JP7634403B2 - Substrate laminate and method for manufacturing said substrate laminate - Google Patents

Description

The present invention relates to a substrate laminate and a method for manufacturing the substrate laminate.

In MEMS sensors such as image sensors, acceleration sensors, and pressure sensors, in order to ensure light transparency and movement of mechanical parts, it is necessary to provide a hollow space in the semiconductor package and adhere a sealing substrate made of glass, metal, ceramic, etc., to the periphery of the package using an adhesive. Conventionally, a bonding method has been used in which a curable resin such as a thermosetting resin or a photosensitive resin is used as the adhesive (Patent Document 1).

JP 2012-041410 A

When non-alkali glass is used as a sealing substrate, the linear expansion coefficient differs from that of the curable resin used as an adhesive, and cracks may occur in the curable resin during reflow at high temperatures, which may reduce the reliability of the semiconductor element. In addition, non-alkali glass is susceptible to alpha rays, which can degrade the imaging characteristics of the image sensor. On the other hand, glass containing alkaline components has a linear expansion coefficient close to that of the curable resin, making it less likely to crack and further suppressing the incidence of alpha rays. However, it has been found that during high-temperature, high-humidity storage tests, "glass discoloration" occurs, where alkaline components such as sodium and potassium in the glass dissolve onto the glass inside the hollow portion, degrading the imaging characteristics of the image sensor.

The present invention has been made in consideration of the above points, and aims to provide a substrate laminate having two substrates and an adhesive layer, at least one of which is made of glass containing an alkaline component, in which glass tarnish is suppressed in a high-temperature, high-humidity storage test, and a method for manufacturing the substrate laminate.

As a result of earnest research conducted by the inventors to solve the above problems, the present invention has been completed by discovering that the above problems can be solved by a substrate laminate having a first substrate, an adhesive layer, and a second substrate, a hollow portion between the first substrate and the second substrate, the adhesive layer being disposed on the outer periphery of the hollow portion, one of the first substrate and the second substrate being glass containing an alkaline component, and a layer containing an organic acidic compound being disposed on the surface of the glass containing an alkaline component facing the hollow portion. That is, the present invention has the following configuration.

[1]. A substrate laminate having a first substrate, an adhesive layer, and a second substrate, the substrate laminate having a hollow portion between the first substrate and the second substrate, the adhesive layer on the outer periphery of the hollow portion, one of the first substrate and the second substrate being glass containing an alkaline component, and the substrate laminate having a layer containing an organic acidic compound on the surface of the glass containing the alkaline component facing the hollow portion.

[2]. The substrate laminate described in [1], in which the boiling point of the organic acidic compound is 300°C or less.

[3]. The substrate laminate according to [1] or [2], wherein the organic acidic compound has a molecular weight of 300 or less.

[4]. The substrate laminate according to any one of [1] to [3], wherein the acid dissociation constant (pKa) of the organic acidic compound is 2.5 to 10.

[5] The substrate laminate according to any one of [1] to [4], wherein the organic acidic compound has at least one functional group selected from the group consisting of a carboxyl group, an acidic group containing phosphorus (P), an ester group containing phosphorus (P), a sulfo group, a sulfonyl group, an amide group, and a cyanuric group.

[6] The substrate laminate described in any one of [1] to [5], wherein the adhesive layer contains at least one resin selected from the group consisting of epoxy resin, acrylic resin, polyimide resin, phenolic resin, and silicone resin.

[7] The substrate laminate described in any one of [1] to [6], wherein the adhesive layer has cationic polymerization properties.

[8] The substrate laminate described in any one of [1] to [7], wherein the adhesive layer is a photosensitive resin.

[9] The substrate laminate described in any one of [1] to [8], wherein the adhesive layer is alkali-soluble.

[10] The substrate laminate described in any one of [1] to [9], wherein the other of the first substrate and the second substrate is a semiconductor element substrate.

[11] A method for manufacturing a substrate laminate, comprising the steps of forming an adhesive layer containing a curable resin and at least one organic acidic compound in a pattern on a first substrate, laminating the surface of the adhesive layer formed on the first substrate with a second substrate to obtain a laminate, and heating the laminate at 180°C to 350°C, wherein either the first substrate or the second substrate is glass containing an alkaline component.

[12] The method for manufacturing a substrate laminate according to [11], in which the organic acidic compound is 0.1 parts by weight to 15 parts by weight per 100 parts by weight of the curable resin.

[13] The method for manufacturing a substrate laminate according to [11] or [12], which has a hollow portion surrounded by the first substrate, the second substrate, and the adhesive layer.

[14] A method for manufacturing a substrate laminate according to any one of [11] to [13], wherein the other of the first substrate and the second substrate is a semiconductor element substrate.

The use of the substrate laminate of the present invention has the effect of providing a substrate laminate with excellent reliability in which glass tarnishing is suppressed during high-temperature, high-humidity storage tests. In addition, the use of the substrate laminate of the present invention makes it possible to provide a hollow structure that can be used even under high-temperature, high-humidity conditions, and is particularly suitable for the manufacture of hollow structures for CMOS/CCD sensors and hollow structures for MEMS devices.

1A to 1C are explanatory diagrams showing a method for manufacturing a substrate laminate according to one embodiment of the present invention. 10A to 10C are explanatory diagrams showing a method for manufacturing a substrate laminate according to another embodiment of the present invention. 10A to 10C are explanatory diagrams showing a method for manufacturing a substrate laminate according to another embodiment of the present invention.

The embodiments of the present invention are described in detail below. Unless otherwise specified in this specification, "A to B" representing a numerical range means "A or more (including A and larger than A) and B or less (including B and smaller than B)."

1. Substrate Laminate
The substrate laminate in the present invention is a substrate laminate having a first substrate, an adhesive layer, and a second substrate, having a hollow portion between the first substrate and the second substrate, having the adhesive layer on the outer periphery of the hollow portion, either the first substrate or the second substrate being glass containing an alkali component, and having a layer containing an organic acidic compound on the surface of the glass containing an alkali component facing the hollow portion.

Either the first substrate or the second substrate is a glass containing an alkaline component, and specific examples include BDA, BDA-E, G-Leaf, glass ribbon, Dinorex (borosilicate glass, manufactured by Nippon Electric Glass Co., Ltd.), D263 series, MEMpax, TEMPAX Float (borosilicate glass, manufactured by Schott), etc. Among these, from the viewpoint of correctly transmitting optical signals, BDA, BDA-E, and D263 are preferred, which are characterized by a smooth surface and ease of dicing and cutting.

The glass containing an alkaline component used as the first substrate or the second substrate has a layer containing an organic acidic compound on the surface facing the hollow portion. By having a layer containing an organic acidic compound, even if moisture penetrates into the hollow portion of the substrate laminate in a high-temperature and high-humidity environment, glass tarnish caused by the elution of alkaline components such as sodium and potassium contained in the glass containing an alkaline component can be suppressed.

The layer containing the organic acidic compound may be formed by coating the surface of glass containing an alkaline component before the production of the substrate laminate, or may be formed by using a curable resin containing an organic acidic compound as an adhesive layer, which is generated and attached as outgas during the production of the substrate laminate. Details of the organic acidic compound will be described later.

Substrates that can be used as the other substrate in the substrate laminate of the present invention include semiconductor element substrates (sensor substrates), silicon wafers, transparent substrates (e.g., alkali-free glass substrates, transparent resin substrates), colored resin substrates, ceramic substrates, and the like. In the manufacture of an image sensor described below, a sensor substrate is used as the first substrate and a glass substrate containing an alkali component is used as the second substrate, or a glass substrate containing an alkali component is used as the first substrate and a sensor substrate is used as the second substrate. The shape of the substrate may be round or square. Since existing semiconductor manufacturing equipment can be used, it is preferable to use a round substrate of 4 to 12 inches. The sizes of the first and second substrates may be the same or different.

