JP2024118865A - Adhesive composition, film-like adhesive, adhesive sheet, semiconductor device, and method for manufacturing semiconductor device - Google Patents

Abstract

To provide an adhesive composition capable of forming a cured adhesive layer with superior flame retardancy and adhesive strength, and a film-like adhesive, an adhesive sheet, a semiconductor device and a method for producing a semiconductor device, each employing the adhesive composition.SOLUTION: An adhesive composition contains a thermoplastic component (A), a thermosetting component (B) and a nitrogen atom-containing flame retardant (C). The content of the nitrogen atom-containing flame retardant (C) is 25 mass% or less relative to the total amount (100 mass%) of components in the solids of the adhesive composition, excluding inorganic fillers. Also provided are a film-like adhesive, an adhesive sheet, a semiconductor device and a method for producing a semiconductor device, each employing the adhesive composition.SELECTED DRAWING: Figure 1

Description

The present invention relates to an adhesive composition, a film-like adhesive, an adhesive sheet, a semiconductor device, and a method for manufacturing a semiconductor device.

In the manufacture of semiconductor devices, a technique is adopted in which a semiconductor chip is die-bonded to a circuit-forming surface of a substrate using an adhesive. In recent years, a three-dimensional packaging technique in which semiconductor chips are stacked on top of each other has been put to practical use, and a film-like adhesive is also used for die-bonding between semiconductor chips.
A film-like adhesive for die bonding may also be used as part of a dicing sheet in the process of producing semiconductor chips by dicing a semiconductor wafer.

Adhesives that are used for die bonding have thermosetting properties. After being applied to an adherend, a thermosetting adhesive can form an adhesive layer that is excellent in impact resistance and the like by being thermally cured. Here, in this specification, a layer that is made of a thermoset product of a thermosetting adhesive composition and is in a state of adhering an object to be bonded is referred to as a "cured adhesive layer."
The cured adhesive layer is required to have excellent adhesive properties capable of firmly bonding a semiconductor chip to a substrate, or between semiconductor chips.

Patent Document 1 discloses a thermosetting die-bonding film that has both the storage modulus and high adhesive strength required for manufacturing semiconductor devices, the thermosetting die-bonding film containing at least an epoxy resin, a phenolic resin, an acrylic copolymer, and a filler, and that has a storage modulus before heat curing at 80°C to 140°C in the range of 10 kPa to 10 MPa, and a storage modulus before heat curing at 175°C in the range of 0.1 MPa to 3 MPa.

JP 2014-158046 A

In recent years, the level of flame retardancy required for electronic components has been increasing from the viewpoint of improving safety. Conventionally, halogen-based flame retardants have been used as flame retardants to improve the flame retardancy of plastic products, but there is a growing trend to refrain from using halogen-based flame retardants because they are suspected of emitting toxic substances when incinerated.
However, according to the investigations of the present inventors, it has become clear that when flame retardancy is attempted using an alternative flame retardant to a halogen-based flame retardant, it becomes difficult to achieve both flame retardancy and excellent adhesion in the cured adhesive layer formed from the adhesive composition.

The present invention has been made in consideration of the above problems, and aims to provide an adhesive composition capable of forming a cured adhesive layer having excellent flame retardancy and adhesion, a film-like adhesive using the adhesive composition, an adhesive sheet, a semiconductor device, and a method for manufacturing a semiconductor device.

The present inventors have found that the above problems can be solved by using an adhesive composition containing a thermoplastic component, a thermosetting component, and a specific amount of a nitrogen atom-containing flame retardant, and have completed the present invention.
[1] An adhesive composition comprising a thermoplastic component (A), a thermosetting component (B), and a nitrogen-containing flame retardant (C),
An adhesive composition, wherein the content of the nitrogen-containing flame retardant (C) is 25 mass% or less relative to the total amount (100 mass%) of all components excluding inorganic fillers in the solid content of the adhesive composition.
[2] The adhesive composition according to the above [1], wherein the thermoplastic component (A) is an acrylic resin.
[3] The adhesive composition according to the above [1] or [2], wherein the thermosetting component (B) is an epoxy resin.
[4] The adhesive composition according to any one of the above [1] to [3], further comprising an inorganic filler (D).
[5] The adhesive composition according to any one of the above [1] to [4], wherein the nitrogen-containing flame retardant (C) is a compound containing a phosphorus atom and a nitrogen atom.
[6] The adhesive composition according to the above [5], wherein the compound containing a phosphorus atom and a nitrogen atom is a compound containing a bond between a phosphorus atom and a nitrogen atom.
[7] The adhesive composition according to the above [6], wherein the compound containing a bond between a phosphorus atom and a nitrogen atom is a compound containing a structure represented by the following general formula (C-1):

(In the formula, R ¹ represents a substituted or unsubstituted aliphatic hydrocarbon group, or a substituted or unsubstituted aromatic hydrocarbon group. Multiple R ^1s may be the same or different. n represents an integer of 3 to 20. -* ¹ and -* ² represent bonds to other atoms. Bond -* ¹ and bond -* ² may be linked to each other to form a cyclic structure.)
[8] A step of die-bonding a semiconductor chip, or
The adhesive composition according to any one of the above [1] to [7], which is used in both a step of dicing a semiconductor wafer and a step of die bonding the semiconductor chips obtained by the dicing.
[9] A film-like adhesive obtained by forming the adhesive composition according to any one of [1] to [8] above into a film.
[10] An adhesive sheet comprising a substrate and the film-like adhesive according to [9] above laminated on one surface of the substrate directly or via another layer.
[11] The adhesive sheet according to the above [10], further comprising a ring-shaped double-sided adhesive sheet laminated on the surface of the film-like adhesive opposite the substrate, and processed into a predetermined shape.
[12] A semiconductor device having a semiconductor chip bonded with the adhesive composition according to any one of [1] to [8] above.
[13] A method for producing a semiconductor device, comprising a step of die-bonding a semiconductor chip using the adhesive composition according to any one of [1] to [8] above.

The present invention provides an adhesive composition capable of forming a cured adhesive layer having excellent flame retardancy and adhesion, a film-like adhesive using the adhesive composition, an adhesive sheet, a semiconductor device, and a method for manufacturing a semiconductor device.

1 is a schematic cross-sectional view showing one embodiment of an adhesive sheet of the present invention. FIG. 2 is a schematic cross-sectional view showing another embodiment of the adhesive sheet of the present invention. FIG. 2 is a schematic cross-sectional view showing yet another embodiment of the adhesive sheet of the present invention. FIG. 2 is a schematic cross-sectional view showing yet another embodiment of the adhesive sheet of the present invention. 1 is a schematic cross-sectional view showing a part of an embodiment of a method for manufacturing a semiconductor device of the present invention. 1 is a schematic cross-sectional view showing a part of an embodiment of a method for manufacturing a semiconductor device of the present invention. 1 is a schematic cross-sectional view showing a part of an embodiment of a method for manufacturing a semiconductor device of the present invention. 1 is a schematic cross-sectional view showing a part of an embodiment of a method for manufacturing a semiconductor device of the present invention.

In this specification, the number average molecular weight (Mn) and the mass average molecular weight (Mw) are values measured by gel permeation chromatography (GPC) in terms of standard polystyrene, specifically, values measured according to the method described in the examples.

In this specification, the lower limit and upper limit values described in stages for preferred numerical ranges (e.g., ranges of content, etc.) can be combined independently. For example, the description "preferably 10 to 90, more preferably 30 to 60" can be combined with the "preferred lower limit (10)" and the "more preferred upper limit (60)" to give "10 to 60."

In this specification, "energy rays" refers to electromagnetic waves or charged particle beams that have an energy quantum. Examples of energy rays include ultraviolet rays, radiation, and electron beams. Ultraviolet rays can be irradiated using an electrodeless lamp, a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, a black light, an LED lamp, etc. Electron beams can be generated by an electron beam accelerator, etc.

In addition, in this specification, "energy ray curable" means a property that is cured by irradiation with energy rays, and "non-energy ray curable" means a property that is not cured even when irradiated with energy rays, and includes thermosetting and non-curing. In addition, in this specification, "thermosetting" means a property that is cured by heating, and "non-curing" means a property that is not cured by heating or irradiation with energy rays, etc.

