TWI616332B - Composite film for forming protective film, method for producing composite film for forming protective film, and method for producing wafer with protective film - Google Patents

Abstract

Provided is a composite film for forming a protective film, which has good holding power for a jig such as a ring frame, has excellent peelability during pickup, and can prevent the second adhesive layer. Defective adhesion to the adhesive layer (first adhesive layer) of the adhesive film.

Provided is a composite film for forming a protective film, which is formed on a first adhesive layer of an adhesive film including a base material and a first adhesive layer as constituent layers, and is provided with a protective film formed through the second adhesive layer. Use a thin film; the shape of the second adhesive layer in the plan view is the shape included in the plan view of the adhesive film, and the first adhesive layer is formed by curing the energy ray-curable adhesive or the energy ray-curable adhesive. The second adhesive layer is composed of an adhesive hardened by an energy ray-curable adhesive, and the second adhesive layer has a tensile elastic modulus of 200 to 2000 MPa at 25 ° C.

Description

Composite film for forming protective film, method for producing composite film for forming protective film, and method for producing wafer with protective film

The present invention relates to a composite film for forming a protective film capable of forming a protective film on a semiconductor wafer and a semiconductor wafer and improving the manufacturing efficiency of the semiconductor wafer. In particular, the present invention relates to a composite film for forming a protective film that is used when a semiconductor wafer is manufactured by a so-called face-down package.

In recent years, a semiconductor device has been manufactured using a so-called face-down packaging method. In the flip-chip method, a semiconductor wafer (hereinafter, also simply referred to as a “wafer”) having electrodes such as bumps is used on a circuit surface, and the electrode is bonded to a substrate. Therefore, the surface (the back surface of the wafer) opposite to the circuit surface of the wafer may be exposed.

The exposed back surface of the wafer may be protected by an organic film. Previously, a wafer having a protective film composed of the organic film was obtained by applying a liquid resin on the back of the wafer using a spin coating method, drying and curing, and cutting the protective film and the wafer simultaneously. However, the thickness accuracy of the protective film formed due to this is insufficient, and the yield of the product may be lowered.

In order to solve the above-mentioned problems, a dicing tape-integrated semiconductor backside film in which a dicing tape is laminated on a dicing tape is disclosed (patent) Reference 1).

The dicing tape that supports the film for semiconductor back surface is required to have a good holding power for a jig such as a ring frame and a good peeling property when picking up.

In recent years, due to the thinness and miniaturization of semiconductor packages, it is necessary to achieve the above-mentioned holding force and peelability at the same time, but it is very difficult to simultaneously solve the problem. It is considered that the adhesive constituting the adhesive layer of the dicing tape must be set to have low adhesiveness in order to obtain excellent releasability of a pickup wafer. However, when the adhesive is made to have low adhesiveness, there is a fear of losing good holding power to the ring frame.

In order to solve such a problem, in Patent Document 1, an adhesive layer is separately provided between the film for semiconductor back surface and the dicing tape, so as to coexist the holding force of the ring frame and the peelability at the time of pickup. To manufacture a semiconductor device using such a dicing tape-integrated semiconductor back film, a wafer having a semiconductor back film is bonded to a substrate or the like, and then the semiconductor back film is cured.

Prior art literature

Patent literature

[Patent Document 1] Japanese Patent Application Laid-Open No. 2012-33637

However, the dicing tape-integrated semiconductor back film of Patent Document 1 may not have sufficient pick-up properties (peelability). After dicing tape-integrated semiconductor back film is attached to the semiconductor wafer, the semiconductor back film is thermally cured, and then used in the process of dicing and picking up. The adhesion between the layer and the back surface film may be increased, and the pick-up property may be deteriorated. In the dicing tape-integrated semiconductor backside film of Patent Document 1, there is a concern that the pick-up property cannot be maintained in a more severe process under such conditions.

Therefore, it is required that the adhesive layer (in the second adhesive layer of the present invention) provided between the film for semiconductor back surface and the dicing tape (in the adhesive film of the present invention) has a good pick-up property. When the adhesiveness of the layer is reduced, the adhesiveness between the dicing tape and the adhesive layer may be reduced. As a result, there may be a case where the adhesive layer remains on the film for semiconductor back surface at the time of pickup. Such a decrease in adhesiveness cannot be coped with by simply improving the adhesiveness of the cutting film (adhesive film).

The object of the present invention is to provide a composite film for forming a protective film, which has a good holding force for a jig such as a ring frame and has excellent peelability during picking up, and can prevent the second adhesive layer and the adhesive layer from being caused. The adhesive layer (the first adhesive layer) of the adhesive film is poor in adhesion.

The present invention includes the following gist.

[1] A composite film for forming a protective film, wherein a protective film is formed on a first adhesive layer of an adhesive film including a base material and a first adhesive layer as constituent layers through a second adhesive layer Use a thin film; the shape of the second adhesive layer in the plan view is the shape included in the plan view of the adhesive film, and the first adhesive layer is formed by curing the energy ray-curable adhesive or the energy ray-curable adhesive. The second adhesive layer is composed of an adhesive hardened by an energy ray-curable adhesive. The tensile modulus of elasticity of the second adhesive layer at 25 ° C is 200 ~ 2000Mpa.

[2] The composite film for forming a protective film according to [1], wherein the tensile elastic modulus of the second adhesive layer at 25 ° C. is 500 to 2000 MP a.

[3] The composite film for forming a protective film according to [1] or [2], wherein the thin film for forming a protective film is thermosetting.

[4] The composite film for forming a protective film according to any one of [1] to [3], wherein the base material is a film including a polypropylene film with one or more layers.

[5] The composite film for forming a protective film according to any one of [1] to [4], wherein in the adhesive force measurement test for peeling the adhesive film from the second adhesive layer, the first adhesive layer and the At least one of the second adhesive layers is caused by cohesive failure or an adhesive force of 0.8 N / 25 mm or more.

[6] A method for producing a composite film for forming a protective film, producing the composite film for forming a protective film as described in any one of the above [1] to [5], which has a first adhesion on the adhesive film A step of laminating a second adhesive layer on the adhesive layer; and a step of hardening the first adhesive layer after laminating the first adhesive layer and the second adhesive layer.

[7] A method for manufacturing a wafer with a protective film, in which the following steps (1) to (3) are performed in order: step (1): the protective film as described in any one of the above [1] to [5] A step of attaching a protective film forming film for forming a composite film to a workpiece; step (2): a step of heating and curing the protective film forming film to obtain a protective film; and step (3): attaching the protective film to the second film The step of separating the adhesive layer.

When the composite film for forming a protective film of the present invention is used, it has a good holding power for a jig such as a ring frame, and has a good pick-up property for a wafer having a protective film. The poor adhesion between the second adhesive layer 3) and the adhesive layer (1 adhesive layer 2 shown in Fig. 1) on the adhesive film is shown.

1‧‧‧ substrate

2‧‧‧ the first adhesive layer

3‧‧‧ 2nd adhesive layer

4‧‧‧ thin film for protective film formation

5‧‧‧ Adhesive diaphragm

10‧‧‧ Composite film for protective film formation

Fig. 1 is a sectional view showing a composite film for forming a protective film of the present invention.

Hereinafter, the detail of the composite film for protective film formation of this invention is demonstrated.

The composite film sheet 10 for forming a protective film as shown in FIG. 1 is formed on the first adhesive layer 2 of the adhesive film 5 including the substrate 1 and the first adhesive layer 2 as constituent layers, and passes through the second The adhesive layer 3 is provided with a thin film 4 for forming a protective film.

[Substrate]

The substrate system is not particularly limited, and for example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, and polyterephthalate can be used. Acid ethylene film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate copolymer film, ionic polymer resin film, ethylene- (meth) acrylic acid copolymer Film, ethylene- (meth) acrylate copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, etc. Moreover, such a crosslinked film can also be used. Moreover, it may be such a laminated film. Among these, when the thin film for forming a protective film is cured and an adhesive film is attached It also has a small deformation, and is easy to recover even if deformed. In terms of ease of maintaining pick-up property and expansion, etc., a substrate made of a film containing a polypropylene film of one or more layers is preferred.

The thickness of the substrate is not particularly limited, but is preferably 30 to 300 μm, and more preferably 50 to 200 μm. By setting the thickness of the substrate to the above range, the composite film sheet for forming a protective film has sufficient flexibility, and thus exhibits good adhesion to a workpiece (for example, a semiconductor wafer or the like).

In addition, on the surface where the substrate is in contact with the first adhesive layer, in order to improve the adhesion with the first adhesive layer, a corona treatment or another layer such as a plasma may be provided.

