Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
  • C09J175/04—Polyurethanes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2301/00—Additional features of adhesives in the form of films or foils
  • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
  • C09J2301/312—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier parameters being the characterizing feature

Definitions

• the present invention relates to a dicing sheet used when dicing a mold package such as a semiconductor package in which a plurality of chip-like components such as semiconductor chips are sealed with a resin. Moreover, this invention relates to the manufacturing method of said dicing sheet, and the manufacturing method of a mold chip using said dicing sheet.
• a component in which a chip-shaped component such as a semiconductor chip is resin-sealed (referred to as a “mold chip” in this specification) is usually as follows when the chip-shaped component to be sealed is a semiconductor chip. In this way, it is manufactured.
• a semiconductor chip is mounted on each base of an assembly formed by connecting a plurality of bases such as a TAB tape, and these semiconductor chips are collectively sealed with an electronic component assembly (this specification) (Referred to as “semiconductor package”).
• the semiconductor package is fixed to the dicing sheet by attaching an adhesive sheet (referred to as a “dicing sheet” in this specification) including a base material and an adhesive layer on one surface of the semiconductor package. .
• the semiconductor package fixed to the dicing sheet is cut and separated (diced) into individual pieces, and a member in which a plurality of mold chips are arranged close to each other on the dicing sheet is manufactured (dicing step).
• the pressure-sensitive adhesive layer of the dicing sheet is designed so that the adhesiveness of the pressure-sensitive adhesive layer with respect to the adherend surface is reduced by a specific stimulus, and for example, energy ray irradiation is adopted as the specific stimulus. And the process of irradiating an energy beam to a dicing sheet before the following processes are performed, and reducing the adhesiveness of the adhesive layer with respect to a to-be-adhered surface is included.
• the dicing sheet in this member is expanded (extends in the main surface direction) to widen the interval between the mold chips arranged on the dicing sheet (expanding process).
• the mold chips thus separated from each other on the dicing sheet are individually picked up and separated from the dicing sheet (pickup process), and transferred to the next process. At this time, picking up is facilitated by including a step of reducing the adhesiveness of the adhesive layer to the surface of the mold chip.
• the dicing step it is required that the semiconductor package and the mold chip formed by dicing the semiconductor package be kept fixed on the dicing sheet. From the viewpoint of achieving this object, it is preferable that the pressure-sensitive adhesive layer of the dicing sheet has high adhesiveness to the semiconductor package surface and the mold chip surface before energy beam irradiation.
• the adherend of the dicing sheet is a semiconductor package
• the adherend surface is usually a sealing resin surface
• the unevenness of the adherend surface is larger than when the semiconductor wafer is the adherend. Tend to be.
• a dicing sheet having a semiconductor wafer as an adherend is diverted as a dicing sheet used in the above process for a semiconductor package, the above adhesiveness to the adherend surface becomes insufficient, and the semiconductor package is cut in the dicing process.
• the mold chip formed as a semiconductor package is separated from the dicing sheet and scattered.
• this defect that occurs in the dicing process is referred to as “chip scattering”.
• the adhesive layer of the dicing sheet is improved in adhesion to the adherend surface in the state before energy beam irradiation.
• a resin material referred to as “tackifying resin” in the present specification
• a general rosin-based material as a tackifying resin is a preferable material from the viewpoint of improving the adhesiveness to the adhesion surface of the pressure-sensitive adhesive layer, that is, the resin sealing surface of the mold package.
• the resin sealing surface has a printing part defined by a recess formed by removing the resin material by laser processing or the like, the following problem may occur. That is, by including a tackifying resin in the pressure-sensitive adhesive layer provided in the dicing sheet, it is possible to achieve an improvement in adhesiveness to a relatively large uneven surface such as a resin-sealed surface, but the resin-sealed surface is When it has a printing part, the material which comprises an adhesive layer tends to enter in the recessed part of a printing part.
• the material constituting the pressure-sensitive adhesive layer remains in the concave portion of the printing portion, and the visibility of printing is reduced.
• the resin sealing surface is generally larger in unevenness than the semiconductor wafer or the protective film, when printing is performed by forming a recess in the resin sealing surface, the unevenness of the unevenness tends to increase. For this reason, it is easy to produce the problem of the visibility reduction of said printing.
• An object of the present invention is to provide a dicing sheet that is less likely to cause problems in the dicing process and problems related to print visibility in the above-described mold chip, and to provide a method for manufacturing a mold chip using the dicing sheet.
• a dicing sheet comprising a base material and an adhesive layer laminated on at least one surface of the base material, and the storage elastic modulus at 23 ° C. of the adhesive layer is irradiated with energy rays.
• the thickness of the pressure-sensitive adhesive layer is less than 20 ⁇ m, and the surface of the pressure-sensitive adhesive layer is In the state before irradiating the energy beam, the amount of energy measured using the probe tack in the method described in JIS Z0237: 1991 with the peeling speed changed to 1 mm / min is 0.10 mJ / 5 mm ⁇ .
• the dicing sheet is characterized by being 0.8 mJ / 5 mm ⁇ or less.
• a resin sealing surface of a mold package is affixed to a surface of the pressure-sensitive adhesive layer opposite to the base material side, and the resin sealing surface has a printing portion formed by a recess, The dicing sheet according to (1) above.
• the pressure-sensitive adhesive layer contains an acrylic polymer (A) having an energy ray polymerizable group and a reactive functional group, and an isocyanate crosslinking agent (B) capable of a crosslinking reaction with the reactive functional group.
