JP2020174064A - Processing method of electronic component and electronic component tape - Google Patents

Abstract

To provide a processing method of an electronic component and an electronic component tape which can sufficiently follow a semiconductor wafer having a large bump in a short time.SOLUTION: An electronic component tape has at least one resin layer 3, and the resin layer 3 has an indenter indentation depth of 10,000 nm to 50,000 nm at any temperature of 60°C to 80°C measured according to ISO14577 using a nanoindenter, and the thickness of the resin layer 3 is 50 μm to 300 μm, and the total thickness is 450 μm or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to tapes for electronic components and methods for processing electronic components. More specifically, the present invention relates to a tape for electronic parts that can be mainly applied to a thin film grinding process of a semiconductor wafer, and a method for processing an electronic part using the tape for electronic parts.

In the semiconductor wafer manufacturing process, the back surface of the semiconductor wafer after pattern formation is usually subjected to back surface grinding, etching, or the like in order to reduce its thickness. At this time, a semiconductor wafer surface protection tape is attached to the pattern surface for the purpose of protecting the pattern on the semiconductor wafer surface. The semiconductor wafer surface protection tape is generally used by laminating an adhesive layer on a base film and attaching an adhesive layer to the back surface of the semiconductor wafer (see, for example, Patent Document 1). ).

In recent years, as mobile phones and personal computers have become smaller and more sophisticated, flip-chip mounting that can be mounted in a smaller space than wire bonding, which is a conventional method for connecting semiconductor chips, has been developed. In the flip chip mounting, when the surface of the semiconductor chip and the substrate are electrically connected, they are connected by ball-shaped or columnar bumps formed on the surface of the semiconductor wafer. Conventionally, such bumps have a height (thickness) of 100 μm or less, but in order to meet the demand for further miniaturization of semiconductor chips, the height (thickness) is ensured. A WLCSP (Wafer level Chip Size Package) for rewiring bumps having a height of more than 200 μm has been proposed.

When the back surface of a wafer is ground as described above using a conventional semiconductor wafer surface protection tape, the semiconductor wafer surface protection tape cannot be sufficiently adhered to and held on the wafer surface due to the high bumps. Then, cutting water and silicon grinding debris injected during grinding infiltrate through the gap between the semiconductor wafer surface protection tape and the wafer, and a phenomenon called seapage that contaminates the wafer surface occurs.

Therefore, in order to make the semiconductor wafer surface protection tape follow the unevenness of the semiconductor wafer surface, an intermediate layer having a storage elastic modulus of 1 × 10 ⁴ to 1 × 10 ⁶ Pa is provided between the base film and the pressure-sensitive adhesive layer. The provided semiconductor wafer surface protection tape has been proposed (see, for example, Patent Document 2). Further, a semiconductor wafer surface protection tape in which a thermoplastic resin intermediate layer having a JIS-A hardness of 10 to 55 and a thickness of 25 to 400 μm is provided between the base film and the pressure-sensitive adhesive layer has also been proposed (for example). , Patent Documents 3 and 4).

Japanese Unexamined Patent Publication No. 2000-8010 Japanese Unexamined Patent Publication No. 2014-17336 Japanese Patent No. 4054113 Japanese Patent No. 37733558

However, in the semiconductor wafer surface protection tape described in the above-mentioned patent document, when the semiconductor wafer surface protection tape is intended to follow the unevenness of the semiconductor wafer surface, the semiconductor wafer surface protection tape is attached to the semiconductor wafer. At that time, since it is necessary to heat the semiconductor wafer surface protection tape to make it flexible, there is a problem that it takes time for bonding.

Therefore, an object of the present invention is to provide a tape for electronic components and a method for processing electronic components, which can sufficiently follow a semiconductor wafer having bumps having a large height in a short time.

In order to solve the above problems, the tape for electronic components according to the present invention has at least one resin layer, and the resin layer is measured at 60 ° C. to 80 ° C. using a nanoindenter in accordance with ISO14577. It is characterized in that the indenter indentation depth of the nanoindenter at any temperature is 10,000 nm to 50,000 nm, the thickness of the resin layer is 50 μm to 300 μm, and the total thickness is 450 μm or less.

Further, in the tape for electronic components, the resin layer preferably has a thermal conductivity of at least 0.30 W / m · K or more at 60 to 80 ° C.

The tape for electronic components is preferably bonded to a circuit forming surface of a semiconductor wafer provided with a step of 10 μm or more.

The thickness of the resin layer of the tape for electronic components is preferably 1 times or more and 2 times or less of the step.

Further, in order to solve the above problems, the method for processing an electronic component according to the present invention is to apply the above-mentioned tape for electronic components to a temperature of 50 to 100 ° C. on a circuit forming surface of a semiconductor wafer provided with a step of 10 μm or more. It is characterized by having a bonding step of bonding with the above, and a grinding step of grinding a surface of the semiconductor wafer opposite to the circuit forming surface after the bonding step.

In the processing method of the electronic component, it is preferable that the bonding speed in the bonding step is 3 mm / S or more.

According to the tape for electronic components according to the present invention, even a semiconductor wafer having a bump having a large height can be sufficiently followed in a short time.

It is sectional drawing which shows typically the structure of the tape for electronic parts which concerns on embodiment of this invention. It is explanatory drawing for schematically explaining the use example of the tape for electronic parts which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing the structure of the tape 1 for electronic components according to the embodiment of the present invention.

