JP2008294044A - Substrate film for dicing, and dicing film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dicing film which leaves little cut chips (string-like or whisker-like chips occurring from a film after dicing) after a dicing step of a semiconductor wafer, is excellent in adhesion between a film front layer and an acrylic-based adhesive and leaves no acrylic-based adhesive on a chip side (that is, contamination of a semiconductor chip can be prevented) after the semiconductor chip is picked up after dicing. <P>SOLUTION: A dicing substrate film of at least a two-layered structure including an A layer and a C layer laminated and a dicing film are provided, wherein the A layer contains a resin composition consisting of the acrylic-based resin of 10-50 wt.% and a styrene-conjugate diene block copolymer hydrogen additive of 50-90 wt.% and the C layer contains thermoplastic resin with rubber elasticity. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a dicing film for fixing a semiconductor wafer or the like when the semiconductor wafer or the like is diced into chips.

  A semiconductor wafer is made in advance in a large area, then diced (cut and separated) into chips and transferred to an expanding process. In the dicing, a dicing film is used for fixing the semiconductor wafer.

  The dicing film is basically composed of an adhesive layer for fixing a semiconductor wafer and a resin layer (a substrate film for dicing) that receives the cutting of a dicing blade. The semiconductor wafer fixed to the dicing film is diced into chips, and is picked up after being uniformly expanded in the surface direction on the expanding ring in order to separate the chips.

  In the semiconductor wafer dicing process, the adhesive layer or a part of the substrate film for dicing is also cut together with the wafer, so that the resin becomes a molten state due to frictional heat of the resin, and resin-derived cutting waste (dicing waste) is generated. Since this cutting waste contaminates the wafer and lowers the yield of chips, it is necessary to reduce it as much as possible.

  For example, the following dicing film has been reported mainly for the purpose of eliminating cutting waste in the dicing process.

  Patent Document 1 describes a polyolefin film such as polyethylene irradiated with 1 to 80 Mrad of an electron beam or γ-ray as a base film. However, since this film crosslinks the entire crosslinkable resin with an electron beam or the like, it becomes hard and sufficient expandability cannot be obtained.

  Patent Document 2 describes an ethylene / methyl methacrylate copolymer film as a base film. However, although this film can reduce a certain amount of cutting waste, it is not always sufficient.

  Patent Document 3 mainly discloses a resin layer B mainly composed of an ionomer resin obtained by crosslinking a terpolymer of ethylene, (meth) acrylic acid, and a (meth) acrylic acid alkyl ester with a metal ion, and an adhesive layer. A semiconductor wafer fixing adhesive tape laminated with A is described. However, since this film contains metal ions, contamination of the wafer becomes a problem.

  Patent Document 4 discloses a resin in which an adhesive coated layer, a thermoplastic elastomer layer, and a resin layer are laminated in this order, and the thermoplastic elastomer layer contains 70% by mass or more of a hydrogenated styrene-butadiene copolymer. An adhesive tape base material comprising a composition and having a layer thickness of 30% or more with respect to the base material thickness is described. However, this film does not always have a sufficient cutting scrap reduction effect.

In Patent Document 5, in a base film comprising at least two layers, polypropylene is used as a resin for the adhesive layer side, and a hydrogenated styrene-butadiene copolymer is used as a layer other than the resin layer on the adhesive layer side. The use is described.
Japanese Patent Laid-Open No. 5-21234 JP-A-5-156214 Japanese Patent Laid-Open No. 9-8111 JP 2005-272724 A JP 2005-174963 A

  The present invention has almost no generation of cutting waste (thread-like or whisker-like waste generated from the film after dicing) in the dicing process of the semiconductor wafer, and has excellent adhesion between the surface layer of the film and the acrylic pressure-sensitive adhesive. An object of the present invention is to provide a dicing film in which no acrylic adhesive remains on the chip side when the semiconductor chip is picked up (that is, contamination of the semiconductor chip can be prevented). Another object of the present invention is to provide a substrate film for dicing used for the dicing film.

  As a result of intensive studies to solve the above problems, the present inventor has found that a resin composition comprising 10 to 50% by weight of an acrylic resin and 50 to 90% by weight of a hydrogenated styrene-conjugated diene block copolymer. A dicing substrate film having at least two layers comprising a layer A containing a product and a C layer containing a thermoplastic resin having rubber elasticity, and a dicing film provided with an acrylic pressure-sensitive adhesive layer on the dicing substrate film However, they found that the above problems could be solved.

  Furthermore, it has B layer containing the resin composition which consists of 10 to 60 weight% of polypropylene resin and 40 to 90 weight% of styrene-conjugated diene block copolymer hydrogenation between said A layer and C layer. It has been found that a substrate film for dicing having at least three layers and a dicing film in which an acrylic pressure-sensitive adhesive layer is provided on the substrate film for dicing can also solve the above problems. Based on this knowledge, further studies have been made and the present invention has been completed.

  That is, the present invention provides the following dicing substrate film and dicing film.