• the acrylic polymer (A) is composed of an acrylic polymer (A1) having the reactive functional group and an isocyanate compound having the energy ray polymerizable group.
• (A2) is obtained by reacting in the presence of an organometallic catalyst (C) containing at least one of titanium and zirconium, according to any one of (1) to (3) above Dicing sheet.
• the mass ratio of the monomer (m1) that gives the structural unit having the reactive functional group in the acrylic polymer (A1) to the whole monomer that gives the acrylic polymer (A1) is:
• the amount of the compound (A2) used is 0.4% relative to the monomer (m1).
• the dicing sheet according to the above (4) which is not less than the equivalent and not more than 0.8 equivalent.
• a dicing sheet that is less likely to cause problems in the dicing process and the above-described problems related to the print visibility in the mold chip.
• a dicing sheet by using such a dicing sheet, it is possible to produce a mold chip that is excellent in print visibility and excellent in quality and cost.
• the dicing sheet which concerns on one Embodiment of this invention is equipped with a base material and an adhesive layer.
• the base material of the dicing sheet according to the present embodiment is not particularly limited as long as it is not broken in the pick-up process or the like, and is usually composed of a film mainly composed of a resin-based material. Is done.
• Specific examples of the film include polyethylene films such as low density polyethylene (LDPE) film, linear low density polyethylene (LLDPE) film, and high density polyethylene (HDPE) film, polypropylene film, polybutene film, polybutadiene film, and polymethylpentene film.
• Polyolefin films such as ethylene-norbornene copolymer film and norbornene resin film; polyvinyl chloride films such as polyvinyl chloride film and vinyl chloride copolymer film; polyester films such as polyethylene terephthalate film and polybutylene terephthalate film Polyurethane film; polyimide film; ionomer resin film; ethylene-vinyl acetate copolymer film; ) Ethylene copolymer films such as acrylic acid copolymer films and ethylene- (meth) acrylic acid ester copolymer films; polystyrene films, polycarbonate films; fluororesin films; and water additives and modified products of these resins Examples include films as main materials.
• the above substrate may be a single type, or may be a laminated film in which two or more types are combined.
• (meth) acrylic acid in the present specification means both acrylic acid and methacrylic acid. The same applies to other similar terms.
• the base material may contain various additives such as a colorant, a flame retardant, a plasticizer, an antistatic agent, a lubricant, and a filler in a film mainly composed of the resin-based material.
• the colorant include pigments such as titanium dioxide and carbon black, and various dyes.
• 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 such an additive is not particularly limited, but should be within a range where the substrate exhibits a desired function and does not lose desired smoothness and flexibility.
• the substrate has transparency to the ultraviolet rays.
• a base material has the transparency of an electron beam.
• the thickness of the base material is not limited as long as the dicing sheet can function properly in each of the aforementioned steps.
• the thickness is preferably 20 to 450 ⁇ m, more preferably 25 to 200 ⁇ m, and particularly preferably 50 to 150 ⁇ m.
• the breaking elongation of the base material in this embodiment is preferably 100% or more as a value measured at 23 ° C. and a relative humidity of 50%, particularly preferably 200% or more and 1000% or less.
• the base material having a breaking elongation of 100% or more is not easily broken even when the expanding step is performed, and the mold chip formed by cutting the mold package is easily separated.
• the elongation at break is the rate of elongation relative to the original length of the test piece when the test piece is broken in a tensile test based on JIS K7161: 1994.
• the tensile stress at 25% strain measured by a test based on JIS K7161: 1994 of the base material in the present embodiment is preferably 5 N / 10 mm or more and 15 N / 10 mm or less, and the maximum tensile stress is 15 MPa or more and 50 MPa or less. It is preferable that If the tensile stress at 25% strain is less than 5 N / 10 mm or the maximum tensile stress is less than 15 MPa, the base material is soft when the mold package is attached to the dicing sheet and then fixed to the ring frame. Looseness may occur and cause a conveyance error.
• the load applied to the dicing sheet increases when the expanding process is performed. May cause problems such as peeling off.
• the elongation at break, tensile stress at 25% strain, and maximum tensile stress in the present invention refer to values measured in the longitudinal direction of the substrate.
• the pressure-sensitive adhesive layer provided in the dicing sheet according to the present embodiment has a thickness of less than 20 ⁇ m and has predetermined characteristics such as storage elastic modulus, as will be described below.
• the pressure-sensitive adhesive layer comprises an acrylic polymer (A) having an energy ray polymerizable group and a reactive functional group, and an isocyanate crosslinking agent (B) capable of a crosslinking reaction with the reactive functional group. It is formed from the adhesive composition to contain.
• the thickness of the pressure-sensitive adhesive layer provided in the dicing sheet according to this embodiment is less than 20 ⁇ m.
• the thickness of the pressure-sensitive adhesive layer is less than 20 ⁇ m, it is difficult for adhesive residue to occur, and the possibility of problems occurring in the dicing process is reduced. Further, it is difficult to cause a problem regarding the print visibility in the above-described mold chip.
• the mold package is separated into mold chips, and when the period until irradiation with energy rays is long (for example, 30 days), the thickness of the adhesive layer is 20 ⁇ m.
• the adhesiveness of the pressure-sensitive adhesive layer to the surface of the mold chip becomes excessively high, and the adhesiveness is not appropriately reduced even when irradiated with energy rays, and the above-mentioned mold chip relates to the print visibility. Problems can easily occur.
• the thickness of the pressure-sensitive adhesive layer is less than 20 ⁇ m, it is difficult to cause such a problem regarding the print visibility in the above-described mold chip.