In this specification, for example, "(meth)acrylic acid" refers to both "acrylic acid" and "methacrylic acid," and similar terms.

In this specification, the "circuit side" of a semiconductor wafer or semiconductor chip refers to the side on which a circuit is formed, and the "back side" of a semiconductor wafer or semiconductor chip refers to the side opposite the circuit side.

In this specification, the "thickness" of an object means the thickness of the entire object, and for example, when the object is made up of multiple layers, means the total thickness of all layers that make up the object.
The thicknesses in this specification are values measured based on the method described in the Examples.

In this specification, "solid content" refers to the components contained in the target composition excluding diluting solvents such as water and organic solvents.

The mechanism of action described in this specification is speculative and does not limit the mechanism by which the effects of the present invention are achieved.

[Adhesive composition]
The adhesive composition of the present embodiment is
An adhesive composition comprising a thermoplastic component (A), a thermosetting component (B), and a nitrogen-containing flame retardant (C),
The adhesive composition has a content of the nitrogen-containing flame retardant (C) of 25 mass % or less relative to the total amount (100 mass %) of all components of the solid content of the adhesive composition excluding inorganic fillers.

The adhesive composition of the present embodiment has at least thermosetting properties, and when thermally cured while adhering objects to be bonded, a cured adhesive layer that bonds the objects to be bonded together is formed.
The cured adhesive layer formed from the adhesive composition of this embodiment has excellent flame retardancy and adhesion, and therefore a semiconductor device manufactured using the adhesive composition of this embodiment as an adhesive has excellent safety and reliability.

The adhesive composition of this embodiment is preferably used in a process for die-bonding a semiconductor chip (hereinafter also referred to as the "die-bonding process"), or in both a process for dicing a semiconductor wafer and a process for die-bonding the semiconductor chip obtained by the dicing (hereinafter also referred to as the "dicing-die-bonding process").

In the die bonding process, for example, an uncured adhesive layer is formed on the back surface of a semiconductor chip using the adhesive composition of this embodiment, and the semiconductor chip having the uncured adhesive layer is attached to a substrate or another semiconductor chip using the adhesive layer as an attachment surface, and the uncured adhesive layer is heated and cured to die bond the semiconductor chip.
A method for forming an uncured adhesive layer using the adhesive composition of this embodiment may be, for example, a method of applying the adhesive composition of this embodiment to the back surface of a semiconductor wafer or semiconductor chip, or a method of forming the adhesive composition of this embodiment in the form of a film-like adhesive of this embodiment described below and attaching the film-like adhesive to the back surface of a semiconductor wafer or semiconductor chip.
In this specification, the film-like adhesive used in the die bonding step as described above may be referred to as a "die bonding film."

In the dicing and die bonding process, for example, the adhesive composition of the present embodiment is used in the form of a film-like adhesive. Specifically, an adhesive sheet having a substrate and a film-like adhesive formed from the adhesive composition of the present embodiment laminated on one side of the substrate is prepared, and a semiconductor wafer is attached to the film-like adhesive of the adhesive sheet. Then, while the semiconductor wafer is supported by the adhesive sheet, the semiconductor wafer is divided into semiconductor chips, and the film-like adhesive is cut into the same shape as the semiconductor chip. After that, the semiconductor chip having the cut film-like adhesive on the back side is separated from the substrate, and the die bonding process is carried out in the same manner as above.
In this specification, the adhesive sheet used in the dicing/die bonding process as described above may be referred to as a "dicing/die bonding sheet".

Below, we will explain in detail each component that may be contained in the adhesive composition of this embodiment.

<Thermoplastic component (A)>
The adhesive composition of the present embodiment contains a thermoplastic component (A), which improves the film-forming properties when the adhesive composition is made into a film-like adhesive, the flexibility and adhesion of the film-like adhesive, and the like. This provides excellent adhesion to the body.
The thermoplastic component (A) may be used alone or in combination of two or more kinds.

Examples of the thermoplastic component (A) include acrylic resins, polyester resins, urethane resins, silicone resins, rubber-based polymers, phenoxy resins, polybutene resins, polybutadiene resins, polystyrene resins, etc. Among these, acrylic resins are preferred from the viewpoint of effectively exerting the above-mentioned effects based on the use of the thermoplastic component (A).

(Acrylic resin)
As the acrylic resin, a known acrylic polymer can be used.
The mass average molecular weight (Mw) of the acrylic resin is not particularly limited, but is preferably 10,000 to 2,000,000, more preferably 100,000 to 1,500,000, and even more preferably 500,000 to 1,200,000.
When the mass average molecular weight (Mw) of the acrylic resin is equal to or greater than the lower limit, the adhesive strength to the adherend tends to be more appropriate. Also, when the mass average molecular weight (Mw) of the acrylic resin is equal to or less than the upper limit, the conformity to the uneven surface of the adherend tends to be better, and the occurrence of voids between the adherend and the resin tends to be suppressed.

The glass transition temperature (Tg) of the acrylic resin (hereinafter simply referred to as "Tg") is not particularly limited, but is preferably -60 to 70°C, more preferably -50 to 50°C.
When the Tg of the acrylic resin is within the above range, the adhesive strength to the adherend tends to be more appropriate.

Examples of monomers constituting the acrylic resin include (meth)acrylic acid esters.
Examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, and hexadecyl (meth)acrylate. alkyl (meth)acrylates in which the alkyl group is chain-like and has 1 to 18 carbon atoms, such as ethyl (meth)acrylate, heptadecyl (meth)acrylate, and octadecyl (meth)acrylate; (meth)acrylates having a cyclic skeleton, such as cycloalkyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and imide (meth)acrylate; hydroxyl group-containing (meth)acrylates, such as hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate; and glycidyl group-containing (meth)acrylates, such as glycidyl (meth)acrylate.
The acrylic resin may also be a copolymer of monomers other than (meth)acrylic acid esters, such as acrylic acid, methacrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide.
The monomer constituting the acrylic resin may be of only one type, or of two or more types.

The acrylic resin may have a functional group, such as a vinyl group, a (meth)acryloyl group, an amino group, a hydroxy group, a carboxy group, an isocyanate group, or a glycidyl group.
When the acrylic resin has a functional group, the functional group may be bonded to another compound, for example, via a crosslinking agent described below, or may be bonded directly to another compound without via a crosslinking agent.

The content of the acrylic resin in the adhesive composition is not particularly limited, but is preferably 1 to 20 mass %, more preferably 3 to 15 mass %, and even more preferably 5 to 10 mass %, relative to the total amount (100 mass %) of the solid contents of the adhesive composition excluding the inorganic filler.
When the content of the acrylic resin is within the above range, the film-forming properties, flexibility and application properties of the film-like adhesive formed from the adhesive composition, as well as the adhesion properties of the cured adhesive layer, tend to be better.

(Thermoplastic component (A) other than acrylic resin)
The adhesive composition of the present embodiment preferably uses an acrylic resin in combination with a thermoplastic component (A) other than an acrylic resin.
As the thermoplastic component (A) other than the acrylic resin, among those exemplified above, from the viewpoints of the film-forming properties, flexibility and application properties of the film-like adhesive formed from the adhesive composition, polyester resins, urethane resins, silicone resins, rubber-based polymers and phenoxy resins are preferred, with polyester resins being more preferred.
Furthermore, from the viewpoint of improving the ability of the adhesive composition to conform to the uneven surface of an adherend when made into a film-like adhesive, and improving the effect of suppressing the occurrence of voids, etc., polyester resins, urethane resins, phenoxy resins, polybutene resins, polybutadiene resins, and polystyrene resins are preferred, and polyester resins are more preferred.

The content of the thermoplastic component (A) other than the acrylic resin in the adhesive composition is not particularly limited, but is preferably 2 to 30 mass %, more preferably 5 to 25 mass %, and even more preferably 10 to 20 mass %, relative to the total amount (100 mass %) of the components excluding the inorganic filler among the solid contents of the adhesive composition.
When the content of the thermoplastic component (A) other than the acrylic resin is within the above range, the film-formability, flexibility and application properties of the film-like adhesive formed from the adhesive composition tend to be better.