As shown in FIG. 1, the tape 1 for electronic components according to the present embodiment has a base film 2, and a resin layer 3 is provided on at least one side of the base film 2. The pressure-sensitive adhesive layer 4 is provided on the upper surface of the resin layer 3, and the release-treated surface of the release film 5 whose surface has been released-treated is in contact with the pressure-sensitive adhesive layer 4 on the upper surface of the pressure-sensitive adhesive layer 4. It is laminated on. Although a release film is provided in the present embodiment, the release film 5 does not necessarily have to be provided.

Hereinafter, each component of the electronic component tape 1 of the present embodiment will be described in detail.

(Base film 2)
Known plastics, rubbers, and the like can be used as the base film 2 of the tape 1 for electronic components of the present invention. As the base film 2, in particular, when a radiation-curable composition is used for the pressure-sensitive adhesive layer 4, it is preferable to select a base film 2 having good radiation transmission at a wavelength at which the composition is cured. Here, radiation is a general term for, for example, light such as ultraviolet rays, laser light, or ionizing radiation such as an electron beam, and hereinafter, these are collectively referred to as radiation.

Examples of resins that can be selected as such a base film 2 include high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), ethylene-vinyl acetate copolymer (EVA), and ethylene acrylic acid. Polyethylenes such as copolymers and ethylene methacrylate copolymers and their metal crosslinks (ionomers), polyesters such as polyethylene terephthalate (PET), polyethylene terephthalate (PEN), and polyethylene terephthalate (PBT), Further, a film formed by cross-linking an acrylic resin can be used. Each resin may be used alone as a single-layer base material, may be mixed by combining resins, or may have a multi-layer structure of different resins. Further, additives may be added as long as the physical properties are not affected, such as blending a coloring pigment or the like for recognizing and identifying the semiconductor wafer surface protective adhesive tape 1.

The base film 2 preferably has a tensile elastic modulus of 0.01 to 10 GPa at 25 ° C., preferably 0.1 to 5 GPa, in order to handle it as a tape 1 for electronic components and suppress warpage during thin film grinding of the semiconductor wafer 6. More preferred.
Further, when the base film 2 is the outermost surface, it is required to withstand the processing heat due to heat bonding of the electronic component tape 1 and polishing of the semiconductor wafer 6, and the back surface of the tape when the electronic component tape 1 is peeled off. When used in a step of heat-pressing and peeling a heat-sealing film, the melting point is preferably 70 to 170 ° C, more preferably 90 to 140 ° C.

The thickness of the base film 2 is not particularly limited and may be set as appropriate, but is preferably 10 to 300 μm, more preferably 25 to 100 μm.

The method for producing the base film 2 is not particularly limited. Conventional methods such as a calendar method, a T-die extrusion method, and an inflation method can be used. In addition, an independently formed film and another film can be bonded together with an adhesive or the like to form a base film.

The surface of the base film 2 on the side where the resin layer 3 is provided may be appropriately subjected to a treatment such as a corona treatment or a primer layer in order to improve the adhesion to the resin layer 3. It is also preferable that the surface of the base film 2 on the side where the resin layer 3 is not provided is textured or coated with a lubricant, whereby the effect of preventing blocking during storage of the tape 1 for electronic components of the present invention can be obtained. be able to.

When the heat seal film is heat-bonded to the back surface of the tape when the tape 1 for electronic components is peeled off, the surface of the base film 2 on the side where the resin layer 3 is not provided is provided with heat seal and adhesiveness. It is also preferable to provide a coating or a resin layer to have. The melting point of these heat seal layers is preferably 70 to 170 ° C, more preferably 90 to 140 ° C. In particular, when a refractory material such as PET is used as the base film 2, the heat seal layer is effective.

(Resin layer 3)
As the resin constituting the resin layer 3, the nano indenter of the resin layer 3 is used, and the pressing depth of the indenter of the nano indenter at any temperature of 60 ° C. to 80 ° C. measured according to ISO14577 is 10,000 nm. A known resin can be used without particular limitation as long as it has a temperature of about 50,000 nm.

Examples of the resin that can be selected as the resin layer 3 include polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-acrylic acid copolymer, and ionomer. Examples thereof include homopolymers and copolymers of α-olefins such as. Each resin may be used alone as a single layer, these resins may be combined and mixed, or a multi-layer structure of different resins may be formed.

The resin layer 3 has an indenter indentation depth of 10,000 nm to 50,000 nm at any temperature of 60 ° C. to 80 ° C. measured in accordance with ISO14577 using a nanoindenter. If the indenter pushing depth of the nanoindenter is less than 10000 nm at any temperature of 60 ° C to 80 ° C, it takes time for the electronic component tape 1 to sufficiently follow the unevenness 61 on the surface of the semiconductor wafer 6. ..

