JP6666875B2 - Film for forming protective film - Google Patents

Description

  The present invention relates to a film for forming a protective film provided on the back surface of a circuit formation surface of a semiconductor wafer, and more particularly to a film for forming a protective film used for manufacturing a semiconductor chip mounted by a so-called face-down method.

  In recent years, semiconductor devices have been manufactured using a mounting method called a so-called face down method. In the face-down method, a semiconductor chip having electrodes such as bumps on a circuit surface (hereinafter, simply referred to as “chip”) is used, and the electrodes are bonded to a substrate. For this reason, the surface of the chip opposite to the circuit surface (chip back surface) may be exposed.

  The exposed chip back surface may be protected by an organic film. Conventionally, a chip having a protective film made of an organic film has been obtained by applying a liquid resin to the back surface of a wafer by spin coating, drying, curing and cutting the protective film together with the wafer. However, since the thickness accuracy of the protective film thus formed is not sufficient, the yield of products may be reduced.

  A film for forming a protective film for a chip having a curable protective film forming layer containing a heat or energy ray curable component is disclosed (Patent Document 1). Further, picking up a chip protected by the backside protective film from the dicing tape causes electrostatic breakdown and lowers the yield, and a method of performing an antistatic treatment on the backside protective film is disclosed (Patent Documents 2 and 3). etc).

JP 2004-214288 A JP 2014-133858 A JP 2014-135469 A

  By the way, in mounting a chip by the face-down method, the back side of the circuit forming surface of the semiconductor wafer may be polished and thinned before the dicing step. In this case, the circuit forming surface is polished before the polishing step. In order to protect the surface, a surface protection film (also referred to as a background film) is temporarily provided on the circuit forming surface of the wafer, and the surface protection film is peeled off during dicing. It has been found that, depending on the type of surface protective film used, the semiconductor wafer is charged when peeled in a later step, and is further charged by the picked-up chip after dicing, whereby the chip may be electrostatically damaged.

  Therefore, an object of the present invention is to prevent the semiconductor chip from being electrostatically damaged even when the chip is picked up through a step of peeling the surface protection film in mounting the semiconductor chip by the face-down method, As a result, an object of the present invention is to provide a film for forming a protective film, which can obtain a semiconductor chip having high quality reliability.

  The present inventors have conducted intensive studies and found that if the relative dielectric constant of the film for forming a protective film at a measurement frequency of 10 Hz is within a predetermined range of the relative dielectric constant of the semiconductor wafer at a measurement frequency of 10 Hz, the surface protective film is peeled off. It has been found that even when the chip is picked up through the step of performing the above, it is possible to suppress the chip from being electrostatically damaged, and as a result, it is possible to improve the quality reliability of the chip. According to the present invention, the following film for forming a protective film is provided.

The protective film forming film according to the present invention is a film for forming a protective film provided on the back surface of the circuit forming surface of the semiconductor wafer,
The relative permittivity of the semiconductor wafer and the film at a measurement frequency of 10 Hz is represented by the following formula (1):
| Ε _S −ε _F | ≦ 9 (1)
(In the formula, ε _S indicates the relative dielectric constant of the semiconductor wafer at the measurement frequency of 10 Hz, and ε _F indicates the relative dielectric constant of the protective film forming film at the measurement frequency of 10 Hz.)
Is satisfied.

  In an aspect of the present invention, the semiconductor wafer may be a silicon wafer.

  In an aspect of the present invention, the protective film forming film may be provided in direct contact with a back surface of a circuit forming surface of the semiconductor wafer.

  In the aspect of the present invention, the protective film forming film may further include a peelable support.

  According to the present invention, the relative dielectric constant of the film for forming a protective film at a measurement frequency of 10 Hz is set to be within a predetermined range from the relative dielectric constant of the semiconductor wafer at a measurement frequency of 10 Hz, thereby removing the surface protection film. Even when the chip is picked up, the semiconductor chip can be prevented from being electrostatically damaged regardless of the type of the surface protection film, and as a result, a semiconductor chip with high quality reliability can be obtained.

[Protective film forming film]
The film for forming a protective film according to the present invention will be described. The film for forming a protective film according to the present invention is a film for forming a protective film provided on the back surface of the circuit forming surface of a semiconductor wafer, and the relative permittivity of the semiconductor wafer and the film at a measurement frequency of 10 Hz is as follows. Equation (1):
| Ε _S −ε _F | ≦ 9 (1)
(In the formula, ε _S indicates the relative dielectric constant of the semiconductor wafer at the measurement frequency of 10 Hz, and ε _F indicates the relative dielectric constant of the protective film forming film at the measurement frequency of 10 Hz.)
Is satisfied. In order to prevent electrostatic destruction of a chip due to static electricity generated when picking up a semiconductor chip after dicing, a dicing tape and a semiconductor chip have been proposed so far as proposed in Patent Documents 2 and 3 and the like. Between them, an adhesive layer containing a cationic antistatic agent or a conductive substance has been provided. However, as described above, in the manufacture of semiconductor chips, the dicing step is performed after the surface protection film provided on the circuit forming surface is peeled off before the semiconductor wafer polishing step. The impact has not been considered before. Therefore, in the present invention, the protective film on the back surface of the circuit forming surface of the semiconductor wafer provided before the surface protective tape is peeled off is formed of a material having a predetermined relative dielectric constant, and thus a step of peeling off the surface protective film is performed. Even when the chip is picked up, the semiconductor chip can be prevented from being electrostatically damaged regardless of the type of the surface protection film, and as a result, a semiconductor chip with high quality reliability can be obtained. .

  In the present invention, the static electricity generated at the time of peeling is generally a relative dielectric constant difference between the semiconductor wafer and the film for forming a protective film in a low frequency range of about 10 Hz where the interface polarization of the measurement object is reflected. And a protective film forming film that satisfies the relationship of the above formula (1), whereby the semiconductor chip is electrostatically damaged regardless of the type of the surface protective film. Can be suppressed. Here, in the present specification, "relative permittivity" means that a 38 mmφ silver paste electrode having a donut-shaped guard electrode on the outer periphery is formed on one surface of an object to be measured, and on the opposite surface, at a position facing the front electrode. After an electrode having a larger area is formed and the sample is left at 23 ° C. and 50% RH for one day in a measurement environment, a test voltage (signal voltage) is measured using an LCR meter (for example, LCR meter IM3536 manufactured by Hioki Denki). The relative dielectric constant is continuously measured 256 times at 5 V and a measurement frequency of 10 Hz, and an average value thereof is meant. In order to more accurately measure the relative dielectric constant at a measurement frequency of 10 Hz, it is preferable to perform the measurement by a parallel plate method in which a sample is formed in a capacitor shape and measured.

The interface polarization described above is a phenomenon in which, when the dielectric is a non-uniform dispersion composed of a plurality of different components, electric charges are accumulated at an interface of the non-uniform part (that is, a boundary surface between different kinds of substances). This phenomenon is observed in a low frequency range of × 10 ⁴ Hz or less. The relative permittivity is a ratio (ε _r ) between the permittivity (ε) of the medium and the permittivity of vacuum (ε ₀ ). The permittivity (ε) of the medium depends on the manner of dielectric polarization of the medium. Although it is a physical property value determined for a medium, the relative permittivity may depend on the measurement frequency depending on the medium. By bringing the relative dielectric constant of the protective film forming film in such a low frequency range close to the relative dielectric constant of the semiconductor wafer, static electricity generated when the protective film forming film is peeled from the semiconductor wafer (peeling withstand voltage) It was unexpected to be able to reduce).

  In the present invention, when the absolute value of the difference between the relative dielectric constants of the semiconductor wafer and the film for forming a protective film at a measurement frequency of 10 Hz exceeds 9, the semiconductor chip is damaged by static electricity generated when the semiconductor chip is picked up. It cannot be effectively prevented from being done. The absolute value of the relative dielectric constant difference is preferably 8.9 or less, more preferably 8.8 or less, and even more preferably 8.7.

  The semiconductor wafer using the protective film forming film is not particularly limited, and a known wafer as a semiconductor material can be used. For example, various types of semiconductor wafers such as a silicon wafer, a GaAs wafer, a SiC wafer, and a GaN wafer can be used, but a silicon wafer having high versatility is preferable.

  Hereinafter, each component constituting the protective film forming film satisfying the above formula (1) will be described in detail. The characteristics required for the protective film forming film of the semiconductor chip include at least (i) that the film (or sheet) shape can be maintained, (ii) that it has initial tackiness, and that it can adhere to the polished semiconductor back surface, Further, (iii) it is required that a protective film can be formed by adhering the protective film forming film to the back surface of the semiconductor chip and then curing the film. In order to satisfy these requirements, the components constituting the protective film-forming film include a film property-imparting polymer component or a reactive film-imparting polymer component, a curable component, a curing accelerating component, an inorganic filler component, a colorant component, Coupling agent components and the like can be mentioned, but are not limited to these components, and components can be appropriately replenished or the like depending on the use of the semiconductor chip.