[First adhesive layer]

The first adhesive layer is composed of an adhesive made by curing an energy ray-curable adhesive or an energy ray-curable adhesive.

By using the above-mentioned adhesive to constitute the first adhesive layer, it is possible to improve adhesion to a second adhesive layer described later. This is considered to be due to the structure formed between the energy ray polymerizable groups of the energy ray hardening adhesive contained in the first adhesive layer and the second adhesive layer described later, and the energy ray polymerizable groups. The affinity is high, and bonds between the energy ray polymerizable groups are generated according to circumstances. In addition, it is considered that the first adhesive layer and the second adhesive layer are composed of an adhesive made by curing an energy ray-curable adhesive, and even if the curing is completed, there are residual energy ray polymerizable groups (unreacted). Energy ray polymerizable groups), so energy ray polymerizable groups can generate bonds. In addition, it is considered that in the step of manufacturing a composite film for forming a protective film described later, even if the first adhesive layer and the second adhesive layer are laminated, and no energy ray irradiation is performed, the first adhesive layer and the second adhesive layer are adhered. Agent lamination After the layer, the bonding reaction between the energy ray polymerizable groups also proceeds slowly and bonding occurs.

As a result, when the wafer having a protective film is manufactured, the first adhesive layer and the second adhesive layer are compared with the adhesion force between the protective film and the second adhesive layer obtained by heating and curing the thin film for forming a protective film. The adhesive force between the adhesive layers is stronger, which makes it easier to peel off between the protective film and the second adhesive layer.

The functional group having a polymerizable carbon-carbon double bond in the energy ray polymerizable group of the present invention includes, as specific examples, a vinyl group, an allyl group, a (meth) acrylfluorenyl group, and the like. Preferred is (meth) acrylfluorenyl. Since the energy ray polymerizable group of the present invention generates a radical in the presence of a radical and easily generates an addition polymerization reaction, it does not mean that it does not have a polymerizable double bond. For example, although each component constituting the energy ray-curable adhesive may contain an aromatic ring, it does not mean that the unsaturated structure of the aromatic ring is an energy ray polymerizable group of the present invention.

The adhesive contains a normal polymer (A) and an energy ray-curable compound (B). The energy ray-curable compound (B) contains an energy ray polymerizable group, and when receiving energy rays such as ultraviolet rays and electron rays, has the function of polymerizing and hardening and reducing the adhesiveness of the adhesive.

In addition, as a combination of the properties of the components (A) and (B) described above, an energy ray-curable polymer (hereinafter described as component (hereinafter referred to as component ( AB). Such an energy ray-curable polymer (AB) has properties that have both the function as a polymer and energy ray-hardenability.

The energy ray-curable adhesive is not particularly limited, and an acrylic adhesive is specifically described as an example. Acrylic adhesive containing An acrylic polymer (A1) is used as the polymer (A).

As the acrylic polymer (A1), a conventionally known acrylic polymer can be used. The weight average molecular weight (Mw) of the acrylic polymer (A1) is preferably 10,000 to 2 million, and more preferably 100,000 to 1.5 million. The glass transition temperature (Tg) of the acrylic polymer (A1) is preferably in the range of -70 to 30 ° C, and more preferably in the range of -60 to 20 ° C.

The monomer constituting the acrylic polymer (A1) is capable of containing at least one (meth) acrylate monomer or a derivative thereof.

Specific examples include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, amyl (meth) acrylate, (formyl) (Hexyl) hexyl acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, Alkyl (meth) acrylates having 1 to 18 carbon atoms in alkyl groups such as lauryl (meth) acrylate, tetradecyl (meth) acrylate, and octadecyl (meth) acrylate; (meth) acrylic rings Hexyl ester, benzyl (meth) acrylate, isoamyl (meth) acrylate, dicyclopentyl (meth) acrylate, dicyclopentene (meth) acrylate, dicyclopentene (meth) acrylate (Meth) acrylic acid esters having a cyclic skeleton, such as oxyethyl ester, (meth) acrylic acid imide, etc .; hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth) ) Hydroxy-containing (meth) acrylates such as 2-hydroxypropyl acrylate and 2-hydroxybutyl (meth) acrylate; glycidyl (meth) acrylate, 3,4-epoxy (meth) acrylate (Methyl) containing epoxy groups such as cyclohexyl methyl ester Acrylates; monomethyl (meth) acrylate, monoethyl (meth) acrylate, diethyl (meth) acrylate, and other (meth) acrylates containing amines; phthalic acid Carboxylic (meth) acrylic acid, such as 2- (meth) acryloxyethyl ester, 2- (meth) acryloxypropyl phthalate ester.

Moreover, (meth) acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, etc. may be copolymerized.

These may be used individually by 1 type, and may use 2 or more types together.

In addition, the (meth) acrylfluorenyl group in this specification is used when it includes both acrylmethylene and methacrylfluorenyl.

The acrylic polymer (A1) may be crosslinked. When the acrylic polymer (A1) is crosslinked, the acrylic polymer (A1) before being crosslinked has a crosslinkable functional group such as a hydroxyl group, and a crosslinker is added to the composition forming the first adhesive layer. . The acrylic polymer (A1) is crosslinked by reacting a crosslinkable functional group with a functional group of a crosslinking agent. By crosslinking the acrylic polymer (A1), the cohesive force of the first adhesive layer can be adjusted.

Examples of the crosslinking agent include an organic polyisocyanate compound and an organic polyimide compound.

Examples of the organic polyisocyanate compound include an aromatic polyisocyanate compound, an aliphatic polyisocyanate compound, an alicyclic polyisocyanate compound, and a terpolymer of the organic polyisocyanate compound, and the organic polyisocyanate compound and a polyol. A terminal isocyanate urethane prepolymer obtained by the reaction of a compound.

Specific examples of the organic polyisocyanate compound include 2,4-toluene diisocyanate, 2,6 tolylene diisocyanate, 1,3-benzenedimethyldiisocyanate, 1,4-benzenedimethyldiisocyanate, and Phenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, Dicyclohexyl Alkan-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, lysine isocyanate, and polyol addition products thereof.

Specific examples of the organic polyimide compound include N, N'-diphenylmethane-4,4'-bis (1-acylcyclopropanecarboxamide), and trimethylolpropane-tri-β. -Acrylpropanepropionate, tetramethylolmethane-tri-β-Acrylpropanepropionate and N, N'-toluene-2,4-bis (1-acylcyclopropanecarboxamide) tris Ethyl melamine and so on.

Relative to 100 parts by mass of the acrylic polymer before crosslinking, the crosslinking agent is usually 0.01 to 20 parts by mass, preferably 0.1 to 15 parts by mass, and more preferably used at a ratio of 0.5 to 12 parts by mass.

In the present invention, regarding the content of the components constituting the first adhesive layer, when the content of the acrylic polymer is specified as a reference, the acrylic polymer obtained by crosslinking the acrylic polymer is used as a reference. The content is the content of the acrylic polymer before being crosslinked.

The energy ray-curable compound (B) is a compound that undergoes polymerization and hardening upon receiving energy rays such as ultraviolet rays and electron rays. Examples of the energy-ray-curable compound include low-molecular-weight compounds (monofunctional and polyfunctional monomers and oligomers) having an energy-ray polymerizable group. Specifically, trimethylolpropanetriazole can be used. Acrylate, tetramethylolmethane tetraacrylate, neopentaerythritol triacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butanediol diacrylate Acrylates such as 1,6-hexanediol diacrylate, cyclic aliphatic skeleton-containing acrylates such as dicyclopentadiene dimethoxydiacrylate, isoamyl acrylate, and polyethylene glycol diacrylic acid Ester, oligoester acrylate, urethane acrylate oligomer, epoxy Acrylate-based compounds such as modified acrylates, polyether acrylates, and itaconic acid oligomers. Such a compound has an energy ray polymerizable group in the molecule, and generally has a molecular weight of 100 to 30,000, preferably about 300 to 10,000.

The low molecular weight compound having an energy ray polymerizable group is usually 0 to 200 parts by mass, and more preferably 1 to 100 parts by mass of the component (A) (including the energy ray-curable polymer (AB) described later). ~ 100 parts by mass, more preferably used in a ratio of about 1 to 30 parts by mass.

The energy ray-curable polymer (AB), which has the properties of the above components (A) and (B), is formed by bonding an energy ray polymerizable group to the polymer's main chain, side chain, or terminal.