• the thickness of the pressure-sensitive adhesive layer included in the dicing sheet according to this embodiment is preferably 17 ⁇ m or less, more preferably 13 ⁇ m or less, and particularly preferably 10 ⁇ m or less.
• the thickness of the pressure-sensitive adhesive layer is preferably 2 ⁇ m or more, more preferably 4 ⁇ m or more, The thickness is particularly preferably 5 ⁇ m or more. Therefore, the most preferable thickness of the pressure-sensitive adhesive layer is 5 ⁇ m or more and 10 ⁇ m or less.
• the material constituting the pressure-sensitive adhesive layer before irradiation with energy rays is less likely to enter the recesses of the sealing resin surface of the mold package, which is the surface to which the pressure-sensitive adhesive layer is attached
• the above-described problems regarding the print visibility in the mold chip are less likely to occur.
• the elasticity modulus before irradiation exists in said range, the adhesiveness with respect to the to-be-adhered surface of an adhesive layer becomes suitable, and it becomes difficult to produce chip
• the pre-irradiation elastic modulus is preferably 50 kPa to 75 kPa, and preferably 50 kPa to 70 kPa. Is more preferable.
• the storage elastic modulus at 23 ° C. (also referred to as “post-irradiation elastic modulus” in the present specification) of the pressure-sensitive adhesive layer after the energy layer is irradiated to the pressure-sensitive adhesive layer included in the dicing sheet according to the present embodiment is as follows. It is 5.0 MPa or more and 120 MPa or less.
• the post-irradiation elastic modulus is 5.0 MPa or more, in the concave portion of the sealing resin surface of the mold package, which is the adhesion surface of the pressure-sensitive adhesive layer, particularly in the concave portion constituting the printing portion, The material constituting the pressure-sensitive adhesive layer is less likely to remain, and the above-described problem regarding the print visibility in the mold chip is less likely to occur.
• the post-irradiation elastic modulus is preferably 10 MPa or more, more preferably 15 MPa or more, and 20 MPa or more. It is particularly preferred.
• the post-irradiation elastic modulus is 120 MPa or less
• the pressure-sensitive adhesive layer is formed in the concave portion of the surface of the sealing resin of the mold package, which is the adhesion surface of the pressure-sensitive adhesive layer, particularly in the concave portion constituting the printing portion.
• the material is likely to be appropriately separated from the recess in the pickup process. For this reason, the problem regarding the print visibility in the above-mentioned mold chip hardly occurs.
• the post-irradiation elastic modulus is preferably 100 MPa or less, more preferably 80 MPa or less, and 60 MPa or less. More preferably, it is particularly preferably 50 MPa or less.
• Tack value The surface of the pressure-sensitive adhesive layer of the dicing sheet according to the present embodiment is a state described in JIS Z0237: 1991 in a state before being irradiated with an energy ray.
• This tack value is obtained as an integrated value of peaks measured from the start of measurement until the probe peels. When the tack value is in the above range, occurrence of chip scattering can be suppressed.
• the tack value is preferably 0.13 mJ / 5 mm ⁇ or more and 0.75 mJ / 5 mm ⁇ or less, preferably 0.15 mJ / 5 mm ⁇ or more and 0.7 mJ / 5 mm ⁇ or less. More preferably, it is 0.18 mJ / 5 mm ⁇ or more and 0.65 mJ / 5 mm ⁇ or less.
• the adhesive composition for forming the adhesive layer with which the dicing sheet which concerns on this embodiment is equipped contains the acrylic polymer (A) which has an energy-beam polymeric group and a reactive functional group in one preferable form.
• the acrylic polymer (A) is an acrylic polymer containing a structural unit based on an acrylic compound having an energy ray polymerizable group and a reactive functional group as a unit constituting its skeleton.
• the acrylic polymer (A) may be a homopolymer obtained by polymerizing one kind of monomer, or may be a copolymer obtained by polymerizing plural kinds of monomers. From the viewpoint of easily controlling the physical characteristics and chemical characteristics of the polymer, the acrylic polymer (A) is preferably a copolymer.
• the acrylic polymer (A) preferably has a weight average molecular weight (Mw) in terms of polystyrene of 10,000 to 2,000,000.
• Mw weight average molecular weight
• Such an acrylic polymer (A) causes an effect of maintaining the cohesiveness of the pressure-sensitive adhesive layer, which is a general function of the pressure-sensitive adhesive main agent. Such an effect is more exhibited as the molecular weight is higher.
• the polystyrene-based weight average molecular weight (Mw) of the acrylic polymer (A) is more preferably 100,000 to 1,500,000.
• the glass transition temperature Tg of the acrylic polymer (A) is preferably in the range of ⁇ 70 to 30 ° C., more preferably in the range of ⁇ 60 to 20 ° C.
• the polystyrene conversion weight average molecular weight in this specification is a polystyrene conversion value measured by gel permeation chromatography (GPC) method.
• the reactive functional group possessed by the acrylic polymer (A) is a functional group capable of undergoing a crosslinking reaction with the isocyanate crosslinking agent (B) described later, and examples thereof include a hydroxyl group, a carboxyl group, and an amino group. Among these, a hydroxyl group having high reactivity with the isocyanate group related to the isocyanate-based crosslinking agent (B) is preferable as the reactive functional group of the acrylic polymer (A).
• the kind of energy ray polymerizable group which the acrylic polymer (A) has is not particularly limited. Specific examples thereof include a functional group having an ethylenically unsaturated bond such as a vinyl group or a (meth) acryloyl group. From the viewpoint of excellent polymerization reactivity, the energy ray polymerizable group is preferably a functional group having an ethylenically unsaturated bond, and among them, from the viewpoint of high reactivity when irradiated with energy rays (meta) An acryloyl group is more preferred.