On the other hand, in order to make the absolute value of the difference between the relative dielectric constants of the semiconductor wafer and the protective film formation film at a measurement frequency of 10 Hz equal to or less than 9, the relative dielectric constant (ε _F ) of the protective film formation film at a measurement frequency of 10 Hz is changed. Need to adjust. The relative dielectric constant (ε _F ) of the film for forming a protective film at a measurement frequency of 10 Hz can be set to a desired range by appropriately adjusting the type and the amount of each component described later. For example, the relative dielectric constant (ε _M ) at a measurement frequency of 10 Hz of an organic material component such as a polymer component or a curable component described later is considerably smaller than the relative dielectric constant (ε _S ) of a semiconductor wafer at a measurement frequency of 10 Hz. Even when | ε _S −ε _M |> 9, it is possible to adjust the type, shape, size, and blending amount of components that are not soluble in organic material components such as inorganic fillers. , the semiconductor wafer and the protective film forming film, the absolute value of the difference between the relative dielectric constant at a measuring frequency 10Hz can be a 9 or less _{(| | ε S -ε F)} . Both the relative dielectric constant (ε _M ) of the organic material component at a measurement frequency of 10 Hz and the relative dielectric constant (ε _I ) of a component that is not dissolved in the organic material component at a measurement frequency of 10 Hz are | ε _S −ε. By selecting a material that satisfies _M | ≦ 9 and | ε _S −ε _I | ≦ 9, the relative dielectric constant (ε _F ) of the film for forming a protective film at a measurement frequency of 10 Hz is | ε _S −ε It is easy to adjust so as to satisfy _F | ≦ 9.

<Film property imparting polymer component>
The protective film forming film according to the present invention needs to contain a component capable of maintaining the film (or sheet) shape in order to function as a protective film on the back surface of the semiconductor. In addition, in this specification, the film property-imparting polymer component means a polymer component having no reactive functional group in order to be distinguished from a reactive film-imparting polymer component described later. Examples of such a film property-imparting polymer component include a thermoplastic polyhydroxypolyether resin, a phenoxy resin which is a condensate of epichlorohydrin and various bifunctional phenol compounds, or a hydroxyl group in a hydroxyether portion present in the skeleton thereof, and various acid anhydrides. Phenoxy resin, polyvinyl acetal resin, polyamide resin, polyamide imide resin, block copolymer, and the like, which are esterified by using acid chloride. These polymers may be used alone or in combination of two or more. In order to maintain the shape of the film (or sheet), the weight average molecular weight (Mw) of these polymers is usually 2 × 10 ⁴ or more, preferably 2 × 10 ^{4 to} 3 × 10 ⁶ .

In the present specification, the value of the weight average molecular weight (Mw) can be measured by a gel permeation chromatography (GPC) method (polystyrene standard) using the following measuring apparatus and measuring conditions.
Measuring device: Waters "Waters 2695"
Detector: Waters "Waters2414", RI (differential refractometer)
Column: Waters “HSPgel Column, HR MB-L, 3 μm, 6 mm × 150 mm” × 2 + Waters “HSPgel Column, HR1.3 μm, 6 mm × 150 mm” × 2
Measurement condition:
Column temperature: 40 ° C
RI detector set temperature: 35 ° C
Developing solvent: tetrahydrofuran Flow rate: 0.5 ml / min Sample volume: 10 μl
Sample concentration: 0.7wt%

  The polyvinyl acetal resin is obtained, for example, by acetalizing a polyvinyl alcohol resin with an aldehyde. The aldehyde is not particularly limited, and includes, for example, formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, and the like.

  Specific examples of the phenoxy resin include FX280 and FX293 manufactured by Toto Kasei Co., Ltd., and YX8100, YL6954, and YL6974 manufactured by Mitsubishi Chemical Corporation.

  Specific examples of the polyvinyl acetal resin include Sekisui Chemical Co., Ltd. eslek KS series, polyamide resin KS5000 series manufactured by Hitachi Chemical Co., and BP series manufactured by Nippon Kayaku Co., Ltd.

  Examples of the polyamide-imide resin include KS9000 series manufactured by Hitachi Chemical Co., Ltd.

  When the thermoplastic polyhydroxypolyether resin has a fluorene skeleton, it has a high glass transition point and is excellent in heat resistance, so it maintains a low coefficient of thermal expansion by a semi-solid or solid epoxy resin and maintains its glass transition point. The cured film obtained has a low coefficient of thermal expansion and a high glass transition point in a well-balanced manner. Further, since the thermoplastic polyhydroxy polyether resin has a hydroxyl group, it exhibits good adhesion to a semiconductor wafer.

  The film property-imparting polymer component may be a polymer obtained by block copolymerizing the monomers constituting the above-mentioned components. The block copolymer is a copolymer having a molecular structure in which two or more types of polymers having different properties are connected by a covalent bond to form a long chain. As the block copolymer, an XYX type or XY-X 'type block copolymer is preferable. In the XYX-type and XYX'-type block copolymers, Y at the center is a soft block, the glass transition temperature (Tg) is low, and both outer A or X 'are hard blocks. Those having a glass transition temperature (Tg) composed of a polymer unit higher than the central Y block are preferred. Glass transition temperature (Tg) is measured by differential scanning calorimetry (DSC).

  Further, among the XYX type and XYX ′ type block copolymers, X or X ′ is composed of a polymer unit having a Tg of 50 ° C. or more, and the glass transition temperature (Tg) of B is A block copolymer comprising a polymer unit having a Tg of X or X 'or less is more preferred. Further, among the XYX-type and XYX'-type block copolymers, those in which X or X 'has high compatibility with a curable component described below are preferable, and Y is a curable component. Are preferably those having low compatibility. In this way, the block at both ends is compatible with the matrix (curable component) and the central block is a block copolymer incompatible with the matrix (curable component), so that the specific block in the matrix is obtained. It is thought that it becomes easy to show a simple structure.

  Among the various polymers described above, a phenoxy resin, a polyvinyl acetal resin, a thermoplastic polyhydroxypolyether resin having a fluorene skeleton, and a block copolymer are preferable.

  The ratio of the film property-imparting polymer component to all components constituting the protective film-forming film is not particularly limited, and is preferably 10 to 50 parts by mass when the total of all components is 100 parts by mass. , More preferably 15 to 45 parts by mass.

<Reactive film property imparting polymer component>
As a component constituting the protective film-forming film, a film-imparting polymer component capable of reacting with a curable component described later may be contained. As such a reactive film property imparting polymer, it is preferable to use a carboxyl group-containing resin or a phenol resin. In particular, it is preferable to use a carboxyl group-containing resin because it easily reacts with the epoxy resin when the epoxy resin is contained as a curable component, and improves the properties as a semiconductor protective film while imparting film formability.

As the carboxyl group-containing resin, the following resins (1) to (7) can be suitably used.
(1) a dialcohol compound, a polycarbonate-based polyol, a diisocyanate such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate, or an aromatic diisocyanate, and a carboxyl group such as dimethylolpropionic acid or dimethylolbutanoic acid; Carboxyl group-containing urethane resin by polyaddition reaction of a diol compound such as a polyether-based polyol, a polyester-based polyol, a polyolefin-based polyol, a bisphenol A-based alkylene oxide adduct diol, a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group,
(2) a carboxyl group-containing urethane resin obtained by a polyaddition reaction between a diisocyanate and a carboxyl group-containing dialcohol compound,
(3) a carboxyl group-containing resin obtained by copolymerization of an unsaturated carboxylic acid such as (meth) acrylic acid and an unsaturated group-containing compound such as styrene, α-methylstyrene, lower alkyl (meth) acrylate, and isobutylene;
(4) A difunctional acid such as adipic acid, phthalic acid or hexahydrophthalic acid is reacted with a bifunctional epoxy resin or a bifunctional oxetane resin, and the resulting hydroxyl groups are reacted with phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride or the like. Carboxyl group-containing polyester resin to which dibasic acid anhydride is added,
(5) a carboxyl group-containing resin obtained by ring-opening an epoxy resin or an oxetane resin and reacting a generated hydroxyl group with a polybasic acid anhydride;
(6) A compound having a plurality of phenolic hydroxyl groups in one molecule, that is, a polyphenol compound is reacted with an alkylene oxide such as ethylene oxide or propylene oxide to obtain a reaction product such as a polyalcohol resin or the like. And (7) a polyalcohol resin obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule, that is, a polyphenol compound with an alkylene oxide such as ethylene oxide and propylene oxide. A carboxyl group-containing resin obtained by reacting an unsaturated group-containing monocarboxylic acid such as (meth) acrylic acid with a reaction product such as acrylic acid, and further reacting a polybasic acid anhydride with the obtained reaction product;
And the like can be suitably used. In addition, in this specification, (meth) acrylate means acrylate, methacrylate, and a mixture thereof.

  Among the above resins, the above (1), (2), (6) and (7) do not contain chlorine and can be used as a non-photosensitive carboxyl group-containing resin. Among these, the resins (6) and (7) are preferable because of a good balance in all properties.

