Laminate and laminate production method

Abstract

This laminate includes: an inorganic material layer; an organic material layer; and an adhesive layer that is disposed between the inorganic material layer and the organic material layer, and bonds the inorganic material layer and the organic material layer. The ratio (X / Y) of the die shear strength X (MPa) between the inorganic material layer and the organic material layer to the thickness Y (μm) of the adhesive layer is 1 or more.

Description

Laminate and method for manufacturing laminate

[0001] The present disclosure relates to laminates and methods for making laminates.

[0002] As electronic devices become smaller, lighter, and more powerful, there is a demand for higher integration of semiconductor chips and the like, in which electrodes are arranged on a substrate. However, it is difficult to fully meet the demand for higher integration simply by miniaturizing circuits. Therefore, in recent years, a method for achieving higher integration by stacking multiple semiconductor substrates to form a multilayer three-dimensional structure has been proposed. Proposed methods for stacking substrates (wafers), chips, and the like (hereinafter sometimes referred to as "substrates, etc.") include a method for directly bonding substrates together (fusion bonding) and a method for bonding substrates together using an adhesive. For example, Patent Document 1 describes an adhesive that does not exhibit adhesive properties during the stacking process of semiconductor chips, etc., but softens and develops adhesive properties when heated, and then quickly hardens.

[0003] JP 2016-47895 A

[0004] In the examples of Patent Document 1, a laminate is produced by bonding a glass plate and a silicon plate using an adhesive, but no examples of using an adhesive to bond inorganic and organic materials are described. Furthermore, in recent years, semiconductor chips have become increasingly highly integrated, making it increasingly important to address heat generation in semiconductor chips. Therefore, efforts have been made to improve the heat dissipation of semiconductor chips by reducing the thickness of the adhesive layer. On the other hand, reducing the thickness of the adhesive layer may result in a decrease in bonding strength. One embodiment of the present disclosure aims to provide a laminate including an adhesive layer that exhibits excellent bonding strength to both inorganic and organic materials even when thin, and a method for manufacturing such a laminate.

[0005] Specific means for solving the above problems include the following: <1> A laminate comprising an inorganic material layer, an organic material layer, and an adhesive layer disposed between the inorganic material layer and the organic material layer to bond the inorganic material layer and the organic material layer, wherein the ratio (X / Y) of the die shear strength X (MPa) between the inorganic material layer and the organic material layer to the thickness Y (μm) of the adhesive layer is 1 or more. <2> The laminate according to <1>, wherein the thickness Y of the adhesive layer is 10 μm or less. <3> The laminate according to <1> or <2>, wherein the die shear strength is 3 MPa or more. <4> The laminate according to any one of <1> to <3>, wherein the elastic modulus of the adhesive layer is 5 GPa or more. <5> A method for producing the laminate according to any one of <1> to <4>, comprising the steps of applying an adhesive to a surface of at least one of the organic material layer and the inorganic material layer to form an adhesive layer, and bonding the inorganic material layer and the organic material layer via the adhesive layer. <6> The method for producing a laminate according to <5>, wherein an adhesive is applied to a surface of the organic material layer in the step of forming the adhesive layer. <7> The method for producing a laminate according to <6>, further comprising a step of subjecting the surface of the organic material layer to a plasma treatment before the step of forming the adhesive layer. <8> The method for producing a laminate according to any one of <5> to <7>, wherein the step of forming the adhesive layer includes a step of curing the adhesive.

[0006] According to one embodiment of the present disclosure, there is provided a laminate including an adhesive layer that exhibits excellent bonding strength to both inorganic materials and organic materials even when the adhesive layer has a small thickness, and a method for manufacturing the laminate.

[0007] In the present disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the upper and lower limits. In numerical ranges described in stages in the present disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in numerical ranges described in the present disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples. In the present disclosure, a "laminate" refers to a structure in which an inorganic material layer, an adhesive layer, and an organic material layer are arranged in this order, and the inorganic material layer and the organic material layer are bonded via the adhesive layer.

[0008] <Laminate> A first embodiment of the present disclosure is a laminate including: an inorganic material layer; an organic material layer; and an adhesive layer disposed between the inorganic material layer and the organic material layer to bond the inorganic material layer and the organic material layer, wherein a ratio (X / Y) of a die shear strength X (MPa) between the inorganic material layer and the organic material layer to a thickness Y (μm) of the adhesive layer is 1 or greater.

[0009] The laminate of the present disclosure has an inorganic material layer and an organic material layer bonded together via an adhesive layer. That is, the adhesive layer included in the laminate of the present disclosure exhibits excellent adhesion to both the inorganic material layer and the organic material layer. Furthermore, the laminate of the present disclosure has a ratio (X / Y) of the die shear strength X (MPa) between the inorganic material layer and the organic material layer to the thickness Y (μm) of the adhesive layer of 1 or more. That is, the adhesive layer included in the laminate of the present disclosure exhibits excellent bonding strength between the inorganic material layer and the organic material layer even when the thickness Y is small.

[0010] From the viewpoint of ensuring sufficient bonding strength between the inorganic material layer and the organic material layer, the ratio (X / Y) of the die shear strength X (MPa) between the inorganic material layer and the organic material layer to the thickness Y (μm) of the adhesive layer is preferably 1.2 or more, more preferably 1.5 or more, and even more preferably 2.0 or more. The upper limit of the ratio (X / Y) of the die shear strength X (MPa) between the inorganic material layer and the organic material layer to the thickness Y (μm) of the adhesive layer is not particularly limited, but may be, for example, 10 or less, 8 or less, or 6 or less.

[0011] In the present disclosure, the die shear strength between an inorganic material layer and an organic material layer is measured by fixing one of the inorganic material layer or the organic material layer bonded via an adhesive layer and applying a force from the side of the other. More specifically, the die shear strength between an inorganic material layer and an organic material layer is measured by the method described in the Examples.