• Examples of the energy beam for reacting the energy beam polymerizable group include ionizing radiation, that is, X-rays, ultraviolet rays, and electron beams. Among these, ultraviolet rays that are relatively easy to introduce irradiation equipment are preferable.
• near ultraviolet rays including ultraviolet rays having a wavelength of about 200 to 380 nm may be used for ease of handling.
• the amount of ultraviolet rays may be appropriately set according to the type of energy beam polymerizable group of the acrylic polymer (A) and the thickness of the pressure-sensitive adhesive layer, and is usually about 50 to 500 mJ / cm 2 , 450 mJ / cm 2 is preferable, and 150 to 400 mJ / cm 2 is more preferable.
• the ultraviolet illumination is usually 50 ⁇ 500mW / cm 2 or so, preferably 100 ⁇ 450mW / cm 2, more preferably 150 ⁇ 400mW / cm 2.
• an ultraviolet-ray source For example, a high pressure mercury lamp, a metal halide lamp, etc. are used.
• the accelerating voltage may be appropriately set according to the type of energy beam polymerizable group of the acrylic polymer (A) and the thickness of the pressure-sensitive adhesive layer.
• the acceleration voltage is preferably about 10 to 1000 kV.
• the irradiation dose may be set in a range in which the reaction of the energy beam polymerizable group of the acrylic polymer (A) proceeds appropriately, and is usually selected in the range of 10 to 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.
• 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.
• the acrylic polymer (A) is an organic polymer in which the acrylic polymer (A1) having a reactive functional group and the isocyanate compound (A2) having an energy ray polymerizable group contain at least one of titanium and zirconium. It was obtained by reacting in the presence of the metal catalyst (C). By reacting in the presence of such an organometallic catalyst (C), the resulting pressure-sensitive adhesive composition containing the acrylic polymer (A) has an appropriate pre-irradiation elastic modulus and an appropriate tack value. An adhesive layer can be formed.
• the acrylic polymer (A1) is an acrylic polymer having the aforementioned reactive functional group.
• the mass ratio of the monomer (m1) that provides the structural unit having a reactive functional group in the acrylic polymer (A1) to the whole monomer that provides the acrylic polymer (A1) is 5% by mass or more and 30% by mass. % Or less is preferable.
• the pressure-sensitive adhesive composition containing the acrylic polymer (A) obtained from the acrylic polymer (A1) by satisfying the above-mentioned regulations regarding the mass ratio has an appropriate pre-irradiation elastic modulus and an appropriate tack value. It becomes possible to form the adhesive layer which has.
• the mass ratio is preferably 7% by mass or more and 25% by mass or less, more preferably 10% by mass or more and 20% by mass or less, and particularly preferably 12% by mass or more and 17% by mass or less.
• the monomer for forming the acrylic polymer (A1) will be described by taking as an example the case where the acrylic polymer (A1) has a hydroxyl group as a reactive functional group.
• An acrylic monomer having a hydroxyl group as a monomer (also referred to as “raw material monomer” in the present specification) that can be a raw material for forming the acrylic polymer (A1) having a hydroxyl group as described above. (Referred to herein as “hydroxyacrylic monomer”), non-acrylic monomers having a hydroxyl group, acrylic monomers having no hydroxyl group, and non-acrylic monomers having no hydroxyl group. .
• the acrylic polymer (A1) having a hydroxyl group is a hydroxy acrylic monomer and an acrylic monomer having no hydroxyl group so that the polymer becomes an acrylic polymer among the above raw material monomers.
• the hydroxyacrylic monomer examples include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (meth) acrylate having a hydroxyl group such as N-methylolacrylamide.
• hydroxy vinyl acetate etc. are mentioned as a specific example of the non-acrylic monomer which has a hydroxyl group.
• the acrylic polymer having a hydroxyl group preferably includes a structural unit derived from a hydroxyacrylic monomer.
• the monomer having a hydroxyl group is preferably a monomer having only one hydroxyl group from the viewpoint that it is easy to control the amount of the energy ray polymerizable group in the acrylic polymer (A).
• acrylic monomers having no hydroxyl group include (meth) acrylic acid, (meth) acrylic acid esters, and derivatives thereof (acrylonitrile, etc.).
• Specific examples of (meth) acrylic acid esters include chain skeletons such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.
• (Meth) acrylates having the following: cycloalkyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) ) (Meth) acrylates having a cyclic skeleton such as acrylate, tetrahydrofurfuryl (meth) acrylate, imide acrylate, etc .; water such as glycidyl (meth) acrylate, N-methylaminoethyl (meth) acrylate And (meth) acrylates having a reactive functional group other than groups.
• the acrylic monomer having no hydroxyl group is alkyl (meth) acrylate
• the alkyl group preferably has 1 to 18 carbon atoms.
• the non-acrylic monomer having no hydroxyl group include olefins such as ethylene and norbornene, vinyl acetate, and styrene.
• the isocyanate compound (A2) is a compound that has an energy ray polymerizable group and can have an isocyanate group upon reaction with the reactive functional group of the acrylic polymer (A1).
• isocyanate compounds include compounds having an isocyanate group, compounds having a blocked isocyanate group, biurets and isocyanurates of compounds having an isocyanate group, compounds having an isocyanate group, ethylene glycol, trimethylolpropane, castor oil, and the like.
• Examples include modified products such as adducts that are reaction products with non-aromatic low-molecular active hydrogen-containing compounds.