The substrate laminate of the present invention can easily obtain a hollow structure by appropriately selecting the width and height of the adhesive layer. In particular, when the substrate laminate is used as a structure for a CMOS/CCD sensor, if the adhesive layer is too low, the sensor substrate may be damaged during assembly, or ghosts and flares may occur, deteriorating the imaging characteristics. If the adhesive layer is too high, a stable cross-sectional shape may not be obtained, and the adhesive performance may deteriorate. From these points, the height of the adhesive layer is 1 μm to 200 μm, preferably 50 μm to 150 μm. If the width of the adhesive layer is too thin, sufficient adhesive strength cannot be obtained. Also, if the width of the adhesive layer is too wide, there will be no space to place the sensor substrate. From these points, the width of the adhesive layer is 1 μm to 1000 μm, preferably 100 μm to 250 μm.

The substrate laminate of the present invention has a hollow portion between the first substrate and the second substrate, and has an adhesive layer on the outer periphery of the hollow portion. In other words, the hollow portion is formed by the first substrate, the second substrate, and the adhesive layer. The adhesive layer is not particularly limited in shape as long as it can form a hollow portion when viewed perpendicularly to the first substrate or the second substrate, but it is preferable that the adhesive layer is formed in a pattern shape from the viewpoint of adhesion reliability and productivity. Examples of the pattern shape include a square shape, a hexagonal shape, and a circle shape.

[2. Organic acidic compounds]
A layer containing an organic acidic compound is formed on the hollow part side of the glass containing an alkaline component. Glass tarnish of a glass containing an alkaline component is generally caused by the alkaline component in the glass dissolving in the moisture attached to the glass surface and reacting (chlorinating) with carbon dioxide or the like in the air. On the other hand, if a layer of an organic acidic compound is present on the surface of the glass containing an alkaline component, the organic acidic compound dissolves in the water attached to the glass surface, thereby suppressing the dissolution of the alkaline component in the glass. Therefore, as long as the organic acidic compound exhibits the above-mentioned reactivity, the organic acidic compound to be used is not particularly limited, but from the viewpoint of hydrophilicity, an acidic compound having at least one functional group selected from the group consisting of a carboxyl group, an acidic group containing phosphorus (P), an ester group containing phosphorus (P), a sulfo group, a sulfonyl group, an amide group, and a cyanuric group is preferable. In particular, from the viewpoint of hydrophilicity and the acidity described later, a carboxyl group, an acidic group containing phosphorus (P), and an ester group containing phosphorus (P) are preferable.

In addition, when the curable resin contains an organic acidic compound as an additive, it is necessary to volatilize the organic acidic compound as an outgas in the heating process into the hollow portion of the substrate laminate in order to form a layer of the organic acidic compound on the glass surface. For example, when the substrate laminate obtained by the present invention is used for an image sensor or MEMS sensor, it is more effective to use an organic acidic compound with a boiling point lower than the highest reflow temperature of 260°C applied, or close to the reflow temperature. Therefore, the upper limit of the boiling point of the organic acidic compound is preferably 300°C or lower, and more preferably 200°C or lower. As for the lower limit of the boiling point, since a layer can be efficiently formed on the glass surface having an alkaline component, it is preferably 23°C or higher, and more preferably 60°C or higher.

From the same viewpoint as the boiling point described above, the upper limit of the molecular weight of the organic acidic compound is preferably 300 or less, and more preferably 200 or less. From the same viewpoint as the boiling point described above, the lower limit of the molecular weight is preferably 40 or more, and more preferably 60 or more.

Furthermore, when an organic acidic compound is included as an additive in a curable resin, if the acidity is too high, problems such as deterioration of the storage stability of the curable resin and an increase in the amount of outgassing due to cleavage of the bonds formed will occur. Therefore, the acid dissociation constant (pKa) of the organic acidic compound when added to a curable resin is preferably 2.5 to 10, more preferably 2.5 to 7, and particularly preferably 3 to 5.

Examples of organic acidic compounds having a carboxyl group include linear or branched saturated carboxylic acids having 1 to 10 carbon atoms, such as formic acid, acetic acid, propionic acid, butanoic acid, hexanoic acid, and octylic acid; unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, benzoic acid, and sorbic acid; dibasic acids, such as oxalic acid, malonic acid, sebacic acid, maleic acid, fumaric acid, and itaconic acid; and aromatic carboxylic acids, such as benzoic acid. Among these, acetic acid, propionic acid, malonic acid, and benzoic acid are preferred because of their excellent balance of acidity and hydrophilicity.

Examples of organic acidic compounds having an acidic group containing phosphorus (P) or an ester group containing phosphorus (P) include ethylphosphinic acid, dimethylphosphinic acid, butylphosphinic acid, butoxyethylphosphinic acid, octylphosphinic acid, (3-hydroxypropyl)butylphosphinic acid, (3-hydroxypropyl)octylphosphinic acid, dibutylphosphinic acid, dioctylphosphinic acid, 3-hydroxypropylphosphinic acid, 2-hydroxyethylmethacrylatephosphinic acid, phenylphosphinic acid, and diphenylphosphinic acid. In particular, ethylphosphinic acid, dimethylphosphinic acid, butylphosphinic acid, and (3-hydroxypropyl)octylphosphinic acid are preferred because of their excellent balance of acidity and hydrophilicity.

Examples of organic acidic compounds having a sulfo group or a sulfonyl group include methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, 10-camphorsulfonic acid, trifluorosulfonic acid, aminoethanesulfonic acid, aminopropanesulfonic acid, and ester derivatives thereof. In particular, ester derivatives of methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid are preferred because they have an excellent balance between boiling point and acidity.

Examples of organic acidic compounds having an amide group include acetamide, acrylamide, malonamide, succinamide, maleamide, fumaramide, benzamide, 2-naphthamide, phthalamide, isonylamide, terephthalamide, nicotinamide, isonicotinamide, 2-furamide, formamide, propionamide, propiolamide, butyramide, isobutyramide, methacrylamide, oxamide, glycolamide, lactamide, glyceramide, pyruvamide, acetoacetamide, benzylamide, diacetamide, triacetamide, dibenzamide, tribenzamide, etc. Malonamide, maleamide, fumaramide, terephthalamide, nicotinamide, and isonicotinamide are particularly preferred because of their excellent balance between boiling point and acidity.

Examples of organic acidic compounds having a cyanuric group include bromoiso-2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylenebis(cyclohexyl isocyanate), isophorone diisocyanate, bicycloheptane triisocyanate, melanin cyanurate, cyanuric acid, etc. In particular, bromoiso-2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, isophorone diisocyanate, and melanin cyanurate are preferred because of their excellent balance between boiling point and acidity.

3. Adhesive Layer
(Hardening Resin)
In the present invention, it is preferable to use a curable resin for the adhesive layer from the viewpoint of adhesive reliability and handling. The curable resin in the present invention refers to a resin that is cured by heat, light, or heat and light. The curable resin is in an uncured or semi-cured state and is not completely cured, so it can function as an adhesive layer that constitutes a substrate laminate. In addition, the curable resin of the present invention preferably contains at least one selected from the group consisting of epoxy resin, acrylic resin, polyimide resin, phenolic resin, and silicone resin.

Examples of epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, glycidylamine type epoxy resins, glycidyl ester type epoxy resins, cresol novolac type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane dimethanol type epoxy resins, naphthylene ether type epoxy resins, trimethylol type epoxy resins, tetraphenylethane type epoxy resins, etc. Epoxy resins may be used alone or in combination of two or more types. In particular, from the viewpoint of adhesiveness, it is preferable to use one or more types selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, and biphenyl type epoxy resin.