If the indenter pushing depth of the nanoindenter exceeds 50,000 nm at any temperature of 60 ° C to 80 ° C, it will be deformed too much by heat bonding, and the thickness accuracy of the electronic component tape 1 will deteriorate. Since the resin layer 3 protrudes from the side surface of the semiconductor wafer 6, burrs and lumps are formed when the tape 1 for electronic components is cut along the side surface of the semiconductor wafer 6 to contaminate the semiconductor wafer 6. When burrs or the like are generated in the cut portion of the resin layer 3, when the back surface of the semiconductor wafer 6 is ground or polished, the burrs or the like are caught in the processed surface, and edge cracks or cracks are generated in the semiconductor wafer 6. Further, the frictional heat generated by processing during polishing of the semiconductor wafer 6 such as dry polishing may exceed 60 ° C., which may cause damage to the semiconductor wafer 6 or poor thickness accuracy. Further, when the electronic component tape 1 is transported or stored at a high temperature, the temperature may exceed 60 ° C., the end portion of the electronic component tape 1 is softened, and the electronic component tape 1 is transported or stored in a scroll shape. In addition, misattachment at the edges and peripheral contamination due to softened resin are also possible.

The indenter indentation depth of the nanoindenter conforms to ISO14577-1: 2002, and a load is applied to the Berkovich indenter made of diamond of the nanoindenter using the nanoindenter, and the indenter is applied to the sample surface at 10 mN. This is the indenter reaching depth when the depth at which the force is applied is set to zero and the sample is pushed in until a force of 50 mN is applied.

The indentation depth of the nanoindenter indenter at 60 to 80 ° C. of the resin layer 3 can be adjusted by, for example, the density of the resin or the comonomer content ratio in the case of a comonomer copolymer. In the case of an ethylene-vinyl acetate copolymer, an ethylene-methyl acrylate copolymer, and an ethylene-butyl acrylate, the comonomer content is preferably 10 to 50% by mass, more preferably 25 to 45%. In the case of α-olefin, the density is preferably 0.87 to 0.93, more preferably 0.88 to 0.90. Further, the molecular weight of the resin can be adjusted, and the weight average molecular weight is preferably 1000 to 20000, more preferably 40,000 to 80,000.

The thermal conductivity of the resin layer 3 at 60 to 80 ° C. is at least 0.30 W / m · K or more, and more preferably 0.4 W / m · K or more at 70 ° C. Thermal conductivity is measured according to JIS A1412. In order to make the thermal conductivity of the resin layer 3 at 60 to 80 ° C. to 0.30 W / m · K or more, a resin having such characteristics may be used, or a thermally conductive filler may be contained. .. The thermally conductive filler is preferably one or more selected from inorganic nitrides, inorganic oxides, and metals, and specific examples thereof include inorganic nitrides such as aluminum nitride and boron nitride. , Inorganic oxides such as alumina, silicon oxide and magnesium oxide, metals such as gold, silver, nickel and aluminum, and anti-blocking agents such as talc, calcium carbonate and silicon dioxide. Of these, aluminum nitride, which exhibits insulating properties and high thermal conductivity, is preferable. More preferably, surface-treated aluminum nitride is used for improving water resistance. These may be used alone or in admixture of two or more. The content ratio of the filler in the resin layer 3 is preferably 3 to 60% by mass, more preferably 20 to 50% by mass, based on the total mass of the resin layer 3.

The resin layer 3 may contain a stabilizer, a lubricant, an antioxidant, a pigment, a plasticizer and the like, if necessary. However, depending on the type and content of the additive, the pressure-sensitive adhesive layer and the semiconductor wafer may be contaminated. In that case, it is preferable to provide a barrier layer between the resin layer 3 and the pressure-sensitive adhesive layer.

The thickness of the resin layer 3 is 50 to 300 μm, preferably 150 to 270 μm. If the thickness of the resin layer 3 is less than 50 μm, it becomes difficult for the tape 1 for electronic components to sufficiently follow the unevenness 61 on the surface of the semiconductor wafer 6. If the thickness of the resin layer 3 is more than 300 μm, the thermal conductivity is deteriorated and it takes time for the resin layer 3 to be flexible when the tape 1 for electronic components is heat-bonded to the surface of the semiconductor wafer 6. It takes time for the tape 1 for electronic components to sufficiently follow the unevenness 61 on the surface of the semiconductor wafer 6.

Further, the thickness of the resin layer 3 is preferably 1 time or more and 2 times or less the step difference on the surface of the semiconductor wafer 6. If the thickness of the resin layer 3 is less than one times the step on the surface of the semiconductor wafer 6, the tape 1 for electronic components may not be able to sufficiently follow the unevenness 61 on the surface of the semiconductor wafer 6. If the thickness of the resin layer 3 is more than twice the step on the surface of the semiconductor wafer 6, the thermal conductivity becomes poor and the resin layer 3 becomes flexible when the tape 1 for electronic components is heat-bonded to the surface of the semiconductor wafer 6. Since it takes time to perform the process, it takes time for the electronic component tape 1 to sufficiently follow the unevenness 61 on the surface of the semiconductor wafer 6.

The method of laminating the resin layer 3 is not particularly limited, but for example, a method of laminating with a base film 2 prepared in advance while extruding into a film with a T-die extruder, a base film. Examples thereof include a method of forming a film of the base film 2 and the base film 3 and dry laminating or heat laminating, and a method of forming the base film 2 and the resin layer 3 at the same time by coextrusion. Examples of the coextrusion method include an inflation method and the like in addition to the T-die extrusion method.