• the isocyanate compound (A2) include (meth) acryloyloxyethyl isocyanate.
• a reaction product of (meth) acrylate in which at least one hydroxyl group remains and a polyisocyanate compound is also given as a specific example of the isocyanate compound (A2).
• an isocyanate compound having only one energy beam polymerizable group is preferable in that it is easy to control the amount of the energy beam polymerizable group in the acrylic polymer (A), and (meth) More preferred is acryloyloxyethyl isocyanate.
• the amount of the compound (A2) used is 0.4 equivalents or more and 0.8 or more with respect to the monomer (m1) related to the acrylic polymer (A). It is preferable that it is below an equivalent.
• regulation regarding the usage-amount of said compound (A2) the adhesive composition containing the acrylic polymer (A1) obtained from the acrylic polymer (A1) and the compound (A2) is thereby It can be avoided that the obtained pressure-sensitive adhesive layer is excessively cured after irradiation with energy rays or that the adhesiveness to the adherend surface is not sufficiently reduced by irradiation with energy rays.
• the amount of the compound (A2) used relative to the monomer (m1) is preferably 0.4 equivalents or more and 0.75 equivalents or less, and more preferably 0.45 equivalents or more and 0.7 equivalents or less. It is particularly preferably 0.5 equivalents or more and 0.7 equivalents or less.
• Isocyanate-based crosslinking agent (B) is a general term for polyisocyanate compounds having crosslinkability.
• Specific examples include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate; dicyclohexylmethane-4,4′-diisocyanate, bicycloheptane triisocyanate, cyclopentylene diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate.
• Cycloaliphatic isocyanate compounds such as hydrogenated xylylene diisocyanate; acyclic aliphatic isocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, and their biuret and isocyanurate bodies, compounds having isocyanate groups, and ethylene Non-aromatic small molecules such as glycol, trimethylolpropane and castor oil Examples include modified products such as adducts that are reaction products with active hydrogen-containing compounds.
• the compound that functions as the isocyanate-based crosslinking agent (B) in the pressure-sensitive adhesive composition may be one type or a plurality of types.
• the content of the isocyanate-based crosslinking agent (B) in the pressure-sensitive adhesive composition is not limited. It sets suitably according to the kind of isocyanate type crosslinking agent (B). As an illustration which is not limited, 0.01 mass% or more and 10 mass% or less are preferred, 0.05 mass% or more and 7 mass% or less are more preferred, and 0.1 mass% or more and 3 mass% to the whole adhesive composition. The following are particularly preferred:
• Organometallic catalyst (C) contains at least one of titanium and zirconium. Specifically, it consists of an organometallic compound containing at least one of titanium and zirconium. Examples of such organometallic compounds include alkoxides, chelates, and acylates of these metal elements, and specific examples include titanium alkoxides, titanium chelates, zirconium alkoxides, and zirconium chelates. Among these, the metal element contained in the organometallic compound preferably contains zirconium, and the metal element is preferably zirconium. The organometallic compound is preferably a chelate compound. Therefore, the organometallic catalyst (C) preferably contains a zirconium-containing chelate compound, and more preferably consists of a zirconium-containing chelate compound.
• the organometallic catalyst (C) does not contain a tin-containing organometallic compound. The reason is not clear, but when the pressure-sensitive adhesive composition does not contain the organometallic catalyst (C) containing a tin-containing organometallic compound, it is easy to form a pressure-sensitive adhesive layer having an appropriate pre-irradiation elastic modulus and an appropriate tack value. Become.
• the amount of the organometallic catalyst (C) used in the reaction for obtaining the acrylic polymer (A) is not limited.
• the amount used is preferably 0.01 parts by mass or more and 0.5 parts by mass or less, and 0.01 parts by mass or more and 0.3 parts by mass or less with respect to 100 parts by mass of the solid content of the acrylic polymer (A1). More preferred is 0.01 part by mass or more and 0.25 part by mass or less.
• the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer provided in the dicing sheet according to the present embodiment comprises a photopolymerization initiator (D), a tackifier resin, You may contain various additives, such as coloring materials, such as dye and a pigment, a flame retardant, a filler, and an antistatic agent.
• the photopolymerization initiator (D) will be described in some detail.
• the photopolymerization initiator (D) 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.
• the irradiation time and irradiation amount can be reduced by blending the photopolymerization initiator (D).
• the pressure-sensitive adhesive layer provided in the dicing sheet according to an embodiment of the present invention comprises an acrylic polymer (A) having an energy ray polymerizable group and a reactive functional group, and
• the pressure-sensitive adhesive composition is formed from a pressure-sensitive adhesive composition containing an isocyanate-based crosslinking agent (B) capable of crosslinking reaction with a reactive functional group
• the method for producing the pressure-sensitive adhesive composition is not limited. It is preferable to manufacture by the method demonstrated below.
• an acrylic polymer (A1) and an isocyanate compound (A2) are reacted in the presence of an organometallic catalyst (C) to produce an acrylic polymer (A) and an organometallic catalyst (C
• an organometallic catalyst (C) to produce an acrylic polymer (A) and an organometallic catalyst (C
• a product comprising components based on A suitable solvent may be used in the above reaction.
• the reaction conditions for the reaction in the first step are appropriately set according to the types and contents of the acrylic polymer (A1), the isocyanate compound (A2) and the organometallic catalyst (C) which are reaction raw materials.
• the component based on the organometallic catalyst (C) preferably maintains catalytic activity.
• an organometallic catalyst (A) is used as a catalyst for the reaction between the acrylic polymer (A) and the isocyanate-based crosslinking agent (B) that is generated when the pressure-sensitive adhesive layer is formed from the pressure-sensitive adhesive composition.