  Item 1. A substrate film for dicing composed of at least two layers formed by laminating an A layer and a C layer, wherein the A layer is 10 to 50% by weight of an acrylic resin and 50 to 90% by weight of a hydrogenated styrene-conjugated diene block copolymer %, And the C layer comprises a thermoplastic resin having rubber elasticity.

  Item 2. The layer A further comprises 10 to 45 parts by weight of an antistatic agent with respect to 100 parts by weight of a resin composition comprising the acrylic resin and a hydrogenated styrene-conjugated diene block copolymer. Base film for dicing.

  Item 3. Item 3. The substrate film for dicing according to Item 1 or 2, wherein the C layer further comprises 10 to 45 parts by weight of an antistatic agent with respect to 100 parts by weight of the thermoplastic resin having rubber elasticity.

  Item 4. Item 4. The dicing substrate according to Item 1, 2, or 3, wherein the total thickness of the substrate film for dicing is 50 to 300 μm, and the thickness of the layer A is 50 to 95% with respect to the total thickness of the substrate film for dicing. Film.

  Item 5. A substrate film for dicing composed of at least three layers formed by laminating an A layer, a B layer and a C layer in this order, wherein the A layer comprises 10 to 50% by weight of an acrylic resin and a hydrogenated styrene-conjugated diene block copolymer The layer B contains a resin composition consisting of 10 to 60% by weight of a polypropylene resin and 40 to 90% by weight of a hydrogenated styrene-conjugated diene block copolymer. , C layer is a substrate film for dicing, comprising a thermoplastic resin having rubber elasticity.

  Item 6. Item 6. The dicing according to Item 5, wherein the A layer further comprises 10 to 45 parts by weight of an antistatic agent with respect to 100 parts by weight of the resin composition comprising the acrylic resin and a hydrogenated styrene-conjugated diene block copolymer. Base film for use.

  Item 7. Item 6. The dicing according to Item 5, wherein the B layer further comprises 10 to 45 parts by weight of an antistatic agent with respect to 100 parts by weight of the resin composition comprising the polypropylene resin and a hydrogenated styrene-conjugated diene block copolymer. Base film for use.

  Item 8. Item 8. The dicing substrate film according to Item 5, 6 or 7, wherein the layer C further comprises 10 to 45 parts by weight of an antistatic agent with respect to 100 parts by weight of the thermoplastic resin having rubber elasticity.

  Item 9. Item 9. The item according to any one of Items 5 to 8, wherein the total thickness of the substrate film for dicing is 50 to 300 μm, and the thickness of layer A + B is 50 to 95% with respect to the total thickness of the substrate film for dicing. Base film for dicing.

  Item 10. Item 10. A dicing film further comprising an acrylic pressure-sensitive adhesive layer on the A layer of the substrate film for dicing according to any one of Items 1 to 9.

  Item 11. A method for producing a substrate film for dicing having at least two layers, comprising a resin composition comprising 10 to 50% by weight of an acrylic resin and 50 to 90% by weight of a hydrogenated styrene-conjugated diene block copolymer A production method comprising multilayer coextrusion molding of a resin for layer C and a resin for layer C containing a thermoplastic resin having rubber elasticity.

  Item 12. A method for producing a substrate film for dicing having at least three layers, comprising a resin composition comprising 10 to 50% by weight of an acrylic resin and 50 to 90% by weight of a hydrogenated styrene-conjugated diene block copolymer A resin for a layer, a resin for a B layer containing a resin composition comprising 10 to 60% by weight of a polypropylene resin and 40 to 90% by weight of a hydrogenated styrene-conjugated diene block copolymer, and a thermoplastic resin having rubber elasticity The manufacturing method characterized by carrying out multilayer coextrusion molding of the resin for C layers containing in this order.

  The substrate film for dicing of the present invention has almost no generation of cutting waste in the dicing process, so there is no concern about contamination of the wafer, and no acrylic adhesive remains on the chip side when the semiconductor chip is picked up. Contamination can be effectively prevented.

I. Dicing Substrate Film The dicing substrate film of the present invention is a dicing substrate film comprising at least two layers formed by laminating an A layer and a C layer. The A layer comprises 10 to 50% by weight of an acrylic resin and styrene- A resin composition comprising 50 to 90% by weight of hydrogenated conjugated diene block copolymer is contained, and the C layer comprises a thermoplastic resin having rubber elasticity.

  The dicing substrate film of the present invention is a dicing substrate film having at least a three-layer structure in which an A layer, a B layer and a C layer are laminated in this order, and the A layer comprises 10 to 50% by weight of an acrylic resin. A resin composition comprising 50 to 90% by weight of a styrene-conjugated diene block copolymer hydrogenated product, and B layer comprises 10 to 60% by weight of a polypropylene resin and 40 to 40% of a styrene-conjugated diene block copolymer hydrogenated product. The layer C includes a thermoplastic resin having rubber elasticity.

  Hereinafter, each layer will be described.

A layer:
A layer contains the resin composition which consists of acrylic resin 10-50 weight% and styrene-conjugated diene block copolymer hydrogenated 50-90 weight%.

