JP7322580B2 - Electronic device manufacturing method - Google Patents

Description

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

Various developments have been made on methods for manufacturing electronic devices. As this type of technology, for example, the technology described in Patent Document 1 is known. Patent Document 1 describes that an adhesive layer made of a photosensitive adhesive composition is attached to an inch silicon wafer, and then exposed and developed (Claim 1 of Patent Document 1, FIG. 6, etc.).

JP 2010-261026 A

However, as a result of investigation by the present inventors, it has been found that there is room for improvement in the manufacturing stability of the electronic device in the manufacturing method of the electronic device described in Patent Document 1 above.

In a general method of manufacturing an electronic device, a photosensitive resin composition is applied to a substrate or an underlying film on the substrate to form a photosensitive resin film. However, if the adhesion between the photosensitive resin film and the underlying film is insufficient, the photosensitive resin film may peel off from the underlying film. This reduces the manufacturing stability of the electronic device.

The inventor of the present invention focused on the substrate adhesion of the photosensitive resin film and proceeded with the study. The present inventors have found that the film can be formed stably and the adhesion between the photosensitive resin film and the base film can be improved by controlling the film thickness to , and have completed the present invention.

According to the invention,
preparing a substrate selected from the group consisting of a semiconductor substrate, a ceramic substrate, a metal substrate, and a resin substrate;
forming a base film on the substrate;
a step of silylating the surface of the underlying film;
applying a photosensitive resin composition on the surface of the silylated underlayer to form a photosensitive resin film;
patterning the photosensitive resin film;
obtaining an electronic device comprising the patterned photosensitive resin film as a permanent film;
In the photosensitive resin composition applied in the step of forming the photosensitive resin film, the surface tension of the droplets composed of the photosensitive resin composition measured by the hanging drop method is 20 mN/m or more and 42 mN/m or less. be,
A method of manufacturing an electronic device is provided.

According to the present invention, a method for manufacturing an electronic device with excellent manufacturing stability is provided.

It is process sectional drawing which shows typically an example of the manufacturing method of the electronic device of this embodiment. It is a sectional view showing typically an example of an electronic device of this embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In addition, in all the drawings, the same constituent elements are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Also, the drawings are schematic diagrams and do not correspond to actual dimensional ratios.
In this embodiment, the front, back, left, right, up, and down directions are specified as shown in the drawings. However, this is defined for convenience in order to simply explain the relative relationship of the constituent elements. Therefore, it does not limit the orientation during manufacture or use of the product embodying the present invention.

An outline of a method for manufacturing an electronic device according to this embodiment will be described.

The method of manufacturing an electronic device according to the present embodiment comprises the steps of preparing a substrate selected from the group consisting of a semiconductor substrate, a ceramic substrate, a metal substrate, and a resin substrate, forming a base film on the substrate, and forming the base film. a step of silylating the surface; a step of applying a photosensitive resin composition on the surface of the silylated underlayer to form a photosensitive resin film; a step of patterning the photosensitive resin film; obtaining an electronic device comprising the coated photosensitive resin film as a permanent film. Then, in the photosensitive resin composition applied in the step of forming the photosensitive resin film, the surface tension of droplets made of the photosensitive resin composition measured by the hanging drop method satisfies 20 mN / m or more and 42 mN / m or less. It is a thing.

According to the knowledge of the present inventors, it is possible to stably form a film by applying a silylation treatment to the underlying film on the substrate and appropriately controlling the surface tension of the photosensitive resin composition applied to the underlying film. It was found that the adhesiveness between the photosensitive resin film and the underlying film can be improved even after development.

Although the detailed mechanism is not clear, modifying the surface of the base film by silylation treatment enhances the interaction with the resin, and the surface tension enhances the wettability of the photosensitive resin composition during application. It is considered that good adhesion can be obtained.

According to the electronic device manufacturing method of the present embodiment, it is possible to improve the manufacturing stability of the electronic device.

Patterned photosensitive resin films are intended to be used as permanent films in electronic devices. In other words, the patterned photosensitive resin film is not completely removed during the process of the electronic device manufacturing method, unlike the sacrificial material, but remains in the device.

A photosensitive resin film can be suitably used as an interlayer film, a surface protection film, a dam material, or a permanent film such as an adhesive film.

The electronic device of the present embodiment can be applied to "electric/electronic equipment". "Electrical/electronic equipment" refers to elements, devices, final products, and other electric Refers to related equipment in general.

Each step of the method for manufacturing the electronic device of this embodiment will be described in detail.
1A to 1D are process cross-sectional views schematically showing an example of a method for manufacturing an electronic device 100 of this embodiment.

In the step of preparing a substrate, as shown in FIG. 1A, a substrate 10 forming part of an electronic device 100 is prepared.

As the substrate 10, one or more substrates selected from the group consisting of a semiconductor substrate, a ceramic substrate, a metal substrate such as an aluminum substrate, and a resin substrate are used. These may be used alone or in combination of two or more. The substrate 10 may be wafer-like or panel.
The substrate does not have to include a glass substrate used for a liquid crystal display or the like.

The substrate 10 may be composed of a semiconductor substrate or a resin substrate. The semiconductor substrate may have a plurality of electronic elements (semiconductor elements) and wiring on its surface. The semiconductor substrate may be made of a semiconductor material such as Si, SiC, or GaN.

The substrate 10 may be composed of a silicon substrate as a semiconductor substrate.
Examples of silicon substrates include a silicon wafer whose surface is protected by an underlying film 20 such as a silicon nitride film or a silicon oxide film, and a silicon wafer whose surface is formed with an underlying film 20 such as a metal wiring such as Ti or Cu. be done.