(Adhesive layer 4)
The pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer 4 is not particularly limited, and conventional ones can be used, but a copolymer containing (meth) acrylic acid ester as a constituent component or (meth) acrylic. Examples thereof include a copolymer having an acid ester as a constituent component. Examples of the monomer component constituting the polymer containing an acrylic acid ester as a component include methyl, ethyl, n-pull pill, isopul pill, n-butyl, t-butyl, isobutyl, amyl, isoamyl, hexyl, and heptyl. A straight chain having 30 or less carbon atoms, preferably 4 to 18 carbon atoms, such as cyclohexyl, 2-ethylhexyl, octyl, isooctyl, nonyl, isononyl, decyl, isodecyl, undecyl, lauryl, tridecyl, tetradecyl, stearyl, octadecyl, and dodecyl. Examples thereof include alkyl acrylates or alkyl methacrylates having a branched alkyl group. These alkyl (meth) acrylates may be used alone or in combination of two or more.

The following monomers can be included as constituents in the acrylic resin other than the above. For example, carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid, and maleic anhydride and itaconic anhydride. Acid anhydride monomer, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, (meth) acrylic acid Hydroxyl group-containing monomers such as 8-hydroxyoctyl, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate and (4-hydroxymethylcyclohexyl) methyl (meth) acrylate, styrene sulfonic acid, allyl sulfonic Sulfonic acid group-containing monomers such as acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, (meth) acrylamidepropanesulfonic acid, sulfopropyl (meth) acrylate and (meth) acryloyloxynaphthalene sulfonic acid, 2-hydroxy Phosphate-containing monomers such as ethylacryloyl phosphate, (meth) acrylamide, (meth) acrylic acid N-hydroxymethylamide, (meth) acrylic acid alkylaminoalkyl esters (eg, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate) Etc.), N-vinylpyrrolidone, acryloylmorpholin, vinyl acetate, styrene, acrylonitrile and the like. These monomer components may be used alone or in combination of two or more.

In addition, the acrylic resin can contain the following polyfunctional monomers as constituent components. Examples are hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth). Acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, dipentaerythritol Hexa (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, urethane (meth) acrylate and the like can be mentioned. These polyfunctional monomers may be used alone or in combination of two or more.

Examples of the acrylic acid ester include ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, and 2-hydroxyethyl acrylate. Further, an acrylic polymer such as one in which the above acrylic acid ester is replaced with a methacrylic acid ester and a curing agent can be used.

As the curing agent, the curing agent described in JP-A-2007-146104 can be used. For example, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, 1,3-bis (N, N-diglycidylaminomethyl) toluene, 1,3-bis (N, N-diglycidylaminomethyl) ) Epoxy compounds having two or more epoxy groups in the molecule such as benzene, N, N, N, N'-tetraglycidyl-m-xylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate , 1,3-Xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate and other isocyanate compounds having two or more isocyanate groups in the molecule, tetramethylol-tri-β-aziridini Lupropionate, Trimethylol-tri-β-aziridinyl propionate, Trimethylolpropan-tri-β-aziridinyl propionate, Trimethylolpropan-tri-β- (2-methylaziridine) propionate, etc. Examples thereof include isocyanate compounds having two or more aziridinyl groups in the molecule of. The content of the curing agent may be adjusted according to the desired adhesive strength and storage elastic modulus, and is preferably 0.01 to 10 parts by mass, more preferably 0.1, with respect to 100 parts by mass of the polymer. ~ 5 parts by mass.

By including a photopolymerizable compound and a photopolymerization initiator in the pressure-sensitive adhesive layer 4 as described above, it is cured by irradiating with ultraviolet rays, and the pressure-sensitive adhesive layer 4 can reduce the adhesive strength. Examples of such a photopolymerizable compound include photopolymerizable carbon in a molecule that can be three-dimensionally networked by light irradiation as disclosed in JP-A-60-196956 and JP-A-60-223139. -Low molecular weight compounds having at least two carbon double bonds are widely used.

Specifically, trimethylolpropan triacrylate, 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.

As the photopolymerization initiator, the photopolymerization initiator described in JP-A-2007-146104 or JP-A-2004-186429 can be used. Isopropylbenzoin ether, isobutylbenzoin ether, benzophenone, Michler's ketone, chlorothioxanthone, benzylmethyl ketal, α-hydroxycyclohexylphenylketone, 2-hydroxymethylphenylpropane and the like can be used in combination.

As the pressure-sensitive adhesive layer 4, a photopolymerizable pressure-sensitive adhesive using a resin composition containing a polymer having a photopolymerizable carbon-carbon double bond in the polymer, a photopolymerization initiator, and a curing agent can be used. it can. The polymer having a carbon-carbon double bond in the polymer is a single amount such as a (meth) acrylic acid ester having an alkyl group having 4 to 12 carbon atoms, more preferably 8 carbon atoms in the side chain. A (meth) acrylic polymer obtained by homopolymerizing or copolymerizing one or more of the body and the copolymerizable modified monomer by an arbitrary method is preferable.

In addition, the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer 4 may be blended with a tackifier, a pressure-sensitive adhesive, a surfactant, or the like, or other modifiers, if necessary. Moreover, you may add an inorganic compound filler as appropriate.