[0012] From the viewpoint of ensuring sufficient bonding strength to the inorganic material layer and the organic material layer, the thickness Y of the adhesive layer is preferably 0.2 μm or more, preferably 0.5 μm or more, more preferably 0.75 μm or more, and even more preferably 1.0 μm or more. From the viewpoint of ensuring sufficient heat dissipation, the thickness Y of the adhesive layer is preferably 10 μm or less, preferably 7.5 μm or less, more preferably 5.0 μm or less, and even more preferably 3.0 μm or less. The thickness Y of the adhesive layer may be 2.6 μm or more.

[0013] In the present disclosure, the thickness of the adhesive layer is measured by the method described in the Examples.

[0014] From the viewpoint of ensuring sufficient bonding strength to the inorganic material layer and the organic material layer, the die shear strength X between the inorganic material layer and the organic material layer is preferably 3 MPa or more, more preferably 4 MPa or more, and even more preferably 5 MPa or more.

[0015] The upper limit of the die shear strength X between the inorganic material layer and the organic material layer is not particularly limited, but may be, for example, 10 MPa or less, 8 MPa or less, or 6 MPa or less.

[0016] The adhesive layer preferably has a modulus of elasticity of 5 GPa or more. When the adhesive layer has a modulus of elasticity of 5 GPa or more, the adhesive layer is sufficiently hard, and misalignment can be effectively suppressed when bonding the inorganic material layer and the organic material layer.

[0017] In the present disclosure, the modulus of elasticity of the adhesive layer refers to the composite modulus at 23°C, and is measured by the method described below. A sample is prepared in which an adhesive layer is formed on a silicon substrate. For this sample, a nanoindenter (product name TI-950 Tribo Indenter, manufactured by Hysitron, Berkovich-type indenter) is used to measure the unloading-displacement curve at 23°C under a test depth of 20 nm. The composite modulus of elasticity (GPa) at 23°C is calculated from the maximum load and maximum displacement according to the calculation method described in the reference document (Handbook of Micro / nano Tribology (second Edition), edited by Bharat Bhushan, CRC Press). Here, the composite modulus of elasticity is defined by the following formula (1). In formula (1), E ｒ represents the composite elastic modulus, and E ｉ represents the Young's modulus of the indenter, which is 1140 GPa, and ν ｉ represents the Poisson's ratio of the indenter, which is 0.07, and E ｓ and ν ｓ represent the Young's modulus and Poisson's ratio of the adhesive layer, respectively.

[0018]

[0019] The adhesive layer preferably contains a cured product of the adhesive. When the adhesive layer contains a cured product of the adhesive, the adhesive layer is sufficiently hard, and misalignment can be effectively suppressed when bonding the inorganic material layer and the organic material layer. The adhesive layer when bonding the inorganic material layer and the organic material layer may be in a completely cured state or in a completely incurable state.

[0020] From the viewpoint of suppressing the generation of voids due to outgassing, the cure rate of the adhesive layer is more preferably 80% or more, even more preferably 85% or more, particularly preferably 90% or more, and even more preferably 93% or more. The cure rate of the adhesive layer may be 100%, 99% or less, 95% or less, or 90% or less.

[0021] The curing rate of the adhesive layer may be determined by, for example, measuring the peak intensity of a specific bond and structure (the sum of the peak intensities when multiple peaks are present, such as with imide or amide) using FT-IR (Fourier transform infrared spectroscopy) in the adhesive layer to be measured and in the fully cured adhesive layer obtained by fully curing the adhesive layer, and determining the rate of increase or decrease in the peak intensity. Note that when band-like peaks that are difficult to separate, such as with siloxane bonds, are present, the maximum peak intensity may be used.

[0022] Specifically, when specific bonds and structures are generated by the curing reaction, the increase rate of the peak intensity can be calculated using the following formula, and the calculated value can be used as the curing rate of the adhesive layer. Peak intensity increase rate (curing rate of adhesive layer) = [(peak intensity of the specific bonds and structures in the adhesive layer to be measured) / (peak intensity of the specific bonds and structures in the fully cured adhesive layer obtained by heating the adhesive layer to be measured at 300°C for 1 hour)] × 100. Note that background signals can be removed using a conventional method. Furthermore, FT-IR measurement can be performed using a transmission method or a reflection method, as necessary.

[0023] In the above-mentioned rate of increase in peak intensity, when there are multiple bonds and structures resulting from the increase in peak intensity, the peak intensity may be interpreted as the total intensity of the multiple peak intensities.

[0024] <Method for manufacturing laminate> A second embodiment of the present disclosure is a method for manufacturing the above-described laminate, which includes the steps of applying an adhesive to a surface of at least one of an organic material layer and an inorganic material layer to form an adhesive layer, and bonding the inorganic material layer and the organic material layer via the adhesive layer.

[0025] In the above method, the method for applying the adhesive to the surface of at least one of the organic material layer and the inorganic material layer is not particularly limited and can be carried out by a known method, such as spin coating, inkjet printing, or screen printing.

[0026] When forming the adhesive layer by applying an adhesive to the surface of the organic material layer, the surface of the organic material layer on which the adhesive layer is to be formed may be subjected to plasma treatment, which, for example, improves the wettability of the adhesive to the organic material layer.

[0027] In the above method, the method for bonding the inorganic material layer and the organic material layer via the adhesive layer is not particularly limited. For example, a method can be used in which the adhesive layer disposed between the organic material layer and the inorganic material layer is pressurized while being heated. The temperature at which the adhesive layer is heated is not particularly limited and can be selected depending on the type of adhesive. The temperature at which the adhesive is heated may be, for example, 150°C or higher, 200°C or higher, or 400°C or lower, or 300°C or lower. The pressure at which the adhesive layer is pressurized is not particularly limited and can be selected depending on the type of adhesive.

[0028] In the above method, the step of forming the adhesive layer may include a step of curing the adhesive. That is, the adhesive layer may be in a state containing a cured product of the adhesive when the inorganic material layer and the organic material layer are bonded. In the step of curing the adhesive, the adhesive may or may not be completely cured. If the adhesive layer is in a state containing a cured product of the adhesive when the inorganic material layer and the organic material layer are bonded, misalignment when the inorganic material layer and the organic material layer are bonded can be effectively suppressed. Furthermore, the adhesive layer has low adhesion when the inorganic material layer and the organic material layer are bonded, allowing the bonding operation to be performed efficiently.