(Content of thermoplastic component (A))
The content of the thermoplastic component (A) in the adhesive composition is not particularly limited, but is preferably 3 to 50 mass %, more preferably 10 to 40 mass %, and even more preferably 15 to 30 mass %, relative to the total amount (100 mass %) of the solid contents of the adhesive composition excluding the inorganic filler.
When the content of the thermoplastic component (A) is equal to or greater than the lower limit, the film-forming property, flexibility, and application property of the film-like adhesive formed from the adhesive composition tend to be better. When the content of the thermoplastic component (A) is equal to or less than the upper limit, the impact resistance, etc. of the cured adhesive layer tend to be better.

<Thermosetting component (B)>
The adhesive composition of the present embodiment contains the thermosetting component (B) and thus has thermosetting properties, making it possible to form a cured adhesive layer that is excellent in impact resistance, adhesiveness, and the like.
The thermosetting component (B) may be used alone or in combination of two or more kinds.

Examples of the thermosetting component (B) include epoxy resins, phenolic resins, melamine resins, urea resins, and thermosetting polyimide resins.
Among these, the thermosetting component (B) is preferably an epoxy resin (B1), and it is preferable to contain a thermosetting agent (B2) together with the epoxy resin (B1).

(Epoxy resin (B1))
Examples of the epoxy resin (B1) include known epoxy resins, such as bisphenol type epoxy resins such as bisphenol A type epoxy resins and bisphenol F type epoxy resins, and hydrogenated products thereof; novolac type epoxy resins such as phenol novolac type epoxy resins, cresol novolac type epoxy resins, and orthocresol novolac type epoxy resins; aralkyl type epoxy resins such as phenol aralkyl type epoxy resins; dicyclopentadiene type epoxy resins; biphenyl type epoxy resins; naphthalene type epoxy resins; anthracene type epoxy resins; fluorene skeleton type epoxy resins; trisphenol type epoxy resins; etc. Among these, bisphenol A type epoxy resins and phenylene skeleton type epoxy resins are preferred.

The number average molecular weight (Mn) of the epoxy resin (B1) is not particularly limited, but from the viewpoint of the curability of the adhesive composition and the strength and heat resistance of the cured adhesive layer, it is preferably 300 to 30,000, more preferably 400 to 10,000, and even more preferably 500 to 3,000.

The epoxy equivalent of the epoxy resin (B1) is not particularly limited, but is preferably 100 to 1,000 g/eq, more preferably 120 to 800 g/eq, and even more preferably 150 to 400 g/eq.
In this specification, the term "epoxy equivalent" means the number of grams of an epoxy resin containing 1 gram equivalent of epoxy groups (g/eq), and can be measured in accordance with JIS K 7236:2001.

(Thermal Curing Agent (B2))
By containing the thermosetting agent (B2) together with the epoxy resin (B1) in the adhesive composition of the present embodiment, the curing properties of the adhesive composition become better, and a cured adhesive layer having superior adhesion tends to be formed.

The heat curing agent (B2) may, for example, be a compound having two or more functional groups capable of reacting with an epoxy group in one molecule.
Examples of functional groups that can react with epoxy groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and groups in which acid groups have been anhydridized. Among these, phenolic hydroxyl groups are preferred. Hereinafter, the heat curing agent (B2) having a phenolic hydroxyl group will be referred to as a "phenolic curing agent."

Examples of phenol-based hardeners include polyfunctional phenols, biphenols, novolac-type phenols, dicyclopentadiene-type phenols, and aralkyl-type phenols. Among these, novolac-type phenols are preferred.

When the adhesive composition contains a heat curing agent (B2), the content of the heat curing agent (B2) in the adhesive composition is not particularly limited, but is preferably 0.1 to 500 parts by mass, more preferably 1 to 200 parts by mass, even more preferably 5 to 150 parts by mass, still more preferably 10 to 100 parts by mass, and particularly preferably 15 to 75 parts by mass, per 100 parts by mass of the epoxy resin (B1).
When the content of the heat curing agent (B2) is equal to or greater than the lower limit, the adhesive composition tends to have better curability, whereas when the content of the heat curing agent (B2) is equal to or less than the upper limit, a cured adhesive layer having excellent moisture absorption resistance tends to be formed.

The total content of the epoxy resin (B1) and the heat curing agent (B2) in the heat curable component (B) is not particularly limited, but is preferably 70 to 100 mass%, more preferably 80 to 100 mass%, and even more preferably 90 to 100 mass%.
When the total content of the epoxy resin (B1) and the thermosetting agent (B2) in the thermosetting component (B) is within the above range, the adhesiveness of the cured adhesive layer tends to be better.

The content of the thermosetting component (B) in the adhesive composition is not particularly limited, but is preferably 50 to 1,000 parts by mass, more preferably 65 to 700 parts by mass, and even more preferably 80 to 400 parts by mass, per 100 parts by mass of the thermoplastic component (A).
When the content of the thermosetting component (B) is within the above range, the adhesiveness of the cured adhesive layer tends to be better.

<Nitrogen Atom-Containing Flame Retardant (C)>
The adhesive composition of the present embodiment contains a nitrogen-atom-containing flame retardant (C), and the content of the nitrogen-atom-containing flame retardant (C) is 25 mass% or less relative to the total amount (100 mass%) of components excluding inorganic fillers in the solid content of the adhesive composition.
The nitrogen-containing flame retardant (C) may be used alone or in combination of two or more kinds.

When the content of the nitrogen-containing flame retardant (C) is within the above range, the cured adhesive layer has excellent flame retardancy and adhesiveness.
The reason for this is unclear, but is presumed to be as follows. In the nitrogen-atom-containing flame retardant (C) contained within the above content range, the phosphorus and nitrogen atoms contribute to flame retardancy, and good compatibility with the thermoplastic component (A) and the thermosetting component (B) is obtained. Furthermore, since the nitrogen-atom-containing flame retardant (C) is unlikely to inhibit the curing of the thermosetting component (B), it is presumed that the homogeneity and strength of the cured product are good, and excellent adhesion is obtained.

From the same viewpoint, the content of the nitrogen atom-containing flame retardant (C) in the adhesive composition is preferably 0.5 to 23 mass%, more preferably 2 to 20 mass%, even more preferably 3 to 17 mass%, even more preferably 4 to 13 mass%, and particularly preferably 5 to 10 mass%, based on the total amount (100 mass%) of the solid content of the adhesive composition excluding the inorganic filler.

Examples of the nitrogen atom-containing flame retardant (C) include compounds containing phosphorus atoms and nitrogen atoms, nitrogen atom-containing heterocyclic compounds, etc. Among these, compounds containing phosphorus atoms and nitrogen atoms are preferred from the viewpoint of improving the flame retardancy and adhesion of the cured adhesive layer.

(Compounds containing phosphorus and nitrogen atoms)
The number of phosphorus atoms contained in one molecule of the compound containing a phosphorus atom and a nitrogen atom is not particularly limited, but is preferably 1 to 20, more preferably 2 to 10, even more preferably 3 to 5, and particularly preferably 3 or 4.
The number of nitrogen atoms contained in one molecule of the compound containing a phosphorus atom and a nitrogen atom is not particularly limited, but is preferably 1 to 20, more preferably 2 to 10, even more preferably 3 to 5, and particularly preferably 3 or 4.
When the numbers of phosphorus atoms and nitrogen atoms in the compound containing phosphorus atoms and nitrogen atoms are within the above ranges, the flame retardancy and adhesion of the cured adhesive layer tend to be better.

The content of phosphorus atoms in the compound containing phosphorus atoms and nitrogen atoms is not particularly limited, but is preferably 5 to 30 mass%, more preferably 7 to 20 mass%, and even more preferably 10 to 15 mass%, relative to the compound containing phosphorus atoms and nitrogen atoms (100 mass%).
The content of nitrogen atoms in the compound containing a phosphorus atom and a nitrogen atom is not particularly limited, but is preferably 1 to 20 mass%, more preferably 2 to 15 mass%, and even more preferably 4 to 10 mass%, relative to the compound containing a phosphorus atom and a nitrogen atom (100 mass%).
When the content of phosphorus atoms and nitrogen atoms in the compound containing phosphorus atoms and nitrogen atoms is within the above range, the flame retardancy and adhesion of the cured adhesive layer tend to be better.