The pressure-sensitive adhesive layer 4 can be formed, for example, by applying the pressure-sensitive adhesive composition on the release film 5, drying it, and transferring it to the resin layer 3. In the present invention, the thickness of the pressure-sensitive adhesive layer 4 is preferably 1 to 130 μm, more preferably 1 to 40 μm, and even more preferably 1 to 20 μm. The role of the pressure-sensitive adhesive layer 4 in the present invention is mainly to secure adhesiveness and peelability to the surface of the semiconductor wafer 6. If the pressure-sensitive adhesive layer 4 is thick, depending on its storage elastic modulus, it may hinder the followability to the semiconductor wafer 6 or cause adhesive residue on the semiconductor wafer 6.

The total thickness of the pressure-sensitive adhesive layer 4 and the resin layer 3 is preferably equal to or greater than the uneven height of the surface of the semiconductor wafer 6. It is more preferable that the thickness of the resin layer 3 alone is 1.0 to 2.0 times the uneven height of the surface of the semiconductor wafer 6.

(Release film 5)
Further, the surface protective adhesive tape 1 may be provided with a release film 5 on the adhesive layer 4. The release film 5 is also called a separator, a release layer, or a release liner, and is provided for the purpose of protecting the pressure-sensitive adhesive layer 4 and for the purpose of smoothing the pressure-sensitive adhesive. Examples of the constituent material of the release film 5 include synthetic resin films such as polyethylene, polypropylene, and polyethylene terephthalate, and paper. The surface of the release film 5 may be subjected to a release treatment such as a silicone treatment, a long-chain alkyl treatment, or a fluorine treatment, if necessary, in order to improve the peelability from the pressure-sensitive adhesive layer 4. Further, if necessary, it is also preferable to carry out an ultraviolet protection treatment so that the pressure-sensitive adhesive layer 4 does not react due to unintended exposure to ultraviolet rays such as environmental ultraviolet rays. The thickness of the release film 5 is usually about 10 to 100 μm, preferably about 25 to 50 μm.

The tape 1 for electronic components of the present invention has a total thickness of 450 μm or less. In the present invention, the total thickness is the thickness in a state of being used as a tape for electronic parts, and when the release film 5 is provided, it is the thickness of the tape 1 for electronic parts after the release film 5 is peeled off. is there. When the total thickness of the electronic component tape 1 is more than 450 μm, when the electronic component tape 1 is heat-bonded to the surface of the semiconductor wafer 6, the thermal conductivity deteriorates and it takes time for the resin layer 3 to become flexible. Therefore, it takes time for the tape 1 for electronic components to sufficiently follow the unevenness 61 on the surface of the semiconductor wafer 6.

<How to use>
Next, a method of using the tape 1 for electronic components of the present invention, that is, a method of processing the semiconductor wafer 6 will be described.

Specifically, first, as shown in FIG. 2 (A), the release film 5 of the electronic component tape 1 is peeled from the adhesive layer 4, and as shown in FIG. 2 (B), the circuit of the semiconductor wafer 6 A bonding step of bonding the tape 1 for electronic components is performed so that the pressure-sensitive adhesive layer 4 serves as a bonding surface on the pattern surface (surface). At this time, it is preferable to heat at a temperature of 50 to 100 ° C. for bonding, and it is more preferable to heat at a temperature of 60 to 80 ° C. for bonding. At this time, since the pushing depth of the indenter of the nanoindenter at any temperature of 60 ° C. to 80 ° C. measured according to ISO14577 using the nanoindenter of the resin layer 3 is 10,000 nm or more, it is used for electronic parts. The tape 1 sufficiently follows the unevenness 61 on the surface of the semiconductor wafer 6 in a short time. The bonding speed is preferably 3 mm / S or more. Heating at the time of bonding is performed by heating a chuck table or a bonding roller that holds the semiconductor wafer 6.

After the bonding step, a cutting step of cutting the electronic component tape 1 along the side surface of the semiconductor wafer 6 is performed by the cutter blade attached to the bonding machine while being held by the chuck table. .. The cutter blade may be heated to about 70 to 150 ° C. in order to improve the cutability.

The semiconductor wafer surface protective tape 1 is preferably used for those having a height difference of 61 uneven surfaces such as bumps formed on the circuit forming surface, that is, a step of the circuit forming surface of 10 μm or more, and having a step of 100 μm or more. It is more preferably used for those having a step of 180 μm or more.

Then, as shown in FIG. 2C, the back surface of the semiconductor wafer 6, that is, the surface side without the circuit pattern, is ground by the grinder 7 until the thickness of the semiconductor wafer 6 reaches a predetermined thickness, for example, 10 to 200 μm. Grinding process is carried out. After that, a polishing step such as dry polishing may be carried out for finishing. At this time, since the tape 1 for electronic components sufficiently follows the unevenness 61 on the surface of the semiconductor wafer 6, the sea page can be suppressed. Further, since the unevenness of the surface of the tape 1 for electronic parts is suppressed, the force from the grinder 7 is uniformly applied to the back surface of the semiconductor wafer 6, the semiconductor wafer 6 is ground and polished with high thickness accuracy, and dimples are also suppressed. Will be done.

After that, when the electronic component tape 1 is photopolymerizable, it is irradiated with energy rays to reduce the adhesive force of the pressure-sensitive adhesive layer 4, and the electronic component tape 1 is peeled off from the semiconductor wafer 6. Even if a dicing / die bonding film (not shown) is attached to the ground / polished surface side of the semiconductor wafer 6 without a circuit pattern after irradiation with energy rays and before the tape 1 for electronic components is peeled off. Good.