  The acrylic resin used in the A layer is a resin containing, as a main monomer unit, an acrylate ester having an alkyl group having 1 to 8 carbon atoms as an ester residue. The content of the acrylate monomer unit in the acrylic resin is generally 70 to 99% by weight. Specific examples of the acrylate monomer include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like. Specific examples of the remaining copolymerizable monomer include, for example, methacrylic acid ester monomers such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate; styrene, p-methylstyrene, o- And aromatic vinyl monomers such as methylstyrene.

  Examples of the hydrogenated styrene-conjugated diene block copolymer used in the A layer include a compound obtained by hydrogenating a carbon-carbon double bond of a styrene-conjugated diene block copolymer. The reason why the hydrogenated product is used is that it has good compatibility with the acrylic resin and prevents brittleness due to oxidative degradation caused by the presence of double bonds in the conjugated diene.

  Specific examples of the conjugated diene include isoprene, butadiene, hexadiene, 1,3-pentadiene and the like. Conjugated diene blocks include hydrogenated polyisoprene blocks in which unsaturated bond portions of polyisoprene blocks mainly composed of isoprene units are hydrogenated, and water in which unsaturated bond portions of polybutadiene blocks mainly composed of butadiene units are hydrogenated. A hydrogenated isoprene / butadiene copolymer block in which an unsaturated bond portion of an isoprene / butadiene copolymer block mainly composed of an isoprene unit and a butadiene unit is hydrogenated is preferable.

  Specific examples of styrene-conjugated diene block copolymer hydrogenated products include styrene-butadiene block copolymer hydrogenated products, styrene-isoprene block copolymer hydrogenated products, or styrene-isoprene / butadiene block copolymer hydrogenated products. The additive may be used alone or as a mixture thereof.

  The content of styrene units in the hydrogenated styrene-conjugated diene block copolymer is preferably 5 to 40% by weight, more preferably 5 to 15% by weight.

  The content of the acrylic resin in the resin composition of the A layer is 10 to 50% by weight, preferably 10 to 40% by weight, and more preferably 10 to 30% by weight. On the other hand, the content of the hydrogenated styrene-conjugated diene block copolymer in the resin composition of the A layer is 50 to 90% by weight, preferably 60 to 90% by weight, more preferably 70 to 90% by weight. . When an acrylic resin is included in the resin composition of the surface layer (A layer) of the base film in this range, the adhesiveness between the A layer and the acrylic pressure-sensitive adhesive is excellent. No adhesive remains. In addition, it is preferable because dicing blade can effectively suppress generation of resin-derived cutting waste (dicing waste) during dicing.

  The layer A may contain an antistatic agent in addition to a resin composition comprising an acrylic resin and a styrene-conjugated diene block copolymer hydrogenated product. As the antistatic agent, known surfactants such as anionic, cationic, and nonionic surfactants can be selected. In particular, from the viewpoint of durability and durability, polyether ester amide resin (hereinafter referred to as “PEEA resin”). ) And nonionic surfactants such as hydrophilic polyolefin resins (hereinafter referred to as “hydrophilic PO resins”) are suitable.

  The PEEA resin is a polymer composed of a polyether ester, which is a main unit component for imparting hydrophilicity, and a polyamide unit, and is commercially available or can be easily produced by a known method. Examples of the PEEA resin include Pelestat NC6321 from Sanyo Chemical Industries, Ltd. In addition, the production method is described in JP-A-64-45429, JP-A-6-287547, etc. According to this, for example, a polydiol component having an ether group in the main chain is added to a dicarboxylic acid. It can be produced by reacting the components into a terminal ester and reacting this with an aminocarboxylic acid or lactam. The PEEA resin has good compatibility with any of the above-mentioned layers of resin, and there is no phenomenon of bleeding out.

  Examples of the hydrophilic PO resin include hydrophilic polyethylene (hereinafter referred to as “hydrophilic PE resin”) or hydrophilic polypropylene (hereinafter referred to as “hydrophilic PP resin”).

  The hydrophilic PE resin or the hydrophilic PP resin is basically a block in which a polyethylene chain or a polypropylene chain and a polyoxyalkylene chain are bonded to each other, exhibiting a high static elimination action and eliminating the accumulation of static electricity. This bonding is performed by an ester group, an amide group, an ether group, a urethane group or the like. From the viewpoint of compatibility with the film resin, this bond is preferably an ester group or an ether group. As the hydrophilic PP resin, for example, Pelestat 230 manufactured by Sanyo Chemical Industries, Ltd. is exemplified.

  The molecular weight of the polyethylene chain or the polypropylene chain in the hydrophilic PE resin or the hydrophilic PP resin is, for example, about 1200 to 6000. This is because, within this molecular weight range, it is easy to acid-modify polyethylene or polypropylene at the stage before block bonding polyethylene or polypropylene to the polyoxyalkylene chain.

  The molecular weight of the polyoxyalkylene chain in the hydrophilic PE resin or hydrophilic PP resin is preferably about 1000 to 15000 from the viewpoint of heat resistance and reactivity with polyethylene or polypropylene after acid modification. The molecular weight described above is a value measured using GPC.

  The hydrophilic PE resin or the hydrophilic PP resin can be produced by, for example, acid-modifying polyethylene or polypropylene having the above-described molecular weight and reacting this with polyalkylene glycol. More details are described in, for example, Japanese Patent Application Laid-Open Nos. 2001-278985 and 2003-48990.