The energy ray polymerizable group bonded to the main chain, side chain, or end of the energy ray hardening polymer can also be bonded to the energy ray hardening type through an alkylene, alkoxy, or polyalkoxy group. The polymer's main chain, side chain, or end.

The weight average molecular weight (Mw) of the energy ray-curable polymer (AB) is preferably 10,000 to 2 million, and more preferably 100,000 to 1.5 million. The glass transition temperature (Tg) of the energy ray-curable polymer (AB) is preferably -70 to 30 ° C, and more preferably in the range of -60 to 20 ° C. When an acrylic polymer containing a functional group such as a hydroxyl group described later is reacted with a polymerizable group-containing compound to obtain an energy ray-curable polymer (AB), Tg is allowed to react with the polymerizable group-containing compound. Tg of the former enoic acid polymer.

The energy ray hardening polymer (AB) is, for example, an acrylic polymer containing a functional group such as a hydroxyl group, a carboxyl group, an amine group, a substituted amine group, an epoxy group, and the like, and having 1 to 5 functional groups per molecule The reactive substituent and the polymerizable group-containing compound having an energy ray polymerizable carbon-carbon double bond are reacted to obtain the compound. Acrylic poly The compound is composed of a (meth) acrylic acid ester monomer or a derivative thereof having a functional group such as a hydroxyl group, a carboxyl group, an amine group, a substituted amine group, an epoxy group, and the like, and a monomer having the aforementioned component (A). The copolymer is preferred. Examples of the polymerizable group-containing compound include (meth) acryloxyethyl isocyanate, m-isopropenyl-α, α-dimethylbenzyl isocyanate, and (meth) propylene Fluorenyl isocyanate, allyl isocyanate, glycidyl (meth) acrylate, (meth) acrylic acid, and the like.

When an acrylic polymer containing a functional group such as a hydroxyl group is reacted with a polymerizable group-containing compound to obtain an energy ray-curable polymer (AB), the energy ray-curable polymer (AB) is polymerized with the above-mentioned acrylic system. The substance (A1) can also be crosslinked.

As described above, the acrylic polymer (A1), the energy ray-curable compound (B), and / or the energy ray-curable polymer (AB) are acrylic adhesives that are hardened by irradiation with energy rays. As the energy ray, specifically, ultraviolet rays, electron rays, and the like can be used.

In addition, by combining a photopolymerization initiator with the energy ray-curable compound (B) and the energy ray-curable polymer (AB), it is possible to shorten the polymerization hardening time and the amount of light exposure.

Examples of such a photopolymerization initiator include diphenylketone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin Isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, benzoin dimethyl ketal, 2,4-diethyl 9-oxosulfur , Α-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethyl thiuram mono sulfide, azobisisobutyronitrile, benzil, dibenzyl , Bisamidine, 1,2-diphenylmethane, 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] acetone, 2,4,6-trimethyl Benzamidinediphenylphosphine oxide and β-chloroanthraquinone. The photopolymerization initiator can be used alone or in combination of two or more kinds.

The blending ratio of the photopolymerization initiator is preferably 0.1 to 10 parts by mass, and 1 to 5 parts by mass relative to 100 parts by mass of the energy ray-curable compound (B) and the energy ray-curable polymer (AB). Is better. When the blending ratio of the photopolymerization initiator is less than 0.1 parts by mass, the photopolymerization may be insufficient and the hardenability may not be satisfied. When it is more than 10 parts by mass, residues that do not contribute to photopolymerization may be generated and cause a defect. situation.

The first adhesive layer may be an adhesive layer composed of an adhesive hardened by an energy ray-curable adhesive. An adhesive layer composed of an adhesive that hardens an energy-ray-curable adhesive is irradiated with energy-rays as described in the production method of a composite film for forming a protective film described later, so that the energy-ray-hardenable adhesive Agent hardened and obtained. The same applies to the second adhesive layer described later.

The thickness of the first adhesive layer is not particularly limited, but is preferably 3 to 80 μm, more preferably 4 to 50 μm, and particularly preferably 5 to 30 μm.

(Second adhesive layer)

The second adhesive layer is composed of an adhesive made by curing an energy ray-curable adhesive. As the energy ray-curable adhesive, the same as the energy ray-curable adhesive in the above-mentioned first adhesive layer can be used, but from the inhibition of low-molecular-weight components (such as energy ray-curable compounds) to the formation of a protective film From the viewpoint of film movement, it is preferable to use an energy ray-curable polymer as the energy ray-curable adhesive. When the low-molecular-weight component moves to the thin film for forming a protective film, the hardenability of the thin film for forming a protective film is lowered, and there is a semiconductor which uses a wafer having a protective film. When the reliability of the body device is poor. The energy ray-curable polymer is not particularly limited, and for example, the same one as the energy ray-curable adhesive contained in the first adhesive layer can be used.

The tensile modulus of elasticity of the second adhesive layer at 25 ° C is 200 to 2000 MPa. When the second adhesive layer having such a configuration is used, the adhesiveness with the first adhesive layer is excellent. On the other hand, the peelability from the protective film is excellent, so the pick-up property of the wafer having the protective film is improved. The tensile elastic modulus of the second adhesive layer at 25 ° C is preferably 500 to 2000 MPa, and more preferably 500 to 1500 MPa. In this range, the pick-up property of the wafer with the protective film is further improved. In particular, even if the adhesive film of the protective film-forming composite film is not removed, and the protective film-forming film is put into the thermosetting step together with the adhesive film, it is an excellent pick-up property of a wafer having a protective film. The tensile elastic modulus of the second adhesive layer at 25 ° C can be controlled by selecting monomers constituting the acrylic polymer. In particular, by adjusting the blending amount of vinyl acetate, it is easy to control the tensile elastic modulus of the second adhesive layer at 25 ° C. When an energy ray-curable polymer is used, the amount of the elastic modulus of the second adhesive layer at 25 ° C. can be controlled by the amount of the polymerizable group-containing compound reacted with the acrylic polymer containing the functional group. .

The thickness of the second adhesive layer is not particularly limited, but is preferably 2 to 80 μm, more preferably 3 to 50 μm, and particularly preferably 5 to 10 μm.

The shape of the second adhesive layer in plan view is not particularly limited as long as it is included in the shape of the above-mentioned adhesive film in plan view. For example, the shape is substantially the same as that of the workpiece, or the shape of the workpiece can be completely included. Its shape.

[Thin film for protective film formation]

The thin film for forming a protective film may be one having (1) film shape maintainability, (2) initial adhesion, and (3) hardenability.

The protective film-forming film is capable of imparting (1) film shape retention and (3) hardenability by adding an adhesive component. As the adhesive component, a first component containing a polymer component and a curable component can be used. A binder component or a second binder component of a curable polymer component having properties of a polymer component and a curable component.

(2) The initial adhesiveness of the function of temporarily adhering to a workpiece in order to harden the thin film for forming a protective film may be pressure-sensitive adhesiveness or may be a property that is adhered by thermal softening. (2) The initial adhesiveness is usually controlled by various characteristics of the binder component, adjustment of the amount of the inorganic filler to be described later, and the like.

(The first adhesive component)

The first adhesive component contains a polymer component and a curable component, thereby imparting shape retention and curability to the film for forming a protective film. In addition, the first adhesive component does not contain a curable polymer component in order to facilitate the difference from the second adhesive component.

Polymer component (a)

The polymer component (a) is added to the protective film-forming film with the main purpose of imparting shape-maintaining properties to the protective film-forming film.

For the above purpose, the weight average molecular weight (Mw) of the polymer component (a) is usually 20,000 or more, and preferably 20,000 to 3,000,000. The value of the weight average molecular weight (Mw) is a value when measured by the gel permeation chromatography (GPC) method (polystyrene standard). The measurement using this method is, for example, using a high-speed GPC device "HLC-8120GPC" manufactured by TOSOH Corporation, and sequentially connecting high-speed columns "TSK gurd column H _XL -H", "TSK Gel GMH _XL ", "TSK Gel G2000H"" _XL " (above, all manufactured by TOSOH) was performed using a detector as a differential refractive index meter under conditions of a column temperature: 40 ° C and a liquid feed rate: 1.0 mL / min.

Moreover, in order to distinguish it from the hardenable polymer component (ab) mentioned later, the polymer component (a) does not have a hardening functional functional group mentioned later.

