WO2025204961A1 - Method for manufacturing electronic device, and electronic device - Google Patents

Abstract

Provided is an electronic device in which an electronic component group is simply and satisfactorily bonded.　A first electronic component (10) having a first insulator (12) and a first conductor (13) on a first-surface (10a) side, and a second electronic component (20) having a second insulator (22) and a second conductor (23) on a second-surface (20a) side, are prepared. A bonding layer (30) composed of an organic compound is provided to the first insulator (12), and the first surface (10a) and the second surface (20a) are made to face each other with the bonding layer (30) interposed therebetween such that the first insulator (12) and the second insulator (22) face each other and the first conductor (13) and the second conductor (23) face each other. Heat treatment is performed, the first insulator (12) and the second insulator (22) are bonded by the bonding layer (30), and the first conductor (13) and the second conductor (23) are brought into contact and bonded within the bonding layer (30) by thermal expansion. There is thereby obtained an electronic device (1) in which the first electronic component (10) and the second electronic component (20) are bonded.

Description

Electronic device manufacturing method and electronic device

The present invention relates to a method for manufacturing an electronic device and an electronic device.

A technique for hybrid bonding semiconductor substrates having an organic insulating film and electrodes on one surface of the base body is known, in which a resin material with a predetermined glass transition temperature and surface roughness is used for the organic insulating film, and heating and pressing are performed at a predetermined high temperature to bond the organic insulating films and the electrodes together (Patent Document 1).

Japanese Patent Application Laid-Open No. 2023-173119

In recent years, instead of using bonding materials such as solder or sintered compacts to bond the conductors of electronic components together, a method of directly bonding the conductors of electronic components has been proposed. With this method, the surfaces of the electronic components on which the conductors and their outer insulators are provided are placed face to face, and the conductors and insulators are bonded together. However, with this method, the process becomes complicated in order to obtain conductors and insulators with the specified surface properties before bonding, and poor bonding between the conductors can still occur even after this process.

In one aspect, the present invention aims to realize an electronic device in which a group of electronic components are easily and effectively joined.

In one aspect, a method for manufacturing an electronic device is provided, including the steps of: preparing a first electronic component having a first insulator and a first conductor on a first surface; preparing a second electronic component having a second insulator and a second conductor on a second surface; providing a bonding layer made of an organic compound on the first insulator; opposing the first surface and the second surface via the bonding layer so that the first insulator and the second insulator face each other and the first conductor and the second conductor face each other; and performing a heat treatment to bond the first insulator and the second insulator together via the bonding layer and to bond the first conductor and the second conductor together by contact within the bonding layer due to thermal expansion.

In another aspect, an electronic device is provided, comprising: a first electronic component having a first insulator and a first conductor on a first surface; a second electronic component having a second insulator and a second conductor on a second surface opposite the first surface, with the second insulator facing the first insulator and the second conductor facing the first conductor; and a bonding layer provided between the first insulator and the second insulator, made of an organic compound, bonding the first insulator and the second insulator together, wherein the first conductor and the second conductor are bonded together within the bonding layer.

In one aspect, it is possible to realize an electronic device in which electronic components are easily and satisfactorily joined together.
The above and other objects, features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings illustrating preferred embodiments of the present invention.

FIG. 1 is a diagram illustrating an example of an electronic device. 1A to 1C are diagrams (part 1) illustrating an example of a method for manufacturing an electronic device. 10A to 10C are diagrams (part 2) illustrating an example of a method for manufacturing an electronic device. 10A to 10C are diagrams (part 3) illustrating an example of a method for manufacturing an electronic device. 10A to 10C are diagrams (part 4) illustrating an example of a method for manufacturing an electronic device. 1A to 1C are diagrams illustrating an example of a conventional method for manufacturing an electronic device. FIG. 1 is a diagram illustrating an example of the configuration of an electronic device.

1 is a diagram illustrating an example of an electronic device, which diagrammatically shows a cross-sectional view of a main part of the example of the electronic device.
The electronic device 1 shown in FIG. 1 includes a first electronic component 10 and a second electronic component 20 that are arranged opposite to each other, and a bonding layer 30 that is interposed between the first electronic component 10 and the second electronic component 20 .

The first electronic component 10 may be any of a variety of electronic components, such as a semiconductor chip, semiconductor package, semiconductor wafer, or circuit board. The first electronic component 10 includes a first body 11, a first insulator 12, and a first conductor 13.

The first body 11 has a predetermined configuration according to the form of the first electronic component 10, for example, a configuration in which various elements such as semiconductor elements such as transistors, semiconductor chips equipped with semiconductor elements, and conductor portions such as wiring or vias are built in. A first insulator 12 and a first conductor 13 are provided on the first body 11 having a predetermined configuration. The first insulator 12 and the first conductor 13 are provided on the first surface 10a side of the first electronic component 10.

The first insulator 12 functions as a surface layer or protective layer of the first body 11. Various insulating materials are used for the first insulator 12. For example, inorganic insulating materials such as silicon oxide (SiO ₂ ), silicon nitride (SiN), silicon carbide (SiC), nitrogen-doped silicon oxide (SiON), and carbon-doped silicon oxide (SiOC) are used for the first insulator 12. In addition, organic insulating materials such as epoxy, polyimide, polyamide, polyamideimide, bismaleimide, benzocyclobutene, and polybenzoxazole may also be used for the first insulator 12.

The first conductor 13 is arranged to protrude from the first insulator 12. The first conductor 13 is electrically connected to a predetermined element built into the first body 11. The first conductor 13 functions as an external connection terminal for the first electronic component 10. Various conductive materials, such as metals, are used for the first conductor 13. As an example, copper (Cu) is used as the metal for the first conductor 13. Other metals that may be used for the first conductor 13 include aluminum (Al), gold (Au), silver (Ag), and nickel (Ni). The first conductor 13 may contain two or more metals. In this case, the first conductor 13 may be an alloy containing two or more metals, or a laminate formed by stacking multiple layers of different types, each containing one or more metals.

The second electronic component 20 may be any of a variety of electronic components, such as a semiconductor chip, semiconductor package, semiconductor wafer, or circuit board. The second electronic component 20 includes a second body 21, a second insulator 22, and a second conductor 23.

The second body 21 has a predetermined configuration according to the form of the second electronic component 20, for example, a configuration in which various elements such as semiconductor elements such as transistors, semiconductor chips equipped with semiconductor elements, and conductor portions such as wiring or vias are built in. The second body 21, which has a predetermined configuration, is provided with a second insulator 22 and a second conductor 23. The second insulator 22 and the second conductor 23 are provided on the second surface 20a of the second electronic component 20, which faces the first surface 10a of the first electronic component 10.

The second insulator 22 functions as a surface layer or protective layer of the second body 21. Various insulating materials are used for the second insulator 22. For example, inorganic insulating materials such as SiO ₂ , SiN, SiC, SiON, and SiOC are used for the second insulator 22. In addition, organic insulating materials such as epoxy, polyimide, polyamide, polyamideimide, bismaleimide, benzocyclobutene, and polybenzoxazole may also be used for the second insulator 22.

The second conductor 23 is arranged to protrude from the second insulator 22. The second conductor 23 is electrically connected to a predetermined element built into the second body 21. The second conductor 23 functions as an external connection terminal for the second electronic component 20. Various conductive materials, such as metals, are used for the second conductor 23. As an example, Cu is used as the metal for the second conductor 23. Other metals such as Al, Au, Ag, and Ni may also be used as the metal for the second conductor 23. The second conductor 23 may contain two or more metals. In this case, the second conductor 23 may be an alloy containing two or more metals, or a laminate formed by stacking multiple layers of different types, each containing one or more metals.

The first electronic component 10 and the second electronic component 20 are arranged so that their first surfaces 10a and second surfaces 20a face each other. A bonding layer 30 is interposed between the first insulator 12 and the second insulator 22 of the opposing first electronic component 10 and second electronic component 20. In the electronic device 1, the first conductor 13 protruding from the first insulator 12 and the second conductor 23 protruding from the second insulator 22 are directly bonded and integrated within the bonding layer 30.

In the electronic device 1, the bonding layer 30 functions as an adhesive that bonds (bonds) the first insulator 12 of the first electronic component 10 to the second insulator 22 of the second electronic component 20, and also functions as a spacer between the first insulator 12 and the second insulator 22. The bonding layer 30 is formed from an organic compound bonding material.