The weight average molecular weight of the reactive film property-imparting polymer varies depending on the resin skeleton, but is generally preferably in the range of 2 × 10 ^{3 to} 1.5 × 10 ⁵ , and more preferably 3 × 10 ³ to 1 The range is × 10 ⁵ , but is not limited to these ranges.

  The ratio of the reactive film property-imparting polymer component to all components constituting the protective film-forming film is not particularly limited, and, for example, 20 to 60 parts by mass of the above-mentioned film property-imparting polymer 100 parts by mass is reactive. It is preferable to substitute a film-imparting polymer.

<Curable component>
As the curable component, any of a component that is cured by heat and a component that is cured by ionizing radiation such as ultraviolet light or an electron beam may be used, but a component that is cured by heat is preferable. Hereinafter, the thermosetting component will be described, but it is not intended to exclude components that are cured by ionizing radiation.

  As the thermosetting component, a conventionally known resin can be used without any particular limitation, but it is preferable to use an epoxy resin. Epoxy resins include solid, semi-solid, and liquid epoxy resins depending on the shape before the reaction. These can be used alone or in combination of two or more.

  Examples of the solid epoxy resin include HP-4700 (a naphthalene type epoxy resin) manufactured by DIC, EXA4700 (a tetrafunctional naphthalene type epoxy resin) manufactured by DIC, and NC-7000 (a polyfunctional solid epoxy resin containing a naphthalene skeleton) manufactured by Nippon Kayaku Co., Ltd. Epoxidized product of a condensate of a phenol such as Nippon Kayaku Co., Ltd. EPPN-502H (trisphenol epoxy resin) with an aromatic aldehyde having a phenolic hydroxyl group (trisphenol epoxy resin); DIC Dicyclopentadiene aralkyl type epoxy resin such as Epicron HP-7200H (dicyclopentadiene skeleton-containing multifunctional solid epoxy resin); biphenyl aralkyl such as Nippon Kayaku Corporation NC-3000H (biphenyl skeleton-containing polyfunctional solid epoxy resin). Type epoxy Resin: Biphenyl / phenol novolak type epoxy resin such as NC-3000L manufactured by Nippon Kayaku Co .; Novolak type epoxy resin such as Epicron N660, Epicron N690 manufactured by DIC, EOCN-104S manufactured by Nippon Kayaku; YX- manufactured by Mitsubishi Chemical Corporation A biphenyl-type epoxy resin such as 4000; a phosphorus-containing epoxy resin such as TX0712 manufactured by Nippon Steel & Sumikin Chemical; a tris (2,3-epoxypropyl) isocyanurate such as TEPIC manufactured by Nissan Chemical Industries.

  Examples of the semi-solid epoxy resin include Epicron 860, Epicron 900-IM, Epicron EXA-4816, Epicron EXA-4822, Araldite AER280 manufactured by Asahi Ciba, Epototo YD-134 manufactured by Toto Kasei, jER834 manufactured by Mitsubishi Chemical, and jER872, a bisphenol A type epoxy resin such as ELA-134 manufactured by Sumitomo Chemical Co., Ltd .; a naphthalene type epoxy resin such as Epicron HP-4032 manufactured by DIC; a phenol novolak type epoxy resin such as Epicron N-740 manufactured by DIC. .

  As the liquid epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, phenol novolak type epoxy resin, tert-butyl-catechol type epoxy resin, glycidylamine type epoxy resin, aminophenol type epoxy resin And alicyclic epoxy resins.

  The above-mentioned curable components can be used alone or in combination of two or more. The amount of the curable component is preferably 10 to 50 parts by weight, and more preferably 20 to 40 parts by weight, when the total of the film-forming polymer and the reactive film-forming polymer is 100 parts by weight. More preferably, 20 to 35 parts by mass is even more preferable. In addition, when the liquid epoxy resin is mixed, the glass transition temperature (Tg) of the cured product is lowered, and the crack resistance may be deteriorated. Therefore, the compounding amount of the liquid epoxy resin is 0 to the entire curable component. It is preferably 45 parts by weight, more preferably 0 to 30 parts by weight, and particularly preferably 0 to 5 parts by weight.

<Curing agent component>
As a component constituting the film for forming a protective film according to the present invention, a curing agent component may be contained. The curing agent component has a functional group that reacts with the above-described curable component. Examples of such a curing agent component include a phenol resin, a polycarboxylic acid and its acid anhydride, a cyanate ester resin, an active ester resin, and the like. One of these may be used alone or in combination of two or more. it can.

  Examples of the phenol resin include a phenol novolak resin, an alkylphenol volak resin, a bisphenol A novolak resin, a dicyclopentadiene-type phenol resin, an Xylok-type phenol resin, a terpene-modified phenol resin, a cresol / naphthol resin, a polyvinylphenol, a phenol / naphthol resin, Conventionally known ones such as an α-naphthol skeleton-containing phenol resin and a triazine-containing cresol novolak resin can be used alone or in combination of two or more.

  Polycarboxylic acids and acid anhydrides thereof are compounds having two or more carboxyl groups in one molecule and acid anhydrides thereof. For example, a copolymer of (meth) acrylic acid, a copolymer of maleic anhydride, In addition to dibasic acid condensates, carboxylic acid-terminated resins such as carboxylic acid-terminated imide resins may be mentioned.

  The cyanate ester resin is a compound having two or more cyanate ester groups (—OCN) in one molecule. Any conventionally known cyanate ester resin can be used. As the cyanate ester resin, for example, phenol novolak type cyanate ester resin, alkylphenol novolak type cyanate ester resin, dicyclopentadiene type cyanate ester resin, bisphenol A type cyanate ester resin, bisphenol F type cyanate ester resin, bisphenol S type cyanate ester resin Is mentioned. Further, a prepolymer partially triazined may be used.

  The active ester resin is a resin having two or more active ester groups in one molecule. The active ester resin can be generally obtained by a condensation reaction between a carboxylic acid compound and a hydroxy compound. Among them, an active ester compound obtained by using a phenol compound or a naphthol compound as the hydroxy compound is preferable. Examples of the phenol compound or naphthol compound include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol , Dicyclopentadienyl diphenol, phenol novolak and the like.

  An alicyclic olefin polymer other than those described above can be used as the curing agent component. Examples of the alicyclic olefin polymer that can be suitably used include (1) an alicyclic olefin having a carboxyl group and / or a carboxylic anhydride group (hereinafter, referred to as a “carboxyl group or the like”), if necessary, (2) An aromatic olefin having a carboxyl group or the like is polymerized with other monomers, if necessary, and the aromatic ring portion of the (co) polymer obtained is hydrogenated. And (3) a copolymer of an alicyclic olefin having no carboxyl group and a monomer having a carboxyl group and the like; (4) an aromatic olefin having no carboxyl group and the like and a carboxyl group and the like. A hydrogenated aromatic ring portion of a copolymer obtained by copolymerization with a monomer having the same. (5) An alicyclic olefin polymer having no carboxyl group or the like has a carboxyl group or the like. (6) The carboxylic acid ester group of the alicyclic olefin polymer having a carboxylic acid ester group obtained as described in the above (1) to (5) is obtained by, for example, hydrolysis or the like. And a carboxyl group.

  Among the above-mentioned curing agent components, a phenol resin, a cyanate ester resin, an active ester resin, and an alicyclic olefin polymer are preferable. In particular, it is more preferable to use a phenol resin because the polarity is high and the relative permittivity is easily adjusted.

  The curing agent component has a ratio of a functional group such as an epoxy group of the curable component (functional group capable of curing reaction) to a functional group of the curing agent component capable of reacting with the functional group (the number of functional groups of the curing agent component). / The number of functional groups of the curable component: equivalent ratio) is preferably 0.2 to 5. By setting the equivalent ratio in the above range, a film for forming a protective film having more excellent protection properties can be obtained.

<Curing accelerator component>
As a component constituting the protective film forming film according to the present invention, a curing accelerator component may be contained. The curing accelerator component promotes the curing reaction of the curable component, and can further improve the adhesion of the protective film to the semiconductor wafer and the heat resistance. Examples of curing accelerator components include imidazole and derivatives thereof; guanamines such as acetoguanamine and benzoguanamine; diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, and polybasic hydrazides. Polyamines such as these; organic acid salts and / or epoxy adducts thereof; amine complexes of boron trifluoride; ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-xylyl Triazine derivatives such as -S-triazine; trimethylamine, triethanolamine, N, N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa (N-methyl) melamine, Amines such as 2,6-tris (dimethylaminophenol), tetramethylguanidine and m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolak and alkylphenol novolak; tributylphosphine, triphenylphosphine, tris- Organic phosphines such as 2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide and hexadecyltributylphosphonium chloride; quaternary ammonium such as benzyltrimethylammonium chloride and phenyltributylammonium chloride Salts; the polybasic acid anhydride; diphenyliodonium tetrafluoroboroate, triphenylsulfonium Photocationic polymerization catalysts such as xafluoroantimonate and 2,4,6-triphenylthiopyrylium hexafluorophosphate; styrene-maleic anhydride resin; equimolar reactants of phenyl isocyanate and dimethylamine, tolylene diisocyanate, and isophorone Conventionally known curing accelerators such as an equimolar reactant of an organic polyisocyanate such as diisocyanate and dimethylamine, and a metal catalyst may be used, and one of these may be used alone or as a mixture of two or more.