As the polymer component (a), acrylic polymers, polyesters, and phenoxy resins (for the sake of convenience to be distinguished from sclerosing polymers described later, preferably those without epoxy groups), polycarbonates, Polyether, polyurethane, polysiloxane, rubber-based polymer, etc. It is also possible to use two or more kinds of these bonds, for example, a propylene fluorene-based polyol having a propylene fluorene-based polymer having a hydroxyl group and a urethane prepolymer having an isocyanate group at the molecular terminal. Acrylic urethane resin and the like obtained by the reaction. In addition, a polymer obtained by combining two or more kinds may be used in combination of two or more kinds.

When an acrylic polymer (a1) is used as a polymer component (a), the same thing as the acrylic polymer (A1) contained in the said acrylic adhesive can be used.

In addition, as the polymer component (a), polyesters, phenoxy resins (for the sake of convenience to be distinguished from the sclerosing polymer described later, preferably those having no epoxy group), polycarbonate, and poly Ether, polyurethane, polysiloxane, rubber-based polymer, or a combination of two or more of these non-acrylic resins (a2) alone or in combination of two or more. As such a resin, those having a weight average molecular weight of 20,000 to 100,000 are more preferable, and those having a weight average molecular weight of 20,000 to 80,000 are more preferable.

The glass transition temperature of the non-acrylic resin (a2) is preferably -30 to 150 ° C, and more preferably -20 to 120 ° C.

When a non-acrylic resin (a2) and an acrylic polymer (a1) are used in combination, a protective film forming film (protective film) after curing is applied to a workpiece using a composite film forming protective film to be described later, and the protection can be protected. The film and the second adhesive layer were easily separated from each other. Moreover, the thin film for protective film formation tends to follow the unevenness | corrugation of a transfer surface easily.

When the non-acrylic resin (a2) and the acrylic polymer (a1) are used together, the content of the non-acrylic resin (a2) is based on the mass ratio of the non-acrylic resin (a2) to the acrylic polymer (a1), which is usually 1: 99 ~ 60: 40, preferably in the range of 1: 99 ~ 30: 70. When the content of the non-acrylic resin (a2) is within this range, the above-mentioned effects can be obtained at a higher level.

(b) Hardening ingredients

The curable component (b) is added to the film for forming a protective film with the main purpose of providing curability to the film for forming a protective film. As the curable component (b), a thermosetting component (b1) can be used. When the film for protective film formation contains a thermosetting component (b1), the film system for protective film formation becomes thermosetting. The thermosetting component (b1) is a compound containing at least a functional group that reacts by heating. The hardening can be achieved by a reaction between the functional groups of the hardening component (b) to form a three-dimensional network structure. Since the curable component (b) is used in combination with the polymer component (a), its weight is usually from the viewpoint of suppressing the increase in the viscosity of the coating composition for forming the protective film-forming film and improving the workability, etc. The average molecular weight (Mw) is 10,000 or less, preferably 100 to 10,000.

(b1) hardening component

As the curable component (b1), for example, an epoxy-based thermosetting component is preferred. The epoxy-based thermosetting component contains a compound (b11) having an epoxy group, and is preferably a combination of a compound (b11) having an epoxy group and a thermosetting agent (b12).

(b11) a compound having an epoxy group

As a compound having an epoxy group (hereinafter referred to as "epoxy compound"), a conventionally known one can be used. Specific examples include polyfunctional epoxy resins, bisphenol A diglycidyl ether and hydrides thereof, o-cresol novolac epoxy resin, dicyclopentadiene type epoxy resin, and biphenyl type Epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenylene skeleton type epoxy resin and the like have an epoxy compound having more than two functions in the molecule. These systems can be used alone or in combination of two or more.

The content of the epoxy compound (b11) with respect to 100 parts by mass of the polymer component (a) is preferably 1 to 1500 parts by mass, and more preferably 3 to 1200 parts by mass.

(b12) Heat hardener

The function of the heat hardener (b12) is as a hardener for epoxy compounds. As a preferable thermosetting agent, the compound which has 2 or more functional groups which can react with an epoxy group in 1 molecule is mentioned. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amine group, a carboxyl group, and an acid anhydride. Among these, a phenolic hydroxyl group, an amino group, an acid anhydride, etc. are mentioned preferably, and a phenolic hydroxyl group and an amino group are more preferable.

Specific examples of the phenol-based curing agent (thermosetting agent having a phenolic hydroxyl group) include polyfunctional phenol resin, biphenol, novolac-type phenol resin, dicyclopentadiene-based phenol resin, and XYLOCK-type phenol resin Aralkylphenol resin. Specific examples of the amine-based curing agent (thermosetting agent having an amine group) include DICY (dicyanodiamide). These systems can be used alone or in combination of two or more.

The content of the thermosetting agent (b12) is preferably 0.1 to 500 parts by mass, and more preferably 1 to 200 parts by mass with respect to 100 parts by mass of the epoxy compound.

(b13) Hardening accelerator

In order to adjust the thermal curing rate of the thin film for forming a protective film, a curing accelerator (b13) may be used. The hardening accelerator (b13) is particularly suitable for using an epoxy-based thermosetting component as the thermosetting component.

Examples of the preferred hardening accelerator (b13) include triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and gins (dimethylaminomethyl) phenol. Primary amines; 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4.methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl Imidazoles such as methyl-5-hydroxymethylimidazole; organic phosphines such as tributylphosphine, diphenylphosphine, triphenylphosphine, etc .; tetraphenylphosphonium tetraphenyl borate, tetraphenylphosphonate tetraphenyl ester And other tetraphenylboron salts. These systems can be used alone or in combination of two or more.

The hardening accelerator (b13) is preferably contained in an amount of 0.01 to 10 parts by mass, and more preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the total amount of the epoxy compound (b11) and the thermosetting agent (b12). . By containing the hardening accelerator (b13) in the above range, the protective film-forming film can have excellent adhesion to the workpiece even when exposed to high temperature and high humidity, and even when exposed to severe reflow conditions High reliability can also be achieved. When the content of the hardening accelerator (b13) is small, the hardening is insufficient and sufficient adhesion cannot be obtained. When the content of the hardening accelerator (b13) is excessive, the hardening accelerator (b13) having a high polarity is thin for forming a protective film under high temperature and humidity The film moves to the bonding interface side, and the reliability of the semiconductor device may be lowered due to segregation.

(Second binder component)

The second binder component contains a curable polymer component (ab) to impart film-forming properties (film-forming properties) and hardenability to a film for forming a protective film.

(ab) Hardening polymer component

The hardening polymer component (ab) is a polymer having a hardening functional functional group. Examples of the hardening functional functional group include a functional group capable of reacting with each other to form a three-dimensional network structure; and a functional group capable of reacting by heating.

The hardening functional functional group may be added to a unit having a continuous structure as a skeleton of the hardening polymer, or may be added to a terminal. When a hardening functional functional group is added to a unit of a continuous structure serving as a skeleton of a hardening polymer component, the hardening functional functional group may be added to a side chain or directly to a main chain. The weight average molecular weight (Mw) of the curable polymer component (ab) is usually 20,000 or more from the viewpoint of achieving the purpose of imparting shape-maintaining properties to the film for forming a protective film.

As a functional group which reacts by heating, an epoxy group is mentioned. Examples of the curable polymer component having an epoxy group include a phenoxy resin having an epoxy group, and specific product names include jER1256 and jER4250 manufactured by Mitsubishi Chemical Corporation.

The curable polymer component having an epoxy group is the same polymer as the acrylic polymer (a1) described above, and may be a polymer obtained by using a monomer having an epoxy group as a monomer (a ring-containing polymer) Oxy acrylic polymer). Examples of such monomers include ring-containing materials such as propylene oxide (meth) acrylate. (Meth) acrylates based on oxy.

When an epoxy group-containing acrylic polymer is used, its preferable aspect is the same as that of the acrylic polymer (A1).

When a curable polymer component having an epoxy group is used, it is the same as when an epoxy-based thermosetting component is used as the curable component, and a thermosetting agent (b12) and a curing accelerator (b13) may be used in combination.

The second adhesive component may contain the polymer component (a) and the curable component (b) as well as the curable polymer component (ab).

When the thin film system for forming a protective film contains any one or both of a thermosetting component (b1) and a hardening polymer component (ab), the thin film system for forming a protective film becomes thermosetting. In order to impart more sufficient thermosetting properties to the thin film for forming a protective film, the thin film for forming a protective matrix preferably contains at least a thermosetting component (b1). However, when the thin film for forming a protective film contains only the thermosetting component (b1), the shape retention of the film of the thin film for forming a protective film may be poor. Therefore, the protective film-forming film is preferably one or both of which contains the thermosetting component (b1), the polymer component (a), and the curable polymer component (ab).