For example, in manufacturing the electronic device 1, the uncured bonding material used to form the bonding layer 30 is placed on the surface of the first insulator 12, the surface of the second insulator 22, or both the surfaces of the first insulator 12 and the second insulator 22. The first electronic component 10 and the second electronic component 20 are arranged facing each other with the bonding material interposed therebetween. The bonding material is then cured at room temperature or by heating through heat treatment or by light irradiation, and the first insulator 12 and the second insulator 22 are bonded together by the cured bonding material, i.e., the bonding layer 30 formed from the bonding material. The heat treatment performed when the bonding material is cured, or by further heat treatment after curing (after the bonding layer 30 is formed), brings the first conductor 13 and the second conductor 23 into contact with each other through thermal expansion and they are bonded together within the bonding layer 30. This results in the manufacturing of the electronic device 1 as shown in FIG. 1. Details of the manufacturing method for the electronic device 1 will be described later (FIGS. 2 to 5).

Here, the above-described bonding layer 30 will be further described.
The bonding layer 30 is formed from a bonding material of an organic compound. For example, the bonding material forming the bonding layer 30 is a material containing a compound that is entirely organic or a compound that has at least an organic group as a functional group. The bonding layer 30 has insulating properties. The bonding layer 30 may also have thermal conductivity. The first insulator 12 and the second insulator 22 are bonded using the bonding layer 30. For example, the bonding layer 30 is provided between the first insulator 12 and the second insulator 22 with a thickness on the order of nanometers. The thickness of the bonding layer 30 is set to a thickness corresponding to the amount of thermal expansion that occurs in the first conductor 13 and the second conductor 23 when the first conductor 13 and the second conductor 23 come into contact and are bonded due to thermal expansion by a predetermined heat treatment.

The bonding layer 30 is formed by applying a bonding material containing compound α to the bonding object to form a coating, which is then dried and hardened. Below, examples of bonding materials used to form the bonding layer 30 and the compound α contained in the bonding material are described in detail.

(Compound α)
The following describes the compound α contained in the bonding material used to form the bonding layer 30. The compound α has a first functional group and a second functional group that can react with and bond to elements present on the surface of the first insulator 12 (the surface on the first surface 10a side of the first electronic component 10) and the surface of the second insulator 22 (the surface on the second surface 20a side of the second electronic component 20), respectively.

Compound α is considered to be a material for forming a joint (bond) between two substances through interfacial molecular bonding. Interfacial molecular bonding refers to the process of placing a compound at the interface between two substances and chemically bonding each substance to the compound through a chemical reaction, thereby bonding the two substances together, or the bond that results from this. Compound α is also known as Interface Molecular Bonding (IMB).

The first functional group is preferably a group that reacts with and bonds to metals or dielectrics. Examples of the first functional group include amino groups, hydrazino groups, hydroxy groups, thiol groups, oxiranyl groups, oxetanyl groups, carboxy groups, aziridinyl groups, azide groups, azidosulfonyl groups, diazomethyl groups, and organic groups containing carbon-carbon double bonds. An azide group, azidosulfonyl group, or diazomethyl group (hereinafter, "azide groups, azidosulfonyl groups, or diazomethyl groups" will also be referred to as "azide groups, etc.") is preferred. Azide groups, etc., can form chemical bonds, such as "-N-C-type," with the object to be bonded through a chemical reaction. When the first functional group is an azide group, etc., a stronger bond with the dielectric can be formed.

Compound α preferably has an aromatic ring or a heterocycle. Examples of the aromatic ring include aromatic carbon rings such as a benzene ring and a naphthalene ring, and examples of the heterocycle include a thiophene ring, a furan ring, and a nitrogen-containing heterocycle. Examples of the nitrogen-containing heterocycle include a pyrrole ring, an imidazole ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, and a triazine ring. Among these, the aromatic ring is preferably an aromatic carbon ring, and more preferably a benzene ring. The nitrogen-containing heterocycle is particularly preferably a triazine ring. As the compound α having a triazine ring in the molecule, preferred are bonding agents containing a triazine ring in the molecule described in WO 2022/270504, WO 2022/145352, JP 2007-221099 A, JP 2001-203462 A, JP 2005-247977 A, JP 2003-129220 A, and JP 2000-160392 A. Furthermore, it is more preferred that the compound α has an aromatic ring, and the first functional group is an azide group, an azidosulfonyl group, or a diazomethyl group directly bonded to the aromatic ring. Examples of the aromatic ring include aromatic carbocycles such as a benzene ring and a naphthalene ring, and aromatic heterocycles such as a thiophene ring, a furan ring, and a triazine ring. Among these, aromatic carbocycles are preferred, and a benzene ring is more preferred. When an azide group or the like is directly bonded to a benzene ring, the reaction rate of a nitrogen molecule (N ₂ ) being detached from the azide group or the like by ultraviolet irradiation or heating is higher than when the azide group or the like is not directly bonded to the benzene ring. Therefore, by using a compound α in which an azide group or the like is directly bonded to a benzene ring, good adhesion can be achieved by a relatively low-temperature, short-time heat treatment and even without ultraviolet irradiation. Therefore, the use of such a compound α enables efficient processing. Furthermore, by using a compound α in which an azide group or the like is directly bonded to a benzene ring, good adhesion can be achieved even when irradiated with long-wavelength ultraviolet light, which is less likely to cause deterioration of metals and dielectrics.

The second functional group is preferably a group that reacts with and bonds to a metal or dielectric. The second functional group is preferably a group that reacts with and bonds to at least one of the metals and, if plated, the metal contained in the plating catalyst. Examples of the second functional group include amino groups, thiol groups, catechol groups, carboxy groups, phosphonic acid groups, silanol groups, and alkoxysilyl groups, with silanol groups and alkoxysilyl groups being preferred. Silanol groups and alkoxysilyl groups can form "-Si-O-M-type" chemical bonds with inorganic substances M, such as metals, through chemical reactions. When the second functional group is one of these groups, stronger bonds with the metal are possible.

An alkoxysilyl group is a group in which an alkoxy group (oxyhydrocarbon group) is bonded to a silicon atom. An alkoxy group is a group in which a hydrocarbon group is bonded to an oxygen atom, and examples include methoxy, ethoxy, propoxy, vinyloxy, phenoxy, and benzyloxy groups. The number of alkoxy groups bonded to the silicon atom may be 1, 2, or 3, with 3 being preferred. In an alkoxysilyl group, a group other than an alkoxy group may be bonded to the silicon atom. Examples of such groups include alkyl, phenyl, hydroxy, and hydrogen atoms. Preferred alkoxy groups are those containing 1 to 12 carbon atoms, with 1 to 3 carbon atoms being more preferred, and methoxy, ethoxy, and propoxy groups being more preferred. Examples of alkoxysilyl groups include trimethoxysilyl, triethoxysilyl, and tribenzyloxysilyl. Furthermore, silanol groups are typically generated by hydrolysis of an alkoxysilyl group.

A suitable form of compound α includes compound α1 represented by the following formula (1) or (2), and compound α2 obtained by hydrolysis and condensation of a hydrolyzable silane compound containing compound α1. When compound α is at least one of compound α1 and compound α2, good adhesion is achieved by heat treatment at a relatively low temperature for a short time, and even without ultraviolet irradiation. Therefore, the use of these compounds enables efficient processing.

(Compound α1)
Compound α1 is a compound represented by the following formula (1) or (2): That is, compound α1 is an example of compound α having an azide group or the like directly bonded to a benzene ring as a first functional group and a silanol group or an alkoxysilyl group as a second functional group.

In the above formula (1), R ¹ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a phenyl group, an alkoxy group having 1 to 12 carbon atoms, or a hydroxy group. Each of the multiple R ^2s is independently a hydrogen atom, a halogen atom, or a monovalent organic group. X ¹ is an azide group, an azidosulfonyl group, or a diazomethyl group. Y ¹ is a single bond, an ester group, an ether group, a thioether group, an amide group, a urethane group, a urea group, a group represented by -NHR ³ -, or a group represented by the following formula (3a) or (3b). R ³ is an alkyl group having 1 to 6 carbon atoms. Z ¹ is a single bond, a methylene group, an alkylene group having 2 to 12 carbon atoms, or a group containing one or more groups selected from -NH-, -O-, -S-, and -S(O)- at the terminal or between the carbon-carbon bonds of the alkylene group having 2 to 12 carbon atoms. m is an integer of 1 to 3. When there are multiple R ¹ , X ¹ , Y ¹ and Z ¹ , they each independently satisfy the above definition, provided that at least one of the one or multiple R ¹ is an alkoxy group having 1 to 12 carbon atoms.