  The curing accelerator component is not essential, but if it is desired to accelerate the curing reaction, it can be used in an amount of preferably 0.01 to 20 parts by mass based on 100 parts by mass of the curable component. When a metal catalyst is used as a curing accelerator component, its content is preferably from 10 to 550 ppm, more preferably from 25 to 200 ppm, in terms of metal, based on 100 parts by mass of the curable component.

<Inorganic filler component>
The film for forming a protective film according to the present invention may contain an inorganic filler component. The inclusion of the inorganic filler component facilitates protection of the semiconductor chip during dicing. In addition, by performing the laser marking on the protective film, the inorganic filler component is exposed at the portion cut off by the laser light, and the reflected light is diffused, so that a color close to white is exhibited. Thus, when the protective film-forming film contains a colorant component described later, a contrast difference is obtained between the laser marking portion and another portion, and the marking (printing) is clarified.

  The above-mentioned inorganic filler does not dissolve in the above-mentioned organic material component constituting the film for forming a protective film, but is dispersed in the organic material component. Therefore, interfacial polarization occurs due to the presence of the interface between the organic material component and the insoluble component. The relative dielectric constant of the film for forming a protective film at a measurement frequency of 10 Hz can be adjusted by controlling interfacial polarization, but both the organic material component and a component that is not dissolved in the organic material component (for example, an inorganic filler component) are used. Is selected from those close to the relative dielectric constant of the semiconductor wafer at the measurement frequency of 10 Hz, the relative dielectric constant of the film for forming a protective film can be easily adjusted within a predetermined range.

  As the inorganic filler component, conventionally known ones can be used without limitation, for example, powders of silica, alumina, talc, aluminum hydroxide, calcium carbonate, titanium oxide, iron oxide, silicon carbide, boron nitride, etc. Spherical beads, single crystal fibers, glass fibers and the like can be mentioned, and one kind can be used alone or two or more kinds can be used in combination. However, when a component that does not dissolve in the organic material component such as an inorganic filler component is included in the film for forming a protective film, the relative dielectric constant at a measurement frequency of 10 Hz may increase when the type of the component that does not dissolve increases. . The relative dielectric constant of the protective film-forming film is not uniquely determined only by the type of the component that does not dissolve in the organic material component. Preferably, it is more preferably within three types. Among the above-mentioned inorganic filler components, silica, alumina, and titanium oxide are preferable in order to control the dielectric constant in the film.

  The inorganic filler component is dispersed without dissolving in the organic material component, and is in a non-uniform dispersion state. In order to make the relative dielectric constant difference between the semiconductor wafer and the film for forming a protective film at a measurement frequency of 10 Hz equal to or less than 9, the interface between the organic material component and the inorganic filler component is reduced, and the influence of interface polarization is reduced. It is preferable to limit the relative permittivity because the relative permittivity is easily controlled. Therefore, as long as the inorganic fillers have the same average particle diameter, those having a spherical shape are more preferable than those having an irregular shape. Further, when the organic material component and the inorganic filler component are contained in the protective film-forming film, the relative dielectric constant of the protective film-forming film at a measurement frequency of 10 Hz is adjusted by the average particle diameter of the inorganic filler and the amount thereof. can do.

  The inorganic filler component preferably has an average particle size of 0.01 to 15 μm, more preferably 0.02 to 12 μm, and particularly preferably 0.03 to 10 μm. In this specification, the average particle diameter is the number average particle diameter calculated by measuring the major axis diameter of 20 randomly selected inorganic fillers with an electron microscope and calculating the arithmetic average value.

  The content of the inorganic filler component is preferably 10 to 400 parts by mass, more preferably 30 to 350 parts by mass, based on 100 parts by mass of all non-volatile physical components constituting the film for forming a protective film. Preferably it is 60 to 300 parts by mass.

In addition, when a component that does not dissolve in the organic material component such as the inorganic filler component is included in the protective film forming film, the influence of interface polarization at the interface between the inorganic filler component and the organic material component is limited, and the relative dielectric constant is reduced. From the viewpoint of easy control, it is preferable that the surface area of the inorganic filler component is small. For example, when the inorganic filler component is contained in the protective film-forming film at a ratio of 20% by mass or more, the interface polarization is adjusted by selecting an inorganic filler component having a specific surface area of 10 m ² / g or less. It will be easier.

On the other hand, when the specific surface area of a component that does not dissolve in an organic material component such as an inorganic filler component exceeds 10 m ² / g, if such a component is dispersed in the organic material component, the protective film-forming film The relative dielectric constant at a measurement frequency of 10 Hz may change significantly. Therefore, it is preferable that the inorganic filler component having a specific surface area of more than 10 m ² / g is contained in the protective film forming film at a ratio of 10% by mass or less. In addition, depending on the specific surface area of the component that does not dissolve in the organic material component, the amount of the component in the protective film forming film is appropriately adjusted, and the relative dielectric constant of the protective film forming film at a measurement frequency of 10 Hz is desired. Value.

<Colorant component>
The film for forming a protective film according to the present invention may contain a colorant component. By including the colorant component, when a semiconductor chip provided with a protective film is incorporated in a device, malfunction of the semiconductor device due to infrared rays or the like generated from peripheral devices can be prevented. Further, when the protective film is engraved by means such as laser marking, marks such as characters and symbols can be easily recognized. That is, in a semiconductor chip on which a protective film is formed, a product number or the like is usually printed on the surface of the protective film by a laser marking method (a method of shaving and printing the surface of the protective film with a laser beam). By containing the same, a sufficient contrast difference is obtained between the portion of the protective film that is cut off by the laser beam and the portion that is not, and the visibility is improved.

  As the colorant component, organic or inorganic pigments and dyes can be used alone or in combination of two or more. Among them, black pigments are preferable from the viewpoint of electromagnetic wave and infrared ray shielding properties. Examples of the black pigment include, but are not limited to, carbon black, perylene black, iron oxide, manganese dioxide, aniline black, activated carbon and the like. From the viewpoint of preventing malfunction of the semiconductor device, carbon black is particularly preferable. Instead of carbon black, a pigment or dye such as red, blue, green, or yellow may be mixed to obtain a black color or a similar black color.

  Examples of the red colorant include monoazo, disazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone, and specific examples include the following. Can be Pigment Red 1, 2, 3, 4, 5, 6, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 112, 114, 146, 147, 151, 170, Monoazo red coloring agents such as 184, 187, 188, 193, 210, 245, 253, 258, 266, 267, 268, 269, disazo red coloring agents such as Pigment Red 37, 38, 41, Pigment Red 48: 1, 48: 2,48: 3,48: 4,49: 1,49: 2,50: 1,52: 1,52: 2,53: 1,53: 2,57: 1,58: 4,63: 1 Monoazo lake-based red colorants such as 63: 2, 64: 1, 68, Pigment Red 171, Pigment Red 175, Pigment Red 176, Pigment Re 185, benzimidazolone red colorant such as PigmentRed208, SolventRed135, SolventRed179, PigmentRed123, PigmentRed149, PigmentRed166, PigmentRed178, PigmentRed179, PigmentRed190, PigmentRed194, perylene-based red coloring agents such as PigmentRed224, PigmentRed254, PigmentRed255, PigmentRed264, PigmentRed270, PigmentRed272 Diketopyrrolopyrrole red colorants, such as Pigment Red 220, Pigment Red 144, Pigment Red 166, Pigment Red 214, Pi gmentRed220, PigmentRed221, condensed azo red colorant such as PigmentRed242, PigmentRed168, PigmentRed177, PigmentRed216, SolventRed149, SolventRed150, SolventRed52, anthraquinone-based red coloring agents such as SolventRed207, PigmentRed122, PigmentRed202, PigmentRed206, PigmentRed207, quinacridone such PigmentRed209 red Coloring agents.