From the viewpoint of providing more sufficient thermosetting properties to the film for forming a protective film, the amount of the thermosetting component (b1) contained in the film for forming a protective film is relative to the polymer component (a) and the hardening polymer component. The total of (ab) is 100 parts by mass, preferably 50 to 300 parts by mass, and more preferably 70 to 250 parts by mass.

The protective film-forming film may contain the following components in addition to the adhesive component.

(c) Inorganic filler

The thin film for forming a protective film may contain an inorganic filler (c). By the protective film shape The blending of the inorganic filler (c) in the production film can adjust the thermal expansion coefficient of the cured protective film-forming film. By optimizing the thermal expansion coefficient of the cured protective film-forming film to the workpiece, the semiconductor device can be optimized. Improved reliability. Moreover, the moisture absorption of the thin film for protective film formation after hardening can also be reduced.

Examples of the preferable inorganic filler (c) include powders of silicon dioxide, aluminum oxide, talc, calcium carbonate, titanium oxide, iron oxide, silicon carbide, and boron nitride, and beads obtained by spheroidizing them. , Single crystal fiber and glass fiber. Among these, silica dioxide filler and alumina filler are preferred. The said inorganic filler system can be used individually or in mixture of 2 or more types. In order to obtain the above-mentioned effect more reliably, the content range of the inorganic filler (c) is preferably 1 to 80 parts by mass, and more preferably 5 to 100 parts by mass of the total solid content constituting the film for forming a protective film. 75 parts by mass, particularly preferably 15 to 60 parts by mass.

(d) Colorants

The thin film for forming a protective film is capable of blending a colorant (d). By blending the colorant (d), it is possible to prevent malfunction of the semiconductor device caused by infrared rays or the like generated from surrounding devices when the semiconductor device is incorporated in the device. In addition, when the protective film-forming film is engraved by means such as a laser mark, a mark having a character, a mark, or the like becomes easy to recognize.

As the colorant (d), organic or inorganic pigments and dyes can be used. Among these, black pigments are preferred in terms of electromagnetic wave and infrared shielding properties. As a black pigment, carbon black, iron oxide, manganese dioxide, aniline black, and activated carbon can be used, but it is not limited to these. From the viewpoint of improving the reliability of semiconductor devices, carbon black is particularly preferred. The blending amount of the colorant (d) is preferably 0.1 to 35 parts by mass, based on 100 parts by mass of the total solid content constituting the film for forming a protective film. It is preferably 0.5 to 25 parts by mass, and particularly preferably 1 to 15 parts by mass.

(e) Coupling agent

In order to improve the cohesiveness of the adhesiveness and / or the protective film-forming film to the workpiece of the protective film-forming film, a coupling agent having a functional group that reacts with an inorganic substance and a functional group that reacts with an organic functional group ( e). By using the coupling agent (e), the heat resistance of the protective film obtained by curing the thin film for protective film formation is not impaired, and the water resistance can be improved. Examples of such a coupling agent (e) include titanate-based coupling agents, aluminate-based coupling agents, and silane coupling agents. Among these, a silane coupling agent is preferable.

As the silane coupling agent, a functional group that reacts with an organic functional group, and a silane coupling agent based on a group that reacts with a functional group possessed by a polymer, a curable component, a curable polymer component, or the like can be suitably used.

Examples of such a silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and γ- (3,4-epoxy (Cyclohexyl) ethyltrimethoxysilane, γ- (methacryloxypropyl) trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6- (amineethyl) -γ-aminepropyl Trimethoxysilane, N-6- (aminoethyl) -γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyl Triethoxysilane, γ-hydrothiopropyltrimethoxysilane, γ-hydrothiopropylmethyldimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfane, Methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, imidazolesilane, etc. These systems can be used individually by 1 type or in mixture of 2 or more types.

For polymer component (a), hardening component (b) and hardening polymer The total amount of the compound component (ab) is 100 mass. The silane coupling agent is usually 0.1 to 20 parts by mass, preferably 0.2 to 10 parts by mass, and more preferably 0.3 to 5 parts by mass. When the content of the silane coupling agent is less than 0.1 part by mass, the above-mentioned effect may not be obtained, and when it is more than 20 parts by mass, it may cause exhaust.

(f) Universal additives

In addition to the above, the protective film-forming film may contain various additives as necessary. Examples of the various additives include leveling agents, plasticizers, antistatic agents, antioxidants, ion trapping agents, deaerators, and chain transfer agents.

The thin film for forming a protective film may be a thin film having a single composition or a laminated film having two or more kinds of films having different compositions. When two or more types of films are used, for example, the film to be adhered to the workpiece is a relatively large amount of a component for improving the adhesion of the film, and the other film (the film in contact with the second adhesive layer) is It is possible to increase the blending amount of the hardening component.

The thickness of the thin film for forming a protective 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 structure of the composite film for protective film formation of this invention which consists of each layer mentioned above is shown in FIG. The composite film 10 for forming a protective film as shown in FIG. 1 is adhered to the first adhesive layer 2 of the adhesive film 5 containing the substrate 1 and the first adhesive layer 2 as constituent layers, and passes through the second adhesive. The agent layer 3 is provided with a protective film-forming film 4. The protective film-forming film 4 is formed on the second adhesive layer 3 in a peelable manner. The thin film 4 for forming a protective film is not particularly limited as long as it is approximately the same shape as the workpiece, or a shape that can completely include the shape of the workpiece. As shown in FIG. 1, it may be the same shape as the second adhesive layer 3.

The shape of the composite film for forming a protective film is not limited to a thin sheet, and it may be a long strip and may be rolled up.

Before using the composite film for protective film formation, in order to maintain the protective film-forming film, the first adhesive layer, and the second adhesive layer, a release film may be laminated on the protective film-forming film. As the release film, a film exemplified as the substrate can be used. The surface tension of the surface of the release film that is in contact with the film for forming a protective film is preferably 40 mN / m or less, more preferably 37 mN / m or less, and particularly preferably 35 mN / m or less. The lower limit value is usually about 25 mN / m. Such a release film having a low surface tension can be obtained by appropriately selecting the material, and can also be obtained by applying a release agent to the surface of the release film and performing a release treatment.

As the release agent used in the peeling treatment, alkyd-based, polysiloxane-based, fluorine-based, unsaturated polyester-based, polyolefin-based, wax-based and the like can be used. Oxygen-based and fluorine-based release agents are particularly preferred.

In order to use the above-mentioned release agent, the surface of a film or the like serving as a substrate of a release film is subjected to a peeling treatment to use a gravure coater, Mayer's bar coater, pneumatic blade coater, roll coater, etc. The release agent may be directly coated without solvent, or diluted with a solvent, and latexed, and the release film coated with the release agent may be provided at ordinary temperature or under heating, or it may be hardened by an electron beam to form a release agent layer. .

The surface tension of the release film can also be adjusted by laminating a film using wet lamination, dry lamination, hot melt lamination, melt extrusion lamination, coextrusion, or the like. That is, the surface tension of at least one surface may be made as thin as the contact surface with the film for forming a protective film of the release film described above. The film is a laminated body in which other thin film layers are laminated so that this surface is a contact surface with the thin film for forming a protective film as a release film.

According to the composite film for forming a protective film according to the structure shown in FIG. 1, in a region surrounding the thin film for forming a protective film, it is possible to form the composite film for forming a protective film with sufficient adhesion of the first adhesive layer. The piece went on to the fixture. At the same time, the adhesion at the interface between the second adhesive layer and the first adhesive layer is controlled to facilitate picking up of a wafer having a protective film.

In addition, when the composite film for forming a protective film functions as a dicing film to support a workpiece in the dicing step, it is not necessary to attach a separate dicing film to the wafer to which the protective film-forming film is attached during the dicing step. Dicing can simplify the manufacturing steps of a semiconductor device.

Furthermore, in an adhesive force measurement test for peeling the adhesive film from the second adhesive layer, the composite film for protective film formation is to cause cohesive failure in at least one of the first adhesive layer and the second adhesive layer, or The adhesion is preferably 0.8N / 25mm or more. When the adhesion between the first adhesive layer and the second adhesive layer is relatively low, although the interface is broken during the adhesion measurement test, and the adhesive force can be measured, the first adhesive layer and the second adhesive layer can be measured. When the adhesiveness between the adhesive layers is remarkably high, either or both of the first adhesive layer and the second adhesive layer cause cohesive failure, and the adhesive force cannot be measured. The adhesive force measurement test is specifically described in Examples described later. The film for forming a protective film has such a feature that the effect of the present invention can be further enhanced by the large adhesiveness between the first adhesive layer and the second adhesive layer, for example, when a wafer having a relatively large size is obtained. When the composite film for forming a protective film of the present invention is used in a manufacturing process, it is possible to prevent undesired peeling of the first adhesive layer and the second adhesive layer. The adhesive film is removed from the second adhesive In the adhesive force measurement test for layer peeling, it is preferable that the composite film sheet for forming a protective film has at least one of the first adhesive layer and the second adhesive layer cause cohesive failure or an adhesive force of 1.2 N / 25 mm or more.