[0029] The method for curing the adhesive is not particularly limited and can be selected depending on the type of adhesive. For example, if the adhesive is thermosetting, a method of heating the adhesive to a temperature at which a curing reaction of the adhesive occurs can be used. The temperature at which the adhesive is heated is not particularly limited, but can be, for example, 150°C or higher and 350°C or lower.

[0030] The details and preferred embodiments of the inorganic material layer, organic material layer, and adhesive layer in the method of the present disclosure are the same as the details and preferred embodiments of the inorganic material layer, organic material layer, and adhesive layer in the laminate of the present disclosure described above.

[0031] (Inorganic Material Layer) In the laminate of the present disclosure, the type of inorganic material constituting the inorganic material layer is not particularly limited. Specific examples of inorganic materials include semiconductors such as Si, InP, GaN, GaAs, InGaAs, InGaAlAs, SiGe, and SiC; boron silicate glass (Pyrex (registered trademark)); quartz glass (SiO ２ ), sapphire (Al ２ O ３ ), ZrO ２ , Si ３ N ４ , SiCN, AlN, MgAl ２ O ４ Oxides, carbides or nitrides of BaTiO ３ , LiNbO ３ , SrTiO ３ , LiTaO ３ , etc.; diamond; metals such as Al, Ti, Fe, Cu, Ag, Au, Pt, Pd, Ta, Nb, etc.; carbon, etc. Among the inorganic materials mentioned above, Si, SiO ２ , SiC and SiCN are preferred.

[0032] The inorganic material layer may be a self-supporting object or may be formed as a layer on the surface of another object. When the inorganic material layer is formed as a layer on the surface of another object, the type of the other object is not particularly limited and may be an inorganic material or an organic material. The inorganic material layer may have an electrode on the surface facing the organic material layer.

[0033] (Organic Material Layer) In the laminate of the present disclosure, the type of organic material constituting the organic material layer is not particularly limited. Specific examples of the organic material include epoxy resin, phenol resin, silicone resin, polyimide, benzocyclobutene resin, and polybenzoxazole.

[0034] The organic material layer may be a self-supporting object or may be formed as a layer on the surface of another object. When the organic material layer is formed as a layer on the surface of another object, the type of the other object is not particularly limited and may be an inorganic material or an organic material. The organic material layer may have an electrode on the surface facing the inorganic material layer.

[0035] The organic material layer may have a hydrophilic group such as a hydroxyl group on the surface facing the inorganic material layer. The hydrophilic group such as a hydroxyl group can be formed by subjecting the surface of the organic material layer facing the inorganic material layer to a surface treatment such as a plasma treatment.

[0036] The organic material layer may contain a filler. Examples of the filler include silica and alumina. When the organic material layer contains a filler, the filler content may be 30% by mass to 90% by mass of the organic material layer.

[0037] (Adhesive Layer) In the laminate of the present disclosure, the type of adhesive constituting the adhesive layer is not particularly limited. From the viewpoint of suppressing misalignment when bonding the inorganic material layer and the organic material layer, the adhesive is preferably a curable adhesive, and more preferably a thermosetting adhesive.

[0038] In one embodiment of the present disclosure, a composition containing the following compound (A), crosslinking agent (B), and polar solvent (C) may be used as an adhesive: Compound (A): A compound having a cationic functional group containing at least one of a primary nitrogen atom and a secondary nitrogen atom and an Si—O bond; Crosslinking agent (B): A compound having three or more —C(═O)OX groups (X is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms) in the molecule, and one to six of the three or more —C(═O)OX groups are —C(═O)OH groups.

[0039] -Compound (A)- Compound (A) has a cationic functional group containing at least one of a primary nitrogen atom and a secondary nitrogen atom. The cationic functional group is not particularly limited as long as it can bear a positive charge and is a functional group containing at least one of a primary nitrogen atom and a secondary nitrogen atom. Compound (A) may contain a tertiary nitrogen atom in addition to the primary nitrogen atom and the secondary nitrogen atom. The number of Si-O bonds contained in compound (A) is preferably two or three.

[0040] As used herein, the term "primary nitrogen atom" refers to a nitrogen atom that is bonded to only two hydrogen atoms and one atom other than a hydrogen atom (e.g., a primary amino group (-NH ２"Secondary nitrogen atom" refers to a nitrogen atom bonded to only one hydrogen atom and two atoms other than hydrogen atoms (i.e., a nitrogen atom contained in a functional group represented by formula (a) below), or a nitrogen atom (cation) bonded to only two hydrogen atoms and two atoms other than hydrogen atoms. "Tertiary nitrogen atom" refers to a nitrogen atom bonded to only three atoms other than hydrogen atoms (i.e., a nitrogen atom that is a functional group represented by formula (b) below), or a nitrogen atom (cation) bonded to only one hydrogen atom and three atoms other than hydrogen atoms.

[0041]

[0042] In formula (a) and formula (b), * indicates the bonding position to an atom other than a hydrogen atom. The functional group represented by formula (a) is a secondary amino group (-NHR ａ group; where R ａ The functional group represented by formula (b) (i.e., a tertiary nitrogen atom) may be a functional group constituting a part of a tertiary amino group (-NR ｂ R ｃ group; where R ｂ and R ｃ each independently represents an alkyl group), or may be a trivalent linking group contained in the skeleton of the polymer.

[0043] The weight average molecular weight of the compound (A) is preferably 130 or more and 10,000 or less, more preferably 130 or more and 5,000 or less, and even more preferably 130 or more and 2,000 or less.