In the above formula (2), the plurality of R ^{4 s} , R ^{5 s} , and R ^{6 s} are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a phenyl group, an alkoxy group having 1 to 12 carbon atoms, or a hydroxy group, and at least one of the plurality of R ^{4 s} , R ^{5 s} , and R ^{6 s} is an alkoxy group having 1 to 12 carbon atoms. The plurality of R ⁷ s are each independently a hydrogen atom, a halogen atom, or a monovalent organic group. X ² is an azide group, an azidosulfonyl group, or a diazomethyl group. The plurality of Z ^{2 s} are each independently a single bond, a methylene group, an alkylene group having 2 to 12 carbon atoms, or a group containing one or more groups selected from -NH-, -O-, -S-, and -S(O)- at the terminal or between the carbon-carbon bonds of the alkylene group having 2 to 12 carbon atoms.

In the above formula (3a), R ⁸ is a hydrogen atom or a methyl group.
Examples of the alkyl group having 1 to 12 carbon atoms represented by R ¹ , R ⁴ , R ⁵ and R ⁶ include a methyl group, an ethyl group, a propyl group, a butyl group and an octyl group.

Examples of the alkoxy group having 1 to 12 carbon atoms represented by R ¹ , R ⁴ , R ⁵ and R ⁶ include a methoxy group, an ethoxy group and a benzyloxy group.
Examples of the halogen atom represented by ^R2 and ^R7 include a fluorine atom, a chlorine atom, and a bromine atom.

Examples of the monovalent organic group represented by ^R2 and ^R7 include a monovalent hydrocarbon group, an alkoxy group, a group represented by -Y1- ^Z1 - ^Si - ^R13 ( ^Y1 , ^Z1 , and ^R1 are respectively defined as ^Y1 , ^Z1 , and ^R1 in formula (1)), -COO-N-(- ^{Z2 -SiR4R5R6} ) _{2 (} ^Z2 , ^R4 , ^R5 , and ^R6 are respectively defined as ^Z2 , ^R4 , ^{R5 ,} and ^{R6 in} formula (2)), and a group represented by formula (14) described below.

Examples of the alkyl group having 1 to 6 carbon atoms represented by ^R3 include a methyl group, an ethyl group, a propyl group, and a butyl group.
The preferred forms of the compound represented by formula (1) are as follows:

R ¹ is preferably an alkoxy group having 1 to 12 carbon atoms, more preferably an alkoxy group having 1 to 6 carbon atoms, and even more preferably an alkoxy group having 1 to 3 carbon atoms.
^R2 is preferably a hydrogen atom.

^X1 is preferably an azide group or an azidosulfonyl group. ^X1 is preferably bonded to the group containing ^Y1 or the like at the para-position or meta-position.
^Y1 is preferably an amide group, and more preferably an amide group represented by *-CONH- (* indicates the bonding site to the benzene ring).

^Z1 is preferably an alkylene group having 2 to 12 carbon atoms, and more preferably an alkylene group having 2 to 6 carbon atoms.
m is preferably 3.

The preferred forms of the compound represented by formula (2) are as follows:
R ⁴ , R ⁵ and R ⁶ are preferably alkoxy groups having 1 to 12 carbon atoms, more preferably alkoxy groups having 1 to 6 carbon atoms, and even more preferably alkoxy groups having 1 to 3 carbon atoms.

^R7 is preferably a hydrogen atom.
^X2 is preferably an azide group or an azidosulfonyl group, _and is preferably bonded to the group represented by —COO—N—(—Z ² —SiR ⁴ R ⁵ R ⁶ ) ² at the para or meta position.

^Z2 is preferably an alkylene group having 2 to 12 carbon atoms, and more preferably an alkylene group having 2 to 6 carbon atoms.
The compound α1 may be a compound represented by the following formula (11), (12), or (13).

In the above formulas (11) to (14), X ¹⁰ , X ¹¹ and X ¹² are each independently an azide group, an azidosulfonyl group or a diazomethyl group. ^{E 11} and E ¹² are each independently a carbonyl group, a methylene group or an alkylene group having 2 to 12 carbon atoms. ^{Y 11} , Y ¹² , Y ¹³ and Y ¹⁴ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or a group represented by -J ¹³ -Si(OA ¹⁰ ) _3-k (R ¹⁰ ) _k . J ¹¹ , J ¹² and J ¹³ are each independently a methylene group, an alkylene group having 2 to 12 carbon atoms or a group containing an oxygen atom (-O-) between the carbon-carbon bond of the alkylene group having 2 to 12 carbon atoms. Y ¹⁵ is a group represented by -R ¹⁵ or -OA ^15. Y ¹⁶ is a group represented by -R ¹⁶ or -OA ^16. A ¹⁰ , A ¹⁵ and A ¹⁶ are each independently an alkyl group having 1 to 4 carbon atoms, a benzyl group or a hydrogen atom. ^{R 10} , R ¹⁵ and R ¹⁶ are each independently an alkyl group having 1 to 4 carbon atoms or a benzyl group. k is an integer of 0 to 2. Q ¹⁰ is a hydrogen atom or an organic group represented by formula (14). In formulas (11) and (12), at least one of Y ¹¹ and Y ¹² contains an oxygen atom. In formula (13), at least one of Y ¹⁵ and Y ¹⁶ contains an oxygen atom. In formula (13), groups X ¹¹ and X ¹² bonded to the benzene ring are each independently bonded to the para position or the meta position.

(Method for synthesizing compound α1)
The synthesis method of compound α1 is not particularly limited, but for example, it can be obtained by reacting a silane coupling agent A having an alkoxysilyl group and a reactive group a other than an alkoxysilyl group with a compound B having a reactive group b capable of bonding with the reactive group a, a benzene ring, and at least one group selected from the group consisting of an azide group, an azide sulfonyl group, and a diazomethyl group, by a known method. Examples of combinations of the reactive group a and the reactive group b include combinations of an isocyanate group, an epoxy group, an amino group, etc., with a carboxy group.

Examples of silane coupling agents A include 3-isocyanatepropyltriethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, bis(3-triethoxysilylpropyl)amine, bis(3-trimethoxysilylpropyl)amine, bis(3-aminopropyl)diethoxysilane, and bis(3-aminopropyl)dimethoxysilane.

Examples of compound B include azidobenzoic acid, azidosulfonylbenzoic acid, diazomethylbenzoic acid, 3-(4-azidophenyl)propionic acid, chlorides of these carboxylic acids, azidoaniline, and azidophenol.

(Compound α2)
In the compound α2, unreacted alkoxysilyl groups usually remain. That is, the compound α2 is also an example of the compound α having an azide group or the like directly bonded to a benzene ring as the first functional group and a silanol group or an alkoxysilyl group as the second functional group.

Compound α2 obtained by hydrolysis and condensation of a hydrolyzable silane compound containing compound α1 has a structural unit A derived from compound α1. Compound α2 may be obtained by another synthetic method as long as its structure is the same as that of the compound obtained by hydrolysis and condensation of a hydrolyzable silane compound containing compound α1. Compound α2 is preferably a silsesquioxane compound. Compound α2 preferably has at least one of an alkoxysilyl group and a hydroxysilyl group, and more preferably has a hydroxysilyl group.

Examples of structural unit A include the structural unit represented by formula (4) below. The structural unit represented by formula (4) below is a structural unit derived from compound α1 represented by formula (1) in which m is 3.

In formula (4), R ¹ , R ² , X ¹ , Y ¹ and Z ¹ have the same meanings as R ¹ , R ² , X ¹ , Y ¹ and Z ¹ in formula (1), respectively. a is an integer of 0 to 2.
Specific examples of R ¹ , R ² , X ¹ , Y ¹ and Z ¹ in formula (4) are the same as the specific examples of R ¹ , R ² , X ¹ , Y ¹ and Z ¹ in formula (1). From the viewpoint of reactivity, R ¹ in formula (4) is preferably a hydroxy group or an alkoxy group, more preferably a hydroxy group. a is preferably 1.

The lower limit of the content of structural unit A relative to all structural units in compound α2 is preferably 10 mol%, more preferably 20 mol%, and even more preferably 30 mol%. On the other hand, the upper limit of this content is preferably 90 mol%, more preferably 80 mol%, and even more preferably 70 mol%.

Compound α2 preferably has a structural unit B containing an amino group (—NH ₂ ). When compound α2 has the structural unit B, there is an advantage that the water solubility of compound α2 is improved. Examples of hydrolyzable silane compounds that provide the structural unit B include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, and N-2-(aminoethyl)-3-aminopropyltrimethoxysilane.