The thin film for protective film formation of such a composite film for protective film formation can be used as a protective film for a wafer. The thin film for forming a protective film is attached to the back surface of a flip-chip wafer, and is cured by an appropriate means to protect the wafer instead of a sealing resin. In addition, when a thin film for forming a protective film is attached to a semiconductor wafer, the protective film has a function of reinforcing the wafer, so that damage to the wafer and the like can be prevented.

[Manufacturing method of composite film for protective film formation]

Next, an example of a method for manufacturing a composite film for forming a protective film shown in FIG. 1 will be described. However, the composite film for forming a protective film of the present invention is not limited to those obtained by using such a manufacturing method.

First, a first adhesive layer is formed on the surface of a substrate to obtain an adhesive film. The method of providing the first adhesive layer on the surface of the substrate is not particularly limited, and examples thereof include coating a release film (first release film) with a predetermined film thickness so as to include a layer containing the first adhesive layer. A method of forming a first coating film with a composition (first adhesive agent) of an energy ray-curable adhesive, and transferring the first coating film to the surface of a substrate; and directly coating the first surface of the substrate with the first adhesive agent to form a first coating film; 1 Coating method. The first film is cured by irradiating the first film with energy rays to obtain a first adhesive layer composed of an adhesive that hardens the energy-ray-curable adhesive. When the first film is not irradiated with energy rays, the first film system becomes a first adhesive layer directly composed of an energy ray-curable adhesive. The first film of the adhesive film is laminated with a second film or a second adhesive layer described later. Before, the first film may be hardened by irradiating the energy ray so that the first film becomes the first adhesive layer. At this time, the hardening may be left at the preliminary hardening so that the unreacted energy ray polymerizable group remains in the first film.

Examples of the energy ray include ultraviolet rays, and near-ultraviolet rays including ultraviolet rays having a wavelength of about 200 to 380 nm may be used. On the amount of ultraviolet (light amount), it is usually about 50 ~ 500mJ / cm ^2, to 100 ~ 450mJ / cm ² preferably, to 200 ~ 400mJ / cm ² is preferred. Further, an ultraviolet line illumination is usually about 50 ~ 500mW / cm ^2, to 100 ~ 450mW / cm ² preferably, to 200 ~ 400mW / cm ² is preferred. The ultraviolet source is not particularly limited, and for example, a high-pressure mercury lamp, a metal halide lamp, a light-emitting diode, or the like can be used. In the following, when ultraviolet rays are irradiated as energy rays, similar conditions may be selected and performed in the same manner. As the release film, a film exemplified as the aforementioned substrate can be used.

In addition, it is also possible to form a film (second film) by applying a composition (second adhesive) containing an energy ray-curable adhesive constituting the second adhesive layer to another release film (second release film). ). Subsequently, another release film (third release film) was laminated on the second film to obtain a laminate of the second release film / second film / third release film. Subsequently, the second film is hardened by irradiating the energy ray to obtain a second adhesive layer held by the second release film and the third release film. In addition, the second film may not be irradiated with energy rays, or may remain in the preliminary hardening mode such that unreacted energy ray polymerizable groups remain in the second film, and may be performed on the first film or the first adhesive layer After lamination, the second film is cured to form a second adhesive layer.

Then, the composition for forming a protective film is applied to another peeling agent. The film (fourth peeling film) forms a protective film-forming film. Subsequently, another release film (5th release film) was laminated | stacked on the film for protective film formation, and the laminated body of 4th release film / protective film formation film / 5th release film was obtained.

Subsequently, the third release film is peeled from the laminate of the second release film / second adhesive layer / third release film, and the fourth release film is removed from the fourth release film / protective film. The laminate of the film / fifth release film is peeled off, and the second adhesive layer and the protective film-forming film are laminated to obtain a second release film / second adhesive layer / protective film-forming film / fifth The laminated body of the diaphragm is peeled. Subsequently, the second adhesive layer and the protective film-forming film are cut into and removed from the workpiece in a shape substantially the same as that of the workpiece to which the protective film-forming film is attached, or a shape that can completely include the shape of the workpiece. When the laminated body of the second release film, the second adhesive layer, the protective film forming film, and the fifth release film is a long strip-shaped body, the fifth release film can be continuously cut without cutting into the fifth release film. A multilayer body of a plurality of second release films, a second adhesive layer, and a protective film-forming film held in a long strip of fifth release films.

When the first release film is laminated on the first film or the first adhesive layer, the first release film is peeled while the second release film / second adhesive layer / protective film is formed. The second release film of the laminated body composed of the film / the fifth release film is laminated with the first film or the first adhesive layer and the second adhesive layer to obtain a substrate / first film or A laminated body composed of a first adhesive layer, a second adhesive layer, a protective film-forming film, and a fifth release film.

When the second film is not irradiated with energy rays, or when the second film is pre-cured and laminated with the first film or the first adhesive layer, the second film is irradiated with energy rays from the substrate side. It is hardened and becomes a 2nd adhesive layer. 1st When the coating system is not hardened or pre-hardened, at this point, the first coating is also irradiated with energy rays at the same time as the second coating, and the first coating system is composed of an adhesive hardened by an energy ray hardening adhesive. The first adhesive layer. In addition, even when the second coating system is hardened, the laminated body of the first coating and the second adhesive layer may be irradiated with energy rays at this time to harden the first coating. As described above, the composite film for forming a protective film of the present invention is obtained.

In particular, when the first adhesive layer of the protective film-forming composite film is composed of an adhesive hardened by an energy ray-curable adhesive, the first film and the second adhesive layer are laminated. Thereafter, since the first adhesive layer is hardened by irradiating the energy ray, the adhesion between the first adhesive layer and the second adhesive layer can be improved, and thus the pick-up property of the wafer having the protective film is excellent.

[Manufacturing method of wafer with protective film]

Next, a method for manufacturing a wafer having a protective film using the composite film for forming a protective film of the present invention will be described.

The method for manufacturing a wafer with a protective film according to the present invention is performed in the order of the following steps (1) to (3).

Step (1): the step of placing the film for forming a protective film on the composite film for forming a protective film on the workpiece, step (2): the step of heating and curing the film for forming a protective film to obtain a protective film, step (3): A step of separating the protective film from the second adhesive layer.

The workpiece can be a silicon wafer or a compound semiconductor wafer such as gallium-arsenic. Examples of the workpiece include various materials such as organic substrates such as glass substrates, ceramic substrates, and FPC substrates, and metal materials such as precision parts. Product. Moreover, it can also be a wafer made of these individual pieces.

In the following, a method for manufacturing a wafer with a protective film using a silicon wafer as a workpiece will be described. As an example, various circuits that have been widely used, including etching and peeling, can be used to form circuits on the wafer surface. The same way. Next, the opposite side (back surface) of the circuit surface of the wafer is ground. The grinding method is not particularly limited, and grinding can be performed using a known means such as a grinder. During back grinding, an adhesive film called a surface protection film is attached to the circuit surface to protect the surface of the circuit. The back surface grinding uses a chuck table or the like to fix the circuit surface side (that is, the surface protective film side) of the wafer and grinds the back surface side on which the circuit is not formed using a grinder. The thickness after wafer grinding is not particularly limited, but is usually about 50 to 500 μm.

Subsequently, if necessary, the crushed layer generated when the back surface is ground is removed. Debris removal is performed using chemical etching, plasma etching, or the like.

Next, a thin film for forming a protective film is attached to the back surface of the wafer. The attaching method is not particularly limited.

Then, the thin film for forming a protective film is heat-hardened to form a protective film on the back surface of the wafer. As a result, a protective film made of a hardened resin is formed on the back surface of the wafer. Compared with when the wafer is alone, the strength is increased, so that damage can be reduced when a thin wafer is handled. In addition, compared with the coating method in which a coating liquid for a resin film is directly coated on the back surface of a wafer and formed into a film, the thickness of the protective film is more uniform.