When layer A contains an antistatic agent, the content of the antistatic agent is 10 to 45 parts by weight with respect to 100 parts by weight of the resin composition comprising the acrylic resin and a hydrogenated styrene-conjugated diene block copolymer. The amount is preferably about 15 to 30 parts by weight. Within such a range, semi-conductivity is effectively imparted without impairing the properties of the film of the present invention, so that the generated static electricity can be quickly eliminated. For example, the film of the present invention containing an antistatic agent in the above-described range has a surface resistivity of about 10 ⁷ to 10 ¹² Ω / □.

B layer:
The B layer contains a resin composition comprising 10 to 60% by weight of a polypropylene resin and 40 to 90% by weight of a hydrogenated styrene-conjugated diene block copolymer.

  Examples of the hydrogenated styrene-conjugated diene block copolymer used in the A layer include those described in the A layer. The types of hydrogenated styrene-conjugated diene block copolymers in the A layer and the B layer may be the same or different.

  The polypropylene resin used in the B layer is preferably crystalline. Examples of the crystalline polypropylene resin include a homopolymer of propylene or a random or block copolymer of propylene and a small amount of α-olefin and / or ethylene. When the polypropylene resin is a copolymer, in the case of a random copolymer, the copolymerization ratio of other α-olefin and / or ethylene in the copolymer is generally 10% by weight or less, preferably Is 0.5 to 7% by weight. In the case of a block copolymer, the copolymerization ratio of other α-olefin and / or ethylene in the copolymer is generally 1 to 40% by weight, preferably 1 to 25%. % By weight, more preferably 2 to 20% by weight, particularly preferably 3 to 15% by weight. These polypropylene polymers may be a mixture of two or more polymers. As an index of the crystallinity of polypropylene, for example, a melting point, a heat of crystal melting, and the like are used.

  The polypropylene-based resin can employ multistage polymerization by combining a gas phase polymerization method, a bulk polymerization method, a solvent polymerization method and any combination thereof, and there is no particular limitation on the number average molecular weight of the polymer, Preferably, it is adjusted to 10,000 to 1,000,000.

  As this crystalline polypropylene resin, MFR (melt flow rate) measured at a temperature of 230 ° C. and a load of 21.18 N in accordance with JIS K7210 is 0.5 to 20 g / 10 minutes, preferably 0.5 to 10 g / 10. Good range of minutes.

  The content of the hydrogenated styrene-conjugated diene block copolymer in the resin composition in the B layer is 40 to 90% by weight, preferably 50 to 80% by weight. The content of the polypropylene resin in the resin composition is 10 to 60% by weight, preferably 30 to 50% by weight. This range is preferable because the generation of resin-derived cutting waste (dicing waste) by the dicing blade can be effectively suppressed during dicing.

  The B layer may further contain an antistatic agent. Examples of the antistatic agent used in the B layer include those described in the A layer. The types of antistatic agents for the A layer and the B layer may be the same or different.

  When the B layer contains an antistatic agent, the content of the antistatic agent is 10 to 45 parts by weight with respect to 100 parts by weight of the resin composition comprising the polypropylene resin and a hydrogenated styrene-conjugated diene block copolymer. The amount is preferably about 15 to 30 parts by weight. Within such a range, semi-conductivity is effectively imparted without impairing the properties of the film of the present invention, so that the generated static electricity can be quickly eliminated.

C layer:
The thermoplastic resin having rubber elasticity used in the C layer is uniformly expanded in contact with the expanding ring. Examples of the thermoplastic resin having rubber elasticity include low-density polyethylene, medium-density polyethylene, linear low-density polyethylene which is an ethylene-α-olefin copolymer, or ultra-low-density polyethylene, and α-olefin is Propylene, butene-1, octene-1, 4methylpentene-1, hexene-1, octene-1 resin, styrene copolymer, ethylene-vinyl acetate copolymer (EVA), ethylene-methyl acrylate copolymer Copolymer (EMA), ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-methyl methacrylate copolymer (EMMA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl methacrylate copolymer And a mixture of these resins. Of these, EMA, EMAA or EMMA is preferable, and EMA is particularly preferable.

  The C layer contains the above-described thermoplastic resin having rubber elasticity as an essential component, but may further contain an antistatic agent. Examples of the antistatic agent used in the C layer include those described in the A layer. The types of antistatic agents for the A layer and the C layer may be the same or different.

When C layer contains an antistatic agent, content of an antistatic agent is 10-45 weight part with respect to 100 weight part of thermoplastic resins which have the said rubber elasticity, Preferably it is 15-30 weight part. Within such a range, the semi-conductivity is effectively imparted without impairing the slipperiness when uniformly expanded in contact with the expanding ring of the C layer, so that the generated static electricity can be quickly eliminated. . For example, the film of the present invention containing the antistatic agent in the above-described range is preferable because the surface resistivity of the back surface is about 10 ⁷ to 10 ¹² Ω / □.