From the viewpoint of further improving the flame retardancy of the cured adhesive layer, it is preferable that the compound containing a phosphorus atom and a nitrogen atom is a compound containing a bond between a phosphorus atom and a nitrogen atom.

From the viewpoint of improving the flame retardancy and adhesion of the cured adhesive layer, the compound containing a bond between a phosphorus atom and a nitrogen atom is preferably an organic compound containing a bond between a phosphorus atom and a nitrogen atom, and more preferably a compound containing a structure represented by the following general formula (C-1).

(In the formula, R ¹ represents a substituted or unsubstituted aliphatic hydrocarbon group, or a substituted or unsubstituted aromatic hydrocarbon group. Multiple R ^1s may be the same or different. n represents an integer of 3 to 20. -* ¹ and -* ² represent bonds to other atoms. Bond -* ¹ and bond -* ² may be linked to each other to form a cyclic structure.)

Examples of the substituted or unsubstituted aliphatic hydrocarbon group represented by R ¹ in the above general formula (C-1) include a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, etc. These aliphatic hydrocarbon groups may be either linear or branched.
The number of carbon atoms in the substituted or unsubstituted aliphatic hydrocarbon group is not particularly limited, but is preferably 1 to 10, more preferably 2 to 8, and even more preferably 3 to 5. When the aliphatic hydrocarbon group has a substituent, the number of carbon atoms does not include the number of carbon atoms of the substituent.
Examples of the substituent that the aliphatic hydrocarbon group may have include a halogen atom, a hydroxy group, a carboxy group, an alkoxy group, a cyano group, an aromatic hydrocarbon group, etc. Examples of the aromatic hydrocarbon group as the substituent include the same aromatic hydrocarbon groups as those represented by ^R1 described below.

Examples of the substituted or unsubstituted aromatic hydrocarbon group include a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, and the like.
The number of carbon atoms in the substituted or unsubstituted aromatic hydrocarbon group is not particularly limited, but is preferably 6 to 12, and more preferably 6 to 8. When the aromatic hydrocarbon group has a substituent, the number of carbon atoms does not include the number of carbon atoms of the substituent.
Examples of the substituent that the aromatic hydrocarbon group may have include a halogen atom, a hydroxy group, a carboxy group, an alkoxy group, a cyano group, an aliphatic hydrocarbon group, etc. Examples of the aliphatic hydrocarbon group as the substituent include the same as the aliphatic hydrocarbon group represented by ^R1 described above.

Among the above options, R ¹ in the above general formula (C-1) is preferably a substituted or unsubstituted phenyl group, and more preferably an unsubstituted phenyl group.

In the above general formula (C-1), n is not particularly limited, but is preferably an integer from 3 to 15, more preferably an integer from 3 to 10, and even more preferably an integer from 3 to 5.

In the above general formula (C-1), -* ¹ and -* ² represent bonds to other atoms.
The bond-* ¹ and the bond-* ² in the above general formula (C-1) may be linked to each other to form a cyclic structure, and preferably form a cyclic structure. In this case, the term "compound containing a structure represented by general formula (C-1)" is synonymous with the term "compound represented by general formula (C-1)".

When the bond -* ¹ and the bond -* ² in the above general formula (C-1) are not linked to each other, it is preferable that -* ¹ is bonded to -N=P(OR ¹ ) ₃ or -N=P(O)(OR ¹ ), and it is preferable that -* ² is bonded to -P(OR ¹ ) ₃ or -P(O)(OR ¹ ). The explanation of R ¹ contained in these groups is the same as the explanation of R ¹ in the above general formula (C-1).

An example of a compound containing a phosphorus atom and a nitrogen atom is a phosphazene compound. Here, in this specification, the term "phosphazene compound" refers to a compound that contains phosphorus atoms and nitrogen atoms alternately, and each phosphorus atom has two substituents.
The phosphazene compound may be either an organic compound or an inorganic compound, but is preferably an organic compound.

Examples of the phosphazene compound include cyclic phosphazene compounds and chain phosphazene compounds, with cyclic phosphazene compounds being preferred.
Examples of the cyclic phosphazene compound include cyclic phenoxyphosphazene compounds such as hexaphenoxycyclotriphosphazene, octaphenoxycyclotetraphosphazene, decafenoxycyclopentaphosphazene, dodecafenoxycyclohexaphosphazene, and tetradecafenoxycycloheptaphosphazene; cyclic propoxyphosphazene compounds such as hexapropoxycyclotriphosphazene, octapropoxycyclotetraphosphazene, decapropoxycyclopentaphosphazene, dodecapropoxycyclohexaphosphazene, and tetradecapropoxycycloheptaphosphazene; etc. Among these, cyclic phenoxyphosphazene compounds are preferred, and hexaphenoxycyclotriphosphazene is more preferred.

The molecular weight of the compound containing phosphorus atoms and nitrogen atoms is not particularly limited, but is preferably 300-3,000, more preferably 400-1,500, and even more preferably 500-800.
When the molecular weight of the compound containing phosphorus atoms and nitrogen atoms is equal to or greater than the lower limit, the compound containing phosphorus atoms and nitrogen atoms tends to be prevented from volatilizing when the adhesive composition is made into a film-like adhesive and when the adhesive composition is thermally cured. When the molecular weight of the compound containing phosphorus atoms and nitrogen atoms is equal to or less than the upper limit, the compound containing phosphorus atoms and nitrogen atoms tends to have better dispersibility in the adhesive composition.

(Nitrogen-containing heterocyclic compound)
Examples of the nitrogen atom-containing heterocyclic compound include a compound having a triazine ring and a compound having an isocyanurate ring, and among these, a compound having a triazine ring is preferred. The triazine ring of the compound having a triazine ring may be any one of a 1,2,3-triazine ring, a 1,2,4-triazine ring, and a 1,3,5-triazine ring, but is preferably a 1,3,5-triazine ring.

Examples of compounds having a 1,3,5-triazine ring include melamine, melamine cyanurate, N ² ,N ⁴ -diethylmelamine, N,N'-diallylmelamine, hexamethylmelamine, acetoguanamine, benzoguanamine, acryloguanamine, methacryloguanamine, melam, ammeline, ammelide, 2,4-diamino-6-methoxy-1,3,5-triazine, 2,4-diamino-6-ethoxy-1,3,5-triazine, 2,4-diamino-6-propoxy-1,3,5-triazine, 2,4-diamino-6-isopropoxy-1,3,5-triazine, and 2,4-diamino-6-nonyl-1,3,5-triazine.

<Inorganic filler (D)>
The adhesive composition of the present embodiment may further contain an inorganic filler (D).
By including the inorganic filler (D) in the adhesive composition of this embodiment, it tends to be possible to form a cured adhesive layer that is even lower in thermal expansion and moisture absorption.
The inorganic filler (D) may be used alone or in combination of two or more kinds.

Examples of the inorganic filler (D) include powders of silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, boron nitride, etc.; beads obtained by spheroidizing these silicas, etc.; single crystal fibers of these silicas, etc.; glass fibers; etc. Among these, silica and alumina are preferred, and silica is more preferred.
The shape of the inorganic filler (D) is not particularly limited and may be, for example, spherical, crushed, fibrous, etc., but is preferably spherical.

The average particle size (D ₅₀ ) of the inorganic filler (D) is not particularly limited, but is preferably 0.01 to 2 μm, more preferably 0.05 to 1 μm, and further preferably 0.1 to 0.8 μm.
In this specification, unless otherwise specified, the term "average particle size (D ₅₀ )" refers to the particle size (D ₅₀ ) value at an integrated value of 50% in a particle size distribution curve determined by a laser diffraction scattering method.

When the adhesive composition contains an inorganic filler (D), the content of the inorganic filler (D) in the adhesive composition is not particularly limited, but is preferably 2 to 25 parts by mass, more preferably 5 to 20 parts by mass, and even more preferably 8 to 15 parts by mass, relative to 100 parts by mass of the total amount of the components excluding the inorganic filler among the solid contents of the adhesive composition.
When the content of the inorganic filler (D) is equal to or greater than the lower limit, the cured adhesive layer tends to have better low thermal expansion and low moisture absorption properties. When the content of the inorganic filler (D) is equal to or less than the upper limit, the film-forming properties and flexibility of the film-like adhesive formed from the adhesive composition tend to be better.