The lower limit of the content of structural unit B relative to all structural units in compound α2 is preferably 10 mol%, more preferably 20 mol%, and even more preferably 30 mol%. On the other hand, the upper limit of this content is preferably 90 mol%, more preferably 80 mol%, and even more preferably 70 mol%.

Compound α2 may have a structural unit C other than structural units A and B. Examples of hydrolyzable silane compounds that provide structural unit C include compounds represented by the following formula (C):

In formula (C), ^Rd represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 15 carbon atoms, or an organic group having a reactive group, and multiple ^Rds may be the same or different. ^Re represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an acyl group having 2 to 6 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and multiple Re ^'s may be the same or different. x represents an integer of 0 to 3. Furthermore, these alkyl groups, alkenyl groups, and aryl groups may be unsubstituted or substituted, and can be selected depending on the properties.

Specific examples of the alkyl group represented by ^Rd and ^Re include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an n-hexyl group, an n-decyl group, a trifluoromethyl group, a 3,3,3-trifluoropropyl group, a 3-glycidoxypropyl group, a 2-(3,4-epoxycyclohexyl)ethyl group, a [(3-ethyl-3-oxetanyl)methoxy]propyl group, a 3-mercaptopropyl group, a 3-isocyanatopropyl group, etc. Specific examples of the alkenyl group represented by ^Rd include a vinyl group, a 3-acryloxypropyl group, a 3-methacryloxypropyl group, etc. Specific examples of the aryl group represented by ^Rd and R ^e include a phenyl group, a tolyl group, a p-hydroxyphenyl group, a p-methoxyphenyl group, a 1-(p-hydroxyphenyl)ethyl group, a 2-(p-hydroxyphenyl)ethyl group, a 4-hydroxy-5-(p-hydroxyphenylcarbonyloxy)pentyl group, and a naphthyl group. Examples of the organic group having a reactive group represented by ^Rd include an isocyanate group and a group having an isocyanurate structure and an alkoxysilyl group. The number of carbon atoms in the organic group having a reactive group represented by ^Rd is preferably 1 or more and 40 or less. A specific example of the acyl group represented by ^{R e} is an acetyl group.

In formula (C), when x=0 it is a tetrafunctional silane, when x=1 it is a trifunctional silane, when x=2 it is a difunctional silane, and when x=3 it is a monofunctional silane.
Specific examples of the hydrolyzable silane compound represented by formula (C) include tetrafunctional silanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraacetoxysilane, and tetraphenoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltri-n-butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltri-n-butoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-hexyltrimethoxysilane, and n-hexyltrimethoxysilane. Siltriethoxysilane, decyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, p-hydroxyphenyltrimethoxysilane, p-methoxyphenyltrimethoxysilane, 1-(p-hydroxyphenyl)ethyltrimethoxysilane, 2-(p-hydroxyphenyl)ethyltrimethoxysilane, 4-hydroxy-5-(p-hydroxyphenylcarbonyloxy)pentyltrimethoxysilane, 1-na butyltrimethoxysilane, 2-naphthyltrimethoxysilane, trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, [(3-ethyl-3-oxetanyl)methoxy]propyltrimethoxysilane, [(3-ethyl-3-oxetanyl) trifunctional silanes such as (3-glycidoxypropyl)triethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-trimethoxysilylpropylsuccinic acid; bifunctional silanes such as dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldiacetoxysilane, di-n-butyldimethoxysilane, diphenyldimethoxysilane, (3-glycidoxypropyl)methyldimethoxysilane, and (3-glycidoxypropyl)methyldiethoxysilane; and monofunctional silanes such as trimethylmethoxysilane, tri-n-butylethoxysilane, (3-glycidoxypropyl)dimethylmethoxysilane, and (3-glycidoxypropyl)dimethylethoxysilane.

Furthermore, hydrolyzable silane compounds represented by formula (C) also include compounds having five or more alkoxy groups bonded to silicon atoms, such as 1,3,5-tris[3-(trimethoxysilyl)propyl]isocyanurate.

The hydrolyzable silane compounds may be used alone or in combination of two or more.
The weight average molecular weight (Mw) of the compound α2 is not particularly limited, but is preferably 1,000 to 100,000, more preferably 2,000 to 50,000, in terms of polystyrene, as measured by GPC (gel permeation chromatography).

(Method for synthesizing compound α2)
Compound α2 can be obtained by (i) hydrolysis and condensation of a hydrolyzable silane compound containing compound α1, or (ii) a method of obtaining a hydrolyzed condensate of a hydrolyzable silane compound by reacting a compound having structural unit B with "a compound X having a reactive group capable of bonding with an amino group, a benzene ring, and at least one group selected from the group consisting of an azide group, an azidosulfonyl group, and a diazomethyl group" (such as azidobenzoic acid, azidosulfonylbenzoic acid, or diazomethylbenzoic acid). In the above method (ii), the amino group in structural unit B reacts with compound X to form structural unit A.

A conventional method can be used for the hydrolysis and condensation to obtain compound α2. For example, a solvent, water, and, if necessary, a catalyst are added to the hydrolyzable silane compound, and the mixture is heated and stirred at 30 to 150°C for approximately 0.5 to 100 hours. During stirring, hydrolysis by-products (alcohols such as methanol) and condensation by-products (water) can be removed by distillation, if necessary.

There are no particular restrictions on the catalyst that can be added as needed, but acid catalysts and base catalysts are preferred. Specific examples of acid catalysts include hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, phosphoric acid, acetic acid, trifluoroacetic acid, formic acid, polycarboxylic acids or their anhydrides, and ion exchange resins. Specific examples of base catalysts include triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, diethylamine, triethanolamine, diethanolamine, sodium hydroxide, potassium hydroxide, alkoxysilanes having amino groups, and ion exchange resins. The amount of catalyst added is preferably 0.01 to 10 parts by mass per 100 parts by mass of hydrolyzable silane compound.

From the viewpoint of storage stability of the solution containing compound α2, it is preferable that the solution after hydrolysis and condensation does not contain a catalyst, and the catalyst can be removed as necessary. There are no particular restrictions on the removal method, but preferred examples include water washing or treatment with an ion exchange resin. Water washing is a method in which the solution is diluted with an appropriate hydrophobic solvent, then washed several times with water, and the resulting organic layer is concentrated using an evaporator. Treatment with an ion exchange resin is a method in which the solution is brought into contact with an appropriate ion exchange resin.

There are no particular restrictions on the solvent used in the hydrolysis condensation reaction, but a compound having an alcoholic hydroxyl group is preferably used. There are no particular restrictions on the compound having an alcoholic hydroxyl group, but a compound with a boiling point of 110 to 250°C under atmospheric pressure is preferred.

Specific examples of compounds having an alcoholic hydroxyl group include acetol, 3-hydroxy-3-methyl-2-butanone, 4-hydroxy-3-methyl-2-butanone, 5-hydroxy-2-pentanone, 4-hydroxy-4-methyl-2-pentanone (diacetone alcohol), ethyl lactate, butyl lactate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, propylene glycol mono-t-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, 3-methoxy-1-butanol, and 3-methoxy-3-methyl-1-butanol. These compounds having an alcoholic hydroxyl group may be used alone or in combination of two or more.

Furthermore, other solvents may be used in addition to the compound having an alcoholic hydroxyl group. Examples of other solvents include esters such as ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, propylene glycol monomethyl ether acetate, 3-methoxy-1-butyl acetate, 3-methyl-3-methoxy-1-butyl acetate, and ethyl acetoacetate; ketones such as methyl isobutyl ketone, diisopropyl ketone, diisobutyl ketone, and acetylacetone; ethers such as diethyl ether, diisopropyl ether, di-n-butyl ether, diphenyl ether, diethylene glycol methyl ethyl ether, and diethylene glycol dimethyl ether; gamma-butyrolactone, gamma-valerolactone, delta-valerolactone, propylene carbonate, N-methylpyrrolidone, cyclopentanone, cyclohexanone, and cycloheptanone.

More specifically, examples of compound α1 and compound α2 include compounds represented by the following formulas (15), (16), (17), (18a), (18b), (18c), and (19). Compounds represented by formulas (15), (16), (17), (18a), (18b), and (18c) are specific examples of compound α1. Compounds represented by formula (19) are specific examples of compound α2. In formulas (15), (16), and (17), Et represents an ethyl group.