• Components based on C) can function.
• a mixture containing the product of the first step, the isocyanate-based crosslinking agent (B), and the photopolymerization initiator (D) as necessary is used as an adhesive composition.
• the product of the first step includes the acrylic polymer (A)
• the product may have undergone a process such as solvent removal.
• the mixing method is not limited, and may be set as appropriate so that the uniformity of the mixture is increased.
• the dicing sheet according to the present embodiment protects the adhesive layer until the adhesive layer is attached to a mold package (a semiconductor package is a specific example) that is an adherend.
• the release surface of the release sheet may be bonded to the surface of the pressure-sensitive adhesive layer opposite to the side facing the substrate.
• the configuration of the release sheet is arbitrary, and examples include a plastic film coated with a release agent.
• 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.
• 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.
• a paper base such as glassine paper, coated paper, and high-quality paper, or a laminated paper obtained by laminating a thermoplastic resin such as polyethylene on a paper base may be used.
• a thermoplastic resin such as polyethylene on a paper base
• the manufacturing method of the manufacturing method of the dicing sheet which concerns on one Embodiment of this invention is not limited.
• the pressure-sensitive adhesive layer included in the dicing sheet according to an embodiment of the present invention includes an acrylic polymer (A) having an energy ray polymerizable group and a reactive functional group, and an isocyanate type capable of a crosslinking reaction with the reactive functional group.
• A acrylic polymer
• B crosslinking agent
• a detailed method is possible as long as the pressure-sensitive adhesive layer formed from the above-mentioned pressure-sensitive adhesive composition can be laminated on one surface of the substrate. Is not particularly limited.
• a coating liquid containing the above-mentioned pressure-sensitive adhesive composition and optionally further containing a solvent is prepared, and a die coater, curtain coater, spray coater, slit coater, knife coater is formed on one surface of the substrate.
• the pressure-sensitive adhesive layer can be formed by applying the coating solution, etc., and drying the coating film on the one surface.
• the properties of the coating liquid are not particularly limited as long as it can be applied, and may contain a component for forming the pressure-sensitive adhesive layer as a solute or a dispersoid.
• the acrylic polymer (A) and the isocyanate crosslinking agent (B) in the coating film may be advanced to form a cross-linked structure at a desired density in the pressure-sensitive adhesive layer.
• the obtained dicing sheet is allowed to stand in an environment of, for example, 23 ° C. and 50% relative humidity for several days. Curing is usually performed.
• the coating liquid is applied onto the release surface of the release sheet to form a coating film, which is dried to form a laminate composed of the adhesive layer and the release sheet.
• a layered body of a dicing sheet and a release sheet may be obtained by sticking a surface of the layer opposite to the side facing the release sheet to one surface of the substrate.
• the release sheet in this laminate may be peeled off as a process material, or may be protected without being peeled off until it is attached to the mold package.
• the manufacturing method includes any of the following steps:
• the pressure-sensitive adhesive composition containing the acrylic polymer (A) and the isocyanate-based crosslinking agent (B) is applied to one surface of the base material, and a pressure-sensitive adhesive layer is formed from the obtained coating film.
• the acrylic polymer (A) is obtained by reacting the acrylic polymer (A1) and the isocyanate compound (A2) in the presence of the organometallic catalyst (C).
• the mass ratio of the monomer (m1) in the acrylic polymer (A1) to the whole monomer giving the acrylic polymer (A1) is preferably 5% by mass or more and 30% by mass or more.
• the amount of the compound (A2) used is preferably 0.4 equivalents or more and 0.9 equivalents or less with respect to the monomer (m1).
• Mold Chip Manufacturing Method A method of manufacturing a mold chip from a mold package using the dicing sheet according to the present embodiment will be described below by taking a case where the mold package is a semiconductor package as a specific example.
• a semiconductor package is an electronic component assembly in which a semiconductor chip is mounted on each base of a base assembly as described above, and these semiconductor chips are collectively resin-sealed. And has a thickness of about 200 to 2000 ⁇ m.
• the resin sealing surface has a rough arithmetic mean roughness Ra (JIS B0601: 2001 (ISO 4287: 1997)) of about 0.5 ⁇ m and is easy to remove from the mold of the sealing device.
• the stopping material may contain a release component. For this reason, when an adhesive sheet is affixed on the resin sealing surface, there is a tendency that sufficient fixing performance is not exhibited.
• the resin sealing surface of this semiconductor package has a printing part defined by a recess formed by removing the resin material by laser processing or the like.
• the semiconductor package has a height difference between the resin sealing surface other than the printing portion and the plane of the printing portion, and in this specification, this height difference is referred to as the (average) depth of the concave portion of the printing portion.
• the average depth of the recesses in the printing unit is preferably 0.5 ⁇ m or more, and more preferably 0.5 ⁇ m or more and 10 ⁇ m or less. In this specification, it is assumed that the average depth of the concave portion of the printing portion is obtained as follows.
• a laser microscope is used to observe the resin sealing surface other than the printing portion of the semiconductor package and the flat surface of the concave portion constituting the printing portion, and measure the height difference.
• 5 points in the area including the border line other than the print part and the print part are taken as measurement points, and the average value of the height difference at the measurement point is taken as the average depth of the recesses in the print part.
• the dicing sheet according to the present embodiment affixes the surface on the pressure-sensitive adhesive layer side (that is, the surface opposite to the base material side of the pressure-sensitive adhesive layer) to the resin sealing surface of the semiconductor package (mold package).