<Curing Accelerator (E)>
The adhesive composition of the present embodiment may further contain a curing accelerator (E).
The curing accelerator (E) is used to adjust the curing speed of the adhesive composition.
The curing accelerator (E) may be used alone or in combination of two or more kinds.

Examples of the curing accelerator (E) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and 1-cyanoethyl-2-phenylimidazole; organic phosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine; and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate. Among these, imidazoles are preferred, and 2-phenyl-4,5-dihydroxymethylimidazole is more preferred.

When the adhesive composition contains a curing accelerator (E), the content of the curing accelerator (E) in the adhesive composition is not particularly limited, but is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.2 to 1 part by mass, relative to 100 parts by mass of the content of the thermosetting component (B).
When the content of the curing accelerator (E) is within the above range, a cured adhesive layer having better adhesiveness tends to be formed.

<Energy Ray Curable Resin (F)>
The adhesive composition of the present embodiment may further contain an energy ray-curable resin (F).
By including the energy ray-curable resin (F) in the adhesive composition of this embodiment, it becomes possible to adjust the adhesive strength of the film-like adhesive formed from the adhesive composition by irradiation with energy rays.
The energy ray curable resin (F) may be used alone or in combination of two or more kinds.

The energy ray curable resin (F) has the property of being cured by irradiation with energy rays.
The energy ray-curable resin (F) may be, for example, a compound having at least one polymerizable double bond in the molecule, and is preferably an acrylate-based compound having a (meth)acryloyl group.
Examples of the acrylate-based compound include (meth)acrylates containing a chain aliphatic skeleton, such as trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. Examples of the acrylate include alicyclic skeleton-containing (meth)acrylates such as dicyclopentanyl di(meth)acrylate and tricyclodecane dimethylol diacrylate, polyalkylene glycol (meth)acrylates such as polyethylene glycol di(meth)acrylate, oligoester (meth)acrylates, urethane (meth)acrylate oligomers, epoxy-modified (meth)acrylates, polyether (meth)acrylates other than the polyalkylene glycol (meth)acrylates, and itaconic acid oligomers. Among these, tricyclodecane dimethylol diacrylate is preferred.

When the adhesive composition contains an energy ray curable resin (F), the content of the energy ray curable resin (F) in the adhesive composition is not particularly limited, but is preferably 0.1 to 20 mass%, more preferably 1 to 10 mass%, and even more preferably 2 to 6 mass%, relative to the total amount (100 mass%) of components excluding inorganic fillers among the solid contents of the adhesive composition.
When the content of the energy ray-curable resin (F) is within the above range, it tends to be easier to adjust the adhesive strength of the film-like adhesive formed from the adhesive composition.

<Photopolymerization initiator (G)>
When the adhesive composition of the present embodiment contains an energy ray curable resin (F), it may further contain a photopolymerization initiator (G) from the viewpoint of efficiently proceeding with the polymerization reaction of the energy ray curable resin (F).
The photopolymerization initiator (G) may be used alone or in combination of two or more kinds.

Examples of the photopolymerization initiator (G) include known ones, such as α-ketol-based compounds such as 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, and 1-hydroxycyclohexyl phenyl ketone; acetophenone-based compounds such as methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, and 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1; benzoin ether-based compounds such as benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether; and ketal compounds such as benzyl dimethyl ketal. aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride; photoactive oxime compounds such as 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; benzophenone compounds such as benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone; thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone; camphorquinone; halogenated ketones; acylphosphinoxides; acylphosphonates; and the like. Among these, 1-hydroxycyclohexyl phenyl ketone is preferred.

When the adhesive composition contains a photopolymerization initiator (G), the content of the photopolymerization initiator (G) in the adhesive composition is not particularly limited, but is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 2 to 5 parts by mass, relative to 100 parts by mass of the energy ray-curable resin (F).
When the content of the photopolymerization initiator (G) is within the above range, it tends to be easier to adjust the adhesive strength of the film-like adhesive formed from the adhesive composition.

<Coupling Agent (H)>
The adhesive composition of the present embodiment may further contain a coupling agent (H).
The adhesive composition of the present embodiment contains a coupling agent (H) having a functional group that reacts with an inorganic compound and a functional group that reacts with an organic functional group, thereby improving the adhesion of the cured adhesive layer. In addition, by using the coupling agent (H), the water resistance of the cured adhesive layer can be improved without impairing the heat resistance.
The coupling agent (H) may be used alone or in combination of two or more kinds.

The coupling agent (H) is preferably a compound having a functional group capable of reacting with a functional group possessed by another component, and is preferably a silane coupling agent.
Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-(methacryloyloxypropyl)trimethoxysilane, 3-aminopropyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, N-6-(aminoethyl)-3-aminopropyltrimethoxysilane, N-6-(aminoethyl)-3-aminopropylmethyldiethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazole silane. Among these, 3-glycidoxypropyltrimethoxysilane and N-phenyl-3-aminopropyltrimethoxysilane are preferable. Furthermore, a silicate compound to which such a silane coupling agent is added may be used as the silane coupling agent.

When the adhesive composition contains a coupling agent (H), the content of the coupling agent (H) in the adhesive composition is not particularly limited, but is preferably 0.01 to 10 mass%, more preferably 0.05 to 5 mass%, and even more preferably 0.1 to 2 mass%, relative to the total amount (100 mass%) of the solid contents of the adhesive composition excluding the inorganic filler.
When the content of the coupling agent (H) is equal to or greater than the lower limit, the above-mentioned effects due to the use of the coupling agent (H) tend to be sufficiently exhibited, whereas when the content of the coupling agent (H) is equal to or less than the upper limit, the generation of outgassing tends to be suppressed.

<Solvent>
From the viewpoint of improving handleability, the adhesive composition of the present embodiment may further contain a solvent.
The solvent may be used alone or in combination of two or more kinds.
Examples of the solvent include hydrocarbons such as toluene and xylene, alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol, and 1-butanol, esters such as ethyl acetate, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran, and compounds having an amide bond such as dimethylformamide and N-methylpyrrolidone. Among these, methyl ethyl ketone is preferred from the viewpoint of facilitating uniform mixing of the various components.

<Other ingredients>
The adhesive composition of the present embodiment may contain other components in addition to the above-mentioned components.
Examples of other components include a crosslinking agent for the thermoplastic component (A), a surface conditioner such as silicone oil, a plasticizer, an antistatic agent, an antioxidant, a pigment, a dye, and a gettering agent.
The other components may be used alone or in combination of two or more. The content of the other components is not particularly limited and may be appropriately selected depending on the purpose.

<Method of producing adhesive composition>
The adhesive composition of the present embodiment can be produced by blending the above-mentioned components.
The order of addition of the components when blending is not particularly limited, and two or more components may be added simultaneously.
The method for mixing the components during blending is not particularly limited, and may be appropriately selected from known methods such as a method of mixing by rotating a stirrer, stirring blades, etc.; a method of mixing using a mixer; a method of mixing by applying ultrasound, etc.
The temperature and time during addition and mixing of each component may be appropriately adjusted depending on the type of component used, etc., but a temperature of 15 to 30°C is preferred.

[Film-type adhesive]
The film-like adhesive of the present embodiment is a film-like adhesive obtained by forming the adhesive composition of the present embodiment into a film.

The film-like adhesive of this embodiment has pressure-sensitive adhesion and thermosetting properties. The film-like adhesive has pressure-sensitive adhesion, and can be applied to an object to be bonded by lightly pressing the uncured adhesive. The film-like adhesive may be softened by heating so that it can be applied to an adherend. In addition, the film-like adhesive has thermosetting properties, and can form a cured adhesive layer with excellent adhesion, impact resistance, etc., by heating.

The film-like adhesive of this embodiment is suitable for the above-mentioned die bonding process and dicing/die bonding process, and is preferably used as a die bonding film in these processes.
When the film-like adhesive of this embodiment is applied to a dicing/die bonding process, it is preferable to use the film-like adhesive of this embodiment in the form of an adhesive sheet, which will be described later.