  An antiblocking agent or the like may be further added to the C layer as long as the effect of the present invention is not adversely affected. By adding an anti-blocking agent, blocking such as when the substrate film for dicing is rolled up is preferably suppressed. Examples of the anti-blocking agent include inorganic or organic fine particles.

The thickness of each layer The substrate film for dicing may be thicker than the cutting depth of the dicing blade and can be easily wound in a roll shape, for example, 50 to 300 μm, preferably 60 It is -250 micrometers, More preferably, it is 70-200 micrometers.

  In the case where the substrate film for dicing has a structure of at least two layers including the A layer and the C layer, the ratio of the thickness of the A layer to the total thickness of the substrate film for dicing is usually 50 to 95%, preferably 50 to 80%. The ratio of the thickness of the C layer is usually 5 to 50%, preferably 10 to 30%.

  As a preferred specific example, when the total thickness of the substrate film for dicing is 130 to 170 μm, the thickness of the A layer is 75 to 140 μm, preferably 80 to 130 μm, more preferably 100 to 130 μm. Moreover, the thickness of C layer is 10-75 micrometers normally, Preferably it is 20-70 micrometers, More preferably, it is 20-50 micrometers.

  The thickness of the A layer needs to be thicker than the depth of the deepest part of the cutting of the dicing blade so that the cutting of the dicing blade does not reach the C layer. By providing the A layer having such a thickness, cutting scraps as a base film are hardly generated.

  In the case where the substrate film for dicing has at least three layers configured in the order of layer A, layer B and layer C, the ratio of the thickness of layer A + layer B to the total thickness of the substrate film for dicing is 50 to 95. %, Preferably 50 to 80%, and the ratio of the thicknesses of the A layer and the B layer is 1:60 to 1: 1, preferably 1:28 to 1: 2, more preferably 1:10 to 1: 3 is preferred. The ratio of the thickness of C layer is 5-50% normally, Preferably it is 10-30%.

  As a preferred specific example, when the total thickness of the substrate film for dicing is 130 to 170 μm, the thickness of the A layer is 5 to 40 μm, preferably 10 to 40 μm, more preferably 15 to 35 μm. The thickness of B layer is 70-100 micrometers, Preferably it is 70-90 micrometers, More preferably, it is 85-95 micrometers. The thickness of the C layer is 10 to 75 μm, preferably 20 to 70 μm, more preferably 20 to 50 μm.

The total thickness of the A layer and the B layer needs to be thicker than the depth of the deepest part of the dicing blade incision, so that the incision of the dicing blade does not reach the C layer. By providing the A layer and the B layer having such a thickness, cutting scraps as a base film are hardly generated.
II. Manufacturing method of substrate film for dicing The substrate film for dicing having at least two layers or at least three layers according to the present invention is obtained by co-extrusion molding of A layer and C layer resins or A layer, B layer and C layer resins, respectively. Manufactured.

  Specifically, the substrate film for dicing having at least two layers is a resin composition comprising 10 to 50% by weight of an acrylic resin and 50 to 90% by weight of a hydrogenated styrene-conjugated diene block copolymer. It is produced by multilayer coextrusion molding of a resin for layer C and a resin for layer C including a thermoplastic resin having rubber elasticity.

  A substrate film for dicing having at least three layers is a resin for layer A containing a resin composition comprising 10 to 50% by weight of acrylic resin and 50 to 90% by weight of hydrogenated styrene-conjugated diene block copolymer B layer resin containing a resin composition comprising 10 to 60% by weight of polypropylene resin and 40 to 90% by weight of hydrogenated styrene-conjugated diene block copolymer, and C layer containing a thermoplastic resin having rubber elasticity Is produced by multilayer coextrusion molding in this order.

  The resin for the A layer is prepared by dry blending or melt-kneading a predetermined ratio of an acrylic resin and a hydrogenated styrene-conjugated diene block copolymer. The B layer resin is prepared by dry blending or melt-kneading a predetermined proportion of a polypropylene resin and a hydrogenated styrene-conjugated diene block copolymer. The C layer resin is prepared from a thermoplastic resin having rubber elasticity. In addition, you may add other additives, such as an antistatic agent and a thermoplastic elastomer, to the resin which comprises each layer as needed.

  The above-mentioned resins for each layer are supplied to the screw type extruder in this order, extruded from a multilayer T die at 180 to 225 ° C., and cooled while passing through a cooling roll at 50 to 70 ° C. It is taken out without stretching. Alternatively, the resin for each layer may be once obtained as pellets and then extruded as described above.

The reason why the film is substantially unstretched at the time of taking is to effectively extend the film after dicing. This substantially non-stretching includes non-stretching or slight stretching that does not adversely affect the expansion of the dicing film. In general, the film may be pulled to such an extent that no sagging occurs during film take-up.
III. Dicing Film The substrate film for dicing obtained as described above is formed by coating a known acrylic pressure-sensitive adhesive on the film to form a pressure-sensitive adhesive layer, and if necessary, providing a release film on the acrylic pressure-sensitive adhesive layer. As a result, a dicing film is manufactured. That is, an acrylic pressure-sensitive adhesive layer and a release film are formed on the A layer of the substrate film for dicing.