Next, a circuit formed on the wafer surface is used to cut the wafer and the protective film (dicing step). Dicing is a method of cutting the wafer and the protective film at the same time. Formula. The composite film for forming a protective film of the present invention can fulfill the task of supporting a dicing film of a wafer. In the dicing step, the outer peripheral portion of the protective film-forming composite film sheet is bonded to another jig such as a ring frame, and the protective film-forming composite film sheet system attached to the semiconductor wafer is fixed to the device. Cutting. The dicing of the semiconductor wafer on the protective film forming composite film can be performed in the same manner as the conventional method using a conventional dicing film. The dicing step may be performed before the step of heating and curing the thin film for forming a protective film to obtain a protective film.

The wafer (the wafer with a protective film) thus diced can be picked up by a widely used means such as a collet, and the protective film can be separated from the second adhesive layer to obtain a wafer with a protective film. . According to the composite film for forming a protective film according to the present invention, a specific adhesive is used to form an adhesive layer, and the tensile elastic modulus of the second adhesive layer is set to a specific range. The obtained protective film was easily peeled from the second adhesive layer. In addition, it is possible to prevent defects such as peeling between the first adhesive layer and the second adhesive layer from being caused during pick-up due to a decrease in adhesion between the first adhesive layer and the second adhesive layer.

Second, laser printing can also be performed on the protective film. Laser printing can be performed using a laser marking method. The surface of the protective film is cut off by irradiating laser light, and the product number is marked on the protective film.

Finally, a semiconductor device can be manufactured by flip-chip packaging a wafer having a protective film on a predetermined base. In addition, a semiconductor device can also be manufactured by attaching a semiconductor wafer having a protective film on the back surface to another component (on a wafer mounting portion) such as a die pad portion or another semiconductor wafer.

Examples

Hereinafter, the present invention will be described by examples, but the present invention is not limited by these examples. In the following examples or comparative examples, <pickability>, <attachment of the second adhesive layer>, <tensile elastic modulus>, and <adhesive force measurement test> were measured and evaluated as follows.

<Pickability>

The protective film-forming film of the protective film-forming composite film was attached to a silicon wafer obtained by grinding the back surface using a # 2000 abrasive stone using a tape mounter (Adwill RAD2700 manufactured by LINTEC). (200 mm diameter, 200 μm thickness) polished surface, and fixed to the ring frame for wafer dicing.

Next, the composite film for forming a protective film and the wafer were placed in an environment of 130 ° C. for 2 hours to form a thin film for forming a protective film.

Subsequently, a dicing apparatus (DFD651 manufactured by DlSCO) was used to cut the silicon wafer to obtain a 5 mm × 5 mm wafer. The cutting amount at the time of cutting was performed by cutting the substrate into 15 μm, and the cutting speed was 40 mm / minute. As the cutting blade, 27HECC manufactured by DlSCO was used, and the number of revolutions of the blade was 35,000 rpm.

It was confirmed that the obtained wafer can be picked up using a pickup device (BEST EMDO2 manufactured by Canon Machinery).

Specifically, an ejector pin (5 needles) is used, and all needles are pushed upward by 1000 μm, and then a central needle (1 needle) is further pushed upward by 400 μm to pick up. The upward speed is performed at 10 mm / second and 20 mm / second. When it can be picked up at a speed of 20mm / s, it is evaluated as "A". When it can be picked up at a speed of 10mm / s, it is evaluated as "B". When it cannot be picked at any speed, it is evaluated as "B" C ".

<Attachment of the second adhesive layer>

It was confirmed that the back surface (protective film surface) of the wafer with a protective film obtained by the pick-up evaluation described above was checked, and whether the second adhesive layer was attached or not was confirmed. The confirmation method is performed by measuring the thickness of a wafer having a protective film and confirming the expected thickness. In addition, a cellophane tape made of NICHIBAN was affixed to the protective film surface, and it was confirmed that the second adhesive layer was not adhered to the cellophane tape at the time of peeling.

A case where no transfer failure occurred was evaluated as "A", and a case where transfer failure occurred was evaluated as "B".

<Tensile elastic modulus>

The tensile elastic modulus of the second adhesive layer was measured using a viscoelasticity measuring device (TA Instruments, DMA Q800).

First, a second adhesive layer on the ultraviolet-curable surface was laminated to obtain a laminated body having a thickness of 200 μm. Subsequently, the ultraviolet irradiation device (of LINTEC Corporation RAD-2000) and the illuminance of 230mW / cm ^2, light quantity of 190mJ / under illumination cm ² (main wavelength 365nm), and those obtained by ultraviolet irradiation to sample.

As the measurement conditions, the measurement part of the sample was installed with a length of 20 mm and a width of 4 mm, and the measurement was performed with an amplitude of 16 μm and a measurement temperature range of -40 to 150 ° C. The tensile elastic modulus at a frequency of 25 Hz was set to 11 Hz As measured value.

<Adhesion measurement test>

The protective film-forming film was removed from the protective film-forming film and cut into a width of 25 mm to prepare a sample. The exposed surface of the second adhesive layer was fixed to a flat plate, and when the adhesive film was peeled from the second adhesive layer at an angle of 180 ° and a speed of 300 mm / minute under an environment of 23 ° C and 50% relative humidity, it was measured. Adhesion.

Manufacture of a thin film for forming a protective film

Moreover, each component which comprises the film for protective film formation, and its compounding quantity are shown below (component / mixing quantity). The blending amount of each component refers to parts by mass in terms of solid content. In the present invention, the term “solid content” refers to a total component other than a solvent.

[Composition for forming protective film]

(a1) Acrylic polymer: acrylic acid consisting of 55 parts by mass of n-butyl acrylate, 10 parts by mass of methyl acrylate, 20 parts by mass of propylene methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate Based polymer (weight average molecular weight: 900,000, glass transition temperature: -28 ° C) / 20 parts by mass

(b1) Thermosetting component:

(b11-1) Bisphenol A epoxy resin (epoxy equivalent 180 ~ 200g / eq) / 20 parts by mass

(b11-2) Dicyclopentadiene type epoxy resin (Epiclon HP-7200HH, manufactured by Dainippon Ink Chemical Industry Co., Ltd.) / 10 parts by mass

(b12) Dicyanodiamine (ADEKA HARDENER-3636AS, manufactured by Asahi Denka) / 0.5 part by mass

(b13) Hardening accelerator: 2-phenyl-4,5-dihydroxymethylimidazole (CUREZOLE 2PHZ, manufactured by Shikoku Chemical Industries, Ltd.) / 0.5 part by mass

(c) Inorganic filler: Silicon dioxide filler (fused silica filler (average particle diameter: 8 μm)) / 60 parts by mass

(d) Colorant: black pigment (carbon black (# MA650, manufactured by Mitsubishi Chemical Corporation, average particle size: 28 nm)) / 2 parts by mass

(e) Coupling agent: Silane coupling agent (A-1110 manufactured by UNICAR Japan) /0.2 parts by mass

A protective film-forming composition was applied to a release film (SP-PET3811, manufactured by LINTEC Corporation, having a thickness of 38 μm) so that the coating amount after drying was 42 g / m ² , and dried at 110 ° C. for 2 minutes to form a protective film-forming film. Then, another release film (SP-PET3811, manufactured by LINTEC Corporation, having a thickness of 38 μm) was laminated on the protective film-forming film to obtain a laminate of the release film / protective film-forming film / release film.

(Example 1)

Manufacture of adhesive diaphragm

Manufactured in an acrylic polymer (2-ethylhexyl acrylate / butyl acrylate / hydroxyethyl acrylate = 35/60/5 (mass ratio), weight average molecular weight: 600,000), 60% equivalent (relative to acrylic acid Is an energy ray-curable polymer obtained by reacting 100 parts by mass of a polymer with 4 parts by mass of isocyanatomethacryloxyethyl isocyanate.

To 100 parts by mass of the energy ray-curable polymer, 3.0 parts by mass of a photopolymerization initiator (IRGACURE (registered trademark) 184 manufactured by CIBA. SPECIALTY.CHEMICALS Co., Ltd.) and an isocyanate compound (Mitsui Takeda Chemical Co., Ltd.) as a crosslinking agent were prepared. Production D-110N) 10 parts by mass (all solid content conversion ratios), and diluted with toluene / ethyl acetate (120/70 parts) as an adhesive (first adhesive).

The first adhesive was applied to a release film (SP-PET3811, manufactured by LINTEC Co., Ltd. with a thickness of 38 μm) so that the coating amount after drying was 5 g / m ² , and dried at 100 ° C. for 2 minutes to form a first film, and then laminated. A corona-treated surface of a polypropylene film (thickness: 80 μm) subjected to corona treatment on one side as a substrate was obtained to obtain a laminated body of a release film sheet / first coating film / base material.