[0044] In this specification, the weight-average molecular weight of a compound refers to the weight-average molecular weight in terms of polyethylene glycol measured by Gel Permeation Chromatography (GPC). Specifically, the weight-average molecular weight of a compound is calculated using an aqueous solution of sodium nitrate with a concentration of 0.1 mol / L as a developing solvent, a Shodex DET RI-101 analyzer, and two analytical columns (TSKgel G6000PWXL-CP and TSKgel G3000PWXL-CP manufactured by Tosoh Corporation) to detect the refractive index at a flow rate of 1.0 mL / min, and using polyethylene glycol / polyethylene oxide as standards with analytical software (Empower3 manufactured by Waters Corporation).

[0045] Compound (A) may further have an anionic functional group, a nonionic functional group, or the like, as necessary. The nonionic functional group may be a hydrogen bond acceptor group or a hydrogen bond donor group. Examples of the nonionic functional group include a hydroxy group, a carbonyl group, and an ether group (—O—). There are no particular limitations on the anionic functional group, as long as it is a functional group that can bear a negative charge. Examples of the anionic functional group include a carboxylic acid group, a sulfonic acid group, and a sulfate group.

[0046] Compound (A) may be a compound having an Si—O bond and an amino group. Examples of compounds having an Si—O bond and an amino group include siloxane diamine, silane coupling agents having an amino group, and siloxane polymers. Examples of silane coupling agents having an amino group include compounds represented by the following formula (A-3):

[0047]

[0048] In formula (A-3), R １ represents an alkyl group having 1 to 4 carbon atoms which may be substituted. ２ and R ３ R each independently represents an alkylene group having 1 to 12 carbon atoms, an ether group, or a carbonyl group which may be substituted (the skeleton may contain a carbonyl group, an ether group, etc.). ４ and R５ each independently represents an optionally substituted alkylene group having 1 to 4 carbon atoms or a single bond. Ar represents a divalent or trivalent aromatic ring. X １ represents hydrogen or an alkyl group having 1 to 5 carbon atoms which may be substituted. X ２ represents hydrogen, a cycloalkyl group, a heterocyclic group, an aryl group, or an alkyl group having 1 to 5 carbon atoms which may be substituted (which may contain a carbonyl group, an ether group, etc. in the skeleton). １ , R ２ , R ３ , R ４ , R ５ , X １ may be the same or different. １ , R ２ , R ３ , R ４ , R ５ , X １ , X ２ In X, the substituents of the alkyl group and alkylene group each independently include an amino group, a hydroxy group, an alkoxy group, a cyano group, a carboxylic acid group, a sulfonic acid group, a halogen atom, etc. The divalent or trivalent aromatic ring in Ar includes, for example, a divalent or trivalent benzene ring. ２ Examples of the aryl group in the formula (I) include a phenyl group, a methylbenzyl group, and a vinylbenzyl group.

[0049] Specific examples of the silane coupling agent represented by formula (A-3) include N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane, N-(2-aminoethyl)-3-aminoisobutylmethyldimethoxysilane, N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, (aminoethylaminoethyl)phenyltriethoxysilane, methylbenzylaminoethylaminopropyltrimethoxysilane, benzylaminoethylaminopropyltriethoxysilane, 3-ureidopropyltriethoxysilane, (aminoethylaminoethyl)phenyltriethoxysilane,

[0033] Examples of suitable silanes include (2-(2-aminoethyl)-3-aminopropyl)phenylaminoethyl)phenethyltrimethoxysilane, (aminoethylaminomethyl)phenethyltrimethoxysilane, N-[2-[3-(trimethoxysilyl)propylamino]ethyl]ethylenediamine, 3-aminopropyldiethoxymethylsilane, 3-aminopropyldimethoxymethylsilane, 3-aminopropyldimethylethoxysilane, 3-aminopropyldimethylmethoxysilane, trimethoxy[2-(2-aminoethyl)-3-aminopropyl]silane, diaminomethylmethyldiethoxysilane, methylaminomethylmethyldiethoxysilane, p-aminophenyltrimethoxysilane, N-methylaminopropyltriethoxysilane, N-methylaminopropylmethyldiethoxysilane, (phenylaminomethyl)methyldiethoxysilane, acetamidopropyltrimethoxysilane, and hydrolysates thereof.

[0050] Examples of silane coupling agents having an amino group other than those represented by formula (A-3) include N,N-bis[3-(trimethoxysilyl)propyl]ethylenediamine, N,N'-bis[3-(trimethoxysilyl)propyl]ethylenediamine, bis[(3-triethoxysilyl)propyl]amine, piperazinylpropylmethyldimethoxysilane, bis[3-(triethoxysilyl)propyl]urea, bis(methyldiethoxysilylpropyl)amine, 2,2-dimethoxy-1,6-diaza-2-silacyclooctane, 3,5-diamino-N-(4-(methoxydimethylsilyl)phenyl)benzamide, 3,5-diamino-N-(4-(triethoxysilyl)phenyl)benzamide, 5-(ethoxydimethylsilyl)benzene-1,3-diamine, and hydrolysates thereof.

[0051] The silane coupling agent having the amino group may be used alone or in combination of two or more kinds.In addition, the silane coupling agent having the amino group may be used in combination with the silane coupling agent not having the amino group.For example, the silane coupling agent having the mercapto group may be used to improve adhesion with metal.

[0052] The compound (A) may be a polymer (siloxane polymer) formed from the above-mentioned silane coupling agent via a siloxane bond (Si—O—Si). For example, a hydrolyzate of 3-aminopropyltrimethoxysilane can produce a polymer having a linear siloxane structure, a polymer having a branched siloxane structure, a polymer having a cyclic siloxane structure, a polymer having a cage siloxane structure, or the like. The cage siloxane structure is represented, for example, by the following formula (A-1):

[0053]

[0054] Examples of siloxane diamines include compounds represented by the following formula (A-2): In formula (A-2), i is an integer of 0 to 4, j is an integer of 1 to 3, and Me is a methyl group.

[0055]

[0056] Examples of siloxane diamines include 1,3-bis(3-aminopropyl)tetramethyldisiloxane (in formula (A-2), i = 0, j = 1) and 1,3-bis(2-aminoethylamino)propyltetramethyldisiloxane (in formula (A-2), i = 1, j = 1).