In the present embodiment, the pressure-sensitive adhesive layer 4 is provided on the upper surface of the resin layer, but the pressure-sensitive adhesive layer 4 may not be provided if it is not necessary. In this case, the semiconductor wafer 6 is directly attached to the resin layer, the back surface of the semiconductor wafer 6 is ground and polished, and after the grinding and polishing are completed, the tape 1 for electronic components is peeled off from the semiconductor wafer 6.

In the present embodiment, an example in which the tape 1 for electronic components is used for grinding / polishing the semiconductor wafer 6 has been described, but the present invention is not limited to this, and is not limited to this, and is used for dicing and transporting electronic components having irregularities on the surface. It can be used for surface protection. Examples of the electronic component include, in addition to the semiconductor wafer 6, glass having irregularities having a step of about 200 μm on the surface, a package having bumps having a height of about 200 μm, and the like.

<Example>
Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples.

[Preparation of adhesive layer composition]
[Adhesive Layer Composition A]
Coronate L (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.) 1.0 mass with respect to 100 parts by mass of a copolymer composed of 80 parts by mass of 2-ethylhexyl acrylate, 15 parts by mass of 2-hydroxyacrylate, and 5 parts by mass of methacrylic acid. Parts were added and mixed to obtain an adhesive composition A.

[Preparation of resin constituting the resin layer]
[Resin B1]
As the resin B1, an ethylene-butylacrate copolymer (EBA) having a butyl acrylate content of 30% and a weight average molecular weight of 100,000 was prepared. The storage elastic modulus of the resin B1 at 70 ° C. was 9.0 × 10 ⁴ Pa, the MFR was 30 g / 10 min, and the molecular weight distribution was 5.8.

[Resin B2]
As the resin B2, an α-olefin resin having a density of 0.88 and a weight average molecular weight of 40,000 was prepared. The storage elastic modulus of the resin B2 at 70 ° C. was 1.4 × 10 ⁵ Pa, the MFR was 40 g / 10 min, and the molecular weight distribution was 2.4.
[Resin B3]
As the resin B3, an ethylene-vinyl acetate acrylate copolymer (EVA) having a vinyl acetate acrylate content of 30% and a weight average molecular weight of 50,000 was prepared. The storage elastic modulus of the resin B3 at 70 ° C. was 6.8 × 10 ⁴ Pa, the MFR was 60 g / 10 min, and the molecular weight distribution was 6.3.
[Resin B4]
As the resin B4, an α-olefin resin having a density of 0.90 and a weight average molecular weight of 50,000 was prepared. The storage elastic modulus of the resin B4 at 70 ° C. was 2.5 × 10 ⁵ Pa, the MFR was 20 g / 10 min, and the molecular weight distribution was 2.4.
[Resin B5]
As the resin B5, an ethylene-vinyl acetate acrylate copolymer (EVA) having a vinyl acetate acrylate content of 40% and a weight average molecular weight of 40,000 was prepared. The storage elastic modulus of the resin B5 at 70 ° C. was 3.6 × 10 ⁴ Pa, the MFR was 70 g / 10 min, and the molecular weight distribution was 6.3.

[Manufacturing tapes for electronic components]
[Example 1]
Resin B1 was extruded to a thickness of 300 μm onto a polyethylene terephthalate (PET) film having a thickness of 50 μm as a base film to form a resin layer, and the resin layer side was subjected to corona treatment. Next, the pressure-sensitive adhesive composition A was applied onto a polyethylene terephthalate (PET) separator having a thickness of 40 μm so that the film thickness after drying was 10 μm, and dried to obtain a pressure-sensitive adhesive layer. Then, the pressure-sensitive adhesive layer was bonded to the resin layer surface and transferred to obtain a tape for electronic parts according to Example 1 having a thickness of 360 μm.

[Example 2]
Resin B1 was extruded to a thickness of 300 μm onto a high-density polyethylene (HD) film having a thickness of 130 μm as a base film to form a resin layer, and the resin layer side was subjected to corona treatment. Next, the pressure-sensitive adhesive composition A was applied onto a polyethylene terephthalate (PET) separator having a thickness of 40 μm so that the film thickness after drying was 10 μm, and dried to obtain a pressure-sensitive adhesive layer. Then, the pressure-sensitive adhesive layer was bonded to the resin layer surface and transferred to obtain a tape for electronic parts according to Example 2 having a thickness of 440 μm.

[Example 3]
20 parts by mass of an aluminum oxide filler was added to 100 parts by mass of the resin B1 and mixed to obtain a resin composition.
The resin layer organism was extruded to a thickness of 300 μm onto a high-density polyethylene (HD) film having a thickness of 130 μm as a base film to form a resin layer, and the resin layer side was subjected to corona treatment. Next, the pressure-sensitive adhesive composition A was applied onto a polyethylene terephthalate (PET) separator having a thickness of 40 μm so that the film thickness after drying was 10 μm, and dried to obtain a pressure-sensitive adhesive layer. Then, the pressure-sensitive adhesive layer was bonded to the resin layer surface and transferred to obtain a tape for electronic parts according to Example 3 having a thickness of 440 μm.