Production of the second adhesive layer

Manufactured in acrylic polymers (2-ethylhexyl acrylate / vinyl acetate / hydroxyethyl acrylate = 40/40/20 (mass ratio), weight average molecular weight: 500,000), and 80% equivalent (relative to acrylic acid Is an energy-ray-curable polymer obtained by reacting 100 parts by mass of a polymer with 21.4 parts by mass) of methacryloxyethyl isocyanate.

To 100 parts by mass of the energy ray-curable polymer, 3.0 parts by mass of a photopolymerization initiator (IRGACURE (registered trademark) 184 manufactured by CIBA. SPECIALTY.CHEMICALS Corporation) and an isocyanate compound (Toyo Ink Manufacturing Co., Ltd.) as a crosslinking agent were prepared. (Manufactured by BH S-8515) 0.5 parts by mass (all solid content conversion ratios) and diluted with methyl ethyl ketone as an adhesive (second adhesive).

A second adhesive was applied to a release film (SP-PET3811, manufactured by LINTEC Co., Ltd. with a thickness of 38 μm) so that the coating amount after drying was 10 g / m ² , and dried at 100 ° C. for 2 minutes to form a second film, and then laminated. The release film (SP-PET3811, manufactured by LINTEC Corporation, thickness: 38 μm) was obtained to obtain a laminate of release film / second film / release film. Subsequently, using an ultraviolet irradiation apparatus (of LINTEC Corporation RAD-2000), the illuminance of 230mW / cm ^2, the amount of light irradiation conditions 190mJ / cm ² (main wavelength 365nm), and irradiated with ultraviolet rays so that the second film is hardened to obtain the second adhesive Floor.

Manufacture of composite film for protective film formation

From the laminate of the release film / protective film forming film / release film and the laminate of the release film / second adhesive layer / release film obtained above, one of the release films is peeled off. The thin film for protective film formation and the second adhesive layer were thermally laminated (60 ° C, 1 m / min).

Subsequently, the second adhesive layer and the protective film-forming film were press-processed (220 diameter) into a circular shape, and at the same time, the release film layer laminated on the second adhesive layer was removed. Thereby, the laminated body which laminated | stacked the protective film formation layer and the 2nd adhesive layer of the same circular shape on the release film sheet in order was obtained. Then, the second adhesive layer and the first coating layer are laminated while peeling off the release film layer of the release film sheet / the first coating layer / the substrate to obtain the release film sheet / the protective film forming film / the first layer. Laminate of 2 adhesive layer / first coating / substrate.

Subsequently, using an ultraviolet irradiation apparatus (of LINTEC Corporation RAD-3600), ^2, under illumination light amount 190mJ / cm ² (main wavelength 365nm), and irradiated with ultraviolet light of the first coating film cured from the substrate side illuminance of 230mW / cm become The first adhesive layer provided a composite film for protective film formation in which a release film was laminated on the film for protective film formation. The evaluation results are shown in Table 1.

(Example 2)

As the energy ray-curable polymer used in the manufacture of adhesive diaphragms, acrylic polymers (butyl acrylate / methyl methacrylate / hydroxyethyl acrylate di 74/20/6 (mass ratio)) and weight average molecular weight are used. : 350,000), an energy ray-curable polymer obtained by reacting 50% equivalent (3 parts by mass with respect to 100 parts by mass of an acrylic polymer) of isopropyl methacryloxyethyl isocyanate.

An isocyanate compound (BHS-8515, manufactured by Toyo Ink Manufacturing Co., Ltd.) was used as a cross-linking agent in the production of the adhesive film, and 0.5 parts by mass was blended with 100 parts by mass of the energy ray-curable polymer.

Except for the above, a composite film for forming a protective film was obtained in the same manner as in Example 1. The evaluation results are shown in Table 1.

(Example 3)

The composite film for forming a protective film was produced in the same manner as in Example 2 except that the ultraviolet film was not irradiated to obtain a composite film for forming a protective film. That is, in Example 3, the uncured first film was used as the first adhesive layer. The evaluation results are shown in Table 1.

(Example 4)

As the energy ray-curable polymer for the production of the second adhesive layer, it is used in an acrylic polymer (2-ethylhexyl acrylate / vinyl acetate / hydroxyethyl acrylate = 60/20/20 (mass ratio) , Weight-average molecular weight: 350,000), an energy ray-curable polymerization obtained by reacting 80% equivalents (21 parts by mass with respect to 100 parts by mass of an acrylic polymer) Thing.

Except for the above, a composite film for forming a protective film was obtained in the same manner as in Example 2. The evaluation results are shown in Table 1.

(Comparative example 1)

Use acrylic polymer (2-ethylhexyl acrylate / butyl acrylate / hydroxyethyl acrylate = 35/60/5 (mass ratio), weight average molecular weight: 500,000) instead of energy ray hardening in the production of adhesive membranes Polymer. In the production of adhesive films, no photopolymerization initiator was formulated.

Furthermore, in the production of the composite film for forming a protective film, ultraviolet irradiation was not performed.

Except for the above, a composite film for forming a protective film was obtained in the same manner as in Example 1. The evaluation results are shown in Table 1.

(Comparative example 2)

As the energy ray-curable polymer for the production of the second adhesive layer, it is used in an acrylic polymer (2-ethylhexyl acrylate / hydroxyethyl acrylate). = 80/20 (mass ratio), weight average molecular weight: 350,000), and 80% equivalent (21 mass ratio with respect to 100 parts by mass of the acrylic polymer) is reacted with Into an energy ray hardening polymer.

Except the above, it carried out similarly to the comparative example 1, and obtained the composite film for protective film formation. The evaluation results are shown in Table 1.

(Comparative example 3)

As the energy ray-curable polymer produced in the second adhesive layer, acrylic polymer 2-ethylhexyl acrylate / vinyl acetate / hydroxyethyl acrylate = 60/20/20 (mass ratio), Weight-average molecular weight: about 350,000), an energy ray-curable polymer made by reacting 80% equivalents (21 parts by mass relative to 100 parts by mass of acrylic polymer) .

Except the above, it carried out similarly to the comparative example 1, and obtained the composite film for protective film formation. The evaluation results are shown in Table 1.

In the adhesive force, “cohesive failure” means that at least one of the first adhesive layer and the second adhesive layer has caused agglomeration failure.

1‧‧‧ substrate

2‧‧‧ the first adhesive layer

3‧‧‧ 2nd adhesive layer

4‧‧‧ thin film for protective film formation

5‧‧‧ Adhesive diaphragm

10‧‧‧ Composite film for protective film formation

Claims (6)

A composite film for forming a protective film is provided on a first adhesive layer of an adhesive film containing a base material and a first adhesive layer as constituent layers, and a protective film forming film is provided through the second adhesive layer. Composite film for protective film formation; the shape of the second adhesive layer in a plan view is a shape included in the plan view of the adhesive film, and the first adhesive layer is an energy ray-curable adhesive or energy ray-curable The second adhesive layer is composed of an adhesive hardened by an energy ray-curable adhesive. The second adhesive layer has a tensile elastic modulus of 200 at 25 ° C. ~ 2000 MPa, an adhesive force measurement test for peeling the adhesive film from the second adhesive layer, and at least one of the first adhesive layer and the second adhesive layer was cohesive and broken. The composite film for forming a protective film as described in item 1 of the scope of the patent application, wherein the tensile modulus of elasticity of the second adhesive layer at 25 ° C. is 500 to 2000 MPa. The composite film for forming a protective film according to item 1 or 2 of the scope of application for a patent, wherein the thin film for forming a protective film is thermosetting. The composite film for forming a protective film according to item 1 or 2 of the scope of application for a patent, wherein the base material is composed of a film containing one or more polypropylene films. A manufacturing method of a composite film for forming a protective film, which manufactures the composite film for forming a protective film according to any one of claims 1 to 4 of the scope of patent application, which comprises: A step of laminating a second adhesive layer on the first adhesive layer of the adhesive film; and a step of hardening the first adhesive layer after laminating the first adhesive layer and the second adhesive layer. A method for manufacturing a wafer with a protective film, in which the following steps (1) to (3) are performed in order: step (1): the protective film is formed as described in any one of claims 1 to 4 of the scope of patent application. A step of attaching a protective film forming film of a composite film to a workpiece; step (2): a step of heating and curing the protective film forming film to obtain a protective film; and step (3): attaching the protective film and a second adhesive Steps of layer separation.