The thickness of the film-like adhesive is not particularly limited, but is preferably 1 to 100 μm, more preferably 2 to 75 μm, and even more preferably 5 to 50 μm.
When the thickness of the film-like adhesive is equal to or greater than the above lower limit, the adhesiveness to the adherend tends to be better, whereas when the thickness of the film-like adhesive is equal to or less than the above upper limit, the cured adhesive layer is prevented from becoming excessively thick.

The film-like adhesive can be produced, for example, by forming the adhesive composition of the present embodiment into a film. Specifically, for example, the adhesive composition of the present embodiment can be applied onto a support sheet such as a substrate or a release film, and dried as necessary to form a film-like adhesive on the support sheet.
The adhesive composition may be applied by a known method, for example, a method using various coaters such as an air knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a roll knife coater, a curtain coater, a die coater, a knife coater, a screen coater, a Mayer bar coater, or a kiss coater.

[Adhesive sheet]
The adhesive sheet of the present embodiment is an adhesive sheet having a substrate and the film-like adhesive of the present embodiment laminated directly or via another layer on one surface of the substrate.
The adhesive sheet of this embodiment is suitable for a dicing/die bonding process, and is preferably used as a dicing/die bonding sheet in this process.
A specific example of use of the adhesive sheet of this embodiment is as described later in the method for producing a semiconductor device of this embodiment.

The adhesive sheet of this embodiment may have other components in addition to the substrate and the film-like adhesive. Examples of other components include a release film provided on the surface of the film-like adhesive opposite the substrate, an intermediate layer provided between the substrate and the film-like adhesive, and a ring-shaped double-sided adhesive sheet provided on the surface of the film-like adhesive opposite the substrate.

The configuration of the adhesive sheet of this embodiment will be described below with reference to the drawings as necessary. Note that the drawings used in the following description may show enlarged essential parts for the sake of convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may not necessarily be the same as in reality.

FIG. 1 is a cross-sectional view that illustrates a schematic diagram of one embodiment of the adhesive sheet of the present invention.
The adhesive sheet 1 shown in FIG. 1 has a structure in which a film-like adhesive 11 is laminated on one surface 10 a of a substrate 10 .

<Film-type adhesive>
The preferred embodiments of the film-like adhesive in the adhesive sheet of this embodiment are the same as the preferred embodiments of the film-like adhesive of this embodiment described above.

<Substrate>
The material of the substrate is preferably various resins, and specific examples thereof include polyethylene (low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE, etc.)), polypropylene, polybutene, polybutadiene, polymethylpentene, styrene-ethylene-butylene-styrene block copolymer, polyvinyl chloride, vinyl chloride copolymer, polyethylene terephthalate, polybutylene terephthalate, polyurethane, polyurethane acrylate, polyimide, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, polystyrene, polycarbonate, fluororesin, water additives, modified products, crosslinked products, or copolymers of any of these resins, and the like.
The resin constituting the substrate may be used alone or in combination of two or more kinds.
The substrate may be made of only one layer, or may be made of two or more layers. When the substrate is made of multiple layers, the materials of the layers may all be the same, all be different, or only some of the layers may be the same.
The surface of the substrate that comes into contact with the film-like adhesive may be subjected to a release treatment such as silicone treatment.
The thickness of the substrate may be appropriately selected depending on the purpose, but is preferably 20 to 300 μm, more preferably 30 to 200 μm, and further preferably 60 to 150 μm.
When the thickness of the substrate is within the above range, the flexibility of the adhesive sheet, its ability to be applied to an adherend, and the ability to pick up a semiconductor chip with a film-like adhesive tend to be improved.

<Release film>
FIG. 2 is a cross-sectional view that illustrates a schematic diagram of one embodiment of the adhesive sheet of the present invention having a release sheet.
The adhesive sheet 2 shown in FIG. 2 has a configuration in which a film-like adhesive 11 and a release film 12 are laminated in this order on one surface 10a of a substrate 10.
As the release film, a conventionally known film can be used, and for example, a film having a release layer that has been subjected to a release treatment with a release agent on a base material for the release film can be mentioned.

<Middle class>
FIG. 3 is a cross-sectional view that illustrates a schematic diagram of one embodiment of an adhesive sheet of the present invention having an intermediate layer.
The adhesive sheet 3 shown in FIG. 3 has a configuration in which an intermediate layer 13, a film-like adhesive 11, and a release film 12 are laminated in this order on one surface 10a of a substrate 10.

An example of the intermediate layer is a pressure-sensitive adhesive layer.
The adhesive layer is formed for the purposes of, for example, stabilizing the fixation of the semiconductor wafer during dicing when the adhesive sheet of this embodiment is used as a dicing/die bonding sheet, and facilitating peeling of the semiconductor chip with the film-like adhesive from the substrate when picking up the semiconductor chip.
The pressure-sensitive adhesive layer can be formed using a known pressure-sensitive adhesive, and examples of the pressure-sensitive adhesive include adhesive resins such as acrylic resins, urethane resins, rubber resins, silicone resins, epoxy resins, polyvinyl ethers, polycarbonates, and ester resins. Among these, acrylic resins are preferred.
The pressure-sensitive adhesive layer may be formed using an energy ray-curable pressure-sensitive adhesive or a non-energy ray-curable pressure-sensitive adhesive. The non-energy ray-curable pressure-sensitive adhesive includes a thermosetting pressure-sensitive adhesive and a non-curable pressure-sensitive adhesive.

The intermediate layer may be composed of only one layer, or may be composed of two or more layers. When the intermediate layer is composed of multiple layers, the materials of the layers may all be the same, all be different, or only some of the layers may be the same.
The thickness of the intermediate layer is not particularly limited, but is preferably 1 to 100 μm.

<Ring-shaped double-sided adhesive sheet>
FIG. 4 is a cross-sectional view that illustrates a schematic diagram of one embodiment of an adhesive sheet of the present invention having a ring-shaped double-sided pressure-sensitive adhesive sheet.
The adhesive sheet 4 shown in Fig. 4 has a film-like adhesive 11 on one surface 10a of a substrate 10, and a ring-shaped double-sided adhesive sheet 14 is laminated in a region near the periphery of the surface 11a of the film-like adhesive 11 opposite the substrate 10. Furthermore, a release film 12 is laminated on the surface 11a (upper surface) of the film-like adhesive 11 and the surface 14a (upper surface) of the ring-shaped double-sided adhesive sheet 14.
The ring-shaped double-sided adhesive sheet 14 is a member for attaching a ring frame when the adhesive sheet of this embodiment is used as a dicing/die bonding tape.

When the adhesive sheet 4 is used, the release film 12 is peeled off, and the back surface of a semiconductor wafer (not shown) is affixed to the area of the surface 10a of the exposed film-like adhesive 11 where the ring-shaped double-sided adhesive sheet 14 is not laminated. In addition, the surface 14a of the ring-shaped double-sided adhesive sheet 14 is affixed to a jig such as a ring frame for use.

The ring-shaped double-sided pressure-sensitive adhesive sheet may be of a single layer structure, or may be of a multi-layer structure in which pressure-sensitive adhesive layers are laminated on both sides of a core sheet.
The thickness of the ring-shaped double-sided pressure-sensitive adhesive sheet is not particularly limited, but is, for example, 20 to 150 μm.
The ring-shaped double-sided pressure-sensitive adhesive sheet has an annular shape in a plan view, and the shapes of its outer edge and inner edge may be determined according to the shape of the ring frame to be used, but it is preferable that both are approximately circular.

In addition, the adhesive sheet of this embodiment may be processed into a predetermined shape, and preferably has a ring-shaped double-sided adhesive sheet laminated on the surface of the film-like adhesive opposite the substrate, and is processed into a predetermined shape.
An example of processing the adhesive sheet of this embodiment into a predetermined shape is to perform a predetermined cutting process (precutting process) on the adhesive sheet of this embodiment so that it can be fixed to a ring frame of a known shape.
The shape of the adhesive sheet in a plan view during precutting may be determined according to the shape of the ring frame to be used, but is preferably substantially circular.

The adhesive sheet of the present embodiment is not limited to that shown in FIGS. 1 to 4, and may have some of the configurations shown in FIGS. 1 to 4 modified or removed, or may have other configurations added to those described so far, within the scope that does not impair the effects of the present invention.
In the adhesive sheet, the size, shape, etc. of each layer can be adjusted as desired depending on the purpose.