• a release sheet is attached to the surface of the dicing sheet on the pressure-sensitive adhesive layer side, the release sheet is peeled off to expose the surface of the pressure-sensitive adhesive layer side to the resin sealing surface of the semiconductor package. What is necessary is just to stick the surface.
• the outer peripheral portion of the dicing sheet is usually attached to an annular jig called a ring frame for conveyance and fixing to the apparatus by an adhesive layer provided in the portion. Since the adhesive layer has an appropriate tack value, etc., even if the semiconductor package affixed to the dicing sheet is subjected to the dicing process, there is a possibility that mold chips formed by dividing the semiconductor package will be scattered during processing. Has been reduced.
• the size of the mold chip formed by the dicing process is usually 5 mm ⁇ 5 mm or less, and in recent years it may be about 1 mm ⁇ 1 mm.
• the pressure-sensitive adhesive layer of the dicing sheet according to this embodiment has an appropriate tack value. Therefore, it is possible to sufficiently cope with such fine pitch dicing.
• a plurality of mold chips can be obtained from the semiconductor package.
• an expanding process for extending the dicing sheet in the main surface direction is usually performed so that a plurality of mold chips arranged close to each other on the dicing sheet can be easily picked up.
• the extent of this extension may be set as appropriate in consideration of the interval between adjacent mold chips and the tensile strength of the substrate.
• the mold chip on the adhesive layer is picked up by general means such as a suction collet.
• the picked-up mold chip is used for the next process such as a transport process.
• the energy beam irradiation is performed from the base material side of the dicing sheet according to the present embodiment after the dicing process is finished and before the pickup process is started, the energy beam polymerization contained in the adhesive layer included in the dicing sheet is included.
• the reaction of the functional group proceeds, and the adhesiveness of the adhesive layer to the surface of the mold chip can be reduced.
• the pressure-sensitive adhesive layer provided in the dicing sheet according to the present embodiment is formed from a suitable pressure-sensitive adhesive composition, it constitutes the inside of the concave portion of the resin sealing surface of the semiconductor package that is the adherend, particularly the printing portion.
• the material constituting the pressure-sensitive adhesive layer is unlikely to remain in the recessed portion. For this reason, the problem regarding the print visibility in the above-mentioned mold chip is not particularly likely to occur.
• the mold chip manufacturing method according to the present embodiment chip scattering is unlikely to occur, and defects are unlikely to occur in subsequent processes. For this reason, the yield is unlikely to decrease in a series of processes from a dicing process and a pick-up process for dividing a mold package such as a semiconductor package into a plurality of mold chips to the next process. Therefore, the mold chip obtained by the manufacturing method according to the present embodiment using the dicing sheet according to the present embodiment is likely to be cost-effective. In addition to chip molds that are directly related to these problems, chip scattering may cause problems such as chipping of mold chips manufactured in the same lot due to chip collisions. Therefore, the mold chip manufactured by the method for manufacturing a mold chip according to the present embodiment is less likely to have such a problem and is excellent in quality.
• Example 1 Preparation of coating solution A coating solution having the following composition was prepared. 75 parts by mass of 2-ethylhexyl acrylate, 10 parts by mass of methyl methacrylate and 15 parts by mass of 2-hydroxyethyl acrylate (HEA) were copolymerized to produce a copolymer (polystyrene equivalent weight average molecular weight 700,000). Obtained as a polymer (A1).
• HOA 2-hydroxyethyl acrylate
• a methacryloyloxyethyl isocyanate (MOI) as a compound (A2) and the above acrylic polymer (A1) are mixed with a zirconium chelate catalyst (“ZC-700” manufactured by Matsumoto Fine Chemical Co., Ltd.) as an organometallic catalyst (C). Reacted in the presence.
• the amount of the compound (A2) used was 0.6 equivalent with respect to HEA positioned as a monomer (m1) that gives a structural unit having a hydroxyl group that is a reactive functional group in the acrylic polymer (A1). .
• the addition amount of the organometallic catalyst (C) was 0.1 part by mass with respect to 100 parts by mass of the solid content of the acrylic polymer (A1).
• the adhesive layer side surface of the above laminate is affixed to one surface (corona-treated, surface tension: 54 mN / m) of a substrate made of an ethylene-methacrylic acid copolymer (EMAA) film having a thickness of 140 ⁇ m.
• EMAC ethylene-methacrylic acid copolymer
• Example 2 The organometallic catalyst (C) used to obtain the acrylic polymer (A) was replaced with a zirconium chelate catalyst, and a titanium chelate catalyst (“TC-750” manufactured by Matsumoto Fine Chemical Co., Ltd.) was used. A dicing sheet was laminated on the surface on the pressure-sensitive adhesive layer side in the same manner as in Example 1 except that 0.03 part by mass with respect to 100 parts by mass of the solid content of the polymer (A1) was laminated. Obtained in the state.
• Example 3 A dicing sheet was prepared in the same manner as in Example 1 except that the amount of MOI used as the compound (A2) used for obtaining the acrylic polymer (A) was 0.7 equivalent to HEA. It was obtained in a state where a release sheet was laminated on the surface on the pressure-sensitive adhesive layer side.
• Example 2 A dicing sheet was prepared in the same manner as in Example 1 except that the amount of MOI used as the compound (A2) used for obtaining the acrylic polymer (A) was 0.9 equivalent to HEA. It was obtained in a state where a release sheet was laminated on the surface on the pressure-sensitive adhesive layer side.
• Example 3 A dicing sheet was prepared in the same manner as in Example 1 except that the amount of MOI used as the compound (A2) used for obtaining the acrylic polymer (A) was 0.3 equivalent to HEA. It was obtained in a state where a release sheet was laminated on the surface on the pressure-sensitive adhesive layer side.