[Example 4]
Resin B1 was extruded to a thickness of 300 μm onto a high-density polyethylene (HD) film having a thickness of 60 μm as a base film to form a resin layer, and the resin layer side was subjected to corona treatment. Next, the pressure-sensitive adhesive composition A was applied onto a polyethylene terephthalate (PET) separator having a thickness of 40 μm so that the film thickness after drying was 10 μm, and dried to obtain a pressure-sensitive adhesive layer. Then, the pressure-sensitive adhesive layer was bonded to the resin layer surface and transferred to obtain a tape for electronic parts according to Example 4 having a thickness of 310 μm.

[Example 5]
Resin B2 was extruded to a thickness of 300 μm onto a high-density polyethylene (HD) film having a thickness of 60 μm as a base film to form a resin layer, and the resin layer side was subjected to corona treatment. Next, the pressure-sensitive adhesive composition A was applied onto a polyethylene terephthalate (PET) separator having a thickness of 40 μm so that the film thickness after drying was 10 μm, and dried to obtain a pressure-sensitive adhesive layer. Then, the pressure-sensitive adhesive layer was bonded to the resin layer surface and transferred to obtain a tape for electronic parts according to Example 5 having a thickness of 310 μm.
[Example 6]
Resin B3 was extruded to a thickness of 300 μm onto a polyethylene terephthalate (PET) film having a thickness of 50 μm as a base film to form a resin layer, and the resin layer side was subjected to corona treatment. Next, the pressure-sensitive adhesive composition A was applied onto a polyethylene terephthalate (PET) separator having a thickness of 40 μm so that the film thickness after drying was 10 μm, and dried to obtain a pressure-sensitive adhesive layer. Then, the pressure-sensitive adhesive layer was bonded to the resin layer surface and transferred to obtain a tape for electronic parts according to Example 6 having a thickness of 360 μm.

[Comparative Example 1]
Resin B1 was extruded to a thickness of 390 μm onto a polyethylene terephthalate (PET) film having a thickness of 50 μm as a base film to form a resin layer, and the resin layer side was subjected to corona treatment. Next, the pressure-sensitive adhesive composition A was applied onto a polyethylene terephthalate (PET) separator having a thickness of 40 μm so that the film thickness after drying was 10 μm, and dried to obtain a pressure-sensitive adhesive layer. Then, the pressure-sensitive adhesive layer was bonded to the resin layer surface and transferred to obtain a tape for electronic parts according to Comparative Example 1 having a thickness of 450 μm.

[Comparative Example 2]
Resin B1 was extruded to a thickness of 300 μm onto a high-density polyethylene (HD) film having a thickness of 190 μm as a base film to form a resin layer, and the resin layer side was subjected to corona treatment. Next, the pressure-sensitive adhesive composition A was applied onto a polyethylene terephthalate (PET) separator having a thickness of 40 μm so that the film thickness after drying was 10 μm, and dried to obtain a pressure-sensitive adhesive layer. Then, the pressure-sensitive adhesive layer was bonded to the resin layer surface and transferred to obtain a tape for electronic parts according to Comparative Example 2 having a thickness of 500 μm.

[Comparative Example 3]
Resin B4 was extruded to a thickness of 300 μm onto a polyethylene terephthalate (PET) film having a thickness of 50 μm as a base film to form a resin layer, and the resin layer side was subjected to corona treatment. Next, the pressure-sensitive adhesive composition A was applied onto a polyethylene terephthalate (PET) separator having a thickness of 40 μm so that the film thickness after drying was 10 μm, and dried to obtain a pressure-sensitive adhesive layer. Then, the pressure-sensitive adhesive layer was bonded to the resin layer surface and transferred to obtain a tape for electronic parts according to Comparative Example 3 having a thickness of 360 μm.

[Comparative Example 4]
Resin B5 was extruded to a thickness of 300 μm onto a polyethylene terephthalate (PET) film having a thickness of 50 μm as a base film to form a resin layer, and the resin layer side was subjected to corona treatment. Next, the pressure-sensitive adhesive composition A was applied onto a polyethylene terephthalate (PET) separator having a thickness of 40 μm so that the film thickness after drying was 10 μm, and dried to obtain a pressure-sensitive adhesive layer. Then, the pressure-sensitive adhesive layer was bonded to the resin layer surface and transferred to obtain a tape for electronic parts according to Comparative Example 4 having a thickness of 360 μm.

[Characteristic measurement and evaluation test]
The characteristics of the tapes for electronic components of the above Examples and Comparative Examples were measured and evaluated as follows. The results are shown in Table 1.

(1) Measurement of Indenter Pushing Depth of Nano Indenter For the resin layers according to Examples and Comparative Examples, sample pieces were prepared according to ISO14577-1: 2002. The Poisson's ratio of the sample piece was 0.25. Using a Nano Indenter G200 (trade name) manufactured by KLA CORPORATION, the indentation depth of the nanoindenter indenter at 70 ° C. of each sample piece was measured. A flat punch indenter having a diameter of 1 mm was used as the indenter, and the measurement was performed under the conditions of a maximum load of 50 mN, a time until the maximum load was applied for 1 second, and a maximum load holding time of 0.5 seconds. The results are shown in Tables 1 and 2.