[0057] The compound (A) has a cationic functional group containing at least one of a primary nitrogen atom and a secondary nitrogen atom, and therefore can strongly adhere to the surface of the inorganic material layer and / or the organic material layer by electrostatic interaction with functional groups such as hydroxyl groups, epoxy groups, carboxy groups, amino groups, and mercapto groups that may be present on the surface of the inorganic material layer and / or the organic material layer, or by forming a covalent bond with the functional groups.

[0058] The compound (A) has a cationic functional group containing at least one of a primary nitrogen atom and a secondary nitrogen atom, and therefore is readily soluble in the polar solvent (C). By using the compound (A) that is readily soluble in the polar solvent (C), the affinity with the surface of the inorganic material layer or the organic material layer is increased when the surface of the inorganic material layer or the organic material layer is hydrophilic. As a result, a smooth adhesive layer can be formed.

[0059] It is preferable that the molar ratio of Si element in the molecule to non-crosslinkable groups such as methyl groups bonded to the Si element (non-crosslinkable group / Si element) is less than 2 (satisfying the relationship non-crosslinkable group / Si element < 2). By satisfying this condition, it is thought that the crosslinking density (crosslinking between Si-O-Si bonds and amide bonds, imide bonds, etc.) of the formed film is improved, and excellent bonding strength can be obtained.

[0060] When compound (A) contains a primary nitrogen atom, the proportion of the primary nitrogen atoms in the total nitrogen atoms in compound (A) is preferably 20 mol % or more, more preferably 25 mol % or more, and even more preferably 30 mol % or more. Compound (A) may also have a cationic functional group that contains a primary nitrogen atom and does not contain any nitrogen atoms other than the primary nitrogen atom (e.g., a secondary nitrogen atom or a tertiary nitrogen atom).

[0061] When compound (A) contains a secondary nitrogen atom, the proportion of the secondary nitrogen atoms in all nitrogen atoms in compound (A) is preferably 5 mol % or more and 50 mol % or less, and more preferably 10 mol % or more and 45 mol % or less.

[0062] Compound (A) may contain a tertiary nitrogen atom in addition to a primary nitrogen atom and a secondary nitrogen atom. When compound (A) contains a tertiary nitrogen atom, the proportion of tertiary nitrogen atoms in all nitrogen atoms in compound (A) is preferably 20 mol % or more and 50 mol % or less, and more preferably 25 mol % or more and 45 mol % or less.

[0063] The content of compound (A) in the composition is not particularly limited, but can be, for example, 0.001% by mass or more and 20% by mass or less, preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.04% by mass or more and 20% by mass or less, relative to the entire composition.

[0064] —Crosslinking Agent (B)—The crosslinking agent (B) is a compound having three or more —C(═O)OX groups (X is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms) in the molecule, preferably a compound having three to six —C(═O)OX groups in the molecule, and more preferably a compound having three or four —C(═O)OX groups in the molecule.

[0065] In the crosslinking agent (B), X in the -C(=O)OX group may be a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and among these, a hydrogen atom, a methyl group, an ethyl group, or a propyl group is preferred. Note that X in the -C(=O)OX group may be the same or different.

[0066] The crosslinking agent (B) is a compound having one to six -C(=O)OH groups in which X is a hydrogen atom in the molecule, preferably one to four -C(=O)OH groups in the molecule, more preferably two to four -C(=O)OH groups in the molecule, and even more preferably two or three -C(=O)OH groups in the molecule.

[0067] The weight-average molecular weight of the compound (B) is not particularly limited. For example, the weight-average molecular weight of the compound (B) may be 200 or more and 600 or less, 200 or more and 500 or less, 200 or more and 450 or less, or 200 or more and 400 or less. When the weight-average molecular weight of the compound (B) is within the above range, the solubility in the composition is improved.

[0068] The crosslinking agent (B) preferably has a ring structure in the molecule. Examples of the ring structure include an alicyclic structure and an aromatic ring structure. The crosslinking agent (B) may have multiple ring structures in the molecule, and the multiple ring structures may be the same or different. When the compound (B) has a ring structure in the molecule, the heat resistance of the adhesive layer is improved.

[0069] Examples of the alicyclic structure include an alicyclic structure having from 3 to 8 carbon atoms, preferably from 4 to 6 carbon atoms, and the ring structure may be saturated or unsaturated. More specific examples of the alicyclic structure include saturated alicyclic structures such as a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, and a cyclooctane ring; and unsaturated alicyclic structures such as a cyclopropene ring, a cyclobutene ring, a cyclopentene ring, a cyclohexene ring, a cycloheptene ring, and a cyclooctene ring.

[0070] The aromatic ring structure is not particularly limited as long as it is a ring structure exhibiting aromaticity, and examples thereof include benzene-based aromatic rings such as a benzene ring, a naphthalene ring, an anthracene ring, and a perylene ring; aromatic heterocycles such as a pyridine ring and a thiophene ring; and non-benzene-based aromatic rings such as an indene ring and an azulene ring.

[0071] The ring structure contained in the molecule of the crosslinking agent (B) is preferably at least one selected from the group consisting of a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a benzene ring, and a naphthalene ring, and from the viewpoint of further increasing the heat resistance of the adhesive layer, at least one of a benzene ring and a naphthalene ring is more preferred.

[0072] As described above, the crosslinking agent (B) may have a plurality of ring structures in the molecule, and when the ring structure is benzene, it may have a biphenyl structure, a benzophenone structure, a diphenyl ether structure, or the like.

[0073] The crosslinking agent (B) may have a fluorine atom in the molecule. For example, it may have 1 to 6 fluorine atoms in the molecule, or may have 3 to 6 fluorine atoms in the molecule. For example, the compound (B) may have a fluoroalkyl group in the molecule, specifically, a trifluoroalkyl group or a hexafluoroisopropyl group. If the crosslinking agent (B) has a fluorine atom in the molecule, the water absorption of the adhesive layer will decrease.