An example of the resin substrate is a fan-out wafer level package (FOWLP) substrate or a panel level package (PLP) substrate.
The FOWLP substrate may have a rewiring area larger than the chip size, and is made of, for example, a sealing resin in which a plurality of electronic components such as semiconductor chips are sealed. In the FOWLP substrate, an insulating resin film may be provided on the surface region on the side where the connection terminals provided on the semiconductor chip are arranged. A known material is used as the insulating resin film, and for example, a polyimide film may be used.
On the other hand, the PLP substrate is a panel-shaped substrate that is larger than an ordinary disk-shaped wafer, and is made of a sealing resin in which a plurality of electronic components are sealed.

In the step of forming an underlying film on the substrate, an underlying film 20 is formed on at least part of the surface of the substrate 10, as shown in FIG. 1(b).

The underlying film 20 may be a natural oxide film formed on the surface of the substrate, or may be an interlayer film forming part of the electronic device. A wiring layer may be formed in the underlying film 20 .

An example of the base film 20 may include an inorganic film.
The inorganic film may be selected from the group consisting of silicon oxide films, silicon nitride films, and aluminum oxide films. These may be used alone or in combination of two or more.

According to this embodiment, even if the underlying film 20 is composed of an inorganic film, the silylation treatment can enhance the interaction with the film made of the photosensitive resin composition containing the organic resin. In addition, by imparting water repellency to the surface by silylation treatment, it is possible to enhance the adhesion between them.

In the step of silylating the surface of the underlying film, at least part of the surface of the underlying film 20 is subjected to silylation treatment 30, as shown in FIG. 1(b).

For the silylation treatment 30, a vaporization method of exposing the surface of the underlying film 20 to a vaporized silylating agent, a spin coating method of applying a liquid silylating agent to the surface of the underlying film 20, or the like may be used.

As a specific example of the vaporization method, the substrate 10 having the base film 20 may be placed in a chamber, and the silylating agent may be vaporized and sprayed. The silylating agent may be vaporized under normal pressure conditions or after adjusting the pressure.
Regarding the vaporization method, for example, an apparatus as described in JP-A-10-41214 can be used.

The lower limit of the temperature for vaporizing the silylating agent is, for example, 40° C. or higher, preferably 60° C. or higher, and more preferably 80° C. or higher. The upper limit of the temperature for vaporizing the silylating agent is, for example, 300° C. or lower, preferably 250° C. or lower, and more preferably 200° C. or lower. By adopting such temperature conditions, it becomes easier to adjust the speed of silylation of the underlying film 20 .

As the pressure conditions for vaporizing the silylating agent, both decompression conditions and pressurization conditions can be employed.
The lower limit of the pressure when the reduced pressure condition is employed is, for example, 0.01 atmosphere or more, preferably 0.1 atmosphere or more. Further, the upper limit of the pressure when the reduced pressure condition is employed is, for example, 0.9 atmosphere or less, preferably 0.8 atmosphere or less.
By adopting such conditions, the surface treatment can be performed at a temperature sufficiently lower than the boiling point of the silylating agent (for example, when hexamethyldisilazane is used, the boiling point is 125° C.), and the equipment used can be It can prolong life.
The lower limit of the pressure when the pressurization condition is employed is, for example, 1.2 atmospheres or more, preferably 1.5 atmospheres or more. Also, the upper limit of the pressure when the pressurization condition is adopted is, for example, 10 atmospheres or less, preferably 5 atmospheres or less.
By adopting such conditions, it becomes easier to adjust the vaporization rate of the silylating agent, and it becomes easier to impart desired water repellency to the underlying film 20 .

Specific examples of compounds that can be used as silylating agents include trimethylchlorosilane, triethylchlorosilane, tri-n-propylchlorosilane, tri-i-propylchlorosilane, tri-n-butylchlorosilane, tri-t-butylchlorosilane, trimethyl Bromosilane, triethylbromosilane, tri-n-propylbromosilane, tri-i-propylbromosilane, tri-n-butylbromosilane, tri-t-butylbromosilane, propyltrichlorosilane, butyltrichlorosilane, isobutyltrichlorosilane , hexyltrichlorosilane, cyclohexyltrichlorosilane, octyltrichlorosilane, decyltrichlorosilane, dodecyltrichlorosilane, tetradecyltrichlorosilane, octadecyltrichlorosilane, and other halogenated alkylsilanes; hexamethyldisilazane, hexaethyldisilazane, hexa- silazanes such as n-propyldisilazane, hexa-i-propyldisilazane, hexa-n-butyldisilazane, hexa-t-butyldisilazane; tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra - quaternary alkoxysilanes such as i-propoxysilane, tetra-n-butoxysilane, tetra-t-butoxysilane; trimethoxymethylsilane, triethoxymethylsilane, tri-n-propoxymethylsilane, trimethoxyethyl Silane, trimethoxy-n-propylsilane, trimethoxy-i-propylsilane, triethoxyethylsilane, triethoxy-n-propylsilane, triethoxy-i-propylsilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane , n-butyltrimethoxysilane, i-butyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltriethoxysilane, i-butyltriethoxysilane, decyltriethoxy Silane, Vinyltriethoxysilane, γ-Methacryloxypropyltrimethoxysilane, γ-Glycidoxypropyltrimethoxysilane, γ-Glycidoxypropylmethyldimethoxysilane, γ-Mercaptopropyltrimethoxysilane, γ-Chloropropyltrimethoxysilane Tertiary alkoxyalkylsilanes such as silane, γ-aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropylmethyldimethoxysilane; dimethoxydimethylsilane , dimethoxydiethylsilane, dimethoxydi-n-propylsilane, dimethoxydi-i-propylsilane, diethoxydimethylsilane, diethoxydiethylsilane and other secondary alkoxyalkylsilanes; methoxytrimethylsilane, ethoxytrimethylsilane, n-propoxytrimethyl Examples include primary alkoxysilanes such as silane, ethoxytriethylsilane, n-propoxytrimethylsilane, n-propoxytriethylsilane. These may be used alone or in combination of two or more.