  Examples of blue colorants include phthalocyanine-based and anthraquinone-based pigments. Pigment-based compounds are classified as Pigment, specifically: PigmentBlue15, PigmentBlue15: 1, PigmentBlue15: 2, PigmentBlue15: 3, Pig15: 4, and Pigment: 15: 4. , PigmentBlue 15: 6, PigmentBlue16, PigmentBlue60, and the like. As the dye system, SolventBlue35, SolventBlue63, SolventBlue68, SolventBlue70, SolventBlue83, SolventBlue87, SolventBlue94, SolventBlue97, SolventBlue97, SolventBlue67, SolventBlue67, SolventBlue122, SolventBlue67, SolventBlue122, SolventBlue122, SolventBlue122, SolventBlue122, SolventBlue122, SolventBlue122, and SolventBlue122, SolventBlue122, SolventBlue122, SolventBlue122, SolventBlue122, SolventBlue122, SolubleBlue122 In addition, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

  Green colorants include phthalocyanine-based, anthraquinone-based, perylene-based, and the like. Specifically, Pigment Green 7, Pigment Green 36, Solvent Green 3, Solvent Green 5, Solvent Green 20, Solvent Green 28, and the like can be used. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

  Examples of the yellow colorant include a monoazo type, a disazo type, a condensed azo type, a benzimidazolone type, an isoindolinone type and an anthraquinone type, and specific examples thereof include the following. SolventYellow163, PigmentYellow24, PigmentYellow108, PigmentYellow193, PigmentYellow147, PigmentYellow199, anthraquinone-based yellow colorant such as PigmentYellow202, PigmentYellow110, PigmentYellow109, PigmentYellow139, PigmentYellow179, isoindolinone-based yellow colorant such as PigmentYellow185, PigmentYellow93, PigmentYellow94, PigmentYellow95, PigmentYellow128, PigmentYellow155, Pigment Yellow 166, pigment yellow 120 such as Pigment Yellow 120, Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 156, Pigment Yellow 175, Pigment Yellow such as Pigment Yellow 1, 181, Pigment Yellow 1, Pigment 2, etc. , 62, 62: 1, 65, 73, 74, 75, 97, 100, 104, 105, 111, 116, 167, 168, 169, 182, 183, etc., and Pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188 Etc. can be used disazo-based yellow colorant such as 198.

  A colorant such as purple, orange, brown, or black may be added for the purpose of adjusting the color tone. Specifically, PigmentViolet 19, 23, 29, 32, 36, 38, 42, SolventViolet 13, 36, C.I. I. Pigment Orange 1, C.I. I. Pigment Orange 5, C.I. I. Pigment Orange 13, C.I. I. Pigment Orange 14, C.I. I. Pigment Orange 16, C.I. I. Pigment Orange 17, C.I. I. Pigment Orange 24, C.I. I. Pigment Orange 34, C.I. I. Pigment Orange 36, C.I. I. Pigment Orange 38, C.I. I. Pigment Orange 40, C.I. I. Pigment Orange 43, C.I. I. Pigment Orange 46, C.I. I. Pigment Orange 49, C.I. I. Pigment Orange 51, C.I. I. Pigment Orange 61, C.I. I. Pigment Orange 63, C.I. I. Pigment Orange 64, C.I. I. Pigment Orange 71, C.I. I. Pigment Orange 73, C.I. I. Pigment Brown 23, C.I. I. Pigment Brown 25, C.I. I. Pigment Black 1, C.I. I. Pigment Black 7 and the like.

  In the above colorant components, pigments and the like are dispersed in the organic material components without being dissolved, and are in a non-uniform dispersion state. Therefore, similarly to the inorganic filler component, the relative dielectric constant at the measurement frequency of 10 Hz of the protective film forming film can be controlled not only by the type and the amount of the colorant component but also by the shape and the specific surface area of the colorant component. it can.

  The colorant component is preferably 0.1 to 35 parts by mass, more preferably 0.5 to 25 parts by mass, and particularly preferably 1 to 15 parts by mass with respect to 100 parts by mass of the total solids constituting the film for forming a protective film. It is contained in the ratio of parts by mass.

<Coupling agent component>
A cup having a functional group that reacts with an inorganic substance and a functional group that reacts with an organic functional group in order to improve the adhesion and adhesion of the film for forming a protective film to an adherend (semiconductor wafer) and / or the cohesiveness of the protective film. A ring agent component may be included. Further, by including the coupling agent component, the water resistance of the protective film obtained by curing the protective film forming film can be improved without impairing the heat resistance. Examples of such a coupling agent include titanate-based coupling agents, aluminate-based coupling agents, and silane coupling agents. Among these, a silane coupling agent is preferable.

  Examples of the organic group contained in the silane coupling agent include, for example, a vinyl group, an epoxy group, a styryl group, a methacryloxy group, an acryloxy group, an amino group, a ureido group, a chloropropyl group, a mercapto group, a polysulfide group, and an isocyanate group. No. Commercially available silane coupling agents can be used, for example, KA-1003, KBM-1003, KBE-1003, KBM-303, KBM-403, KBE-402, KBE-403, KBM-1403. , KBM-502, KBM-503, KBE-502, KBE-503, KBM-5103, KBM-602, KBM-603, KBE-603, KBM-903, KBE-903, KBE-9103, KBM-9103, KBM -573, KBM-575, KBM-6123, KBE-585, KBM-703, KBM-802, KBM-803, KBE-846, KBE-9007 (all trade names; manufactured by Shin-Etsu Silicone Co., Ltd.). it can. These may be used alone or in combination of two or more.

<Other ingredients>
In the film for forming a protective film according to the present invention, various additives may be blended as necessary, in addition to the components described above. Examples of the various additives include a leveling agent, a plasticizer, an antioxidant, an ion scavenger, a gettering agent, a chain transfer agent, and a release agent.

  The thickness of the protective film-forming film is not particularly limited, but is preferably 3 to 300 μm, more preferably 5 to 250 μm, and particularly preferably 7 to 200 μm.

  The film for forming a protective film according to the present invention has an initial adhesive property and a thermosetting property. In an uncured state, the film is easily adhered to a semiconductor wafer or a chip by pressing. When pressing, any of heating and pressing may be performed on the protective film forming film. Finally, a protective film having high impact resistance can be formed through thermal curing. The protective film formed using the protective film-forming film according to the present invention has excellent adhesive strength and can maintain a sufficient protective function even under severe high temperature and high humidity conditions. The film for forming a protective film may have a single-layer structure or a multilayer structure.

  The film for forming a protective film according to the present invention preferably has a maximum transmittance at a wavelength of 300 to 1200 nm of 20% or less, which is a measure showing the transmittance of visible light and / or infrared light and ultraviolet light, and 0 to 15%. It is more preferably, more preferably more than 0% and 10% or less, particularly preferably 0.001 to 8%. By setting the maximum transmittance of the film for forming a protective film at a wavelength of 300 to 1200 nm in the above range, the transmittance in the visible light wavelength region and / or the infrared wavelength region is reduced, and malfunction of the semiconductor device due to infrared light is caused. The effect of prevention and improvement of the visibility of printing can be obtained. The maximum transmittance of the protective film-forming film at a wavelength of 300 to 1200 nm can be adjusted by the type and content of the above-described colorant component. In the present specification, the maximum transmittance of the protective film-forming film (25 μm thickness) of the cured protective film-forming film (25 μm in thickness) was measured using a UV-vis spectrum inspection device (manufactured by Shimadzu Corporation). The total light transmittance at ~ 1200 nm is measured, and the highest value of transmittance (maximum transmittance) is referred to.

[Method for producing protective film-forming film]
The film for forming a protective film according to the present invention can be obtained by using a composition (composition for forming a protective film) obtained by mixing the above-mentioned components in proportions. When the composition is prepared, the above formula ( It is necessary to mix each component so as to have a relative dielectric constant satisfying 1). The composition for forming a protective film may be diluted with a solvent in advance, or may be added to the solvent at the time of mixing. When using the composition for forming a protective film, the composition may be diluted with a solvent. Examples of the solvent include ethyl acetate, methyl acetate, diethyl ether, dimethyl ether, acetone, methyl ethyl ketone, acetonitrile, hexane, cyclohexane, toluene, heptane and the like.

  The composition for forming a protective film prepared as described above is coated on a support and formed into a film to form a film for forming a protective film. As a film forming method, a conventionally known method can be applied, and a composition for forming a protective film is coated on a support by a known means such as a roll knife coater, a gravure coater, a die coater, and a reverse coater, By drying, a film for forming a protective film can be obtained. Further, by adjusting the coating amount of the composition for forming a protective film, a film for forming a protective film having the above-mentioned thickness can be obtained.

  As the support, conventionally known materials such as a separate paper, a separate film, a separate paper, a release film, and a release paper can be suitably used. In addition, a release paper substrate made of a polyester film such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), a polyolefin film such as an oriented polypropylene film (OPP), or a plastic film such as a polyimide film is released on one or both surfaces of a release paper substrate. What formed the layer may be used. The release layer is not particularly limited as long as it has a release property, and examples thereof include a silicone resin, an organic resin-modified silicone resin, and a fluororesin.

[Method of Manufacturing Semiconductor Device]
The method of using the film for forming a protective film according to the present invention will be described by taking as an example a case where the method is applied to the manufacture of a semiconductor device.

  First, a semiconductor wafer is prepared, and a circuit is formed on one surface. The semiconductor wafer may be a silicon wafer or a compound semiconductor wafer such as gallium arsenide (GaAs). Formation of a circuit on the wafer surface can be performed by various methods including a commonly used method such as an etching method and a lift-off method.