[Semiconductor device and method for manufacturing the semiconductor device]
The semiconductor device of this embodiment is a semiconductor device having a semiconductor chip bonded with the adhesive composition of this embodiment.
The method for producing a semiconductor device of this embodiment is a method for producing a semiconductor device that includes a step of die-bonding a semiconductor chip using the adhesive composition of this embodiment.

In the method for manufacturing a semiconductor device of this embodiment, the adhesive composition is preferably used in the form of the film-like adhesive of this embodiment or the adhesive sheet of this embodiment.
The method for manufacturing a semiconductor device using the adhesive sheet of this embodiment is preferably a manufacturing method using the adhesive sheet of this embodiment as a dicing/die bonding sheet, and more preferably a manufacturing method including the following steps 1 to 4.
Step 1: A step of attaching the back surface of a semiconductor wafer to the exposed surface of the film-like adhesive of the adhesive sheet of this embodiment (hereinafter also referred to as the "attaching step").
Step 2: A step of producing semiconductor chips by dividing the semiconductor wafer, and producing semiconductor chips with a film-like adhesive by cutting the film-like adhesive along the division points of the semiconductor wafer (hereinafter also referred to as a "dicing step").
Step 3: A step of peeling off the semiconductor chip with the film-like adhesive from the substrate and picking it up (hereinafter also referred to as the "pick-up step").
Step 4: A step of die-bonding the picked-up semiconductor chip with the film-like adhesive to a substrate or another semiconductor chip with the film-like adhesive as the adhesive surface (hereinafter also referred to as the "die-bonding step").
Each step will be described below with reference to the drawings.

<Step 1: Attachment step>
FIG. 5 is a schematic cross-sectional view for explaining the dicing step.
The adhesive sheet 5 shown in Figure 5 has a film-like adhesive 11 on one surface 10a of a substrate 10, and a ring-shaped double-sided adhesive sheet 14 is laminated in an area near the peripheral portion of the surface 11a of the film-like adhesive 11 opposite the substrate 10.
In the attachment step, as shown in FIG. 5, the back surface of a semiconductor wafer 20 is attached to an area of the surface 11a of the film-like adhesive 11 of the adhesive sheet 5 where the ring-shaped double-sided adhesive sheet 14 is not laminated.
The method for attaching the semiconductor wafer is not particularly limited, and any conventionally known method can be applied.

<Step 2: Dicing step>
FIG. 6 is a schematic cross-sectional view for explaining the dicing step.
6, in the dicing process, the semiconductor wafer 20 attached in the attaching process is divided into semiconductor chips 21, and the film-like adhesive 11 is cut to form cut film-like adhesives 11'. These processes are performed by attaching a ring frame (not shown) to the ring-shaped double-sided adhesive sheet 14.
By the above dicing step, a plurality of semiconductor chips 22 with a film-like adhesive are formed, each of which is composed of a semiconductor chip 21 and a film-like adhesive 11' provided on the rear surface of the semiconductor chip 21 after cutting.

The division of the semiconductor wafer and the cutting of the film-like adhesive can both be performed by known methods. For example, the division of the semiconductor wafer and the cutting of the film-like adhesive can be performed successively by dicing methods such as blade dicing, laser dicing by laser irradiation, and water dicing by spraying water containing an abrasive. The division of the semiconductor wafer and the cutting of the film-like adhesive may also be performed in stages rather than simultaneously. For example, after the semiconductor wafer is divided by laser dicing, the film-like adhesive can be cut in an expanding process or a picking up process.

<Process 3: Pick-up process>
FIG. 7 is a schematic cross-sectional view for explaining the pick-up step.
In the pick-up step, as shown in FIG. 7, the semiconductor chip 22 with the film-like adhesive attached is picked up by being separated from the base material 10 in the direction of the arrow X using a separating means 23.
As the pick-up method, a known method can be adopted, for example, a separation means using a vacuum collet or the like can be applied.

<Step 4: Die bonding step>
FIG. 8 is a schematic cross-sectional view for explaining the die bonding step.
In the die bonding process, the semiconductor chip 22 with the film-like adhesive is attached to the circuit formation surface 24a of the substrate 24 with the film-like adhesive 11' as the adhesive surface.
Thereafter, the film-like adhesive 11 ′ is thermally cured to form a cured adhesive layer that bonds the semiconductor chip 21 and the substrate 24 .
The method for attaching the semiconductor chip with the film-like adhesive to the substrate may be a known method. The conditions for thermally curing the film-like adhesive are not particularly limited, and may be appropriately adjusted and determined depending on the type of material constituting the film-like adhesive.

After the die bonding process, the desired semiconductor package and semiconductor device can be manufactured using the same method as the conventional method. For example, if necessary, one or more additional semiconductor chips can be stacked on the semiconductor chip die-bonded using the above method, and wire bonding is performed. The film-like adhesive is then thermally cured, and the entire result is sealed with resin. Through these steps, a semiconductor package can be produced. This semiconductor package can then be used to manufacture the desired semiconductor device.

The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples. The physical properties in each example were measured by the following methods.

[Mass average molecular weight (Mw)]
Measurements were carried out under the following conditions using a gel permeation chromatograph (manufactured by Tosoh Corporation, product name "HLC-8320GPC"), and the values measured were converted into standard polystyrene equivalent values.
(Measurement conditions)
Column: "TSKgel guardcolumn SuperHZH", "TSKgel SuperHZM-M", "TSKgel SuperHZM-M", and "TSKgel SuperHZ2000" (all manufactured by Tosoh Corporation) connected in sequence Column temperature: 40°C
Developing solvent: tetrahydrofuran; Standard material: polystyrene; Injection volume: 20 μl
Flow rate: 0.35 mL/min Detector: differential refractometer

[Thickness of each layer]
The thickness was measured at any five points at 23° C. using a constant pressure thickness gauge manufactured by Tecrock Corporation (model number: “PG-02J”, standard specifications: compliant with JIS K6783, Z1702, Z1709), and the average of the measured values was calculated.

Examples 1 to 6, Comparative Examples 1 to 3
(Production of Adhesive Composition)
The components shown in Table 1 were mixed according to the composition shown in Table 1, and methyl ethyl ketone was further mixed to obtain an adhesive composition. Note that the amounts of the components other than the solvent shown here do not include the solvent.

(Production of film adhesives and adhesive sheets)
The adhesive composition obtained above was applied using an applicator to the release-treated surface of a release film (manufactured by Lintec Corporation, product name "SP-PET381031", thickness 38 μm) in which one side of a polyethylene terephthalate film had been subjected to a silicone treatment for release, and dried at 100° C. for 2 minutes to form a film-like adhesive having a thickness of 25 μm on the release film. Next, a polyolefin substrate (thickness 100 μm) was attached to the exposed surface of this film-like adhesive to obtain an adhesive sheet with a release film.

[Evaluation method]
The adhesive sheets obtained in each example were evaluated by the methods described below. The results are shown in Table 1.

(Method of evaluating flame retardancy)
The release film was peeled off from the adhesive sheet with release film obtained in each example, and the exposed film-like adhesive was attached to a silicon wafer piece (a 150 μm thick silicon wafer with a No. 2,000 polished surface cut into a rectangular shape with a length of 125 mm and a width of 13 mm) using a laminator at 60° C. and a speed of 0.3 m/min. Thereafter, the polyolefin substrate was peeled off from the film-like adhesive to obtain a silicon wafer piece with a film-like adhesive. Next, the film-like adhesive attached to the silicon wafer piece was heat-cured by heating at 160° C. for 1 hour in an air atmosphere in a state where the aluminum plate/release film/silicon wafer piece with film-like adhesive/release film/aluminum plate were stacked in this order. Note that, during heat curing, the release films on both sides were stacked so that the release agent layer was on the side of the silicon wafer piece with the film-like adhesive, and the aluminum plate was 5 mm thick and large enough to cover the silicon wafer piece. Next, unnecessary portions of the cured film adhesive were cut and removed so as to have the same shape as the silicon wafer piece, thereby obtaining a silicon wafer piece having a cured adhesive layer. The silicon wafer piece having the cured adhesive layer was used as a test piece for evaluating flame retardancy.
The obtained test pieces were conditioned for 48 hours in a thermostatic chamber at a temperature of 23° C. and a humidity of 50%, and a flame retardancy test was carried out in accordance with the UL94V test (vertical flame test) of the UL94 test (combustion test of plastic materials for equipment parts) specified by Underwriters Laboratories (UL) in the United States. The burned length was measured using a ruler, and the flame retardancy was evaluated based on the following evaluation criteria.
A: The burned length was less than 70 mm.
B: The burned length was 70 mm or more and less than 100 mm.
F: The burned length was 100 mm or more.

