AP) is 8 to 40% by mass,
The product of the ratio of the mass of the structural part derived from the methyl (meth) acrylate (A1) to the total mass of the acrylic copolymer (AP) and the gel fraction of the adhesive is 100 to 1800. A sheet for semiconductor processing, characterized in that there is.   The semiconductor processing sheet according to claim 1, wherein the pressure-sensitive adhesive has a gel fraction of 12.5 to 100%.   The sheet for semiconductor processing according to claim 1, wherein the pressure-sensitive adhesive composition further contains a crosslinking agent (B).   The sheet for semiconductor processing according to any one of claims 1 to 3, wherein the polyester-based resin of the base material is polybutylene terephthalate.   The semiconductor processing sheet according to claim 1, wherein a semiconductor wafer having a through electrode is used as a workpiece.

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