The content of the epoxy resin in the curable resin is preferably 5% by weight or more, more preferably 10% by weight or more, and even more preferably 15% by weight or more, from the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulating reliability. The upper limit of the epoxy resin content is not particularly limited as long as the effects of the present invention are achieved, but is preferably 50% by weight or less. Examples of commercially available epoxy resins include jER828, jER806, jER807, YX8000, YX8034, and YX834 manufactured by Mitsubishi Chemical Corporation, YD-128, YDF-170, ZX-1059, and ST-3000 manufactured by Nippon Steel Chemical & Material Co., Ltd., EPICLON830, EPICLON835, EPICLON840, EPICLON850, N-730A, and N-695 manufactured by DIC Corporation, and RE-306 manufactured by Nippon Kayaku Co., Ltd.

As the acrylic resin, for example, a carboxy group-containing acrylic ester copolymer resin, an epoxy group-containing acrylic ester copolymer resin, a hydroxy group-containing acrylic ester copolymer resin, a hydroxy group-containing acrylic ester copolymer resin, or an acrylic copolymer is preferably contained as the main component (preferably 80% by weight or more). Furthermore, as the acrylic copolymer to be used, an acrylic copolymer having at least an epoxy group and a carboxyl group as essential components in the side chain is preferable.

Acrylic resins are highly compatible with epoxy resins and are suitable for use in controlling viscoelasticity. Commercially available acrylic resins include, for example, Teisan Resin SG-70L, SG-708-6, WS-023, SG-700AS, SG-280TEA, SG-80H, SG-80H-3, SG-P3, SG-600TEA, and SG-790 manufactured by Nagase ChemteX Corporation, and ME-2000, W-116.3, W-197C, KG-25, and KG-3000 manufactured by Negami Chemical Industries, Ltd.

Examples of polyimide resins include condensation polyimides, bismaleimide polyimides, nadic acid polyimides, acetylene polyimides, allylnadimide polyimides, maleimide polyimides, triazine polyimides, and Michael addition polyimides.

Polyimide resins have excellent high-temperature properties and are ideal for use in improving reflow resistance. In addition, no condensation water or other volatile substances are produced during curing, making them less susceptible to voids or cracks. Commercially available polyimide resins include Ube Industries' Upilex-S, Upilex-SGA, Upilex-VT, Upilex-NVT, Upilex-ST, Upilex-AT, Falda, Photoneece, and Kapton, both manufactured by DuPont-Toray, Elecolit, manufactured by Panacol-Elosol GmbH, and SPIXARIAAD, manufactured by Somar.

Examples of phenolic resins include bisphenol-type phenolic resins, aralkyl-type phenolic resins, phosphorus-containing phenolic resins, resol-type phenolic resins, and novolac-type phenolic resins.

Phenol-based resins have high electrical insulation properties and are suitable for use in electronic materials. They also have the advantage of being highly acid-resistant, meaning that the cured resin components are less likely to decompose even when organic acidic compounds are added. Commercially available phenol-based resins include PR-30-40P, PR-100L-50P, PR-50, PR-55, WR-101, WR-102, WR-103, and WR-104 manufactured by DIC, and DL-92, HF-1M, MEHC-7800, MEHC-7851, MEHC-7841-4S, MEH-7500, MEH-7600-4H, and MEH7000 manufactured by Meiwa Kasei Co., Ltd.

The silicone resin may be a type that contains it as the main component, or may be a type that is modified with organic resins such as urethane resin, epoxy resin, and acrylic resin. Examples include addition type silicone resin, condensation type silicone resin, ultraviolet curing type silicone resin, electron beam curing type silicone resin, and solventless type silicone resin.

Silicone resins have high heat resistance and excellent electrical insulation properties, making them suitable for use in electronic materials. Commercially available silicone resins include, for example, KS-774, KS-775, KS-778, KS-779H, KS-856, X-62-2422, and X-62-2461 manufactured by Shin-Etsu Chemical Co., Ltd.; DKQ3-202, DKQ3-203, DKQ3-204, DKQ3-205, and DKQ3-210 manufactured by Dow Corning Asia Co., Ltd.; YSR-3022, TPR-6700, TPR-6720, and TPR-6721 manufactured by Toshiba Silicone Co., Ltd.; and SD7220, SD7226, and SD7229 manufactured by Dow Corning Toray Co., Ltd.

Among the above resins, it is preferable to use either an epoxy resin or a silicone resin, from the viewpoint of heat resistance and adhesive strength that prevents peeling when the package expands during reflow.

(alkali soluble)
The curable resin used in the adhesive layer of the present invention is preferably a photosensitive resin since it can form a delicate pattern shape. In particular, it is preferable that the curable resin has alkali solubility from the viewpoint of compatibility with conventional manufacturing equipment and reduction of environmental burden, since an alkaline aqueous solution developer can be used instead of an organic solvent in the pattern formation process by photolithography. As an alkali soluble group that exhibits alkali solubility, for example, the curable resin has the following formula (X1) or (X2) as an alkali soluble group.

The structures represented by formula (X1) or (X2) are preferable from the viewpoint of heat resistance and reducing swelling of the pattern due to alkaline development.

The amount of alkali-soluble groups in the curable resin of the present invention is preferably 1 to 90 parts by weight of the curable resin, and more preferably 5 to 60 parts by weight, which is appropriate for patterning.

(cationic polymerizable)
The curable resin in the present invention is preferably cationic polymerizable because it can provide sufficient adhesive strength to withstand the reflow process. Examples of resins that exhibit cationic polymerizability include resins having cationic polymerizable functional groups such as epoxy groups, oxetane groups, and vinyl ether groups. Specific examples of such resins include novolac phenol-type epoxy resins, biphenyl-type epoxy resins, dicyclopentadiene-type epoxy resins, cyclohexyl epoxy group-containing polyorganosiloxanes (cyclic or linear), glycidyl group-containing polyorganosiloxanes (cyclic or linear), bisphenol F diglycidyl ether, bisphenol A diglycidyl ether, 2,2'-bis(4-glycidyloxycyclohexyl)propane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, vinylcyclohexene dioxide, 2-(3,4-epoxycyclohexyl)-5, Examples of such bisglycidyl esters include 5-spiro-(3,4-epoxycyclohexane)-1,3-dioxane, bis(3,4-epoxycyclohexyl)adipate, 1,2-cyclopropanedicarboxylic acid bisglycidyl ester, triglycidyl isocyanurate, monoallyl diglycidyl isocyanurate, diallyl monoglycidyl isocyanurate, 1,4-bis{(3-ethyl-3-oxetanyl)methoxy}methyl}benzene, bis{1-ethyl(3-oxetanyl)}methyl ether, 3-ethyl-3-(phenoxymethyl)oxetane, and 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane.

Among the cationic polymerizable functional groups, the epoxy group is preferred from the viewpoint of stability, and among the epoxy groups, the alicyclic epoxy group or the glycidyl group is preferred, and the alicyclic epoxy group is preferred in terms of excellent cationic polymerizability by light and heat. A resin exhibiting cationic polymerizability may have at least one cationic polymerizable functional group in one molecule, but it is preferable to have two or more, and more preferable to have three or more. If there are three or more cationic polymerizable functional groups, a cured product with a high crosslink density can be obtained, and the cured product has the advantage of excellent heat resistance. Each cationic polymerizable functional group may be the same, or may be two or more different functional groups.

The amount of the cationically polymerizable group in the curable resin of the present invention is preferably 1 to 90 parts by weight, more preferably 5 to 60 parts by weight, of the curable resin.

The curable resin in the present invention is preferably alkali-soluble and cationic polymerizable. The curable resin used in the adhesive layer of the present invention may be a mixture of an alkali-soluble molecule and a cationic polymerizable molecule, but from the viewpoint of patterning properties, it is preferable that one molecule has both alkali-solubility and cationic polymerizability.