Among the above compounds, hexamethyldisilazane, hexaethyldisilazane, hexa-n-propyldisilazane, hexa-i-propyldisilazane, hexa-n-butyldisilazane, hexa-t-butyldisilazane A compound having a Si--NH--Si structure in the molecule such as is preferably used. When a compound having such a structure is used, the silylating agent is converted into ammonia molecules (NH ₃ ) during surface treatment, and can be easily removed from the system.

Moreover, from the viewpoint of availability, etc., hexamethyldisilazane (HMDS) can be exemplified as a particularly preferable silylating agent.

In the step of forming a photosensitive resin film, as shown in FIG. 1(c), a liquid photosensitive resin composition is applied onto the surface of the silylated base film 20, and prebaked as necessary. Thus, a photosensitive resin film 50 is formed.

In the photosensitive resin composition used for coating, the surface tension of droplets of the photosensitive resin composition measured by the hanging drop method satisfies 20 mN/m or more and 42 mN/m or less.

The surface tension is measured by filling a syringe with a 18G needle with a photosensitive resin composition that is liquid at 25°C, and using a fully automatic contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., DM-901) to measure the photosensitive resin composition. Create a 5 μL droplet consisting of Next, by the young-Laplace method, the shape of the produced droplet is analyzed to measure the surface tension (mN/m) of the droplet.

By setting the surface tension to the above upper limit or less, the wettability of the liquid photosensitive resin composition to the surface of the base film 20 that has been subjected to the silylation treatment 30 can be increased, and cissing and coating unevenness during coating can be suppressed. The film formation property of the photosensitive resin film on the entire silylation-treated substrate can be enhanced.
Further, by making the surface tension equal to or higher than the above lower limit, it becomes easier to control the thickness of the photosensitive resin film, so that the handleability can be improved.

The upper limit of the surface tension of the photosensitive resin composition is 45 mN/m or less, preferably 43 mN/m or less, more preferably 42 mN/m or less. On the other hand, the lower limit of the surface tension of the photosensitive resin composition is 20 mN/m or more, preferably 22 mN/m or more, more preferably 25 mN/m or more.

The photosensitive resin composition can be applied by spin coating, spray coating, immersion, printing, roll coating, inkjet method, or the like. Among these, spin coating may be used from the viewpoint of realizing a thin coating film.

After coating, if necessary, pre-baking may be performed by heat drying.
The prebaking temperature is usually 80 to 140°C, preferably 90 to 120°C. The prebaking time is usually 30 to 600 seconds, preferably about 30 to 300 seconds. A photosensitive resin film is formed by removing the solvent by this heat drying. Heating is typically done with a hot plate, an oven, or the like.

Here, the composition of the photosensitive resin composition used in the method for manufacturing an electronic device will be described.

The photosensitive resin composition may contain, for example, a polymer containing a cyclic olefin-derived structural unit in the molecule and a photosensitizer.

The photosensitive adhesive composition can contain a copolymer having a structural unit A derived from a norbornene-based monomer and a structural unit B derived from maleic anhydride, maleimide, or derivatives thereof.
At least one of the structural unit A and the structural unit B may have the functional group in the copolymer, and both may have the functional group.

The structural unit A derived from the norbornene-based monomer can contain a structural unit represented by the following formula (2). Structural unit A may be used alone or in combination of two or more. Since the structural unit A has a norbornene skeleton derived from a norbornene-based monomer, it is possible to reduce the dielectric constant of the cured product of the photosensitive adhesive composition and achieve low dielectric properties.

In the above formula (2), R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom, a hydroxyl group or an organic group having 1 to 30 carbon atoms, preferably an organic group having 1 to 10 carbon atoms. is. These organic groups may have functional groups such as carboxyl groups, glycidyl groups, and oxetanyl groups.
In formula (2), n is, for example, 0, 1 or 2, preferably 0 or 1, more preferably 0.
In the present specification, "-" means including upper and lower limits unless otherwise specified.

The organic group constituting R ₁ to R ₄ may contain one or more atoms selected from O, N, S, P and Si in its structure.

In the present embodiment, examples of organic groups constituting R ₁ to R ₄ include alkyl groups, alkenyl groups, alkynyl groups, alkylidene groups, aryl groups, aralkyl groups, alkaryl groups, cycloalkyl groups, and heterocyclic groups. be done.
Examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, Octyl, nonyl, and decyl groups are included. Alkenyl groups include, for example, allyl groups, pentenyl groups, and vinyl groups. Alkynyl groups include ethynyl groups. The alkylidene group includes, for example, a methylidene group and an ethylidene group. Aryl groups include, for example, tolyl, xylyl, phenyl, naphthyl, and anthracenyl groups. Aralkyl groups include, for example, benzyl groups and phenethyl groups. Cycloalkyl groups include, for example, adamantyl, cyclopentyl, cyclohexyl, and cyclooctyl groups. Heterocyclic groups include, for example, epoxy groups and oxetanyl groups.

Furthermore, in the alkyl group, alkenyl group, alkynyl group, alkylidene group, aryl group, aralkyl group, alkaryl group, cycloalkyl group, and heterocyclic group constituting R ₁ to R ₄ , one or more hydrogen atoms are replaced by halogen atoms. may be substituted by Halogen atoms include fluorine, chlorine, bromine, and iodine. Among them, a haloalkyl group in which one or more hydrogen atoms in an alkyl group are substituted with a halogen atom is preferable. By using a haloalkyl group for at least one of R ₁ to R ₄ , when a cured film is formed using a copolymer, the dielectric constant of the cured film can be lowered. Moreover, by using a haloalkyl alcohol group, not only can the solubility in an alkaline developer be appropriately adjusted, but also the resistance to heat discoloration can be improved.
From the viewpoint of increasing the light transmittance of a film containing a polymer, any one of R ₁ to R ₄ is preferably hydrogen. For example, when employing the structural unit of formula (2) is preferably all of R ₁ to R ₄ are hydrogen.