(Method of Evaluating Adhesion)
The release film was peeled off from the adhesive sheet with release film obtained in each example, and the exposed film-like adhesive was attached to the polished surface of a silicon wafer piece (a 6-inch silicon wafer with a thickness of 350 μm and a polished surface of No. 2,000 cut into 1/4 to form a sector shape with a central angle of 90°) using a laminator at 60°C and a speed of 0.3 m/min. Furthermore, the polyolefin substrate was peeled off from the attached film-like adhesive, and a copper foil (specification: JIS H3100, (width 10 mm x length 50 mm x thickness 150 μm)) was attached to the surface of the exposed film-like adhesive using the same laminator at 60°C and a speed of 0.3 m/min to obtain a laminate of copper foil, film-like adhesive, and silicon wafer piece (hereinafter also referred to as "laminate (1)"). Next, in a state in which the aluminum plate/release film/laminate (1)/release film/aluminum plate were stacked in this order, the film-like adhesive was thermally cured by heating in an air atmosphere at 160° C. for 1 hour, to obtain a laminate having a silicon wafer, a cured adhesive layer, and a copper foil in this order (hereinafter also referred to as "laminate (2)"). During thermal curing, the release films on both sides were stacked so that the release agent layer was on the side of the silicon wafer piece with the film-like adhesive, and an aluminum plate was used that was 5 mm thick and large enough to sufficiently cover the silicon wafer piece.
Next, the copper foil of the laminate (2) obtained above was peeled off at a peeling speed of 50 mm/min and a peeling angle of 90° using a universal tensile tester (manufactured by Shimadzu Corporation, product name "Autograph AG-IS") to measure the adhesive strength. The adhesive strength was measured four times for each example, the average value was calculated, and the adhesiveness was evaluated based on the following evaluation criteria.
A: 3.0N/10mm or more B: 1.5N/10mm or more, less than 3.0N/10mm F: less than 1.5N/10mm

The details of each component in Table 1 are as follows:

<Thermoplastic component (A)>
(A)-1: a copolymer of n-butyl acrylate (55 parts by mass), methyl acrylate (10 parts by mass), glycidyl methacrylate (20 parts by mass), and 2-hydroxyethyl acrylate (15 parts by mass), Acrylic resin having a mass average molecular weight (Mw) of 900,000. (A)-2: Polyester resin (manufactured by Toyobo Co., Ltd., product name "Vylon 220")

<Thermosetting component (B)>
(Epoxy resin (B1))
(B1)-1: Bisphenol A type epoxy resin (manufactured by Nippon Shokubai Co., Ltd., product name "BPA328", epoxy equivalent 238±10 g/eq)
(B1)-2: Phenylene skeleton type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product name "EPPN-502H", epoxy equivalent 158 to 178 g/eq)

(Thermal Curing Agent (B2))
(B2)-1: Novolac type phenolic resin (manufactured by Showa Denko K.K., product name "BRG-556")

<Nitrogen Atom-Containing Flame Retardant (C)>
Hexaphenoxycyclotriphosphazene (compound represented by formula (C-2) below)

<Metal Phosphinic Acid Salt (C')>
Aluminum trisdiethylphosphinate (manufactured by Clariant Chemicals, product name "EXOLIT OP935", average particle size (D ₅₀ ) 2 to 3 μm)

<Inorganic filler (D)>
Spherical silica (manufactured by Admatechs Co., Ltd., product name "SC2050MA", average particle size ( _D50 ) 0.5 μm)

<Curing Accelerator (E)>
2-Phenyl-4,5-dihydroxymethylimidazole

<Energy Ray Curable Resin (F)>
Tricyclodecane dimethylol diacrylate

<Photopolymerization initiator (G)>
1-Hydroxycyclohexyl phenyl ketone

<Coupling Agent (H)>
(H)-1: A silicate compound to which 3-glycidoxypropyltrimethoxysilane has been added (H)-2: Phenylaminopropyltrimethoxysilane

<Other ingredients>
Silicone oil: Aralkyl-modified silicone oil (manufactured by Momentive Performance Materials Japan, LLC, product name "XF42-334")

It can be seen from Table 1 that the cured adhesive layers formed from the adhesive compositions of Examples 1 to 6 of this embodiment have excellent flame retardancy and adhesion.
On the other hand, the cured adhesive layer formed from the adhesive composition of Comparative Example 1, which did not contain the nitrogen-containing flame retardant (C), had poor flame retardancy.
Furthermore, the cured adhesive layer formed from the adhesive composition of Comparative Example 2, in which a metal phosphinate was blended in place of the nitrogen-containing flame retardant (C), was insufficiently cured, and it was not possible to evaluate the flame retardancy and adhesion.
Furthermore, the cured adhesive layer formed from the adhesive composition of Comparative Example 3, in which the content of the nitrogen-containing flame retardant (C) exceeded 25 mass% relative to the total amount (100 mass%) of the components excluding the inorganic filler, had poor adhesion.

1, 2, 3, 4, 5: Adhesive sheet 10 Substrate 10a Surface of substrate 11 Film-like adhesive 11a Surface of film-like adhesive 11' Film-like adhesive after cutting 12 Release film 13 Intermediate layer 14 Ring-shaped double-sided adhesive sheet 14a Surface of ring-shaped double-sided adhesive sheet 20 Semiconductor wafer 21 Semiconductor chip 22 Semiconductor chip with film-like adhesive 23 Peeling means 24 Substrate 24a Surface of substrate X direction

Claims (13)

An adhesive composition comprising a thermoplastic component (A), a thermosetting component (B), and a nitrogen-containing flame retardant (C),
an adhesive composition, wherein the content of the nitrogen-containing flame retardant (C) is 25 mass% or less relative to the total amount (100 mass%) of all components excluding inorganic fillers in the solid content of the adhesive composition. The adhesive composition according to claim 1, wherein the thermoplastic component (A) is an acrylic resin. The adhesive composition according to claim 1 or 2, wherein the thermosetting component (B) is an epoxy resin. The adhesive composition according to claim 1 or 2, further comprising an inorganic filler (D). The adhesive composition according to claim 1 or 2, wherein the nitrogen atom-containing flame retardant (C) is a compound containing a phosphorus atom and a nitrogen atom. The adhesive composition according to claim 5, wherein the compound containing a phosphorus atom and a nitrogen atom is a compound containing a bond between a phosphorus atom and a nitrogen atom. The adhesive composition according to claim 6, wherein the compound containing a bond between a phosphorus atom and a nitrogen atom is a compound containing a structure represented by the following general formula (C-1):

(In the formula, R ¹ represents a substituted or unsubstituted aliphatic hydrocarbon group, or a substituted or unsubstituted aromatic hydrocarbon group. Multiple R ^1s may be the same or different. n represents an integer of 3 to 20. -* ¹ and -* ² represent bonds to other atoms. Bond -* ¹ and bond -* ² may be linked to each other to form a cyclic structure.) A step of die-bonding a semiconductor chip; or
The adhesive composition according to claim 1 or 2, which is used in both a step of dicing a semiconductor wafer and a step of die bonding the semiconductor chips obtained by the dicing. A film-like adhesive formed by forming the adhesive composition according to claim 1 or 2 into a film. An adhesive sheet having a substrate and the film-like adhesive according to claim 9 laminated directly or via another layer on one side of the substrate. The adhesive sheet according to claim 10, further comprising a ring-shaped double-sided adhesive sheet laminated on the surface of the film-like adhesive opposite the substrate, and processed into a predetermined shape. A semiconductor device having a semiconductor chip bonded with the adhesive composition according to claim 1 or 2. A method for manufacturing a semiconductor device, comprising a step of die-bonding a semiconductor chip using the adhesive composition according to claim 1 or 2.