(Polysiloxane Compounds)
The curable resin used in the adhesive layer of the present invention preferably contains a polysiloxane compound from the viewpoint of heat resistance during reflow and reduction of outgassing. In the present invention, the polysiloxane compound is not particularly limited as long as it is a compound having a siloxane unit Si-O-Si. The higher the content of T units (XSiO _3/2 ) or Q units (SiO _4/2 ) among the siloxane units in the polysiloxane compound, the higher the hardness of the obtained cured product and the more excellent the heat resistance reliability. In addition, the higher the content of M units (X ₃ SiO _1/2 ) or D units (X ₂ SiO _2/2 ) among the siloxane units in the polysiloxane compound, the more flexible and low-stress the obtained cured product is.

From the viewpoint of compatibility with other components and patterning properties, it is preferable that the polysiloxane compound in the curable resin has a cationically polymerizable group in the molecule, and it is even more preferable that the polysiloxane compound has both a cationically polymerizable group and an alkali-soluble group in the molecule.

[4. Other Additives]
(Crosslinking Agent)
In order to adjust the workability, reactivity, adhesiveness and strength of the cured product, a crosslinking agent having two or more photopolymerizable functional groups other than cationic polymerizable functional groups in one molecule can be added to the curable resin. The crosslinking agent is not particularly limited as long as it is selected according to the curing reaction type, and examples of the crosslinking agent include alkoxysilane compounds and (meth)acrylate compounds.

(Photoacid generator)
When the curable resin is a photosensitive resin, it is preferable to contain a photoacid generator. The photoacid generator is not particularly limited as long as it is a compound that can release an acidic active substance that can crosslink the photopolymerizable functional group of the curable resin by being irradiated with active energy rays.

As the photoacid generator, a known photoacid generator can be used. For example, the photoacid generator may be any of the various compounds that are suitable in JP-A-2000-1648, JP-T-2001-515533, and WO-A-2002/83764, but is not particularly limited thereto. The photoacid generator is preferably a sulfonate ester, a carboxylate ester, or an onium salt, and more preferably an onium salt.

As the sulfonate esters, various sulfonic acid derivatives can be used, such as disulfones, disulfonyldiazomethanes, disulfonylmethanes, sulfonylbenzoylmethanes, imide sulfonates such as trifluoromethylsulfonate derivatives, benzoin sulfonates, sulfonates of 1-oxy-2-hydroxy-3-propyl alcohol, pyrogallol trisulfonates, and benzyl sulfonates.

Specific examples of the above sulfonate esters include diphenyl disulfone, ditosyl disulfone, bis(phenylsulfonyl)diazomethane, bis(chlorophenylsulfonyl)diazomethane, bis(xylylsulfonyl)diazomethane, phenylsulfonylbenzoyldiazomethane, bis(cyclohexylsulfonyl)methane, 1,8-naphthalenedicarboxylic acid imide methyl sulfonate, 1,8-naphthalenedicarboxylic acid imide tosyl sulfonate, 1,8-naphthalenedicarboxylic acid imide trifluoromethyl sulfonate, 1,8-naphthalenedicarboxylic acid imide camphorsulfonate, succinic acid imide phenyl sulfonate, succinic acid imide dotosylsulfonate, succinimide trifluoromethylsulfonate, succinimide camphorsulfonate, phthalimide trifluorosulfonate, cis-5-norbornene-endo-2,3-dicarboxylic acid imide trifluoromethylsulfonate, benzoin tosylate, 1,2-diphenyl-2-hydroxypropyl tosylate, 1,2-di(4-methylmercaptophenyl)-2-hydroxypropyl tosylate, pyrogallol methylsulfonate, pyrogallol ethylsulfonate, 2,6-dinitrophenyl methyl tosylate, ortho-nitrophenyl methyl tosylate, and para-nitrophenyl tosylate.

These can be used alone or in combination of two or more. In the present invention, carboxylic acid esters can also be used as photoacid generators.

In general, sulfonate esters and carboxylate esters may require a heating step (50°C to 100°C) to liberate the acid.

Examples of the onium salt include sulfonium salts and iodonium salts having anions such as tetrafluoroborate (BF ₄ ⁻ ), hexafluorophosphate (PF ₆ ⁻ ), hexafluoroantimonate (SbF ₆ ⁻ ), hexafluoroarsenate (AsF ₆ ⁻ ), hexachloroantimonate (SbCl ₆ ⁻ ), tetraphenylborate, tetrakis(trifluoromethylphenyl)borate, tetrakis(pentafluoromethylphenyl)borate, fluoroalkylfluorophosphate, perchlorate ion (ClO ₄ ⁻ ), trifluoromethanesulfonate ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ), toluenesulfonate ion, trinitrobenzenesulfonate anion, and trinitrotoluenesulfonate anion. From the viewpoint of absorption wavelength, the photoacid generator is preferably an aromatic sulfonium salt.

The anions in the photoacid generator ^, listed in order of increasing acid strength, are _SbF6- , B _{( C6F5} ) _4- ^, _PF6- , _CF3SO3- , and ^HSO4- . The stronger the acid strength ^of the anion in the photoacid generator, the higher _the film retention rate tends to be. The pKa of the acid generated from the photoacid generator is preferably ^less than ₃ , and more preferably less than 1.

There are no particular limitations on the amount of photoacid generator contained, but from the viewpoint of the balance between the curing speed and the physical properties of the cured product, the amount of photoacid generator contained is preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the curable resin.

If the amount of photoacid generator is small, it may take a long time to cure or the product may not be sufficiently cured. If the amount of photoacid generator is too large, color may remain in the cured product or the product may cure too quickly, resulting in coloration or loss of heat or light resistance, which may be undesirable.

When the curable resin is a thermosetting resin, it may contain a curing accelerator. Examples of the curing accelerator include phosphorus-based curing accelerators, amine-based curing accelerators, and imidazole-based curing accelerators. The curing accelerator may be used alone or in combination of two or more types.

Examples of phosphorus-based curing accelerators include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, etc., with triphenylphosphine and tetrabutylphosphonium decanoate being preferred. Commercially available products may be used as phosphorus-based curing accelerators, such as "TBP-DA" manufactured by Hokko Chemical Co., Ltd.

Examples of amine-based curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5.4.0)-undecene, with 4-dimethylaminopyridine and 1,8-diazabicyclo(5.4.0)-undecene being preferred.

Examples of imidazole-based curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl- (1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 2-methylimidazoline, 2-phenylimidazoline, etc. As the imidazole-based curing accelerator, commercially available products may be used, for example, "P200-H50" manufactured by Mitsubishi Chemical Corporation.

(Basic Compound)
The curable resin may contain a basic compound to improve the remaining film rate and resolution when performing photolithography. The basic compound acts as a quencher. That is, by blending an appropriate amount of the basic compound in the curable resin, it is possible to prevent the crosslinking caused by the photoacid generator from reaching the unexposed portion. This improves the remaining film rate, and the contrast between the exposed portion and the unexposed portion becomes clear, improving the resolution.

The amount of the basic compound is preferably 0.001 to 2.0 parts by weight, and more preferably 0.01 to 1.0 parts by weight, based on 100 parts by weight of the compound having a cationic polymerizable functional group. If the amount of the basic compound is 0.001 parts by weight or more, the effect as a quencher can be sufficiently exhibited. If the amount of the basic compound is 2.0 parts by weight or less, the sensitivity can be improved.

The weight ratio ((B)/(A)) of the basic compound (B) to the photoacid generator (A) is 0.001 to 0.2, and preferably 0.01 to 0.15. If the weight ratio is 0.001 or more, the basic compound can fully exert its effect as a quencher. If the weight ratio is 0.2 or less, crosslinking can be performed sufficiently.