[0074] Examples of the crosslinking agent (B) include carboxylic acid compounds such as alicyclic carboxylic acids, benzenecarboxylic acids, naphthalenecarboxylic acids, diphthalic acids, and fluorinated aromatic ring carboxylic acids, and carboxylic acid ester compounds such as alicyclic carboxylic acid esters, benzenecarboxylic acid esters, naphthalenecarboxylic acid esters, diphthalic acid esters, and fluorinated aromatic ring carboxylic acid esters.

[0075] A carboxylic acid ester compound is a compound that has a carboxy group (-C(=O)OH group) in the molecule and has three or more -C(=O)OX groups, where at least one X is an alkyl group having 1 to 6 carbon atoms (i.e., has an ester bond). When the crosslinking agent (B) contained in the adhesive is a carboxylic acid ester compound, aggregation due to association between the compound (A) and the crosslinking agent (B) in the composition is suppressed, and aggregates and pits in the cured product are reduced. As a result, an adhesive layer with higher smoothness is obtained, and the thickness of the adhesive layer can be easily adjusted.

[0076] The carboxylic acid compound is preferably a tetravalent or less carboxylic acid compound containing four or less —C(═O)OH groups, and more preferably a trivalent or tetravalent carboxylic acid compound containing three or four —C(═O)OH groups.

[0077] The carboxylic acid ester compound is preferably a compound containing three or less carboxy groups (—C(═O)OH groups) and three or less ester bonds in the molecule, and more preferably a compound containing two or less carboxy groups and two or less ester bonds in the molecule.

[0078] In the carboxylic acid ester compound, when X in three or more —C(═O)OX groups is an alkyl group having from 1 to 6 carbon atoms, X is preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and from the viewpoint of further suppressing aggregation due to association between the compound (A) and the crosslinking agent (B) in the composition, X is preferably an ethyl group or a propyl group.

[0079] Specific examples of the carboxylic acid compound include, but are not limited to, alicyclic carboxylic acids such as 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,3,5-cyclohexanetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, and 1,2,3,4,5,6-cyclohexanehexacarboxylic acid; benzenecarboxylic acids such as 1,2,4-benzenetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, pyromellitic acid, benzenepentacarboxylic acid, and mellitic acid; and 1,4,5,8-naphthalenetetracarboxylic acid. naphthalenecarboxylic acids such as 2,3,6,7-naphthalenetetracarboxylic acid; 3,3',5,5'-tetracarboxydiphenylmethane, biphenyl-3,3',5,5'-tetracarboxylic acid, biphenyl-3,4',5-tricarboxylic acid, biphenyl-3,3',4,4'-tetracarboxylic acid, benzophenone-3,3',4,4'-tetracarboxylic acid, 4,4'-oxydiphthalic acid, 3,4'-oxydiphthalic acid, 1,3-bis(phthalic acid)tetramethyldisiloxane, 4,4'-(ethyn-1,2-diyl)diphthalic acid diphthalic acids such as 4,4'-(1,4-phenylenebis(oxy))diphthalic acid, 4,4'-([1,1'-biphenyl]-4,4'-diylbis(oxy))diphthalic acid, and 4,4'-((oxybis(4,1-phenylene))bis(oxy))diphthalic acid; perylene carboxylic acids such as perylene-3,4,9,10-tetracarboxylic acid; anthracene carboxylic acids such as anthracene-2,3,6,7-tetracarboxylic acid;Examples of fluorinated aromatic carboxylic acids include 4,4'-(hexafluoroisopropylidene)diphthalic acid, 9,9-bis(trifluoromethyl)-9H-xanthene-2,3,6,7-tetracarboxylic acid, and 1,4-ditrifluoromethylpyromellitic acid;

[0080] Specific examples of the carboxylic acid ester compound include compounds in which at least one carboxy group in the specific examples of the carboxylic acid compound described above has been substituted with an ester group. Examples of the carboxylic acid ester compound include half-esterified compounds such as compounds represented by the following general formulas (B-1) to (B-6). As the carboxylic acid ester compound, a carboxylic acid ester compound having two aromatic rings in the molecule is preferred, and a carboxylic acid ester compound represented by the following formulas (B-2) to (B-5) is more preferred.

[0081]

[0082] In the general formulae (B-1) to (B-6), R is an alkyl group having 1 to 6 carbon atoms, and among these, a methyl group, an ethyl group, a propyl group, or a butyl group is preferable, and an ethyl group or a propyl group is more preferable. In the general formula (B-2), Y is O, C═O, or C(CF ３ ) ２ is.

[0083] The half-esterified compound can be produced, for example, by mixing a carboxylic acid anhydride, which is an anhydride of the above-mentioned carboxylic acid compound, with an alcohol solvent and ring-opening the carboxylic acid anhydride.

[0084] The content of the crosslinking agent (B) in the composition is, for example, preferably an amount such that the ratio (COOH / N) of the number of carboxy groups in the crosslinking agent (B) to the total number of nitrogen atoms in the compound (A) is 0.1 or more and 3.0 or less, more preferably 0.3 or more and 2.5 or less, and even more preferably 0.4 or more and 2.2 or less. By using a composition having a COOH / N ratio of 0.1 or more and 3.0 or less, crosslinked structures such as amide bonds and imide bonds are sufficiently formed between the compound (A) and the crosslinking agent (B) after heat treatment, and an adhesive layer with excellent heat resistance and insulating properties is formed.

[0085] When the composition contains an amine compound as a component other than the compound (A) and the crosslinking agent (B), the ratio (COOH / N) of the number of carboxy groups in the crosslinking agent (B) to the total number of all nitrogen atoms contained therein and the total number of nitrogen atoms contained in the compound (A) is preferably 0.1 or more and 3.0 or less.