  Next, the opposite surface (back surface) of the circuit surface of the semiconductor wafer is ground. The grinding method is not particularly limited, and the grinding may be performed by a known means using a grinder or the like. When grinding the back surface, a surface protection film (background film) is attached to the circuit surface to protect the circuit on the front surface. In the back surface grinding, the circuit surface side (that is, the surface protection film (background film) side) of the wafer is fixed by a chuck table or the like, and the back surface side where no circuit is formed is ground by a grinder. The thickness of the wafer after grinding is not particularly limited, but is usually about 50 to 500 μm.

  Subsequently, a crushed layer generated at the time of back surface grinding is removed as necessary. Removal of the crushed layer is performed by chemical etching, plasma etching, or the like.

  Then, a film for forming a protective film with a support is adhered to the back surface of the semiconductor wafer, and the support film is peeled off from the film for forming a protective film to obtain a laminate of the semiconductor wafer and the film for forming a protective film. At this time, it is preferable that the semiconductor wafer and the film for forming a protective film are in direct contact with each other in order to suppress an increase in peeling voltage. When another layer exists between the semiconductor wafer and the protective film forming film, the relative permittivity of the other layer is a value between the relative permittivity of the semiconductor wafer and the relative permittivity of the protective film forming film. It is preferred to have.

  Next, the protective film forming film is cured to form a protective film on the entire surface of the wafer. Specifically, the protective film forming film is cured by heat curing. As a result, a protective film made of the above-described resin composition is formed on the back surface of the wafer, and the strength is improved as compared with the case of using only the wafer. Therefore, it is possible to reduce breakage during handling of the wafer that has been thinned by polishing. Also, the uniformity of the thickness of the protective film is excellent as compared with a coating method in which a coating liquid for a protective film is directly applied to the back surface of the wafer or chip and formed into a film.

  Here, the method of forming the protective film over the entire surface of the wafer by curing the protective film forming film after peeling the support film from the protective film forming film has been described, but the order of the support peeling step and the curing step is as follows. May be reversed. That is, a film for forming a protective film with a support is adhered to the back surface of the semiconductor wafer, and then the film for forming a protective film is cured to form a protective film on the entire surface of the wafer. You may peel off.

  After forming the protective film, it is preferable to perform laser printing on the protective film. Laser printing is performed by a laser marking method, and a part number and the like are marked on the protective film by shaving off the surface of the protective film by irradiating a laser beam.

  Subsequently, a dicing tape is attached to the back surface side of the semiconductor wafer to fix the wafer, and then the surface protection film adhered when grinding the wafer is peeled off. At the time of this peeling, a method in which a peeling tape is bonded to a surface protective film by thermocompression bonding or the like, and the peeling tape is pulled up to peel off the surface protective film. There is a method of imparting such a function that the surface protective film can be peeled off by lowering the adhesive strength of the surface protective film by irradiating ultraviolet rays.

  After peeling off the surface protection film on the circuit side of the semiconductor wafer, dicing is performed for each circuit formed on the wafer surface. Dicing is performed so as to cut both the wafer and the protective film. The dicing of the wafer is performed by an ordinary method using a dicing sheet. As a result, a semiconductor chip group having a protective film on the back surface, which is singulated on the dicing sheet, is obtained.

  Finally, a semiconductor chip provided with a protective film on the back surface (a chip with a protective film) is picked up by a general-purpose means such as a collet to obtain a chip with a protective film. Then, the semiconductor device can be manufactured by mounting the chip with the protective film on a predetermined base in a face-down manner. In addition, a semiconductor device can be manufactured by bonding a chip with a protective film on another member such as a die pad portion or another semiconductor chip (on a chip mounting portion). According to the present invention, the relative dielectric constant of the film for forming a protective film at a measurement frequency of 10 Hz is set to be within a predetermined range from the relative dielectric constant of the semiconductor wafer at a measurement frequency of 10 Hz, thereby removing the surface protection film. Even when the chip is picked up, the semiconductor chip can be prevented from being electrostatically damaged regardless of the type of the surface protection film, and as a result, a semiconductor chip with high quality reliability can be obtained. Note that whether or not electrostatic breakdown is caused can be evaluated by measuring a peeling voltage.

  A method for measuring a peeling voltage in the present invention will be described. First, the back surface of the semiconductor wafer to which the surface protection film has been adhered is polished to a predetermined thickness. The film for forming a protective film, which has been neutralized, is attached to the polished surface using a hand roller. After the support is separated from the protective film-forming film, a predetermined heat treatment is performed, and the protective film-forming film is cured to form a protective film. Next, a dicing tape, which has been neutralized in advance, is attached to the protective film side of the obtained chip with a protective film using a hand roller. After the sample thus obtained is left for a predetermined time, the surface protective film is peeled off from the sample. The next peeling of the dicing tape is performed so that the dicing tape is fixed to an automatic winding device and the peeling angle is 170 ± 5 ° and the peeling speed is 10 mm / sec. The potential of the surface on the protective film forming film side generated at this time is measured by a potential measuring instrument fixed at a position of 50 mm from the surface of the protective film forming film. The measurement is performed in an environment of 23 ° C. and 50% RH.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “parts” means parts by mass.

<Synthesis of polymer with reactive film>
In an autoclave equipped with a thermometer, a nitrogen introducing device, an alkylene oxide introducing device and a stirring device, a bisphenol A-formaldehyde type phenol resin (trade name “BPA-D” manufactured by Meiwa Kasei Co., Ltd., OH equivalent: 120) Then, 0 g, 1.20 g of potassium hydroxide and 120.0 g of toluene were charged, the inside of the system was replaced with nitrogen while stirring, and the temperature was raised by heating. Next, 63.8 g of propylene oxide was gradually dropped, and reacted at 125 to 132 ° C. and 0 to 4.8 kg / cm ² for 16 hours.

  Thereafter, the reaction solution was cooled to room temperature, and 1.56 g of 89% phosphoric acid was added to and mixed with the reaction solution to neutralize potassium hydroxide. The nonvolatile content was 62.1%, and the hydroxyl value was 182.2 g / eq. A propylene oxide reaction solution of bisphenol A-formaldehyde type phenol resin was obtained. This was an average of 1.08 mol of alkylene oxide added per equivalent of phenolic hydroxyl group.

  293.0 g of an alkylene oxide reaction solution of the obtained novolak type cresol resin, 43.2 g of acrylic acid, 11.53 g of methanesulfonic acid, 0.18 g of methylhydroquinone and 252.9 g of toluene were stirred with a stirrer, a thermometer and an air blowing tube. Was charged into the reactor, and air was blown at a rate of 10 ml / min, and the mixture was reacted at 110 ° C. for 12 hours with stirring.

  12.6 g of water produced by the reaction was distilled off as an azeotrope with toluene. Thereafter, the reaction solution was cooled to room temperature, and the obtained reaction solution was neutralized with 35.35 g of a 15% aqueous sodium hydroxide solution, and then washed with water. Thereafter, toluene was distilled off while replacing the toluene with 118.1 g of propylene glycol monomethyl ether acetate using an evaporator to obtain a novolak type acrylate resin solution.

Next, 332.5 g of the obtained novolak type acrylate resin solution and 1.22 g of triphenylphosphine were charged into a reactor equipped with a stirrer, a thermometer and an air blowing tube, and air was blown at a rate of 10 ml / min. While stirring, 60.8 g of tetrahydrophthalic anhydride was gradually added and reacted at 95 to 101 ° C. for 6 hours to obtain a carboxyl group-containing resin having an acid value of 88 mgKOH / g and a nonvolatile content of 71% as a solid. This is designated as a resin solution A. The weight average molecular weight of the reactive film property imparting polymer (carboxyl group-containing resin) component contained in the resin solution A was 4 × 10 ³ .

The value of the weight average molecular weight (Mw) was measured by a gel permeation chromatography (GPC) method (polystyrene standard) under the following measuring apparatus and measuring conditions.
Measuring device: Waters "Waters 2695"
Detector: Waters "Waters2414", RI (differential refractometer)
Column: Waters “HSPgel Column, HR MB-L, 3 μm, 6 mm × 150 mm” × 2 + Waters “HSPgel Column, HR 1.3 μm, 6 mm × 150 mm” × 2
Measurement condition:
Column temperature: 40 ° C
RI detector set temperature: 35 ° C
Developing solvent: tetrahydrofuran Flow rate: 0.5 ml / min Sample volume: 10 μl
Sample concentration: 0.7wt%

<Preparation of film 1 for forming protective film>
The following components were dissolved and dispersed in methyl ethyl ketone to prepare a protective film forming composition solution 1 having a solid content of 20% by mass.
・ 50 parts of phenoxy resin (FX293 manufactured by Toto Kasei) ・ 70.4 parts of resin solution A ・ 30 parts of naphthalene type epoxy resin (NC-7000 manufactured by Nippon Kayaku) ・ Bixylenol type epoxy resin (YX- manufactured by Mitsubishi Chemical Corporation) 4000) 10 parts, phenolic resin (DEN-431 manufactured by The Dow Chemical Company) 10 parts, C.I. I. Pigment Blue 15: 3 0.8 parts C.I. I. 0.55 parts of Pigment Yellow 147, 1.5 parts of Paliogen Red K3580, 100 parts of spherical silica (Admafine SO-E2 manufactured by Admatechs), 150 parts of aluminum hydroxide (Heidilite H-42M manufactured by Showa Denko KK) 150 parts -2 parts of silane coupling agent (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.)-2 parts of 2-phenylimidazole (2PZ manufactured by Shikoku Chemical Industry Co., Ltd.)