The basic compound is not particularly limited, but examples include primary, secondary and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, amide derivatives and imide derivatives. Among these, aromatic amines and heterocyclic amines are preferably used as the basic compound.

Examples of the aromatic amines and heterocyclic amines include aniline, pyrrole, oxazole, thiazole, imidazole, pyrazole, furazan, pyrroline, pyrrolidine, imidazoline, imidazolidine, pyridine, pyridazine, pyrimidine, pyrazine, pyrazoline, pyrazolidine, piperidine, piperazine, morpholine, indole, isoindole, 1H-indazole, indoline, quinoline, cinnoline, quinazoline, quinoxaline, phthalazine, purine, pteridine, carbazole, phenanthridine, acridine, phenazine, 1,10-phenanthroline, adenine, adenosine, guanine, guanosine, uracil, and uridine, as well as derivatives thereof. Examples of the heterocyclic amines include 2,6-lutidine.

Among these, morpholine derivatives are preferably used as the basic compound. Specific examples of morpholine derivatives include bis(2-morpholinoethyl)ether, 4,4'-carbonyldimorpholine, 4-[2-(ethoxycarbonyl)ethyl]morpholine, and 4-(p-tolyl)morpholine.

Hindered amine light stabilizers (HALS) can be used as the heterocyclic amines.

The above basic compounds may be used alone or in combination of two or more.

(Sensitizer)
The curable resin may contain a sensitizer. The sensitizer can improve the sensitivity of the curable resin to visible light and can also impart sensitivity to high wavelength light such as g-line (436 nm), h-line (405 nm) and i-line (365 nm). The curability of the curable resin can be adjusted by using these sensitizers in combination with the photoacid generator. Examples of such sensitizers include anthracene-based compounds and thioxanthone-based compounds.

Specific examples of the anthracene-based compounds include anthracene, 2-ethyl-9,10-dimethoxyanthracene, 9,10-dimethylanthracene, 9,10-dibutoxyanthracene, 9,10-dipropoxyanthracene, 9,10-diethoxyanthracene, 1,4-dimethoxyanthracene, 9-methylanthracene, 2-ethylanthracene, 2-tert-butylanthracene, 2,6-di-tert-butylanthracene, 9,10-diphenyl-2,6-di-tert-butylanthracene, etc. In particular, from the viewpoint of easy availability, anthracene, 9,10-dimethylanthracene, 9,10-dibutoxyanthracene, 9,10-dipropoxyanthracene, 9,10-diethoxyanthracene, etc. are preferred as the anthracene-based compounds. As the anthracene-based compound, anthracene is preferred from the viewpoint of excellent transparency of the cured product, and 9,10-dibutoxyanthracene, 9,10-dipropoxyanthracene, 9,10-diethoxyanthracene, etc. are preferred from the viewpoint of excellent compatibility with the photosensitive composition.

Specific examples of the thioxanthone compounds include thioxanthone, 2-chlorothioxanthone, and 2,5-diethyldioxanthone.

One of these sensitizers may be used, or two or more may be used in combination.

The content of the sensitizer is not particularly limited as long as it is an amount that can exert a sensitizing effect, but is preferably 0.01 to 300 moles, and more preferably 0.01 to 100 moles, per mole of the added photoacid generator. If the amount of sensitizer is small, the sensitizing effect may not be obtained, and curing may take a long time or may have an undesirable effect on developability. On the other hand, if the amount of sensitizer is large, color may remain in the cured product, coloring may occur due to rapid curing, or heat resistance or light resistance may be impaired.

(Adhesion improver)
The curable resin may contain an adhesion improver, which may include, in addition to commonly used adhesives, various coupling agents, epoxy compounds, oxetane compounds, phenolic resins, coumarone-indene resins, rosin ester resins, terpene-phenolic resins, α-methylstyrene-vinyltoluene copolymers, polyethylmethylstyrene, aromatic polyisocyanates, and the like.

An example of a coupling agent is a silane coupling agent. The silane coupling agent is not particularly limited as long as it is a compound having at least one functional group reactive with an organic group and at least one hydrolyzable silicon group in the molecule. As the group reactive with an organic group, from the viewpoint of handleability, at least one functional group selected from an epoxy group, a methacryl group, an acrylic group, an isocyanate group, an isocyanurate group, a vinyl group, and a carbamate group is preferred, and from the viewpoint of curability and adhesiveness, an epoxy group, a methacryl group, or an acrylic group is particularly preferred. As the hydrolyzable silicon group, from the viewpoint of handleability, an alkoxysilyl group is preferred, and from the viewpoint of reactivity, a methoxysilyl group or an ethoxysilyl group is particularly preferred.

Examples of preferred silane coupling agents include alkoxysilanes having an epoxy functional group such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane; alkoxysilanes having a methacryl group or an acryl group such as 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, methacryloxymethyltrimethoxysilane, methacryloxymethyltriethoxysilane, acryloxymethyltrimethoxysilane, and acryloxymethyltriethoxysilane; tris[3-(trimethoxysilylpropyl)]isocyanurate; and γ-isocyanatopropyltrimethoxysilane. Furthermore, these coupling agents, silane coupling agents, epoxy compounds, etc. may be used alone or in combination of two or more.

The amount of silane coupling agent added can be set appropriately, but is preferably 0.1 to 20 parts by weight, more preferably 0.3 to 10 parts by weight, and even more preferably 0.5 to 5 parts by weight, per 100 parts by weight of the compound having a cationic polymerizable functional group. If the amount added is too small, the adhesiveness improving effect will not be achieved, and if the amount added is too large, it may have an adverse effect on the curability and physical properties of the cured product.

(Thermoplastic resin)
For the purpose of improving the properties of the curable resin, it is also possible to add various thermoplastic resins to the curable resin. Examples of the thermoplastic resin include acrylic resins such as polymethyl methacrylate-based resins (e.g., Optretz manufactured by Hitachi Chemical Co., Ltd.) which are homopolymers of methyl methacrylate or random, block or graft polymers of methyl methacrylate and other monomers, and polybutyl acrylate-based resins (e.g., homopolymers of butyl acrylate or random, block or graft polymers of butyl acrylate and other monomers), polycarbonate-based resins such as polycarbonate resins containing bisphenol A, 3,3,5-trimethylcyclohexylidene bisphenol, etc. as monomer structures (e.g., APEC manufactured by Teijin Ltd.), norbornene derivatives, resins obtained by homopolymerizing or copolymerizing vinyl monomers, resins obtained by ring-opening metathesis polymerization of norbornene derivatives, and cycloolefin resins such as hydrogenated products thereof (e.g., cycloolefin resins such as cycloolefin resins obtained by copolymerizing norbornene derivatives and vinyl monomers, and ...). For example, APEL manufactured by Mitsui Chemicals, ZEONOR and ZEONEX manufactured by Nippon Zeon Co., Ltd., ARTON manufactured by JSR Corporation, etc.), olefin-maleimide resins such as copolymers of ethylene and maleimide (for example, TI-PAS manufactured by Tosoh Corporation, etc.), polyester resins such as polyesters obtained by polycondensation of bisphenols (bisphenol A and bis(4-(2-hydroxyethoxy)phenyl)fluorene, etc.) or diols (diethylene glycol, etc.) with phthalic acids (terephthalic acid, isophthalic acid, etc.) or aliphatic dicarboxylic acids (for example, O-PET manufactured by Kanebo Co., Ltd., etc.), polyethersulfone resins, polyarylate resins, polyvinyl acetal resins, polyethylene resins, polypropylene resins, polystyrene resins, polyamide resins, silicone resins, fluororesins, etc., as well as rubber-like resins such as natural rubber and EPDM, but are not limited thereto. As the thermoplastic resin, a single one may be used, or a plurality of thermoplastic resins may be used in combination.