  As the pressure-sensitive adhesive component used in the acrylic pressure-sensitive adhesive layer, known ones can be used. For example, the pressure-sensitive adhesive component described in JP-A No. 5-21234 can be used. A known release film is also used.

Specific examples of acrylic pressure-sensitive adhesives include acrylic polymers selected from homopolymers and copolymers having (meth) acrylic acid ester as the main constituent monomer unit, and other functional monomers And a mixture of these polymers. For example, (meth) acrylic acid ester includes ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, Glycidyl acrylate, 2-hydroxyethyl acrylate and the like can be preferably used. The molecular weight of the acrylic polymer is ^{1.0 × 10 5 ~10.0 × 10 5} , ^{preferably, 4.0 × 10 5 ~8.0 × 10} 5.

  Further, by including a radiation polymerizable compound in the pressure-sensitive adhesive layer as described above, the adhesive strength can be reduced by irradiating the pressure-sensitive adhesive layer with radiation after the wafer is cut and separated. As such a radiation polymerizable compound, for example, a low molecular weight compound having at least two photopolymerizable carbon-carbon double bonds in a molecule that can be three-dimensionally reticulated by light irradiation is widely used (for example, JP JP-A-60-196,956, JP-A-60-223,139, etc.).

  Specifically, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and the like are used.

  Furthermore, in addition to the acrylate compounds as described above, urethane acrylate oligomers can also be used as the radiation polymerizable compound. The urethane acrylate oligomer is obtained by reacting an acrylate or methacrylate having a hydroxyl group with a terminal isocyanate urethane prepolymer obtained by reacting a polyol compound such as a polyester type or a polyether type with a polyvalent isocyanate compound. This urethane acrylate oligomer is a radiation polymerizable compound having at least one carbon-carbon double bond.

  Further, in the pressure-sensitive adhesive layer, in addition to the above-mentioned pressure-sensitive adhesive and radiation-polymerizable compound, if necessary, a compound that is colored by radiation irradiation (such as a leuco dye), a light-scattering inorganic compound powder, abrasive grains (A particle size of about 0.5 to 100 μm), an isocyanate curing agent, a UV initiator, and the like can also be contained.

  The dicing film is usually obtained in a rolled state cut into a tape shape.

  In the dicing film of the present invention, adhesion to the acrylic pressure-sensitive adhesive is improved by adding an acrylic resin to the surface layer of the substrate film for dicing (the layer on which the pressure-sensitive adhesive layer is formed, that is, the A layer). Yes. Therefore, when the semiconductor chip is picked up, no adhesive remains on the chip side, and contamination of the semiconductor chip can be prevented.

  Hereinafter, the present invention will be described in more detail using Examples and Comparative Examples, but the present invention is not limited to these Examples. “%” Means% by weight, and “part” means part by weight.

In the examples and comparative examples, the following raw materials were used.
-Styrene-butadiene block copolymer hydrogenated product: MD6945 manufactured by Kraton Polymer Japan Co., Ltd.
・ Hydrogen 7311 made by Kuraray Co., Ltd.
Acrylic resin: Kuraray Co., Ltd. Parapet SA-1000-FR201
・ Polypropylene resin: PC412 manufactured by Sun Allomer Co., Ltd.
・ Ethylene-methyl acrylate copolymer: 9MA manufactured by Atofina Japan Co., Ltd.
-Hydrophilic PO resin-based antistatic agent: Pelestat 230 manufactured by Sanyo Chemical Co., Ltd.

Example 1
90% by weight of styrene-butadiene block copolymer hydrogenated product and 10% by weight of acrylic resin were dry blended to obtain a resin for layer A. Ethylene-methyl acrylate copolymer was used as the resin for the C layer.

The resin for the A layer and the resin for the C layer are respectively put into an extruder having a barrel temperature of 180 to 220 ° C., extruded from a multilayer T die at 230 ° C., and cooled and solidified with a take-up roll having a set temperature of 40 ° C. It wound up in the state.
The thickness of the obtained multilayer film was A layer 120 μm, C layer 30 μm, and overall thickness 150 μm. See Table 1.

Example 2-4
A multilayer film was obtained by processing in the same manner as in Example 1 with the blending amounts shown in Table 1. The thickness of each film is as shown in Table 1.

Example 5
90% by weight of a hydrogenated styrene-isoprene block copolymer and 10% by weight of an acrylic resin were dry blended to obtain a resin for layer A. Ethylene-methyl acrylate copolymer was used as the resin for the C layer.

  The resin for the A layer and the resin for the C layer are respectively put into an extruder having a barrel temperature of 180 to 220 ° C., extruded from a multilayer T die at 230 ° C., and cooled and solidified with a take-up roll having a set temperature of 40 ° C. It wound up in the state.

  The thickness of the obtained multilayer film was A layer 120 μm, C layer 30 μm, and overall thickness 150 μm. See Table 2.

Example 6-8
A multilayer film was obtained by processing in the same manner as in Example 1 with the blending amounts shown in Table 2. The thickness of each film is as shown in Table 2.