(2) Measurement of Thermal Conductivity of Base Film For the base films according to Examples and Comparative Examples, the thermal conductivity at 70 ° C. was determined by using XFA500 (trade name) manufactured by LINSESIS according to JIS-R1611. The measurement was performed under the conditions of a charging voltage of 350 V and a pulse length of 5 mS. The results are shown in Tables 1 and 2.

(3) Measurement of Thermal Conductivity of Resin Layer The thermal conductivity of the resin layers according to Examples and Comparative Examples was measured at 70 ° C. using XFA500 (trade name) manufactured by LINSESIS according to JIS-R1611. The results are shown in Tables 1 and 2.

(4) Evaluation of bonding speed Using RAD3510F / 8 (trade name) manufactured by Lintec Corporation as a bonding machine, tapes for electronic components according to Examples and Comparative Examples are bonded to a semiconductor wafer at a bonding temperature of 70 ° C. It fits. As the semiconductor wafer, a semiconductor wafer having bumps having a height of 200 μm and a pitch of 400 μm on the surface, a scrib with a width of 100 μm, and a chip size of 5 mm square and a diameter of 8 inches was used. They were bonded at linear speeds of 2 m / min, 3 m / min, and 5 m / min, and it was confirmed by the following method whether or not the followability was good. The thickness was measured from the electronic component tape side using a dial gauge in the state after the electronic component tape was attached. When the thickness of the central portion of the semiconductor wafer was α μm and the thickness of the end portion of the semiconductor wafer without bumps was β μm, α−β ≦ 60 μm was determined to have good followability. Those with good followability at all linear speeds were evaluated as non-defective products, and although the followability was not good at linear speeds of 5 m / min, the followability was good at linear speeds of 3 m / min and 2 m / min. Those with good followability were evaluated as defective products only when the linear speed was 2 m / min, and those with poor followability even when the linear speed was 2 m / min were evaluated as defective products. It was evaluated by XX.

(5) Evaluation of Environmental Stability After the tapes for electronic components according to the roll-shaped examples and comparative examples were left to stand in an environment of 60 ° C. or 70 ° C. for 24 hours, the resin squeezed out to the end face of the roll visually. The presence was confirmed. Those with no resin squeeze out at 70 ° C are evaluated as the best products with ◎, those with no resin squeeze out at 60 ° C are evaluated as good products, and those with resin squeeze out are evaluated as defective products with ×. evaluated. The results are shown in Tables 1 and 2.

As shown in Table 1, in Examples 1 to 6, the indenter indentation depth at 70 ° C. measured according to ISO14577 using a nanoindenter is 15,000 nm to 50,000 nm, and the thickness of the resin layer is 240 μm to 300 μm. Since the total thickness was 440 μm or less, good results were obtained in the evaluation of the bonding speed and the environmental stability. In particular, in Example 3, the thermal conductivity of the resin layer at 70 ° C. was 0.7 W / m · K, which was higher than in other examples, so that the evaluation of the bonding speed was excellent. Further, in Examples 4 and 5, the total thickness of the tape for electronic components was 310 μm, which was thinner than in other Examples, so that the evaluation of the bonding speed was excellent. Although Example 6 is inferior to Examples 1 to 5 in terms of environmental stability, the indentation depth at 70 ° C. measured using a nanoindenter is as large as 50,000 nm, so that the evaluation of the bonding speed is good. became.

On the other hand, as shown in Table 2, the thickness of the resin layer of Comparative Example 1 exceeded 300 μm, and that of Comparative Example 2 exceeded 450 μm, resulting in inferior results in the evaluation of the bonding speed. In Comparative Example 3, since the indenter indentation depth at 70 ° C. measured according to ISO14577 using a nanoindenter was less than 10000 nm, the result was inferior in the evaluation of the bonding speed. In Comparative Example 4, since the indenter indentation depth at 70 ° C. measured according to ISO14577 using a nanoindenter exceeds 50,000 nm, the result is inferior in the evaluation of environmental stability.

1: Tape for electronic parts 2: Base film 3: Resin layer 4: Adhesive layer 5: Release film 6: Semiconductor wafer 61: Concavo-convex 7: Grinding machine

Claims (6)

It has at least one resin layer and
The resin layer has an indenter indentation depth of 10,000 nm to 50,000 nm at any temperature of 60 ° C. to 80 ° C. measured in accordance with ISO14577 using a nanoindenter.
A tape for electronic components, wherein the resin layer has a thickness of 50 μm to 300 μm and a total thickness of 450 μm or less. The tape for electronic components according to claim 1, wherein the resin layer has a thermal conductivity at 60 to 80 ° C. of at least 0.30 W / m · K or more. The tape for electronic components according to claim 1 or 2, wherein the tape is bonded to a circuit forming surface of a semiconductor wafer provided with a step of 10 μm or more. The tape for electronic components according to claim 3, wherein the thickness of the resin layer is 1 times or more and 2 times or less the step. A bonding step in which the tape for electronic components according to any one of claims 1 to 3 is bonded to a circuit forming surface of a semiconductor wafer provided with a step of 10 μm or more at a temperature of 50 to 100 ° C. When,
A method for processing an electronic component, which comprises, after the bonding step, a grinding step of grinding a surface of the semiconductor wafer opposite to the circuit forming surface. The method for processing an electronic component according to claim 5, wherein the bonding speed in the bonding step is 3 mm / S or more.