The compound represented by formula (19) is a silsesquioxane compound composed of one, m, and n units of the three types of structural units shown in formula (19) bonded together, respectively. X is an azide group, 1 is any integer of 0 or greater, m is any integer of 1 or greater, and n is any integer of 0 or greater. R ^a , R ^b , and R ^c are each independently a hydrogen atom, a hydroxy group, an alkoxy group, or —O—. ^{R f} is a hydrogen atom, a hydroxy group, an alkoxy group, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 15 carbon atoms, or an organic group having a reactive group, and multiple R ^fs may be the same or different. These alkyl groups, alkenyl groups, and aryl groups may be unsubstituted or substituted, and can be selected depending on the properties. The compound represented by formula (19) ("IMB-4KP") is water-soluble, for example, when the ratio of m:n is 1:1:0. Generally, this compound is water-soluble except when the value of the ratio 1/(m+n) is close to 0 (for example, less than 0.2 or less than 0.1). That is, from the viewpoint of water solubility, the lower limit of the value of the ratio 1/(m+n) is preferably 0.2, more preferably 0.5, and even more preferably 1. The upper limit of the value of the ratio 1/(m+n) is preferably 5, and more preferably 2.

Other forms of the compound α include a compound α3 represented by the following formula (5) and a compound α4 obtained by hydrolyzing and condensing a hydrolyzable silane compound containing the compound α3.
(Compound α3)
The compound α3 is a compound represented by the following formula (5).

In formula (5), X ²¹ is a first functional group. X ²² is a first functional group or a group represented by -N(R ²¹ ) _2. The multiple R ²¹ are each independently a hydrogen atom, a hydrocarbon group having from 1 to 24 carbon atoms, or a group represented by -R ²² -Si(OR ²³ ) _3-p (R ²⁴ ) _p . R ²² is a methylene group or an alkylene group having from 2 to 12 carbon atoms. R ²³ is a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms. R ²⁴ is an alkyl group having from 1 to 4 carbon atoms. p is an integer of from 0 to 2. However, at least one of the multiple R ²¹ in the compound represented by formula (5) is a group represented by -R ²² -Si(OR ²³ ) _3-p (R ²⁴ ) _p .

The first functional group represented by X ²¹ or X ²² is preferably an amino group, a thiol group, an azide group, an azidosulfonyl group or a diazomethyl group, more preferably an azide group, an azidosulfonyl group or a diazomethyl group, and even more preferably an azide group.

X ²² is preferably a first functional group.
As the compound α3, for example, n-TES, P-TES, A-TES, etc. manufactured by Io Chemical Research Institute Co., Ltd. can be used.

Specific examples of compound α3 include 2,4-diazido-6-(3-triethoxysilylpropyl)amino-1,3,5-triazine (hereinafter referred to as "IMB-P"), 2,4-diazido-6-(4-triethoxysilylbutyl)amino-1,3,5-triazine, 6-(3-triethoxysilylpropyl)amino-1,3,5-triazine-2,4-dithiol, and 2,4-diamino-6-(3-triethoxysilylpropyl)amino-1,3,5-triazine.

(Compound α4)
The compound α4 is a compound obtained by hydrolysis and condensation of a hydrolyzable silane compound including the compound α3. The compound α4 is a hydrolysis and condensation product similar to the compound α2, except that the compound α3 is used instead of the compound α1.

The compound α can be used alone or in combination of two or more.
The bonding material containing compound α is usually a solution containing compound α and a solvent. Examples of the solvent include alcohols such as methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, cellosolve, carbitol, and 3-methoxy-3-methyl-1-butanol; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, octane, decane, dodecane, and octadecane; esters such as ethyl acetate, methyl propionate, and methyl phthalate; ethers such as tetrahydrofuran (THF), ethyl butyl ether, anisole, and propylene glycol monomethyl ether acetate (PGMEA); and water. The solvents exemplified for use in hydrolysis and condensation can also be used. Among these, alcohols, ethers, and water are preferred. The solvents can be used alone or in combination.

The concentration of compound α in the bonding material (solution containing compound α) is preferably 0.05% by mass or more and 5% by mass or less. By setting the concentration of compound α within this range, it is possible to effectively form a bonding layer 30 containing compound α of an appropriate thickness, thereby improving the bond (adhesion) between the first insulator 12 and the second insulator 22, and the contact and bonding between the first conductor 13 and the second conductor 23, which are joined within the bonding layer 30 due to thermal expansion.

The bonding material may contain other components in addition to compound α and the solvent. Examples of other components include unreacted materials from the synthesis of compound α, by-reaction products, surfactants, etc. However, the content of compound α relative to the total solid content of the bonding material (all components other than the solvent) is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. The content of compound α relative to the total solid content of the bonding material may be 100% by mass.

Methods for applying the bonding material to the surface of the substrate include conventional coating methods such as inkjet coating, gravure coating, kiss coating, die coating, lip coating, comma coating, blade coating, roll coating, knife coating, spray coating, bar coating, spin coating, dip coating, and mist CVD. When using dip coating, the immersion time is preferably, for example, between 3 and 60 seconds.

The bonding layer 30 can exhibit stronger bonding properties by undergoing at least one or a combination of the following processes: heating the bonding layer 30 or its bonding material, applying pressure, irradiating with ultraviolet light, and irradiating with plasma.

The bonding layer 30 uses, for example, an oligomer having multiple functional groups, i.e., an oligomer having two types of first and second functional groups, such as the azide group and alkoxyl group described above. When the bonding layer 30 is provided between the first insulator 12 and the second insulator 22, the two types of first and second functional groups possessed by the oligomer are chemically bonded to the opposing surfaces of the first insulator 12 and the second insulator 22. In a bonding layer 30 using an oligomer, the first insulator 12 and the second insulator 22 can be bonded by chemical bonding of the first and second functional groups of the oligomer, which has a shorter main chain length than a polymer. Therefore, the bonding layer 30 for bonding the first insulator 12 and the second insulator 22 can be made thin, on the order of nanometers. The bonding layer 30 can firmly bond the first insulator 12 and the second insulator 22 even when it is thin, on the order of nanometers.

In addition, the bonding layer 30 provided between the first insulator 12 and the second insulator 22 may contain other components such as a solvent, a curing agent, a viscosity adjuster, etc. in addition to the oligomer having two types of first and second functional groups bonded to the main chain as described above, depending on the specifications of the bonding layer 30, the specifications of the electronic device 1 in which the bonding layer 30 is used, and the specifications of its manufacturing process.

The surfaces of the first insulator 12 and the second insulator 22, which are joined via the bonding layer 30, are, for example, both flat surfaces. Note that this "flat surface" includes surfaces with a surface roughness below a certain level. Additionally, at least one of the surfaces of the first insulator 12 and the second insulator 22 may have concave or convex portions (concave or convex portions exceeding a certain surface roughness) partially or entirely. The first insulator 12 and the second insulator 22 are joined via the bonding layer 30. Therefore, the surfaces of the first insulator 12 and the second insulator 22 do not necessarily need to be as highly flat as when they are joined directly. The first insulator 12 and the second insulator 22 can also be joined by the bonding layer 30, which is provided to fill the gap between the surfaces, at least one of which has concave or convex portions. If at least one of the surfaces of the first insulator 12 and the second insulator 22 has a concave or convex portion, the bonding area, i.e., the area in contact with the bonding layer 30, increases, thereby enhancing the bonding strength between the first insulator 12 and the second insulator 22. Furthermore, when obtaining the surface of the first insulator 12 or the surface of the second insulator 22 through a planarization process, it becomes possible to reduce the level of flatness.

Furthermore, when recesses or protrusions are provided on the surface of the first insulator 12, the recesses or protrusions may be formed unavoidably when the first insulator 12 is formed, or may be formed intentionally by etching after the formation of the first insulator 12 or by depositing a further material, etc. Furthermore, when recesses or protrusions are provided on the surface of the second insulator 22, the recesses or protrusions may be formed unavoidably when the second insulator 22 is formed, or may be formed intentionally by etching after the formation of the second insulator 22 or by depositing a further material, etc.

Next, a method for manufacturing the electronic device 1 having the above-described configuration will be described.
2 to 5 are diagrams illustrating an example of a method for manufacturing an electronic device. Figures 2(A) and 2(B), 3(A) to 3(C), 4(A) and 4(B), and 5(A) and 5(B) each show a schematic cross-sectional view of a main part of an example of each step in the manufacturing of an electronic device.