Example 9
45% by weight of styrene-butadiene block copolymer hydrogenated product, 45% by weight of styrene-isoprene block copolymer hydrogenated product and 10% by weight of acrylic resin were dry blended to obtain a resin for layer A. Ethylene-methyl acrylate copolymer was used as the resin for the C layer.

  The resin for the A layer and the resin for the C layer are respectively put into an extruder having a barrel temperature of 180 to 220 ° C., extruded from a multilayer T die at 230 ° C., and cooled and solidified with a take-up roll having a set temperature of 40 ° C. It wound up in the state.

  The thickness of the obtained multilayer film was A layer 120 μm, C layer 30 μm, and overall thickness 150 μm. See Table 3.

Examples 10-12
A multilayer film was obtained by processing in the same manner as in Example 1 with the blending amounts shown in Table 3. The thickness of each film is as shown in Table 3.

Example 13
A dry blend of 90% by weight of hydrogenated styrene-butadiene block copolymer and 10% by weight of acrylic resin was added, and 10 parts by weight of hydrophilic PO resin antistatic agent was added to 100 parts by weight of the blend. A layer resin was obtained. Ethylene-methyl acrylate copolymer was used as the resin for the C layer.

The resin for the A layer and the resin for the C layer are respectively put into an extruder having a barrel temperature of 180 to 220 ° C., extruded from a multilayer T die at 230 ° C., and cooled and solidified with a take-up roll having a set temperature of 40 ° C. It wound up in the state.
The thickness of the obtained multilayer film was A layer 120 μm, C layer 30 μm, and overall thickness 150 μm. See Table 4.

Example 14
A multilayer film was obtained by the same treatment as in Example 13 with the blending amounts shown in Table 4. Table 4 shows the thickness of each film.

Example 15
90% by weight of styrene-butadiene block copolymer hydrogenated product and 10% by weight of acrylic resin were dry blended to obtain a resin for layer A. A B-layer resin was prepared by blending 65% by weight of a styrene-butadiene block copolymer and 35% by weight of a polypropylene resin. Ethylene-methyl acrylate copolymer was used as the resin for the C layer.

  A layer resin, B layer resin and C layer resin are respectively put into an extruder having a barrel temperature of 180 to 220 ° C, extruded from a 230 ° C multilayer T die, and cooled and solidified by a take-up roll having a set temperature of 40 ° C. And wound up in an unstretched state.

  The thickness of the obtained multilayer film was A layer 20 μm, B layer 100 μm, C layer 30 μm, and overall thickness 150 μm. See Table 5.

Examples 16-18
A multilayer film was obtained by the same treatment as in Example 15 with the blending amounts shown in Table 5. The thickness of each film is as shown in Table 5.

Example 19
A dry blend of 90% by weight of hydrogenated styrene-butadiene block copolymer and 10% by weight of acrylic resin was added, and 10 parts by weight of hydrophilic PO resin antistatic agent was added to 100 parts by weight of the blend. A layer resin was obtained. A B-layer resin was prepared by blending 65% by weight of a styrene-butadiene block copolymer and 35% by weight of a polypropylene resin. Ethylene-methyl acrylate copolymer was used as the resin for the C layer.

A layer resin, B layer resin and C layer resin are respectively put into an extruder having a barrel temperature of 180 to 220 ° C, extruded from a 230 ° C multilayer T die, and cooled and solidified by a take-up roll having a set temperature of 40 ° C. And wound up in an unstretched state.
The thickness of the obtained multilayer film was A layer 30 μm, B layer 90 μm, C layer 30 μm, and overall thickness 150 μm. See Table 6.

Example 20
A multilayer film was obtained by the same treatment as in Example 19 with the blending amounts shown in Table 6. Table 6 shows the thickness of each film.

Comparative Example 1
A multilayer film was obtained in the same manner as in Example 1 except that 95% by weight of a hydrogenated styrene-butadiene block copolymer and 5% by weight of an acrylic resin were dry blended to obtain a resin for layer A.

  The thickness of the obtained multilayer film was A layer 120 μm, C layer 30 μm, and overall thickness 150 μm. See Table 7.

Comparative Example 2
A multilayer film was obtained in the same manner as in Example 1 except that 40% by weight of styrene-butadiene block copolymer hydrogenated product and 60% by weight of acrylic resin were dry blended to obtain a resin for layer A.

  The thickness of the obtained multilayer film was A layer 120 μm, C layer 30 μm, and overall thickness 150 μm. See Table 7.

Test Example 1 (Evaluation method for cutting waste)
A part of the multilayer film obtained in Examples 1 to 20 and Comparative Examples 1 and 2 was cut into a circle having a diameter of 180 mm to obtain a measurement sample, and a grinding apparatus (AUTOMATIC DICING SAW DAD- manufactured by DISCO Corporation) was used. 2H / 6), cut into the base film under the following conditions, then remove the sample from the grinding machine and let it dry at room temperature in a clean booth for 24 hours, then digital microscope manufactured by Keyence Corporation (VHX) -100), the presence or absence of cutting waste was evaluated at a magnification of 150 times.