[0086] The content ratio (charge ratio) of the compound (A) to the crosslinking agent (B) in the composition is preferably a molar ratio of 2:0.9 to 2:1.1, more preferably 2:1, of the compound (A):crosslinking agent (B), from the viewpoint of minimizing the amount of unreacted crosslinking agent (B) remaining. It is believed that the compound (A) and the crosslinking agent (B) in the composition exist as a mixture in the polar solvent (C) in which the amino group of the compound (A) and the carboxy group of the crosslinking agent (B) form a salt. It is believed that the cured product obtained by heating a composition containing the compound (A) and the crosslinking agent (B) contains, as a structural unit, a reaction product of the compound (A) and the crosslinking agent (B), as exemplified below.

[0087]

[0088] - Polar Solvent (C) - The composition contains a polar solvent (C). In the present disclosure, "polar solvent" refers to a solvent having a relative dielectric constant of 5 or more at room temperature (25°C). When the composition contains the polar solvent (C), the solubility of each component in the composition is improved. The polar solvent (C) may be used alone or in combination of two or more.

[0089] Specific examples of the polar solvent (C) include protic solvents such as water and heavy water; alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, isopentyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 2-methoxyethanol, 2-ethoxyethanol, benzyl alcohol, diethylene glycol, triethylene glycol, and glycerin; ethers such as tetrahydrofuran and dimethoxyethane; aldehydes and ketones such as furfural, acetone, ethyl methyl ketone, and cyclohexanone; acid derivatives such as ethyl acetate, butyl acetate, ethylene carbonate, propylene carbonate, formaldehyde, N-methylformamide, N,N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and hexamethylphosphoric acid amide; nitriles such as acetonitrile and propionitrile; and nitro compounds such as nitromethane and nitrobenzene; and sulfur compounds such as dimethyl sulfoxide. The polar solvent (C) preferably contains a protic solvent, more preferably contains water, and further preferably contains ultrapure water as the water.

[0090] The content of the polar solvent (C) in the composition is not particularly limited, and may be, for example, 1.0 mass% or more and 99.99896 mass% or less, or 40 mass% or more and 99.99896 mass% or less, relative to the entire composition.

[0091] From the viewpoint of volatilizing the polar solvent (C) by heating the composition and reducing the amount of residual solvent in the composition, the boiling point of the polar solvent (C) is preferably 150°C or lower, more preferably 120°C or lower.

[0092] Other Components The composition may contain known additives, such as an acid having a carboxy group and a weight average molecular weight of 46 to 195, a base having a nitrogen atom and no ring structure and a weight average molecular weight of 17 to 120, and a solvent other than the polar solvent (C).

[0093] The composition may contain a solvent other than the polar solvent (C). Examples of the solvent other than the polar solvent include normal hexane.

[0094] The composition may also contain benzotriazole or a derivative thereof, for example to inhibit copper corrosion.

[0095] The pH of the composition is not particularly limited, but is preferably 2.0 or more and 12.0 or less. When the pH of the composition is 2.0 or more and 12.0 or less, damage to the substrate by the composition is suppressed. The composition preferably has a sodium and potassium content of 10 mass ppb or less on an elemental basis. When the sodium or potassium content is 10 mass ppb or less on an elemental basis, it is possible to suppress the occurrence of problems in the electrical characteristics of the semiconductor device, such as transistor malfunction.

[0096] When the composition contains components other than the compound (A), the crosslinking agent (B), and the polar solvent (C), the total content of the compound (A) and the crosslinking agent (B) is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more of the total mass of nonvolatile components in the composition. In the present disclosure, "nonvolatile components" refers to components other than components (such as solvents) that are removed when the composition becomes a cured product.

[0097] -Method for producing the composition- The method for producing the composition is not particularly limited and can be carried out by a known method. For example, the composition can be produced by a method including the following steps (a), (b), and (c): Step (a): A step of mixing compound (A) and water to obtain solution A containing a hydrolysate of compound (A); Step (b): A step of adding alcohol to a precursor of crosslinking agent (B), heating, and refluxing to prepare solution B containing a half ester compound of crosslinking agent (B); Step (c): A step of blending solution A, solution B, polar solvent (C), and water.

[0098] The composition can be cured by heating. The heating temperature for curing the composition is preferably 150°C to 450°C, more preferably 150°C to 400°C, and even more preferably 180°C to 400°C. The above temperature refers to the temperature of the surface of the composition.

[0099] The heating time of the composition is not particularly limited and may be, for example, 3 hours or less or 1 hour or less. The lower limit of the heating time is not particularly limited and may be, for example, 5 minutes or more. In order to shorten the heating time, the composition may be irradiated with ultraviolet (UV) rays.

[0100] Whether or not the composition has cured after heating can be confirmed, for example, by measuring the peak intensity of specific bonds and structures using FT-IR (Fourier transform infrared spectroscopy). Examples of specific bonds and structures include bonds and structures generated by crosslinking reactions. For example, when amide bonds, imide bonds, etc. are formed in the composition, it can be determined that the composition has cured. The presence or absence of amide bonds can be confirmed by measuring the peak intensity of specific bonds and structures using FT-IR (Fourier transform infrared spectroscopy). Examples of specific bonds and structures include bonds and structures generated by crosslinking reactions. For example, when amide bonds, imide bonds, etc. are formed in the composition, it can be determined that the composition has cured. －１ and approximately 1520 cm －１ The presence or absence of an imide bond can be confirmed by the presence or absence of a vibration peak at approximately 1770 cm －１ and approximately 1720 cm －１ This can be confirmed by the presence or absence of a vibration peak.

[0101] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0102] Example 1 (1) Preparation of Adhesive 50% by mass of 3-aminopropyldiethoxymethylsilane (3APDES: structure shown below) and 50% by mass of water were mixed to obtain a solution A containing a hydrolysate of 3APDES.

[0103]

[0104] Solution B containing 70% by mass of ethyl oxydiphthalate half ester (eheODPA) and 30% by mass of ethanol was obtained. eheODPA was produced by adding oxydiphthalic anhydride (ODPA: structure shown below) to ethanol and refluxing the mixture in an oil bath heated to 90°C for 5 hours to completely dissolve the raw material powder. Proton NMR confirmed that ester groups were formed in the produced eheODPA.