Specific examples of monomers having a norbornene skeleton include 2-norbornene; 5-methyl-2-norbornene, 5,5-dimethyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2- norbornenes having an alkyl group (C1-C10 alkyl group) such as norbornene; norbornenes having an alkenyl group such as 5-ethylidene-2-norbornene; 5-methoxycarbonyl-2-norbornene, 5-methyl-5-methoxycarbonyl Norbornenes having an alkoxycarbonyl group such as -2-norbornene; norbornenes having a cyano group such as 5-cyano-2-norbornene; 5-phenyl-2-norbornene, 5-phenyl-5-methyl-2-norbornene, etc. octaline; octaline having an alkyl group such as 6-ethyl-octahydronaphthalene;

These norbornene-based monomers can be used alone or in combination of two or more. Among these bicyclic olefins, norbornenes such as norbornene and norbornene having an alkyl group (C1-C10 alkyl group such as methyl group and ethyl group) are preferred.

The structural unit B derived from maleic anhydride, maleimide, or derivatives thereof may contain a structural unit derived from maleic anhydride or a maleic anhydride derivative (maleic anhydride-based monomer).

Examples of the maleic anhydride or maleic anhydride derivative include maleic anhydride, citraconic anhydride, dimethyl maleic anhydride, and derivatives thereof. These may be used alone or in combination of two or more. Thus, the copolymer can have structural units derived from an unsaturated carboxylic anhydride having a cyclic structure in the molecule.

The structural unit derived from maleic anhydride or maleic anhydride derivative can include a structural unit represented by the following formula (1).

In the above formula (1), R _X and R _Y are each independently preferably hydrogen or an organic group having 1 to 3 carbon atoms, and are each independently hydrogen or an organic group having 1 carbon atoms. More preferably, R _{1 X} is hydrogen and R 1 _Y is hydrogen or an organic group having 1 carbon atom, and R _{1 X} and R 1 _Y are still more preferably hydrogen.

In the present embodiment, examples of organic groups constituting R _{1 X} and _RY in formula (1) include alkyl groups, alkenyl groups, alkynyl groups, alkylidene groups, cycloalkyl groups, and heterocyclic groups. Examples of alkyl groups include methyl, ethyl and n-propyl groups. Alkenyl groups include, for example, allyl groups and vinyl groups. Alkynyl groups include ethynyl groups. The alkylidene group includes, for example, a methylidene group and an ethylidene group. A cycloalkyl group includes, for example, a cyclopropyl group. Heterocyclic groups include, for example, epoxy groups and oxetanyl groups.

The copolymer can have a structural unit derived from an ester compound in which the acid anhydride ring in the structural unit A represented by the following formula (1) is opened, preferably the acid anhydride ring of maleic anhydride is It can have a structural unit C derived from a ring-opened ester compound.

The structural unit C can contain, for example, a structural unit represented by the following formula (B2). These may be used alone or in combination of two or more.

R ^{1 B1} in general formula (B2) contains hydrogen or an organic group having 1 to 30 carbon atoms. This R ^B1 may be an organic group bonded through a bonding group such as an ester bond, an amide bond, a ketone bond, a urea bond, or a urethane bond.

Examples of the organic group constituting R ^B1 in the general formula (B2) include an alkyl group, an alkenyl group, an alkynyl group, an alkylidene group, an aryl group, an aralkyl group, an alkaryl group, a cycloalkyl group, an alkoxy group, and a heterocyclic ring. groups.

Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group and heptyl group. , octyl, nonyl, and decyl groups. Alkenyl groups include, for example, allyl groups, pentenyl groups, and vinyl groups. Alkynyl groups include ethynyl groups. The alkylidene group includes, for example, a methylidene group and an ethylidene group. Aryl groups include, for example, tolyl, xylyl, phenyl, naphthyl, and anthracenyl groups. Aralkyl groups include, for example, benzyl groups and phenethyl groups. The alkaryl group includes, for example, a tolyl group and a xylyl group. Cycloalkyl groups include, for example, adamantyl, cyclopentyl, cyclohexyl, and cyclooctyl groups. Alkoxy groups include, for example, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, s-butoxy, isobutoxy and t-butoxy, n-pentyloxy, and neopentyloxy groups. , n-hexyloxy group. Heterocyclic groups include, for example, epoxy groups and oxetanyl groups.
R ^B1 in the general formula (B2) is, for example, preferably one or more selected from the group consisting of an alkyl group, an alkenyl group, and an alkynyl group, and is preferably an alkyl group or an alkenyl group. preferable. As a result, cleavage of the bond in R ^B1 can be suppressed. Therefore, the heat resistance of the copolymer can be improved.

In the above general formula (B2), R ^B1 is, for example, an aliphatic group formed by one or more atoms selected from the group consisting of hydrogen atoms and carbon atoms bonded via an ester bond. is preferred, and a hydrocarbon group is more preferred.

The structural unit B derived from maleic anhydride, maleimide, or derivatives thereof may contain a structural unit derived from maleimide or a maleimide derivative. Thereby, workability and heat resistance can be improved.

The structural unit derived from the maleimide or maleimide derivative can include a structural unit derived from a maleimide-based monomer represented by the following formula (8). These may be used alone or in combination of two or more.

R ₁₂ is a hydrogen atom or a C1-C30 organic group. Examples of the C1 to C30 organic groups constituting R ₁₂ include hydrocarbon groups such as alkyl groups, alkenyl groups, alkynyl groups, alkylidene groups, aryl groups, aralkyl groups, alkaryl groups and cycloalkyl groups. Examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, Octyl, nonyl, and decyl groups are included. Alkenyl groups include, for example, allyl groups, pentenyl groups, and vinyl groups. Alkynyl groups include ethynyl groups. The alkylidene group includes, for example, a methylidene group and an ethylidene group. Aryl groups include, for example, phenyl groups and naphthyl groups. Aralkyl groups include, for example, benzyl groups and phenethyl groups. Examples of alkaryl groups include tolyl and xylyl groups. Cycloalkyl groups include, for example, adamantyl, cyclopentyl, cyclohexyl, and cyclooctyl groups. One or more hydrogen atoms contained in _R5 may be substituted with a halogen atom such as fluorine, chlorine, bromine or iodine.