• Crosslinker trimethylolpropane tolylene diisocyanate (TDI-TMP), manufactured by Toyochem "BHS 8515”
• Energy ray-curable compound 10-functional urethane acrylate, molecular weight: 1700, “UV-1700B” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.
• the laminate of the dicing sheet and the simulated semiconductor package thus obtained is mounted on a dicing ring frame (“2-6-1” manufactured by Disco) and used with a dicing apparatus (“DFD-651” manufactured by Disco). Then, a dicing process of cutting from the simulated semiconductor package side was performed, and divided into 1 mm ⁇ 1 mm mold chips.
• the dicing conditions were as follows. Dicing blade: “ZBT-5074 (Z1110LS3)” manufactured by DISCO Corporation Blade thickness: 0.17 mm Blade length: 3.3 mm Blade rotation speed: 30000 rpm Cutting speed: 100 mm / min Depth of cut into substrate: 50 ⁇ m Cutting water amount: 1.0 L / min Cutting water temperature: 20 ° C
• the member obtained by the dicing process where the mold chip is attached to the surface of the dicing sheet on the pressure-sensitive adhesive layer side, is visually observed, and the number of mold chips that have dropped from the dicing sheet during the dicing process is counted.
• the number was divided by the number of divisions in the dicing step to obtain the chip scattering rate (unit:%).
• the case where the chip scattering rate was less than 10% was judged as good, and the case where it was 10% or more was judged as bad.
• Table 1 In Table 1, “A” means that it was determined to be good, and “B” means that it was determined to be bad.
• the average depth of the concave portion of the printing portion was 2 ⁇ m.
• the average depth of the concave portion of the printing portion was determined as follows. A laser microscope (“VK-9700” manufactured by KEYENCE Corp.) was used to observe the resin sealing surface other than the printed part of the semiconductor package and the flat surface of the concave part constituting the printed part, and the height difference was measured. In addition, 5 points in the area including the border line other than the print part and the print part were taken as measurement points, and the average value of the height difference at the measurement point was taken as the average depth of the recesses in the print part.
• the surface of the dicing sheet manufactured according to the above-described examples and comparative examples is pasted on the sealing resin surface of the prepared simulated semiconductor package. did.
• the laminate of the dicing sheet and the simulated semiconductor package thus obtained is mounted on a dicing ring frame (“2-6-1” manufactured by Disco) and used with a dicing apparatus (“DFD-651” manufactured by Disco). Then, a dicing process of cutting from the simulated semiconductor package side was performed and divided into 10 mm ⁇ 10 mm mold chips.
• the dicing conditions were as follows.
• Dicing blade “ZBT-5074 (Z1110LS3)” manufactured by DISCO Corporation Blade thickness: 0.17 mm Blade length: 3.3 mm Blade rotation speed: 30000 rpm Cutting speed: 100 mm / min Depth of cut into substrate: 50 ⁇ m Cutting water amount: 1.0 L / min Cutting water temperature: 20 ° C
• the mold chip group was placed on the dicing sheet and left still for 30 days. After standing for 30 days, ultraviolet irradiation (illuminance 230 mW / cm 2 , light intensity) was performed in a nitrogen atmosphere from the substrate side of the dicing sheet after the dicing process using an ultraviolet irradiation device (RAD-2000m / 12 manufactured by Lintec). 190 mJ / cm 2 ).
• a dicing sheet in a member formed by adhering a mold chip to the surface of the dicing sheet on the pressure-sensitive adhesive layer side is expanded at a speed of 1 mm / second using an expanding device (“ME-300B type” manufactured by JCM Co., Ltd.). An expanding step of extending 20 mm in the main surface direction of the sheet was performed.
• a pick-up test was performed on 100 mold chips located on the dicing sheet. That is, the part in contact with the mold chip to be picked up in the dicing sheet is pushed up by 1.5 mm from the substrate side with a needle, and a vacuum collet is attached to the surface of the protruding mold chip opposite to the side facing the dicing sheet, The mold chip attached to the vacuum collet was lifted. The area including the printed part of the resin-sealed surface of the picked-up mold chip is observed, and if necessary, the concave part of the printed part is measured by microscopic FT-IR (“Spectrum One” manufactured by Perkin Elmer). The print visibility was evaluated according to the following criteria. The results are shown in Table 1.
• A There was no mold chip where it was recognized that the visibility of printing was lowered.
• B Although there was a mold chip in which it was recognized that the visibility of printing was slightly decreased, a decrease in the visibility was not recognized for many mold chips. For mold chips whose visibility was found to be slightly reduced, the concave portion of the printed part was measured using microscopic FT-IR, but adhesion of a substance identified as the material constituting the adhesive layer was not confirmed. . C: There were a considerable number of mold chips that were recognized as having a slight drop in the print visibility. For mold chips whose visibility was found to be slightly reduced, the concave portion of the printed part was measured using microscopic FT-IR, but adhesion of a substance identified as the material constituting the adhesive layer was not confirmed.
• the dicing sheet of the example satisfying the conditions of the present invention was less likely to cause problems in the dicing process, and it was also difficult to cause problems related to print visibility in the above-described mold chip.
• the dicing sheet according to the present invention is suitably used as a dicing sheet for a mold package having a printing portion on a resin sealing surface which is a deposition surface.

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• Chemical & Material Sciences (AREA)
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• 2015
  • 2015-10-20 CN CN201580060026.8A patent/CN107078038B/zh active Active
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• 2016
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