The thermoplastic resin may have a crosslinkable group. Examples of the crosslinkable group include an epoxy group, an amino group, a radically polymerizable unsaturated group, a carboxyl group, an isocyanate group, a hydroxyl group, and an alkoxysilyl group. From the viewpoint that the heat resistance of the obtained cured product is likely to be high, it is preferable that the thermoplastic resin has, on average, one or more crosslinkable groups per molecule.

There are no particular limitations on the molecular weight of the thermoplastic resin, but from the viewpoint of improving compatibility with polysiloxane-based compounds, the number average molecular weight is preferably 10,000 or less, and more preferably 5,000 or less. On the other hand, from the viewpoint of improving toughness of the resulting cured product, the number average molecular weight is preferably 10,000 or more, and more preferably 100,000 or more. There are no particular limitations on the molecular weight distribution, but from the viewpoint of reducing the viscosity of the mixture and improving moldability, the molecular weight distribution is preferably 3 or less, more preferably 2 or less, and even more preferably 1.5 or less.

There are no particular limitations on the amount of the thermoplastic resin added, but it is preferably 5 to 50% by weight, and more preferably 10 to 30% by weight, based on the total curable resin. If the amount of the thermoplastic resin added is small, the resulting cured product may be brittle. If the amount of the thermoplastic resin added is large, the heat resistance (elastic modulus at high temperatures) is likely to be low.

The thermoplastic resin may be dissolved in the curable resin and mixed in a uniform state, or may be pulverized and mixed in a particulate state, or may be dissolved in a solvent and mixed to form a dispersed state. In that the resulting cured product is more likely to be transparent, it is preferable to dissolve the thermoplastic resin in the curable resin and mix in a uniform state. In this case, too, the thermoplastic resin may be directly dissolved in the curable resin, or may be mixed uniformly using a solvent, or the solvent may be removed thereafter to form a uniform dispersed or mixed state.

When a thermoplastic resin is dispersed and used, the average particle size of the thermoplastic resin can be set as appropriate, but the preferred lower limit of the average particle size is 10 nm, and the preferred upper limit of the average particle size is 10 μm. The particle system may have a distribution, and may be monodispersed or have multiple peak particle sizes, but from the viewpoint of low viscosity of the curable composition and good moldability, it is preferable that the coefficient of variation of the particle size is 10% or less.

(Filling material)
The above-mentioned curable resin may contain a filler as necessary.Various types of filler are used, including inorganic fillers such as silica-based fillers (quartz, fume silica, precipitated silica, silicic anhydride, fused silica, crystalline silica, and ultrafine amorphous silica), silicon nitride, silver powder, alumina, aluminum hydroxide, titanium oxide, glass fiber, carbon fiber, mica, carbon black, graphite, diatomaceous earth, clay, clay, talc, calcium carbonate, magnesium carbonate, barium sulfate, and inorganic balloon, as well as fillers that are generally used or proposed as fillers for conventional sealing materials, such as epoxy-based fillers.

(Anti-aging agent)
An antioxidant may be added to the curable resin. Examples of the antioxidant include commonly used antioxidants such as hindered phenol-based antioxidants, as well as citric acid, phosphoric acid, and sulfur-based antioxidants.

As the above hindered phenol-based anti-aging agent, various types can be used, including Irganox 1010 available from BASF.

The above-mentioned sulfur-based anti-aging agents include mercaptans, mercaptan salts, sulfides (such as sulfide carboxylates and hindered phenol-based sulfides), polysulfides, dithiocarboxylates, thioureas, thiophosphates, sulfonium compounds, thioaldehydes, thioketones, mercaptals, mercaptols, monothioacids, polythioacids, thioamides, and sulfoxides.

These antioxidants may be used alone or in combination of two or more.

(Radical Inhibitor)
A radical inhibitor may be added to the curable resin. Examples of the radical inhibitor include phenol radical inhibitors such as 2,6-di-t-butyl-3-methylphenol (BHT), 2,2'-methylene-bis(4-methyl-6-t-butylphenol) and tetrakis(methylene-3(3,5-di-t-butyl-4-hydroxyphenyl)propionate)methane, and amine radical inhibitors such as phenyl-β-naphthylamine, α-naphthylamine, N,N'-sec-butyl-p-phenylenediamine, phenothiazine and N,N'-diphenyl-p-phenylenediamine. These radical inhibitors may be used alone or in combination of two or more.

(solvent)
When the curable resin has a high viscosity, it can be dissolved in a solvent before use. The solvent is not particularly limited, and specifically includes hydrocarbon solvents such as benzene, toluene, hexane, and heptane; ether solvents such as tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, and diethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; glycol solvents such as propylene glycol-1-monomethyl ether-2-acetate (PGMEA) and ethylene glycol diethyl ether; ester solvents such as isobutyl isobutyrate, butyl acetate, and ethyl lactate; and halogen-based solvents such as chloroform, methylene chloride, and 1,2-dichloroethane. These solvents may be used alone or as a mixed solvent of two or more kinds.

The amount of solvent used can be set appropriately, but the preferred lower limit for the amount used per 1 g of the curable resin is 0.1 mL, and the preferred upper limit is 10 mL. If the amount of solvent used is small, it may be difficult to obtain the effects of using the solvent, such as low viscosity. Furthermore, if a large amount of solvent is used, the solvent may remain in the material, which may cause problems such as thermal cracking, and may be disadvantageous in terms of cost, resulting in a decrease in industrial value.

(others)
To the curable resin, colorants, release agents, flame retardants, flame retardant assistants, surfactants, defoamers, emulsifiers, leveling agents, anti-repellents, ion trapping agents (antimony-bismuth, etc.), thixotropy imparting agents, tackifiers, storage stability improvers, ozone degradation inhibitors, light stabilizers, thickeners, plasticizers, reactive diluents, antioxidants, heat stabilizers, electrical conductivity imparting agents, antistatic agents, radiation shielding agents, nucleating agents, phosphorus-based peroxide decomposers, lubricants, pigments, metal deactivators, thermal conductivity imparting agents, physical property adjusters, and the like can be added within a range that does not impair the objects and effects of the present invention.

(Method of manufacturing substrate laminate)
Regarding the manufacturing method of the substrate laminate according to the present embodiment, a curable resin containing an organic acidic compound is used as an adhesive layer, and an organic acidic compound-containing layer is formed by generating and adhering the organic acidic compound as outgas during manufacturing. The manufacturing method of the substrate laminate used in the image sensor will be described in detail with reference to the drawings.

This method includes the steps of forming an adhesive layer containing a curable resin and at least one organic acidic compound in a pattern on a first substrate, laminating the surface of the adhesive layer formed on the first substrate with a second substrate to obtain a laminate, and heating the laminate at 180°C to 350°C. Either the first substrate or the second substrate is glass containing an alkaline component.

First, a curable resin composition containing a curable resin and at least one organic acidic compound is formed in a pattern on a glass substrate (first substrate) containing an alkaline component as an adhesive layer. In the curable resin composition for forming the adhesive layer, the content of the organic acidic compound is preferably 0.1 to 15 parts by weight, more preferably 0.3 to 10 parts by weight, and even more preferably 0.5 to 5 parts by weight, relative to 100 parts by weight of the curable resin. By setting the content within this range, a layer containing a sufficient amount of the organic acidic compound as outgassing when the adhesive layer is heated and cured is formed. If the amount of the organic acidic compound is less than 0.1 parts by weight, it may be difficult to suppress glass fading because the amount of the organic acidic compound is too small, and if the amount exceeds 15 parts by weight, the outgassing of the organic acidic compound itself may increase, or impurities may be generated by decomposition of the curable resin forming the adhesive layer, which may cause damage to the substrate, such as a decrease in transparency.