  The protective film forming composition solution 1 was applied to a polyethylene terephthalate film (PET film) having a surface subjected to a release treatment, and dried at 100 ° C. for 5 minutes to prepare a protective film forming film 1 having a thickness of 20 μm.

<Preparation of protective film forming film 2>
The following components were dissolved and dispersed in methyl ethyl ketone to prepare a protective film forming composition solution 2 having a solid content concentration of 20%.
・ 50 parts of phenoxy resin (FX293 manufactured by Toto Kasei) ・ 70.4 parts of resin solution A ・ 30 parts of epoxy resin (trade name: Epicoat 1001; manufactured by JER) ・ Phenol resin (DEN- manufactured by The Dow Chemical Company) 431) 10 parts I. Pigment Blue 15: 3 0.8 parts C.I. I. 0.55 parts of Pigment Yellow 147, 1.5 parts of Paliogen Red K3580, 300 parts of spherical silica (Admafine SO-E2 manufactured by Admatechs), 2 parts of silane coupling agent (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) 2- Phenylimidazole (2PZ, manufactured by Shikoku Chemicals) 2 parts

  The protective film forming composition solution 2 was applied to a polyethylene terephthalate film (PET film) having a surface subjected to a release treatment, and dried at 100 ° C. for 5 minutes to prepare a protective film forming film 2 having a thickness of 20 μm.

<Preparation of protective film forming film 3>
The following components were dissolved and dispersed in methyl ethyl ketone to prepare a protective film forming composition solution 3 having a solid content concentration of 20%.
・ 50 parts of phenoxy resin (FX293 manufactured by Toto Kasei) ・ 70.4 parts of resin solution A ・ 30 parts of naphthalene type epoxy resin (NC-7000 manufactured by Nippon Kayaku) ・ Bixylenol type epoxy resin (YX- manufactured by Mitsubishi Chemical Corporation) 4000) 10 parts ・ Phenol resin (DEN-431 manufactured by The Dow Chemical Company) 10 parts ・ Carbon black (carbon MA-100) 10 parts ・ Spherical silica (Admafine SO-E2 manufactured by Admatechs) 200 parts -15 parts of titanium oxide (CR-90 manufactured by Ishihara Sangyo Co., Ltd.)-2 parts of silane coupling agent (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.)-2 parts of 2-phenylimidazole (2PZ manufactured by Shikoku Chemicals Co., Ltd.)

  The protective film forming composition solution 3 was applied to a polyethylene terephthalate film (PET film) having a surface subjected to a release treatment, and dried at 100 ° C. for 5 minutes to prepare a protective film forming film 3 having a thickness of 20 μm.

<Preparation of protective film forming film 4>
The following components were dissolved and dispersed in methyl ethyl ketone to prepare a protective film forming composition solution 4 having a solid content concentration of 20%.
・ 100 parts of polystyrene resin (Wako Pure Chemical Industries Reagent Great) ・ 30 parts of epoxy resin (Epicoat 1001 manufactured by JER) ・ 10 parts of phenolic resin (DEN-431 manufactured by The Dow Chemical Company) ・ 10 parts of aluminum hydroxide (Japanese) 100 parts, calcium carbonate (NITOREX # 23P, manufactured by Nitto Powder Co., Ltd.) 100 parts, C.I. I. Pigment Blue 15: 3 0.8 parts C.I. I. 0.55 parts of Pigment Yellow 147, 1.5 parts of Paliogen Red K3580, 2 parts of silane coupling agent (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) 2 parts, 2-phenylimidazole (2PZ manufactured by Shikoku Chemicals Co., Ltd.) 2 parts

  The composition solution 4 for forming a protective film was applied to a polyethylene terephthalate film (PET film) whose surface had been subjected to a release treatment, and dried at 80 ° C. for 5 minutes to prepare a film 4 for forming a protective film having a thickness of 20 μm.

<Preparation of protective film forming film 5>
The following components were dissolved and dispersed in methyl ethyl ketone to prepare a protective film forming composition solution 5 having a solid content concentration of 20%.
・ 50 parts of phenoxy resin (FX293 manufactured by Toto Kasei) ・ 70.4 parts of resin solution A ・ 30 parts of naphthalene type epoxy resin (NC-7000 manufactured by Nippon Kayaku) ・ Bixylenol type epoxy resin (YX- manufactured by Mitsubishi Chemical Corporation) 4000) 10 parts ・ Phenol resin (DEN-431 manufactured by The Dow Chemical Company) 10 parts ・ Carbon black (carbon MA-100) 10 parts ・ Spherical silica (Admafine SO-E2 manufactured by Admatechs) 200 parts・ Precipitation method silica (Nippil L300 manufactured by Tosoh Silica Co., Ltd.) 15 parts ・ Silane coupling agent (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) 2 parts ・ 2-phenylimidazole (2PZ manufactured by Shikoku Chemicals Co., Ltd.)

  The protective film forming composition solution 5 was applied to a polyethylene terephthalate film (PET film) having a surface subjected to a release treatment, and dried at 100 ° C. for 5 minutes to prepare a protective film forming film 5 having a thickness of 20 μm.

<Preparation of protective film forming film 6>
The following components were dissolved and dispersed in methyl ethyl ketone to prepare a protective film forming composition solution 6 having a solid content concentration of 20%.
・ 50 parts of phenoxy resin (FX293 manufactured by Toto Kasei) ・ 70.4 parts of resin solution A ・ 30 parts of naphthalene type epoxy resin (NC-7000 manufactured by Nippon Kayaku) ・ Bixylenol type epoxy resin (YX- manufactured by Mitsubishi Chemical Corporation) 4000) 10 parts ・ Phenol resin (DEN-431 manufactured by The Dow Chemical Company) 10 parts ・ Carbon black (carbon MA-100) 10 parts ・ Spherical silica (Admafine SO-E2 manufactured by Admatechs) 180 parts・ Precipitated silica (Nippil L300, manufactured by Tosoh Silica Co., Ltd.) 15 parts ・ Spherical alumina (DAW0525, manufactured by Denki Kagaku Kogyo Co., Ltd.) 20 parts -2 parts of phenylimidazole (2PZ manufactured by Shikoku Chemicals Co., Ltd.)

  The protective film forming composition solution 6 was applied to a polyethylene terephthalate film (PET film) having a surface subjected to a release treatment, and dried at 100 ° C. for 5 minutes to prepare a protective film forming film 6 having a thickness of 20 μm.

<Preparation of surface protection film>
A 100 μm thick polyolefin film is used as a base film, and an aqueous solution of polyethylene dioxythiophene (trade name: Conisol F-205, manufactured by Inscontec Co., Ltd.) is gravure coated on one main surface of the base film. As a result, an antistatic layer having a thickness of 0.1 μm was formed. Thereafter, 100 parts of an acrylic copolymer containing 0.5 meq / g of a photocurable unsaturated carbon bond in the molecule of a base polymer and a polyisocyanate compound as a curing agent (Coronate, trade name, manufactured by Nippon Polyurethane Co., Ltd.) L) 1 part and 2 parts of α-hydroxycyclohexyl phenyl ketone as a photoinitiator were blended to prepare an adhesive coating solution. Using a comma coater, apply a pressure-sensitive adhesive coating solution on a polyethylene terephthalate film (thickness: 25 μm) with silicone release treatment on one side on the opposite side of the release treatment at a linear velocity of 2 m / min. A pressure-sensitive adhesive layer was formed through a set hot-air drying furnace, and the resultant was bonded to an antistatic treatment base film, to produce a surface protective film A having a coating thickness of 30 μm after drying. Further, a surface protection film B was prepared in the same manner as the surface protection film A except that the thickness of the pressure-sensitive adhesive layer was changed to 300 μm, thereby increasing the distance from the antistatic layer to increase the risk of electrostatic breakdown.

<Production of dicing tape>
As the pressure-sensitive adhesive layer forming material, a mixture of 80 parts of trade name "WINTEC WFX4M" (manufactured by Nippon Polypropylene Co., Ltd.) and 20 parts of trade name "Tafselen H5002" (manufactured by Sumitomo Chemical Co., Ltd.) was used. In addition, an ethylene-vinyl acetate copolymer (EVA) (trade name “Evaflex P-1007”, manufactured by Du Pont-Mitsui Co., Ltd.) was used as a base layer forming material. Each of the pressure-sensitive adhesive-forming material and the base material layer-forming material was charged into an extruder, and was subjected to T-die melt co-extrusion to obtain a dicing tape having a pressure-sensitive adhesive layer thickness of 40 µm and a base material layer thickness of 80 µm.