In addition to the structural units A to C described above, the copolymer may contain a structural unit D derived from another compound having an ethylenic double bond. Other compounds having an ethylenic double bond include, for example, styrene, styrenes such as hydroxystyrene, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3- methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, etc., having 2 to 20 carbon atoms α-olefin; 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, non-conjugated dienes such as 1,7-octadiene; acrylic acid, methacrylic acid, α- acrylic acids such as ethyl acrylic acid and 2-hydroxyethyl (meth)acrylic acid; and maleic acids such as maleic acid, dimethyl maleic acid, diethyl maleic acid and dibutyl maleic acid. These monomers may be used alone or in combination of two or more.

In the photosensitive adhesive composition of the present embodiment, the content of the copolymer is 20% by mass or more and 80% by mass or less with respect to 100% by mass of the non-volatile components of the photosensitive adhesive composition. It is preferably 30% by mass or more and 70% by mass or less, more preferably 40% by mass or more and 60% by mass or less. By setting it as such a numerical range, it is possible to aim at balance with adhesiveness and workability.

In the present embodiment, the non-volatile component of the photosensitive adhesive composition refers to the remainder after excluding volatile components such as water and solvent. The content of the total non-volatile components of the photosensitive adhesive composition refers to the total content of the non-volatile components excluding the solvent in the photosensitive adhesive composition when a solvent is included.

The photosensitive adhesive composition of this embodiment can contain a cross-linking agent. The cross-linking agent is not particularly limited as long as it can undergo a cross-linking reaction with the copolymer. This can improve adhesion.

The cross-linking agent can contain a compound having a cyclic ether group.
By including a compound having a cyclic ether group, the adhesiveness in post-curing after exposure and development can be improved. Although the detailed mechanism is not clear, since the curing reaction of the resin film made of the photosensitive adhesive composition can be suppressed until before the bonding process of the first circuit board and the second circuit board, the curing reaction can be sufficiently suppressed in the post-curing. It is thought that it becomes possible to proceed and achieve high adhesion at the time of post-curing.

Compounds having cyclic ether groups can include, for example, epoxy resins or oxetane compounds.

As the epoxy resin, for example, an epoxy resin having two or more epoxy groups in one molecule can be used. Monomers, oligomers, and polymers in general can be used as epoxy resins, and their molecular weights and molecular structures are not particularly limited. Examples of epoxy resins include phenol novolak type epoxy resin, cresol novolak type epoxy resin, cresol naphthol type epoxy resin, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, phenoxy resin, naphthalene skeleton type epoxy resin, and bisphenol A type epoxy resin. , bisphenol A diglycidyl ether type epoxy resin, bisphenol F type epoxy resin, bisphenol F diglycidyl ether type epoxy resin, bisphenol S diglycidyl ether type epoxy resin, glycidyl ether type epoxy resin, cresol novolac type epoxy resin, aromatic polyfunctional Epoxy resins, aliphatic epoxy resins, aliphatic polyfunctional epoxy resins, alicyclic epoxy resins, polyfunctional alicyclic epoxy resins, and the like. Epoxy resins may be used singly or in combination.

In addition, the epoxy resin may include a trifunctional or higher polyfunctional epoxy resin (that is, one having 3 or more epoxy groups in one molecule). As the polyfunctional epoxy resin, those having a functionality of 3 or more and 20 or less are more preferable.
Polyfunctional epoxy resins include, for example, 2-[4-(2,3-epoxypropoxy)phenyl]-2-[4-[1,1-bis[4-([2,3-epoxypropoxy]phenyl) Ethyl]phenyl]propane, phenolic novolac epoxy, tetrakis(glycidyloxyphenyl)ethane, α-2,3-epoxypropoxyphenyl-ω-hydropoly(n=1-7){2-(2,3-epoxypropoxy) benzylidene-2,3-epoxypropoxyphenylene}, 1-chloro-2,3-epoxypropane·formaldehyde·2,7-naphthalenediol polycondensate, dicyclopentadiene type epoxy resin, and the like are used. These may be used singly or in combination.

The oxetane compound is not particularly limited as long as it is a compound having an oxetanyl group. )] methyl ether, 4,4′-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, 4,4′-bis(3-ethyl-3-oxetanylmethoxy)biphenyl, ethylene glycol bis(3- ethyl-3-oxetanylmethyl)ether, diethylene glycol bis(3-ethyl-3-oxetanylmethyl)ether, bis(3-ethyl-3-oxetanylmethyl)diphenoate, trimethylolpropane tris(3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis(3-ethyl-3-oxetanylmethyl) ether, poly[[3-[(3-ethyl-3-oxetanyl)methoxy]propyl]silasesquioxane] derivative, oxetanyl silicate, phenol novolac-type oxetane, 1,3-bis[(3-ethyloxetan-3-yl)methoxy]benzene and the like. These may be used alone or in combination of two or more.

The lower limit of the content of the cross-linking agent is, for example, 10% by mass or more, preferably 15% by mass or more, and more preferably 20% by mass or more, relative to the total nonvolatile components of the photosensitive adhesive composition. is. Thereby, it is possible to improve the heat resistance and mechanical strength of the cured product of the photosensitive adhesive composition. On the other hand, the upper limit of the content of the cross-linking agent is, for example, 50% by mass or less, preferably 45% by mass or less, more preferably 40% by mass, based on the total nonvolatile components of the photosensitive adhesive composition. It is below. Thereby, it is possible to improve patterning properties in the photosensitive adhesive composition.