As a method for forming a pattern of the adhesive layer, if the curable resin is a thermosetting resin, a dispensing method, a pin transfer method, a screen printing method, etc. can be used, and if the curable resin is a photosensitive resin, photolithography can also be used in addition to the above.

In the pattern formation process, when a pattern is formed by photolithography using a negative photosensitive resin, a coating film 11 is first formed on a glass substrate 2 containing an alkaline component, which is the first substrate, using a method such as spin coating, roll coating, or bar coating (FIG. 1(a)), and then the coating film 11 is irradiated with light through a photomask to harden the exposed area and form an adhesive layer 1 (FIG. 1(b)). The wavelength of the irradiated light is usually in the range of 200 to 450 nm. Examples of light sources include high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, high-power metal halide lamps, xenon lamps, carbon arc lamps, and light-emitting diodes.

The exposure dose in the portion irradiated with light is preferably 1 to 10,000 mJ/cm ² , more preferably 1 to 4,000 mJ/cm ^2. When the exposure dose is 1 mJ/cm ² or more, curing can be promoted, and when the exposure dose is 10,000 mJ/cm ² or less, discoloration due to rapid curing can be suppressed. The time for irradiating the coating with light is preferably 1 to 600 seconds, more preferably 1 to 150 seconds.

After exposure, the non-exposed areas are removed from the glass substrate 2 with a developer containing an alkaline component, to obtain a patterned adhesive layer 1 (FIG. 1(c)). The developer used here can be appropriately selected depending on the photosensitive resin used. For example, in the case of solvent development, examples of the developer include the aforementioned hydrocarbon solvents, ether solvents, ketone solvents, glycol solvents, ester solvents, and halogen solvents. Examples of alkaline developer containing an alkaline component include tetramethylammonium hydroxide (TMAH), choline, potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, and lithium carbonate.

From the viewpoint of easily achieving contrast between exposed and non-exposed areas, the concentration of the alkaline component in the alkaline developing solution is preferably 25% by weight or less, more preferably 10% by weight or less, and even more preferably 5% by weight or less. Methods for contacting the non-exposed areas with the alkaline developing solution include immersion, paddle, and spray methods. After development, the substrate may be washed and dried.

Next, the glass substrate 2 containing an alkaline component and having a patterned adhesive layer 1 is laminated so that the adhesive layer 1 side of the glass substrate 2 and the semiconductor element substrate 3 (second substrate) face each other to obtain a laminate (FIG. 1(d)), and then the laminate is heated to obtain a substrate laminate. The heating temperature is usually 180°C to 350°C, but is preferably 180°C to 300°C. In addition, in order to adhere the adhesive layer 1 to the semiconductor element substrate 3, which is the second substrate, it is also possible to heat the substrate while applying a load during lamination. The load can be about 10g to 5000g.

By undergoing the heating process, the organic acidic compound contained in the adhesive layer 1 volatilizes as outgassing and fills the hollow space, resulting in a substrate laminate in which a layer 5 containing the organic acidic compound is formed on the hollow space side of the glass containing alkaline components (Figure 1 (e)).

In the above, a glass substrate 2 containing an alkaline component is used as the first substrate, and a semiconductor element substrate 3 is used as the second substrate, but the present invention is not limited to this. A semiconductor element substrate 3 is used as the first substrate, and an adhesive layer 1 is patterned and formed on the surface of the semiconductor element substrate 3 on the side of the light receiving element 4 so as to surround the light receiving element 4 (FIG. 2(a)). A glass substrate 2 containing an alkaline component is laminated as the second substrate (FIG. 2(b)). The organic acidic compound is volatilized as outgassing by heating, and a layer 5 containing an organic acidic compound is formed on the hollow portion side of the glass substrate 2 containing an alkaline component (FIG. 2(c)).

In the substrate laminate according to this embodiment, when the first substrate and the second substrate are laminated and hardened via the adhesive layer, the organic acidic compound is released as outgassing into the hollow portion, and a layer containing the organic acidic compound is formed on the glass substrate containing an alkaline component, which is the first substrate or the second substrate. Therefore, during a high temperature and high humidity test, the organic acidic compound dissolves in moisture adhering to the glass containing an alkaline component, and the elution of the alkaline component from the glass containing an alkaline component, which is the cause of glass tarnish, can be suppressed.
That is, according to this embodiment, a substrate laminate in which glass tarnishing during a high-temperature, high-humidity test is suppressed can be obtained.

In another method for manufacturing the substrate laminate according to this embodiment, a liquid organic acidic compound is applied to the glass substrate 2 containing an alkaline component in advance so as to cover at least the surface of the substrate laminate on the hollow portion side, or a solution containing an organic acidic compound is applied and dried to form a layer 5 containing an organic acidic compound (FIG. 3(a)). At this time, the solution may be applied only to the surface on the hollow portion side, or may be applied to the entire surface on the hollow portion side. Methods for applying the solution containing an organic acidic compound to glass containing an alkaline component include spin coating, roll coating, bar coating, and the like.

Then, the adhesive layer 1 can be laminated with a semiconductor element substrate 3 (second substrate) on which the adhesive layer 1 is formed in a pattern (FIG. 3(b)) to obtain a substrate laminate. The substrate on which the adhesive layer is formed in a pattern can be appropriately selected depending on the type of curable resin and the pattern formation method used. In addition, when using a method in which a layer containing an organic acidic compound is formed in advance, the adhesive layer is formed using a curable resin composition that does not contain an organic acidic compound.

In this method, the curable resin composition does not contain any organic acidic compounds, so the present invention can be applied to curable resin compositions whose pot life is easily affected by organic acidic compounds.

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

(Patterning Evaluation)
The following patterning evaluation samples were prepared for the photosensitive resin compositions (Examples 1 to 7, and Comparative Example 1). First, the photosensitive resin composition was spin-coated on a glass substrate. The obtained substrate was heated for 10 minutes on a hot plate heated to 120 ° C. Furthermore, using an exposure device (high pressure mercury lamp, manual exposure machine, manufactured by Dai Nippon Kaken Co., Ltd.), exposure was performed with an optimal integrated light amount for each resin composition through a mask engraved with a 1 cm x 1 cm square with a line width of 300 μm (soft contact exposure), and the sample was left for 5 minutes after exposure. Thereafter, the sample was immersed in an alkaline developer (a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH)) for 45 seconds, washed with water for 30 seconds, and the moisture on the surface was removed with compressed air or compressed nitrogen to form a pattern. The obtained patterning evaluation sample was measured for the line width of the pattern formed using a 3D measurement laser microscope (LEXT OLS4000, manufactured by Olympus Corporation) and evaluated according to the following criteria.
<Evaluation criteria>
◎: Very good level (line width 200 μm ± 10 μm)
◯: Practical level (line width 200 μm ± 20 μm)
×: Not suitable for practical use (line width 200 μm ± 30 μm)

(Adhesion Evaluation)
For Examples 1 to 7 and Comparative Example 1, a silicon wafer cut to 2 cm square was heated to 150° C. on a hot plate, and the above-mentioned patterning evaluation sample was placed on top of it with the surface on which the photosensitive resin was formed facing the silicon wafer side. A load of 800 g was applied from above to bond the resin layer and the silicon wafer together, producing a three-layer laminate of glass, resin film, and silicon wafer.