<Preparation of semiconductor wafer>
Two types of semiconductor wafers were prepared: a 4-inch, 525 μm-thick P-type silicon wafer and a 4-inch, 625 μm-thick, non-doped GaAs wafer manufactured by Canosys.

<Measurement of relative permittivity of film for forming protective film>
The relative dielectric constant of the protective film forming films 1 to 6 obtained as described above was measured as follows. First, a film for forming a protective film having a thickness of 20 μm was laminated on a copper-clad laminate using a hand roller, the PET film was peeled off, and the film was cured by heating at 150 ° C. for 30 minutes. The laminate was cooled to room temperature. The thickness of the film for forming a protective film was measured using a surf coater SE-2300 from Kosaka Laboratory. The thickness was an average value measured five times. Next, a circular electrode having a diameter of 38 mmφ was formed by screen printing using a silver paste (AF-5000, manufactured by Taiyo Ink Mfg. Co., Ltd.) on the protective film forming film side of the protective film forming film laminate. At this time, a donut-shaped guard electrode having an inner diameter of 40 mmφ and an outer diameter of 50 mmφ was also formed on the concentric outer periphery of the 38 mmφ circular electrode. After printing the silver paste, it was dried at 80 ° C. for 30 minutes to form silver electrodes, thereby obtaining samples 1 to 6 for measuring relative dielectric constant.

  The obtained relative dielectric constant measurement samples 1 to 6 were left at 23 ° C. and 50% RH for 1 day. Using a LCR meter IM3536 manufactured by Hioki Denki, 38 mmφ circular silver electrodes and copper foil of a copper-clad laminate are each connected to an LCR meter, and the film laminate for forming a protective film is placed in a shielding box and placed in an environment of 23 ° C. and 50% RH. The relative permittivity was measured 256 times continuously at a test voltage (signal voltage) of 0.5 V and a measurement frequency of 10 Hz, and the average value was calculated. The measurement results were as shown in Table 1 below.

<Measurement of relative permittivity of semiconductor wafer>
After laminating the surface protection film A prepared above on one side of the semiconductor wafer, the opposite side was polished until the wafer thickness became 300 μm. Next, from the side of the surface protective film A, a high-pressure mercury lamp was irradiated with irradiation energy of 200 mJ / cm ² for 1 minute, and then fixed to an automatic winding device so that the peeling angle was 170 ± 5 ° and the peeling speed was 10 mm / sec. The surface protective film A was peeled off.

  A silver electrode (AF-5000 manufactured by Taiyo Ink Mfg. Co., Ltd.) was used on one side of the obtained 300 μm-thick semiconductor wafer, and a circular electrode having a diameter of 80 mmφ was formed by screen printing almost at the center of the semiconductor wafer. After drying for 30 minutes, a silver electrode was formed. On the opposite surface, a circular electrode having a diameter of 38 mmφ was formed by screen printing almost at the center of the semiconductor wafer. At this time, a donut-shaped guard electrode having an inner diameter of 40 mmφ and an outer diameter of 50 mmφ was also formed on the concentric outer periphery of the 38 mmφ circular electrode. After printing the silver paste, it was dried at 80 ° C. for 30 minutes to form a silver electrode, thereby obtaining a sample for measuring the relative dielectric constant of the semiconductor wafer.

  A sample for measuring the relative dielectric constant of the obtained semiconductor wafer was left at 23 ° C. and 50% RH for 1 day. Using a Hioki LCR meter IM3536, a 38 mmφ circular silver electrode and an 80 mmφ circular silver electrode were connected to the LCR meter, respectively, and a sample for measuring the relative dielectric constant of the semiconductor wafer was placed in a shielding box and placed under an environment of 23 ° C. and 50% RH. The relative dielectric constant was measured 256 times continuously at a test voltage (signal voltage) of 0.5 V and a measurement frequency of 10 Hz, and the average value was calculated. The measurement results were as shown in Table 1 below.

<Example 1>
After bonding the surface protection film A prepared above to one surface of the silicon wafer, the other side was polished until the wafer thickness became 300 μm. Next, the protective film forming film 1 was bonded to the polished surface using a hand roller, and the PET film was peeled off from the protective film forming film 1, and then heated at 150 ° C. for 30 minutes to form a protective film. Subsequently, the adhesive layer side of the dicing tape, which had been neutralized in advance, was adhered to the protective film side using a hand roller, thereby producing Sample 1.

The sample 1 obtained as described above was allowed to stand for 1 day in an environment of 23 ° C. and 50% RH, and then, under the measurement environment, a high-pressure mercury lamp was irradiated with 200 mJ / cm ² irradiation energy for 1 minute from the surface protective film A side. After irradiation, the film was fixed to an automatic winding device, and the surface protective film A was peeled off at a peeling angle of 170 ± 5 ° and a peeling speed of 10 mm / sec.

  Ten minutes after the surface protective film A was peeled off, the sample was set at a position 50 mm directly below the sensor of the potential measuring device with the dicing tape side up. The dicing tape was fixed to an automatic winding device, and the dicing tape was peeled off at a peeling angle of 170 ± 5 ° and a peeling speed of 10 mm / sec.

  The potential of the protective film forming film side generated at this time was measured by a potential measuring instrument (KSD-2000, manufactured by Kasuga Electric) fixed at a predetermined position. When the peeling voltage was within ± 0.2 kv, it was judged as ○, when it exceeded +0.2 kv, or when the negative value became larger than -0.2 kv, it was judged as x. The judgment results were as shown in Table 1 below.

<Example 2>
In Example 1, the peeling electrification voltage was measured in the same manner as in Example 1 except that the film 1 for forming a protective film was used instead of the film 1 for forming a protective film. The judgment results were as shown in Table 1 below.

<Example 3>
In Example 1, the peeling electrification voltage was measured in the same manner as in Example 1 except that the film 1 for forming a protective film was used instead of the film 1 for forming a protective film. The judgment results were as shown in Table 1 below.

<Example 4>
The peeling voltage was measured in the same manner as in Example 3 except that a GaAs wafer was used instead of the silicon wafer. The judgment results were as shown in Table 1 below.

<Example 5>
In Example 1, the peeling electrification voltage was measured in the same manner as in Example 1 except that the film 5 for forming a protective film was used instead of the film 1 for forming a protective film. The judgment results were as shown in Table 1 below.

<Comparative Example 1>
In Example 1, the peeling electrification voltage was measured in the same manner as in Example 1 except that the film 1 for forming a protective film was used instead of the film 1 for forming a protective film. The judgment results were as shown in Table 1 below.

<Comparative Example 2>
The peeling voltage was measured in the same manner as in Example 1 except that a GaAs wafer was used instead of the silicon wafer. The judgment results were as shown in Table 1 below.

<Comparative Example 3>
In Example 1, the peeling voltage was measured in the same manner as in Example 1 except that the film 6 for forming a protective film was used instead of the film 1 for forming a protective film. The judgment results were as shown in Table 1 below.

  As is clear from the evaluation results shown in Table 1, when the protective film forming film has a relative dielectric constant that satisfies the above formula (1) in relation to the semiconductor wafer (Examples 1 to 5). All showed favorable evaluation results of the peeling charge voltage. On the other hand, when the relative dielectric constant of the film for forming a protective film did not satisfy the above-described formula (1) in relation to the semiconductor wafer (Comparative Examples 1 to 3), the peeling voltage was high.

<Example 5>
Example 1 was repeated except that the surface protective film A was replaced with the surface protective film B in which the thickness of the adhesive layer was 10 times larger and the distance from the antistatic layer was increased to increase the risk of electrostatic breakdown. The peeling voltage was measured in the same manner as in Example 1. As a result, as in Example 1, the evaluation result of the peeling electrostatic voltage was ○. From the above results, it can be seen that the peeling voltage can be suppressed to a small value by using a protective film forming film that satisfies the formula (1) regardless of the surface protective film.

Claims (5)

A film for forming a protective film provided on the back surface of the circuit formation surface of the semiconductor wafer,
The relative permittivity of the semiconductor wafer and the film at a measurement frequency of 10 Hz is represented by the following formula (1):
| Ε _S −ε _F | ≦ 9 (1)
(In the formula, ε _S indicates the relative dielectric constant of the semiconductor wafer at the measurement frequency of 10 Hz, and ε _F indicates the relative dielectric constant of the protective film forming film at the measurement frequency of 10 Hz.)
Satisfied,
A film for forming a protective film, which is obtained by using the composition for forming a protective film.   The film for forming a protective film according to claim 1, wherein the semiconductor wafer is a silicon wafer.   The film for forming a protective film according to claim 1, wherein the film for forming a protective film is provided in direct contact with a back surface of a circuit forming surface of the semiconductor wafer.   The film for forming a protective film according to any one of claims 1 to 3, wherein the film for forming a protective film further comprises a peelable support. The film for forming a protective film according to any one of claims 1 to 4, wherein the composition for forming a protective film includes at least an organic material component and a component that is insoluble in the organic material component.