[0105]

[0106] The obtained solution A (24 g), solution B (15.6 g), 1-propanol (20 g) and water (40.4 g) were mixed together to prepare a solution containing an adhesive.

[0107] (2) Formation of Adhesive Layer An epoxy resin composition (R4121-2C) manufactured by Nagase ChemteX Corporation was molded under the following conditions to obtain an epoxy resin substrate. The epoxy resin substrate was then subjected to plasma treatment to form hydrophilic groups (hydroxyl groups). Molding: 125°C x 400 seconds Post-mold cure: 150°C x 30 minutes

[0108] The adhesive prepared in (1) above was applied by spin coating onto a plasma-treated epoxy resin substrate and dried at 150°C for 1 minute. The substrate was then heated at 200°C for 1 hour under a nitrogen atmosphere to form an adhesive layer containing imide-crosslinked siloxane (structure shown below). The adhesive layer had a tack-free surface. The concentration of the adhesive was adjusted so that the thickness of the formed adhesive layer would be the value shown in Table 1.

[0109]

[0110] (3) Bonding of Organic Material Layer and Inorganic Material Layer A silicon chip (5 mm × 5 mm × 525 μm) was placed on the adhesive layer formed in (2) above, and heated and pressurized at 200° C. for 5 minutes at 5 MPa to obtain a laminate in which the organic material layer (epoxy resin substrate) and the inorganic material layer (silicon chip) were bonded via the adhesive layer.

[0111] Comparative Example 1 (1) Preparation of Adhesive 180 parts by mass of an epoxy resin (EPICLON 840, manufactured by DIC Corporation) as a thermosetting compound, 300 parts by mass of a phenol novolac resin (HF-4M, manufactured by Meiwa Kasei Co., Ltd.) as a heat curing agent, 200 parts by mass of silica particles (S-100, manufactured by Nippon Shokubai Co., Ltd.) as an inorganic filler, 280 parts by mass of thermoplastic resin particles (Fine Particle Polymer F351, manufactured by Aica Kogyo Co., Ltd.), 20 parts by mass of an imidazole catalyst (2E4MZ, manufactured by Shikoku Kasei Co., Ltd.) as a curing accelerator, and 20 parts by mass of a silane coupling agent (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) were thoroughly mixed using a triple roll to form a homogeneous liquid, thereby obtaining the adhesive of Comparative Example 1.

[0112] (2) Formation of Adhesive Layer The adhesive obtained above was applied onto the epoxy resin substrate used in Example 1 using a slit coater, and dried at 100° C. for 30 minutes to form an adhesive layer.

[0113] (3) Bonding of Organic Material Layer and Inorganic Material Layer A silicon chip (5 mm × 5 mm × 525 μm) was placed on the adhesive layer formed in (2) above, and heated at 150° C. for 90 minutes to obtain a laminate in which the organic material layer (epoxy resin substrate) and the inorganic material layer (silicon chip) were bonded via the adhesive layer.

[0114] Comparative Example 2 An adhesive layer was formed in the same manner as in Comparative Example 1, except that the adhesive applied to the epoxy resin substrate was dried at 100°C for 30 minutes and then heated at 150°C for 90 minutes. A silicon chip was then placed on the adhesive layer, and the mixture was heated and pressurized at 200°C for 5 minutes at 5 MPa. As a result, the silicon chip did not adhere to the adhesive layer, and no laminate was obtained.

[0115] <Measurement of die shear strength> The die shear strength between the inorganic material layer and the organic material layer in the laminates produced in Example 1 and Comparative Example 1 was measured using a die shear tester (manufactured by Nordson Advanced Technologies, Inc.) under the following conditions. The results are shown in Table 1. Load cell: 50 kgf, moving speed: 5 mm / s, temperature: room temperature (25°C).

[0116] <Measurement of adhesive layer thickness> A sample with an adhesive layer formed on an epoxy resin substrate was embedded in epoxy resin and polished from the cross-sectional direction to perform surface polishing. The surface polished area was observed with an SEM, and the thickness of the adhesive layer was measured on the screen. The results are shown in Table 1.

[0117]

[0118] As shown in Table 1, the laminate of Example 1, in which the ratio (X / Y) of the die shear strength X (MPa) between the inorganic material layer and the organic material layer to the thickness Y (μm) of the adhesive layer is 1 or more, exhibits sufficient bonding strength even though the thickness of the adhesive layer is small, compared to the laminate of Comparative Example 1, in which the ratio (X / Y) of the die shear strength X (MPa) between the inorganic material layer and the organic material layer to the thickness Y (μm) of the adhesive layer is less than 1.

[0119] The disclosure of Japanese Patent Application No. 2023-119427 is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated by reference into this specification to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A laminate comprising an inorganic material layer, an organic material layer, and an adhesive layer disposed between the inorganic material layer and the organic material layer to bond the inorganic material layer and the organic material layer, wherein the ratio (X / Y) of the die shear strength X (MPa) between the inorganic material layer and the organic material layer to the thickness Y (μm) of the adhesive layer is 1 or more.

2. The laminate according to claim 1, wherein the thickness Y of the adhesive layer is 10 μm or less.

3. The laminate according to claim 1, having a die shear strength of 3 MPa or more.

4. The laminate according to claim 1, wherein the adhesive layer has an elastic modulus of 5 GPa or more.

5. A method for producing a laminate according to any one of claims 1 to 4, comprising the steps of: applying an adhesive to a surface of at least one of an organic material layer and an inorganic material layer to form an adhesive layer; and bonding the inorganic material layer and the organic material layer via the adhesive layer.

6. The method for producing a laminate according to claim 5, wherein an adhesive is applied to the surface of the organic material layer in the step of forming the adhesive layer.

7. The method for producing a laminate according to claim 6, further comprising the step of subjecting a surface of the organic material layer to a plasma treatment prior to the step of forming the adhesive layer.

8. The method for producing a laminate according to claim 5, wherein the step of forming an adhesive layer includes a step of curing the adhesive.

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