For Examples 8 to 9 and Comparative Examples 2 to 3, the thermosetting resin composition was applied to a 9 mm x 9 mm square on a glass cut to 1 cm square using a dispenser so that the line width was 200 μm to 400 μm. A silicon wafer cut to 2 cm square was heated to 150 ° C. on a hot plate, and the glass coated with the thermosetting resin composition was placed on the silicon wafer with the resin surface facing the Si wafer. A three-layer laminate of glass, resin film, and silicon wafer was produced by laminating the resin layer and silicon wafer from above while applying a load of 100 g. The obtained adhesion evaluation sample was observed at the glass-resin boundary in the hollow part using a 3D measuring laser microscope (LEXT OLS4000, manufactured by Olympus Corporation) and evaluated according to the following criteria.
<Evaluation criteria>
◎: Very good level (no peeling or bubbles in the adhesive)
Good: Practical level (peeling or bubbles of 100 μm or less in the adhesive area)
×: Not suitable for practical use (peeling or bubbles of a size exceeding 100 μm in the adhesive portion)

(High temperature and humidity test)
The adhesion evaluation sample obtained above was pretreated according to the reliability evaluation JESD22 A101 standard, which examines the resistance of devices/packages to long-term temperature, humidity, and electrical stress. The treated evaluation sample was stored in a thermo-hygrostat (manufactured by Nagano Science Co., Ltd.) at 85°C and 85% for 24 hours, and then left at room temperature and humidity for 3 hours after being removed from the device. The glass surface in the hollow part of this sample was observed using a 3D measuring laser microscope (LEXT OLS4000, manufactured by Olympus Co., Ltd.) and evaluated according to the following criteria.
<Evaluation criteria>
◎: Good level (no discoloration on the glass surface inside the hollow area)
◯: Practical level (stains on the glass surface in the hollow section at intervals of 50 μm or more)
×: Not suitable for practical use (stains are present on the glass surface within the hollow portion at intervals of less than 50 μm)

(Production Example 1)
40 g of diallyl isocyanuric acid and 29 g of diallyl monomethyl isocyanuric acid were dissolved in 264 g of dioxane, and 139 μL of a xylene solution of platinum vinyl siloxane complex (platinum vinyl siloxane complex containing 3 wt% platinum, Pt-VTSC-3X, manufactured by Umicore Precious Metals Japan) was added. The solution thus obtained was added dropwise over 3 hours to a solution of 85 g of 1,3,5,7-tetrahydrogen-1,3,5,7-tetramethylcyclotetrasiloxane dissolved in 171 g of toluene heated to 105° C. in a nitrogen atmosphere containing 3% oxygen.

Thirty minutes after the end of the dropwise addition, it was confirmed by ¹ H-NMR that the reaction rate of the alkenyl group was 95% or more. Then, a solution prepared by dissolving 60 g of 1-vinyl-3,4-epoxycyclohexane in 60 g of toluene was dropped into the above solution over one hour. Thirty minutes after the end of the dropwise addition, it was confirmed by ¹ H-NMR that the reaction rate of the alkenyl group was 95% or more, and the reaction was then terminated by cooling. The solvents dioxane and toluene were distilled under reduced pressure and replaced with isobutyl isobutyrate to obtain "Solution A", a colorless and transparent 70% by weight cationic curable compound solution.

(Examples 1 to 7, Comparative Example 1)
A photosensitive resin composition was obtained by mixing and stirring solution A and each component in the ratio shown in Table 1. In Table 1, CPI-210S (manufactured by San-Apro Co., Ltd.) is a photoacid generator, Celloxide 2021P (manufactured by Daicel Corporation) is a bifunctional epoxy crosslinking agent, and KBM-9659 (manufactured by Shin-Etsu Chemical Co., Ltd.) is a silane coupling agent, and the units of the amounts mixed in Table 1 are parts.

(Examples 8 and 9, Comparative Examples 2 and 3)
A thermosetting resin composition was obtained by blending and stirring the components in the ratio shown in Table 1. In Table 1, jER806 (manufactured by Mitsubishi Chemical Corporation) is a bisphenol F type epoxy resin, SG-70L (manufactured by Nagase Chemtec Corporation) is a carboxyl group-containing acrylic acid ester copolymer resin, MEH-7700 (manufactured by Meiwa Kasei Co., Ltd.) is a phenol-based curing agent, Celloxide 2021P (manufactured by Daicel Corporation) is a bifunctional epoxy crosslinking agent, and KBM-9659 (manufactured by Shin-Etsu Chemical Co., Ltd.) is a silane-based coupling agent, and the units of blend amounts in Table 1 are parts.

(result)
The above-mentioned evaluations were carried out on the resin compositions obtained in Examples 1 to 9 and Comparative Examples 1 to 3. The results are shown in Table 2.

In Examples 1 to 9, the resin composition contains an organic acidic compound, and the organic acidic compound added during the process of producing the substrate laminate sufficiently fills the hollow portion as outgassing, forming a layer containing the organic acidic compound on the hollow portion side of the glass containing an alkaline component, which has the effect of suppressing the occurrence of tarnish. In particular, Examples 1 to 3, 8, and 9 have an excellent balance of the molecular weight, boiling point, and acidity of the organic acidic compound added, and therefore a high suppression effect against the occurrence of tarnish in the high temperature and high humidity test was obtained. On the other hand, Comparative Examples 1 to 3 do not contain an organic acidic compound in the resin composition, and therefore tarnish occurred in all of them.

1: Adhesive layer 2: Substrate containing an alkaline component 3: Semiconductor element substrate 4: Light receiving element 5: Layer containing an organic acidic compound 11: Coating film

Claims (12)

A substrate laminate having a first substrate, an adhesive layer, and a second substrate,
A hollow portion is provided between the first substrate and the second substrate,
The adhesive layer is provided on an outer periphery of the hollow portion,
Either the first substrate or the second substrate is a glass containing an alkali component,
a layer containing an organic acidic compound is provided on a surface of the glass containing an alkali component facing the hollow portion,
The substrate laminate , wherein the adhesive layer is a cured product of a curable resin containing 0.1 to 15 parts by weight of an organic acidic compound relative to 100 parts by weight of the curable resin (provided that the organic acidic compound does not include a photoacid generator). The substrate laminate according to claim 1, wherein the boiling point of the organic acidic compound is 300°C or less. The substrate laminate according to claim 1 or 2, wherein the organic acidic compound has a molecular weight of 300 or less. The substrate laminate according to any one of claims 1 to 3, wherein the acid dissociation constant (pKa) of the organic acidic compound is 2.5 to 10. The substrate laminate according to any one of claims 1 to 4, wherein the organic acidic compound has at least one functional group selected from the group consisting of a carboxyl group, an acidic group containing phosphorus (P), an ester group containing phosphorus (P), a sulfo group, a sulfonyl group, an amide group, and a cyanuric group. The substrate laminate according to any one of claims 1 to 5, wherein the adhesive layer contains at least one resin selected from the group consisting of epoxy resin, acrylic resin, polyimide resin, phenolic resin, and silicone resin. The substrate laminate according to any one of claims 1 to 6, wherein the adhesive layer has cationic polymerization properties. The substrate laminate according to any one of claims 1 to 7, wherein the adhesive layer is a photosensitive resin. The substrate laminate according to any one of claims 1 to 8, wherein the adhesive layer is alkali-soluble. The substrate laminate according to any one of claims 1 to 9, wherein the other of the first substrate and the second substrate is a semiconductor device substrate. forming an adhesive layer containing a curable resin and at least one organic acidic compound on a first substrate in a pattern;
laminating a surface of the first substrate on the side of the adhesive layer and a second substrate to obtain a laminate;
Heating the laminate at 180°C to 350°C;
Either the first substrate or the second substrate is a glass containing an alkali component,
a hollow portion surrounded by the first substrate, the second substrate, and the adhesive layer;
The method for producing a substrate laminate , wherein the adhesive layer is a curable resin containing 0.1 to 15 parts by weight of an organic acidic compound relative to 100 parts by weight of the curable resin (provided that the organic acidic compound does not include a photoacid generator). The method for manufacturing a substrate stack according to claim 11, wherein the other of the first substrate and the second substrate is a semiconductor element substrate.