In manufacturing the electronic device 1, a first electronic component 10 and a second electronic component 20 as shown in FIGS. 2A and 2B are prepared, respectively.
As shown in Fig. 2A, the first electronic component 10 includes a first body 11, a first insulator 12, and a first conductor 13. The first body 11 has a predetermined configuration according to the form of the first electronic component 10 (semiconductor chip, semiconductor package, semiconductor wafer, circuit board, etc.). A first insulator 12 made of _SiO2 , resin, etc., and a first conductor 13 made of Cu, etc., are provided on the first body 11. The first insulator 12 and the first conductor 13 are provided on one side, a first surface 10a, of the first electronic component 10. On the first surface 10a side of the first electronic component 10, the first conductor 13 is provided so as to be exposed from the first insulator 12.

As an example, the first surface 10a of the first electronic component 10 is a flat surface. Note that this "flat surface" includes surfaces with a certain level of surface roughness or less. The surface 12a of the first insulator 12 and the surface 13a of the first conductor 13 are located within the flat first surface 10a. For example, the flat first surface 10a is formed by a planarization process such as a polishing method such as CMP (Chemical Mechanical Polishing) or etching, or a combination of a polishing method such as CMP and etching. Note that the first surface 10a may be treated with a chemical solution or gas depending on the materials of the first insulator 12 and the first conductor 13 to clean the surfaces 12a and 13a, for example, to remove an oxide film (natural oxide film) present on the surface 13a of the first conductor 13.

2B , the second electronic component 20 includes a second body 21, a second insulator 22, and a second conductor 23. The second body 21 has a predetermined configuration according to the form of the second electronic component 20 (e.g., semiconductor chip, semiconductor package, semiconductor wafer, or circuit board). A second insulator 22 made of SiO ₂ or resin, and a second conductor 23 made of Cu, are provided on the second body 21. The second insulator 22 and the second conductor 23 are provided on one side of the second surface 20a of the second electronic component 20. The second insulator 22 and the second conductor 23 of the second electronic component 20 are provided at positions corresponding to the first insulator 12 and the first conductor 13 of the first electronic component 10, respectively. On the second surface 20a of the second electronic component 20, the second conductor 23 is provided so as to be exposed from the second insulator 22.

As an example, the second surface 20a of the second electronic component 20 is a flat surface. Note that this "flat" surface includes a surface with a certain degree of surface roughness. The surface 22a of the second insulator 22 and the surface 23a of the second conductor 23 are located within the flat second surface 20a. For example, the flat second surface 20a is formed by a planarization process such as a polishing method such as CMP, etching, or a combination of a polishing method such as CMP and etching. Note that the second surface 20a may be treated with a chemical solution or gas appropriate to the materials of the second insulator 22 and the second conductor 23 to clean the surfaces 22a and 23a, for example, to remove an oxide film (natural oxide film) present on the surface 23a of the second conductor 23.

After preparing the first electronic component 10 and the second electronic component 20 as described above, for example, a bonding material 31 (a bonding material containing the compound α) for forming the bonding layer 30 is formed on one of the first electronic components 10 by the steps shown in Figures 3(A) to 3(C).

To form the bonding material 31, first, as shown in FIG. 3(A), a resist 100 is formed on the surface 13a of the first conductor 13 of the first electronic component 10 using photolithography technology. Various resist compositions can be used for the resist 100.

Next, as shown in FIG. 3(B), an uncured bonding material 31 is formed on the first surface 10a of the first electronic component 10. For example, liquid bonding material 31 is applied to the first surface 10a using a method such as spraying, dipping, printing, or dripping. After application, the bonding material 31 may be subjected to a heat treatment (pre-baking) at a predetermined temperature and atmosphere, or may be brought into a semi-cured state by the heat treatment. The bonding material 31 is formed so as to cover the first insulator 12 and the resist 100. The thickness of the bonding material 31 is set based on the amount of thermal expansion that occurs in the first conductor 13 and the second conductor 23 when the first conductor 13 and the second conductor 23 come into contact and are bonded due to thermal expansion by the heat treatment described below.

Next, as shown in FIG. 3(C), the resist 100 is removed from the first surface 10a together with the bonding material 31 covering it. For example, the resist 100 is removed from the first surface 10a using a stripping liquid. As a result, the bonding material 31 is formed on the surface 12a of the first insulator 12 on the first surface 10a, and the surface 13a of the first conductor 13 is exposed from the bonding material 31, resulting in the first electronic component 10.

In the step of removing the resist 100 (Figure 3(C)), a stripping liquid may be used that can remove the oxide film (natural oxide film) present on the surface 13a of the first conductor 13 while removing the resist 100. Such a stripping liquid may be a stripping liquid such as that described in JP 2004-302271 A. When removing the resist 100 using a stripping liquid, ashing using oxygen plasma or the like may be performed before contact with the stripping liquid, and stripping conditions such as the temperature and contact time of the stripping liquid may be adjusted.

Furthermore, after removing the resist 100 using a stripping solution, the exposed surface 13a of the first conductor 13 may be treated with a specified chemical solution or gas to remove any oxide film present on the surface 13a.

After the bonding material 31 has been formed, as shown in FIG. 4(A), the first surface 10a of the first electronic component 10 on which the bonding material 31 has been formed is opposed to the second surface 20a of the second electronic component 20. In this case, the first surface 10a and the second surface 20a are opposed so that the first insulator 12 of the first electronic component 10 and the second insulator 22 of the second electronic component 20 face each other, and the first conductor 13 of the first electronic component 10 and the second conductor 23 of the second electronic component 20 face each other.

The surface 13a of the first conductor 13 of the first electronic component 10 and the surface 23a of the second conductor 23 of the second electronic component 20 may be activated by ion bombardment with an inert gas. For example, corona treatment or plasma treatment may be performed to remove oxide films and impurities from the surfaces 13a and 23a, resulting in highly active, clean surfaces with high surface energy. Activating the surfaces 13a and 23a makes it easier to achieve solid-state diffusion bonding between the first conductor 13 and the second conductor 23 by heat treatment, as described below, and reduces the resistance between the joined first conductor 13 and second conductor 23.

The opposed first electronic component 10 and second electronic component 20 are brought close together, and as shown in FIG. 4(B), the bonding material 31 provided on the surface 12a of the first insulator 12 of the first electronic component 10 comes into contact with the second insulator 22 of the second electronic component 20. From this state, heat treatment is performed in a predetermined atmosphere at a temperature ranging from 150°C to 220°C. This heat treatment hardens the bonding material 31, forming a bonding layer 30 that bonds the first insulator 12 and the second insulator 22. Furthermore, this heat treatment thermally expands the first conductor 13 of the first electronic component 10 and the second conductor 23 of the second electronic component 20, bringing them into contact and bonding them within the bonding layer 30.

If the heat treatment temperature is below 150°C, the first conductor 13 and the second conductor 23 may not be able to thermally expand sufficiently, which may make it impossible to achieve contact and solid-state diffusion bonding as described below. Furthermore, if the heat treatment temperature is above 220°C, the thermal expansion of the first conductor 13 and the second conductor 23 may become so great that the gap between the first electronic component 10 and the second electronic component 20 widens, resulting in an increase in the size of the electronic device 1, or the first electronic component 10 and the second electronic component 20 may be thermally damaged, resulting in performance degradation or breakage.

Here, Figure 5(A) schematically shows an example of the state of the first electronic component 10 and the second electronic component 20 at part P1 in Figure 4(B) before they are joined. Figure 5(B) schematically shows an example of the state of the first electronic component 10 and the second electronic component 20 at part P1 in Figure 4(B) after they are joined.

As shown in Figure 5 (A), the first conductor 13 of the first electronic component 10 and the second conductor 23 of the second electronic component 20 thermally expand in a direction in which the first conductor 13 protrudes from the first insulator 12 and the second conductor 23 protrudes from the second insulator 22 due to the heat treatment performed when forming the bonding layer 30 from the bonding material 31. In other words, the first conductor 13 and the second conductor 23 thermally expand in directions in which they approach each other.

As this thermal expansion progresses with heat treatment, the first conductor 13 and the second conductor 23 come into contact, as shown in FIG. 5(B). If heat treatment is continued while the conductors are in this contact state, solid-state diffusion occurs between the contacting first conductor 13 and second conductor 23, and the first conductor 13 and the second conductor 23 are bonded together, i.e., solid-state diffusion bonded. As a result, the first conductor 13 and the second conductor 23 are bonded together and integrated, and electrically connected. The first electronic component 10 and the second electronic component 20 are electrically connected through the bonded and integrated first conductor 13 and second conductor 23. Even if further thermal expansion occurs after the first conductor 13 and the second conductor 23 come into contact, the amount of thermal expansion can be absorbed by deformation (thickness increase, etc.) of the bonding layer 30, thereby maintaining the bond between the first insulator 12 and the second insulator 22.