The photosensitive adhesive composition of this embodiment can contain a phenolic resin as a curing agent. Monomers, oligomers, and polymers in general can be used as the phenol resin, and the molecular weight and molecular structure are not particularly limited. Compatibility and workability can be improved by including a phenol resin. Although the detailed mechanism is not clear, it is believed that the compatibility between the copolymer and the photosensitive agent can be enhanced in the varnish-like photosensitive adhesive composition. In addition, when a diazoquinone compound is used as a photosensitive agent, it can undergo an azo-coupling reaction with a phenol compound, which can reduce film loss during development and improve resolution.

The phenolic resin preferably contains a polyfunctional phenolic resin having two or more phenolic hydroxyl groups in the molecule.

As the phenol resin, the following phenol resins and low-molecular-weight phenol compounds can be used. The phenolic resin can be appropriately selected from among known phenolic resins, and for example, a novolak phenolic resin, a resol phenolic resin, a trisphenylmethane phenolic resin, and an arylalkylene phenolic resin can be used. A novolak-type phenolic resin can be used from the viewpoint of good developing properties. Low molecular weight phenol compounds include biphenol, 4-ethylresorcinol, 2-propylresorcinol, 4-butylresorcinol, 4-hexylresorcinol, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid. acid, 4,4'-dihydroxydiphenyl sulfide, 3,3'-dihydroxydiphenyl disulfide, 4,4'-dihydroxydiphenyl sulfone, 2,2'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenylmethane, 2,2'- Dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, biphenol, 4,4'-(1,3-dimethylbutylidene)diphenol, 4,4'-(2-ethylhexylidene)diphenol, 4,4' -ethylidene bisphenol, 2,2'-ethylenedioxydiphenol, 3,3'-ethylenedioxydiphenol, 1,5-bis(o-hydroxyphenoxy)-3-oxapentane, bisphenol A, bisphenol F, phloroglucide , α, α, α'-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene and the like. These may be used alone or in combination of two or more.

The content of the phenol resin is, for example, 1 part by mass or more and 30 parts by mass or less, preferably 3 parts by mass or more, when the total content of the copolymer in the photosensitive adhesive composition is 100 parts by mass. It is 20 parts by mass or less, more preferably 5 parts by mass or more and 15 parts by mass or less. By blending within the above range, the heat resistance and strength of the cured product are improved.

Examples of the photosensitizer include diazoquinone compounds, diaryliodonium salts, triarylsulfonium salts, onium salts such as sulfonium borate salts, 2-nitrobenzyl ester compounds, N-iminosulfonate compounds, imidosulfonate compounds, 2,6-bis( trichloromethyl)-1,3,5-triazine compounds, or dihydropyridine compounds can be used. Among these, it is particularly preferable to use a diazoquinone compound which is excellent in sensitivity and solvent solubility.

The content of the photosensitive agent in the photosensitive adhesive composition of the present embodiment is not particularly limited, but is preferably 5 parts by mass or more, and 8 parts by mass with respect to 100 parts by mass of the copolymer. More preferably, it is at least 1 part. The content of the photosensitive agent in the photosensitive adhesive composition is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, relative to 100 parts by mass of the copolymer. Favorable patterning performance can be exhibited by content of a photosensitive agent being in the said range.

The photosensitive adhesive composition of this embodiment can contain a surfactant. By including a surfactant, a uniform resin film can be obtained, and thin film coatability can be improved. In addition, it can be expected to prevent residues and patterns from lifting during development.
Examples of the surfactant include fluorine-based surfactants, silicon-based surfactants, alkyl-based surfactants, and acrylic surfactants.

The surfactant preferably contains a surfactant containing at least one of a fluorine atom and a silicon atom. This contributes to obtaining a uniform resin film (improvement of coatability), improvement of developability, and improvement of adhesion strength.

More specifically, the surfactant is preferably a nonionic surfactant containing at least one of a fluorine atom and a silicon atom. Examples of commercial products that can be used as surfactants include F-251, F-253, F-281, F-430, F-477, F-551 of the "Megafac" series manufactured by DIC Corporation, F-552, F-553, F-554, F-555, F-556, F-557, F-558, F-559, F-560, F-561, F-562, F-563, F- 565, F-568, F-569, F-570, F-572, F-574, F-575, F-576, R-40, R-40-LM, R-41, R-94, etc. Fluorine-containing oligomer structure surfactants, fluorine-containing nonionic surfactants such as Phthagent 250 and Phthagent 251 manufactured by Neos Co., Ltd., SILFOAM (registered trademark) series manufactured by Wacker Chemie (for example, SD 100 TS , SD 670, SD 850, SD 860, SD 882).

The reason why the nonionic surfactant containing at least one of a fluorine atom and a silicon atom can improve the adhesive strength is not clear, but presumed causes are, for example, (i) as a result of smoothing the film surface, (ii) the uneven distribution of the surfactant on the surface of the resin film (cured film) causes the surface of the cured film to partially melt with heat; It is conceivable that it will become easier.

The content of the surfactant is usually 0.001 to 1% by mass, preferably 0.003 to 0.5% by mass, more preferably 0.003 to 0.5% by mass, based on the total amount of nonvolatile components in the photosensitive adhesive composition. 005 to 0.3% by mass, more preferably 0.008 to 0.1% by mass, and particularly preferably 0.01 to 0.08% by mass. By setting the content in this range, it can be expected that the effect of improving the adhesive strength described above can be further obtained.

The photosensitive adhesive composition of this embodiment can contain an adhesion aid.
This makes it possible to further improve the adhesion to the substrate. Although the detailed mechanism is unknown, the adhesion group (functional group that exerts adhesion ability) of the adhesion aid is relatively stable against heating, and a certain amount of adhesion is maintained even after curing at 180 to 250 ° C. As a result of the adjuvant remaining in the cured film, the remaining adhesion adjuvant is considered to contribute to the improvement of the adhesive force.