The surface of the sample was arbitrarily observed at 10 locations, and “◯” was given when there was no cutting waste, and “X” was given when it was recognized that there was even a small amount of cutting waste. The results are summarized in Table 8.
(Cutting conditions)
Rotation speed: 30000rpm
Speed: 80mm / sec
Cut mode: Full-auto dicing of 10mm □ Cut depth: 100μm
Blade: Disco B1A801 SDC 400N50M51 (outer diameter 56mm x thickness 0.2mm x inner diameter 40mm)
Water volume: 1.2L / min

Test Example 2 (Adhesive evaluation method)
Acrylic adhesive was applied to the thickness of 10 μm on the surface of layer A of the multilayer films obtained in Examples 1 to 20 and Comparative Examples 1 and 2, and a polyimide sheet with a thickness of 100 μm was pasted thereon. A sample for measurement was cut into a circle having a diameter of 180 mm. This sample was set in a grinding machine (AUTOMATIC DICING SAW DAD-2H / 6 manufactured by DISCO Corporation), and cut from the polyimide sheet side under the following conditions.
(Cutting conditions)
Rotation speed: 30000rpm
Speed: 80mm / sec
Cut mode: Full auto dicing of 3mm □ Cut depth: 150μm
Blade: Disco B1A801 SDC 400N50M51 (outer diameter 56mm x thickness 0.2mm x inner diameter 40mm)
Water volume: 1.2L / min

  Next, the sample was removed from the grinding apparatus, and the polyimide sheets cut to 3 mm × 3 mm were peeled one by one, and it was visually confirmed whether or not the acrylic adhesive was attached to the 900 polyimide sheet side. Among the 900 pieces of polyimide sheets, those having an acrylic adhesive on the polyimide sheet side were designated as “◯” for 29 pieces or less, and “x” for 30 pieces or more. The results are summarized in Table 8.

Claims (12)

A substrate film for dicing composed of at least two layers formed by laminating an A layer and a C layer, wherein the A layer is 10 to 50% by weight of an acrylic resin and 50 to 90% by weight of a styrene-conjugated diene block copolymer hydrogenated product. %, And the C layer comprises a thermoplastic resin having rubber elasticity. The layer A further comprises 10 to 45 parts by weight of an antistatic agent with respect to 100 parts by weight of a resin composition comprising the acrylic resin and a hydrogenated styrene-conjugated diene block copolymer. Base film for dicing. The substrate film for dicing according to claim 1 or 2, wherein the C layer further comprises 10 to 45 parts by weight of an antistatic agent with respect to 100 parts by weight of the thermoplastic resin having rubber elasticity.   The dicing substrate film according to claim 1, 2 or 3, wherein the total thickness of the dicing substrate film is 50 to 300 µm, and the thickness of the layer A is 50 to 95% with respect to the total thickness of the dicing substrate film. Base film. A substrate film for dicing composed of at least three layers formed by laminating an A layer, a B layer and a C layer in this order, wherein the A layer comprises 10 to 50% by weight of an acrylic resin and a hydrogenated styrene-conjugated diene block copolymer The layer B contains a resin composition consisting of 10 to 60% by weight of a polypropylene resin and 40 to 90% by weight of a hydrogenated styrene-conjugated diene block copolymer. , C layer is a substrate film for dicing, comprising a thermoplastic resin having rubber elasticity. The layer A further comprises 10 to 45 parts by weight of an antistatic agent with respect to 100 parts by weight of a resin composition comprising the acrylic resin and a hydrogenated styrene-conjugated diene block copolymer. Base film for dicing. The layer B further comprises 10 to 45 parts by weight of an antistatic agent with respect to 100 parts by weight of a resin composition comprising the polypropylene resin and a hydrogenated styrene-conjugated diene block copolymer. Base film for dicing. The substrate film for dicing according to claim 5, 6 or 7, wherein the C layer further comprises 10 to 45 parts by weight of an antistatic agent with respect to 100 parts by weight of the thermoplastic resin having rubber elasticity.   9. The total thickness of the substrate film for dicing is 50 to 300 μm, and the thickness of layer A + B is 50 to 95% with respect to the total thickness of the substrate film for dicing. Substrate film for dicing.   A dicing film further comprising an acrylic pressure-sensitive adhesive layer on the A layer of the substrate film for dicing according to any one of claims 1 to 9. A method for producing a substrate film for dicing having at least two layers, comprising a resin composition comprising 10 to 50% by weight of an acrylic resin and 50 to 90% by weight of a hydrogenated styrene-conjugated diene block copolymer A production method comprising multilayer coextrusion molding of a resin for layer C and a resin for layer C containing a thermoplastic resin having rubber elasticity. A method for producing a substrate film for dicing having at least three layers, comprising a resin composition comprising 10 to 50% by weight of an acrylic resin and 50 to 90% by weight of a hydrogenated styrene-conjugated diene block copolymer A resin for a layer, a resin for a B layer containing a resin composition comprising 10 to 60% by weight of a polypropylene resin and 40 to 90% by weight of a hydrogenated styrene-conjugated diene block copolymer, and a thermoplastic resin having rubber elasticity The manufacturing method characterized by carrying out multilayer coextrusion molding of the resin for C layers containing in this order.