As shown in Figure 5(B), the thickness T1 of the bonding layer 30 is set to a value corresponding to the amounts of thermal expansion t1 and t2 that occur in the first conductor 13 and the second conductor 23, respectively, when the first conductor 13 and the second conductor 23 come into contact and are bonded due to thermal expansion by heat treatment. The thickness of the bonding material 31 provided on the first insulator 12 is set by the process shown in Figures 3(A) to 3(C) above so that a bonding layer 30 of such thickness T1 is obtained when the first insulator 12 and the second insulator 22 are bonded by the bonding layer 30 and when the first conductor 13 and the second conductor 23 are bonded by heat treatment.

When joining the first insulator 12 and the second insulator 22 with the bonding layer 30, and when joining the first conductor 13 and the second conductor 23 by thermal expansion, the first electronic component 10 may be pressurized toward the second electronic component 20, or the second electronic component 20 may be pressurized toward the first electronic component 10. This pressurization may improve the adhesion between the bonding layer 30 and the first insulator 12 and the second insulator 22, or the bonding between the first insulator 12 and the second insulator 22 by the bonding layer 30, or may adjust the thickness of the bonding layer 30 interposed between the first insulator 12 and the second insulator 22.

The bonding of the first conductor 13 and the second conductor 23 due to thermal expansion may be achieved by performing a separate heat treatment after the heat treatment used to form the bonding layer 30 (hardening the bonding material 31). In this case, the conditions for the heat treatment used to form the bonding layer 30 may be the same as or different from the conditions for the heat treatment used to bond the first conductor 13 and the second conductor 23. The heat treatment used to bond the first conductor 13 and the second conductor 23 is performed, for example, in a predetermined atmosphere at a temperature ranging from 150°C to 220°C. Furthermore, when the first conductor 13 and the second conductor 23 are bonded using a separate heat treatment in this manner, the prior formation of the bonding layer 30 (hardening the bonding material 31) does not necessarily have to be performed by heat treatment, and may instead be performed by irradiation with light such as ultraviolet light.

For example, the electronic device 1 is manufactured through the steps shown in Figures 2(A) and 2(B), 3(A) to 3(C), 4(A) and 4(B), and 5(A) and 5(B). In the manufacturing method of the electronic device 1, the first insulator 12 of the first electronic component 10 and the second insulator 22 of the second electronic component 20 are joined using a bonding layer 30 formed from an IMB bonding material 31. Then, within the bonding layer 30, the first conductor 13 and the second conductor 23, which thermally expand due to heat treatment, are brought into contact and joined by solid-state diffusion bonding. The first electronic component 10 and the second electronic component 20 are electrically connected via the first conductor 13 and the second conductor 23. The manufacturing method described above realizes an electronic device 1 in which the first electronic component 10 and the second electronic component 20 are simply and satisfactorily joined.

Here, an example has been given in which a first electronic component 10 having a flat first surface 10a and a second electronic component 20 having a flat second surface 20a are prepared (FIGS. 2(A) and 2(B)), and these are used to bond via a bonding layer 30 (FIGS. 3(A) to 3(C), 4(A) and 4(B), and 5(A) and 5(B)). Additionally, at least the surface 12a of the first insulator 12 of the first surface 10a, or at least the surface 22a of the second insulator 22 of the second surface 20a, may have a concave or convex portion. Because the first insulator 12 and the second insulator 22 are bonded via the bonding layer 30, their surfaces 12a and 22a do not necessarily need to be highly flat, as in the case of direct bonding. The first insulator 12 and the second insulator 22 may be bonded via a bonding layer 30 that is provided to fill the gap between the surfaces 12a and 22a. If at least one of the surfaces 12a and 22a has a recess or protrusion, the contact area of the bonding layer 30 increases, thereby enhancing the bonding strength between the first insulator 12 and the second insulator 22. Furthermore, when the surface 12a of the first insulator 12 or the surface 22a of the second insulator 22 is obtained by a planarization process, the level of flatness can be reduced.

The recessed or protruding portions may be provided on the surface 13a of the first conductor 13 or the surface 23a of the second conductor 23. Even if there are recessed or protruding portions on the surface 13a or surface 23a, contact due to thermal expansion and solid-state diffusion bonding after contact are possible.

Furthermore, the first electronic component 10 may have, on the side opposite the first surface 10a (the side opposite the side of the second electronic component 20 to which it is joined), an insulator and conductor similar to the first insulator 12 and first conductor 13 on the first surface 10a. The insulator and conductor on the opposite side of the first electronic component 10 may be further joined and electrically connected to another electronic component according to the example above. Furthermore, the second electronic component 20 may have, on the side opposite the second surface 20a (the side opposite the side of the first electronic component 10 to which it is joined), an insulator and conductor similar to the second insulator 22 and second conductor 23 on the second surface 20a. The insulator and conductor on the opposite side of the second electronic component 20 may be further joined and electrically connected to another electronic component according to the example above.

Figure 6 is a diagram illustrating an example of a conventional method for manufacturing electronic devices. Figure 6(A) shows a schematic cross-sectional view of a key portion of an example of a group of electronic components in a conventional method. Figures 6(B) and 6(C) show schematic examples of the state of electronic components before and after bonding, respectively, in a conventional method.

Conventionally, there is known a method for joining electronic components together without using the bonding material 31 and bonding layer 30 described above. In this method, for example, electronic components 210 and 220 as shown in FIG. 6(A) are prepared. Electronic component 210 has a configuration in which conductor 213 having surface 213a is provided at a position recessed from surface 212a of insulator 212. Electronic component 220 similarly has a configuration in which conductor 223 having surface 223a is provided at a position recessed from surface 222a of insulator 222.

Generally, electronic components 210 and 220 having such a configuration are formed using a polishing method such as CMP, utilizing the dishing of conductors 213 and 223 that occurs during this process. However, methods that utilize dishing can result in variations between the amount of recession s1 of surface 213a of conductor 213 relative to surface 212a of insulator 212 and the amount of recession s2 of surface 223a of conductor 223 relative to surface 222a of insulator 222.

6B, when the electronic components 210 and 220 are bonded together, the insulators 212 and 222 are directly bonded together. For example, if _SiO2 is used for the insulators 212 and 222, the insulators 212 and 222 are directly bonded together by plasma activation (dangling bond formation), water rinsing (cleaning), room temperature pressure welding, and condensation (siloxane condensation formation).

Subsequently, heat treatment is performed, causing conductor 213 to thermally expand toward conductor 223, and conductor 223 to thermally expand toward conductor 213, as shown in FIG. 6(C). If the recess amounts s1 and s2 (FIG. 6(A)) of conductors 213 and 223 are appropriate, this heat treatment will cause conductors 213 and 223 to come into contact and be joined by solid-state diffusion bonding. However, if there is variation in recess amounts s1 and s2 (FIG. 6(A)), and one of recess amounts s1 and s2 (in this example, recess amount s2) exceeds the amount of thermal expansion due to the heat treatment, it is possible that conductors 213 and 223 will not come into contact and will not be joined, as shown in FIG. 6(C).

In contrast, the manufacturing method for the electronic device 1 shown in Figures 2 to 5 does not require dishing or other methods to recess the first conductor 13 of the first electronic component 10 and the second conductor 23 of the second electronic component 20 below the first insulator 12 and second insulator 22, respectively. The first insulator 12 of the first electronic component 10 and the second insulator 22 of the second electronic component 20 are not directly bonded, but are bonded using a bonding layer 30 formed from an IMB bonding material 31. Then, within the bonding layer 30, the first conductor 13 and second conductor 23, which thermally expand due to heat treatment, are brought into contact and bonded by solid-state diffusion bonding.

Therefore, the manufacturing method for the electronic device 1 does not require dishing the first conductor 13 and the second conductor 23 to a predetermined recess amount, or processing for directly bonding the first insulator 12 and the second insulator 22. The manufacturing method for the electronic device 1 makes it possible to easily and satisfactorily bond the first electronic component 10 and the second electronic component 20.

An example of the configuration of the electronic device 1 will be further described.
7A to 7D are diagrams illustrating examples of the configuration of an electronic device, each of which schematically shows a cross-sectional view of a main part of the example of the configuration of an electronic device.

The first electronic component 10 and the second electronic component 20 of the electronic device 1 may each be a semiconductor chip, a semiconductor package, a semiconductor wafer, a circuit board, or the like.
7A shows an example of the electronic device 1. The electronic device 1A includes a semiconductor device 10A and a semiconductor device 20A. The semiconductor device 10A is a semiconductor chip or a semiconductor package, and is an example of the first electronic component 10. The semiconductor device 20A is a semiconductor chip or a semiconductor package, and is an example of the second electronic component 20.