Examples of the adhesion aid include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacrylic oxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(aminoethyl )-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane Silane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxypropyl)tetrasulfide, 3-isocyanate propyltriethoxysilane, 3-trimethoxysilylpropylsuccinic anhydride, bis(3-(triethoxysilyl)propyl)disulfide, bis(3-(triethoxysilyl)propyl)tetrasulfide, a silicon compound having an amino group Examples include, but are not limited to, silicon compounds obtained by reacting acid dianhydrides or acid anhydrides.

The content of the adhesion aid is usually 0.01 to 20% by mass, preferably 0.1 to 10% by mass, based on the total amount of nonvolatile components in the photosensitive adhesive composition. By setting the content in this range, it can be expected that the effect of improving the adhesive strength described above can be further obtained.

The photosensitive adhesive composition of this embodiment can contain a solvent.
Any solvent can be used without particular limitation as long as it can dissolve each component of the photosensitive adhesive composition and does not chemically react with each component. Examples of such organic solvents include acetone, methyl ethyl ketone, toluene, propylene glycol methyl ethyl ether, propylene glycol dimethyl ether, propylene glycol 1-monomethyl ether 2-acetate, diethylene glycol ethyl methyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol mono Butyl ether acetate, benzyl alcohol, propylene carbonate, ethylene glycol diacetate, propylene glycol diacetate, propylene glycol monomethyl ether acetate, γ-butyrolactone, butyl acetate, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide, diethylene glycol Dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, methyl lactate, ethyl lactate, butyl lactate, methyl-1,3-butylene glycol acetate, 1,3-butylene glycol-3-monomethyl Organic solvents such as ether, methyl pyruvate, ethyl pyruvate and methyl-3-methoxypropionate are included. Only one type of organic solvent may be used, or two or more types may be used in combination.

The organic solvent is preferably used so that the total concentration of nonvolatile components in the photosensitive adhesive composition is 1 to 50 mass %, preferably 5 to 40 mass %. By setting it as this range, each component can fully be melt|dissolved and a favorable thin film coatability can be ensured.

In addition to the components described above, the photosensitive adhesive composition of the present embodiment may contain other additives as necessary. Other additives include antioxidants, fillers such as silica, sensitizers, film-forming agents, adhesion aids, and the like.

The method for preparing the photosensitive oil composition is not particularly limited, and it can be produced by a generally known method.

In the step of patterning the photosensitive resin film, as shown in FIG. 1D, a predetermined pattern is formed on the photosensitive resin film 50 by exposure processing and development processing.

As actinic rays for exposure, for example, X-rays, electron beams, ultraviolet rays, visible rays, and the like can be used. In terms of wavelength, actinic rays of 200 to 500 nm are preferred. The light source is preferably g-line, h-line or i-line of a mercury lamp in terms of pattern resolution and handleability. Also, two or more rays may be mixed and used. A contact aligner, mirror projection or stepper is preferred as the exposure device.
After exposure and before development, the photosensitive resin film may be heated again (post-exposure heat treatment). The temperature and time of the post-exposure heat treatment are usually 80 to 200° C. and 10 to 300 seconds, for example.

Development can be carried out using a suitable developer, for example, by dipping, puddle, rotary spraying, and the like. Thereby, a patterned photosensitive resin film 50 can be obtained.

The developer that can be used is not particularly limited, but in the present embodiment, an alkaline aqueous solution is preferred. Specifically, inorganic alkaline aqueous solutions such as sodium hydroxide, sodium carbonate, sodium silicate and ammonia; organic amine aqueous solutions such as ethylamine, diethylamine, triethylamine and triethanolamine; tetramethylammonium hydroxide; tetrabutylammonium hydroxide; and an aqueous solution of a quaternary ammonium salt of. A water-soluble organic solvent such as methanol or ethanol, or a surfactant may be added to the developer.
As the developer, an aqueous tetramethylammonium hydroxide solution is preferred. The concentration of tetramethylammonium hydroxide in this aqueous solution is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass.

After the development step, the developer may not be washed with the rinse liquid, but the developer may be removed by washing with the rinse liquid, if necessary. Examples of rinse liquids include distilled water, methanol, ethanol, isopropanol, propylene glycol monomethyl ether, and the like. These may be used alone or in combination of two or more.

After exposure, if necessary, the photosensitive resin film 50 may be bleached.
Bleaching can reduce the amount of the photosensitive agent remaining in the photosensitive resin film 50 by decomposing the photosensitive agent by heating or exposure.

An oven is preferable as one aspect of the heating means. Alternatively, a hot plate or the like may be used. The atmosphere during curing may be air or an inert gas such as nitrogen or argon. Heating under reduced pressure may also be used.

As a result, the electronic device 100 including the substrate 10, the base film 20, and the patterned photosensitive resin film 50 as permanent films is obtained as shown in FIG. 1(d).

Further, the method of manufacturing an electronic device according to the present embodiment may include a step of bonding another substrate via a patterned photosensitive resin film 50, as shown in FIG. 1(e). As a result, an electronic device 110 as shown in FIG. 2(a) and an electronic device 120 as shown in FIG. 2(b) are obtained.

FIG. 2 is a cross-sectional view schematically showing an example of the electronic devices 110 and 120 of this embodiment.

The electronic device 110 of FIG. 2A has a structure in which the photosensitive resin films 50 and 52 provided on the respective surfaces of the substrate 10 and the substrate 12 are in close contact with each other. An underlying film 20 may be provided between the substrate 10 and the photosensitive resin film 50 , and an underlying film 22 may be provided between the substrate 12 and the photosensitive resin film 52 . The substrates 10 and 12 may be electrically connected by electrodes 60 embedded in the photosensitive resin films 50 and 52 .