In the electronic device 1A shown in FIG. 7(A), the insulator 12A and conductor 13A provided on the body 11A of the semiconductor device 10A face the insulator 22A and conductor 23A provided on the body 21A of the semiconductor device 20A. The insulator 12A and the insulator 22A are joined by a bonding layer 30A, and the conductor 13A and the conductor 23A are directly joined within the bonding layer 30A. The semiconductor devices 10A and 20A are electrically connected through the conductor 13A and the conductor 23A.

As an example of the electronic device 1, for example, an electronic device 1B as shown in FIG. 7(B) is realized. This electronic device 1B has a configuration using semiconductor devices 10B, 20B, and 40B. Electronic device 1B is an example of a three-dimensional stacked device. Semiconductor device 10B is a semiconductor chip or a semiconductor package. Semiconductor device 20B is a semiconductor chip or a semiconductor package. Semiconductor device 40B is a semiconductor chip or a semiconductor package, or a circuit board such as an interposer. Semiconductor device 10B and semiconductor device 40B are examples of the first electronic component 10 and second electronic component 20, respectively. Alternatively, semiconductor device 40B and semiconductor device 20B are examples of the first electronic component 10 and second electronic component 20, respectively.

In the electronic device 1B shown in FIG. 7(B), an insulator 12Ba and a conductor 13Ba provided on one side of the body 11B of the semiconductor device 10B face an insulator 42Ba and a conductor 43B penetrating the body 41B provided on one side of the body 41B of the semiconductor device 40B. The insulator 12Ba and the insulator 42Ba are joined by a bonding layer 30Ba, and the conductor 13Ba and the conductor 43B are directly joined within the bonding layer 30Ba. Furthermore, an insulator 42Bb and a conductor 43B provided on the other side of the body 41B of the semiconductor device 40B face an insulator 22B and a conductor 23B provided on the body 21B of the semiconductor device 20B. The insulator 42Bb and the insulator 22B are joined by a bonding layer 30Bb, and the conductor 43B and the conductor 23B are directly joined within the bonding layer 30Bb. Semiconductor device 10B, semiconductor device 40B, and semiconductor device 20B are electrically connected through conductor 13Ba, conductor 43B, and conductor 23B.

Furthermore, for example, the semiconductor device 10B may have an insulator 12Bb and a conductor 13Bb provided on the other side of the main body 11B. These insulators 12Bb and conductors 13Bb may further be joined to electronic components such as other semiconductor devices or circuit boards, following the example above, and electrically connected via the conductors 13Bb.

Furthermore, as an example of the electronic device 1, for example, an electronic device 1C as shown in FIG. 7(C) is realized. This electronic device 1C has a configuration using a substrate 10C and a semiconductor device 20C. The substrate 10C is a semiconductor wafer or circuit board, and is an example of the first electronic component 10. The semiconductor device 20C is a semiconductor chip or semiconductor package, and is an example of the second electronic component 20.

In the electronic device 1C shown in Figure 7 (C), the insulator 12C and conductor 13C provided on the main body 11C of the substrate 10C face the insulator 22C and conductor 23C provided on the main body 21C of the semiconductor device 20C. The insulator 12C and the insulator 22C are bonded by a bonding layer 30C, and the conductor 13C and the conductor 23C are directly bonded within the bonding layer 30C. The substrate 10C and the semiconductor device 20C are electrically connected through the conductor 13C and the conductor 23C.

Furthermore, as an example of the electronic device 1, for example, electronic device 1D as shown in FIG. 7(D) is realized. This electronic device 1D has a configuration using substrate 10D and substrate 20D. Substrate 10D is a semiconductor wafer or a circuit board, and is an example of the first electronic component 10. Substrate 20D is a semiconductor wafer or a circuit board, and is an example of the second electronic component 20.

In the electronic device 1D shown in FIG. 7(D), an insulator 12D and a conductor 13D provided on a main body 11D of a substrate 10D face an insulator 22D and a conductor 23D provided on a main body 21D of a substrate 20D. The insulators 12D and 22D are joined by a bonding layer 30D, and the conductors 13D and 23D are directly joined within the bonding layer 30D. The substrates 10D and 20D are electrically connected via the conductors 13D and 23D.

As such, various types of first electronic component 10 and second electronic component 20 can be used for electronic device 1 such as that shown in Figure 1 above. The manufacturing method shown in Figures 2 to 5 above can be applied to joining first electronic component 10 and second electronic component 20 of various types.

The foregoing merely illustrates the principles of the present invention. Moreover, since numerous modifications and changes are possible to those skilled in the art, the present invention is not limited to the exact constructions and applications shown and described above, and all corresponding modifications and equivalents are deemed to be within the scope of the present invention as defined by the appended claims and their equivalents.

REFERENCE SIGNS LIST 1, 1A, 1B, 1C, 1D Electronic device 10 First electronic component 10A, 10B, 20A, 20B, 20C, 40B Semiconductor device 10C, 10D, 20D Substrate 10a First surface 11 First body 11A, 11B, 11C, 11D, 21A, 21B, 21C, 21D, 41B Body 12 First insulator 12A, 12Ba, 12Bb, 12C, 12D, 22A, 22B, 22C, 22D, 42Ba, 42Bb, 212, 222 Insulator 12a, 13a, 22a, 23a, 212a, 213a, 222a, 223a Surface 13 First conductor 13A, 13Ba, 13Bb, 13C, 13D, 23A, 23B, 23C, 23D, 43B, 213, 223 Conductor 20 Second electronic component 20a Second surface 21 Second body 22 Second insulator 23 Second conductor 30, 30A, 30Ba, 30Bb, 30C, 30D Bonding layer 31 Bonding material 100 Resist 210, 220 Electronic component T1 Thickness t1, t2 Amount of thermal expansion s1, s2 Amount of recess

Claims (11)

preparing a first electronic component having a first insulator and a first conductor on a first surface side;
preparing a second electronic component having a second insulator and a second conductor on a second surface side;
providing a bonding layer made of an organic compound on the first insulator;
a step of opposing the first surface and the second surface via the bonding layer so that the first insulator and the second insulator face each other and the first conductor and the second conductor face each other;
a step of performing a heat treatment to bond the first insulator and the second insulator together by the bonding layer and to bring the first conductor and the second conductor into contact with each other within the bonding layer by thermal expansion, and bonding the first conductor and the second conductor together;
A method for manufacturing an electronic device, comprising: The method for manufacturing an electronic device described in claim 1, wherein the temperature of the heat treatment is in the range of 150°C or higher and 220°C or lower. The method for manufacturing an electronic device according to claim 1, wherein the first conductor and the second conductor comprise copper. The method for manufacturing an electronic device described in claim 1, wherein the step of joining the first conductor and the second conductor includes a step of joining the first conductor and the second conductor that have been brought into contact by the thermal expansion by solid-state diffusion bonding. the step of preparing the first electronic component includes a step of forming the first surface using at least a polishing method;
The method for manufacturing an electronic device according to claim 1 , wherein the step of preparing the second electronic component includes the step of forming the second surface by using at least a polishing method. The method for manufacturing an electronic device described in claim 1, wherein the step of providing the bonding layer on the first insulator includes a step of providing the bonding layer on the first insulator with a thickness corresponding to the amount of thermal expansion that occurs in the first conductor and the second conductor during the heat treatment. The step of providing the bonding layer on the first insulator includes:
forming a resist covering the first conductor;
applying the bonding layer to the first surface side after the resist is formed;
removing the resist;
The method for manufacturing an electronic device according to claim 1 , comprising: The method for manufacturing an electronic device described in claim 7, wherein the step of removing the resist includes a step of removing the resist using a stripping solution that removes an oxide film present on the surface of the first conductor. The method for manufacturing an electronic device according to claim 1, further comprising a step of activating the surfaces of the first conductor and the second conductor by ion bombardment of an inert gas prior to the heat treatment. The method for manufacturing an electronic device according to claim 1, wherein the first electronic component and the second electronic component are each a semiconductor chip, a semiconductor package, a semiconductor wafer, or a circuit board. a first electronic component having a first insulator and a first conductor on a first surface side;
a second electronic component having a second insulator and a second conductor on a second surface side opposite to the first surface, the second insulator facing the first insulator and the second conductor facing the first conductor;
a bonding layer provided between the first insulator and the second insulator, the bonding layer being made of an organic compound and bonding the first insulator and the second insulator together;
Including,
The electronic device, wherein the first conductor and the second conductor are bonded within the bonding layer.