On the other hand, the electronic device 120 of FIG. 2B has a structure in which the substrate 10 and the substrate 12 are in close contact with the photosensitive resin film 50 provided on the surface of the substrate 10 and one surface of the substrate 12 . One surface of the substrate 12 is the surface opposite to the surface on which the photosensitive resin film 52 is provided. The substrates 10 and 12 may be electrically connected via bonding wires 70 .

The substrate 12, the base film 22, and the photosensitive resin film 52 shown in FIGS. 2A and 2B may be those exemplified above, or may be obtained from known materials.

As shown in FIG. 1E, for example, a photosensitive resin film 52 provided on one surface of the substrate 12 is bonded to the photosensitive resin film 50 on the substrate 10 . At this time, at least one of the photosensitive resin film 50 and the photosensitive resin film 52, preferably both, may be in a semi-cured state (B-stage state).

After bonding the substrates together, a curing treatment may be performed, if necessary.
The heating temperature for the curing treatment is preferably 170° C. or higher, more preferably 200° C. or higher. The upper limit is, for example, 400° C. or less, preferably 300° C. or less. By adjusting the heating temperature appropriately, it is expected that the cured state will be optimized and the adhesive strength will be further increased.
Also, the heating time may be generally 0.5 to 300 minutes, preferably 1 to 270 minutes, more preferably 3 to 240 minutes.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than those described above can be adopted. Moreover, the present invention is not limited to the above-described embodiments, and includes modifications, improvements, etc. within the scope of achieving the object of the present invention.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to the description of these Examples.

<Synthesis of polymer>
Polymer (A-1): Cyclic olefin resin 1 synthesized in Synthesis Example 1
(Synthesis Example 1: Synthesis of polymer (A-1))
In a sealable reaction vessel methyl glycidyl ether norbornene (45.1 g, 250 mmol), 2-norbornene (23.5 g, 250 mmol), 1-butyl hydrogen maleate (51.7 g, 300 mmol), and maleic anhydride ( 24.5 g, 250 mmol) was weighed. Further, 105 g of PGME in which dimethyl 2,2′-azobis(2-methylpropionate) (12.1 g, 53 mmol) was dissolved was added to the reaction vessel and stirred and dissolved. After removing dissolved oxygen in the system by nitrogen bubbling, the container was sealed and reacted at 70° C. for 16 hours. The reaction mixture was then cooled to room temperature and diluted by adding 202 g of acetone. The diluted solution was poured into a large amount of hexane to precipitate a polymer. The polymer was then collected by filtration, further washed with hexane, and vacuum dried at 30° C. for 16 hours. The amount of polymer obtained was 101 g, and the yield was 70%. Through the above operation, a cyclic olefin resin (copolymer 1) having a weight average molecular weight Mw of 6,300 and a repeating unit represented by the following formula (A-1) was obtained.

Polymer (A-2): Cyclic olefin resin 2 synthesized in Synthesis Example 2
(Synthesis Example 2: Synthesis of polymer (A-2))
In an appropriately sized reaction vessel equipped with a stirrer, condenser, 122.4 g (1.25 mol) of maleic anhydride, 117.6 g (1.25 mol) of 2-norbornene and dimethyl 2,2′-azobis(2- 11.5 g (0.05 mol) of methyl propionate was weighed and dissolved in 150.8 g of methyl ethyl ketone and 77.7 g of toluene, nitrogen was bubbled through the solution for 10 minutes to remove oxygen, and then , with stirring at 60° C. for 16 hours (polymerization step).
After that, 320 g of MEK was added to this solution, and then a suspension of 12.5 g (0.31 mol) of sodium hydroxide, 463.1 g (6.25 mol) of butanol, and 480 g of toluene was added to a cyclic structure derived from maleic anhydride. Mixing was carried out at 45° C. for 3 hours so that 50% or more of the repeating units among the repeating units in the body were in a ring-closed state. Then, this mixed solution was cooled to 40° C. and treated with 49.0 g (0.94 mol) of an 88% by weight formic acid aqueous solution for protonation (ring-opening step).
MEK and water were then added and the aqueous layer separated to remove inorganic residues. Then, unreacted monomers were removed by adding methanol and hexane and separating the organic layer. Further, propylene glycol-1-monomethyl ether-2-acetate (PGMEA) was added, and methanol and butanol in the system were distilled off under reduced pressure until the residual amount was less than 1%. As a result, a PGMEA solution of a cyclic olefin resin (copolymer 2) having a repeating unit represented by the following formula (A-2) and having a weight average molecular weight Mw of 13,700 was obtained.

<Preparation of photosensitive resin composition>
Raw materials of each component blended according to Table 1 were stirred at room temperature until the raw materials were completely dissolved to obtain a mixed solution. Thereafter, the mixed solution was filtered through a 0.2 μm polyethylene filter to obtain a photosensitive resin composition having a solid content of 40% by mass.

Details of raw materials for each component in Table 1 are as follows.

<Polymer (A)>
(A-1): Polymer (A-1) synthesized in Synthesis Example 1 above
(A-2): Polymer (A-2) synthesized in Synthesis Example 2 above
(A-3): Epoxy resin EOCN-1020-55 (manufactured by Nippon Kayaku Co., Ltd.)
<Photosensitizer (B)>
(B-1) DS-427 (manufactured by Daito Chemix Co., Ltd.)
(B-2) CPI-310B (manufactured by San-Apro Co., Ltd.)
<Crosslinking agent (C)>
(C-1) VG3101L (manufactured by Printec Co., Ltd.)
(C-2) LX-01 (manufactured by Daiso Co., Ltd.)
<Adhesion aid (D)>
(D-1) KBM-403E (manufactured by Shin-Etsu Chemical Co., Ltd.)
(D-2) X-12-967C (manufactured by Shin-Etsu Chemical Co., Ltd.)
<Solubilizer (E)>
(E-1) phloroglucide (manufactured by Kanto Chemical Co., Ltd.)
<Surfactant (F)>
(F-1) FC4432 (manufactured by 3M Corporation)
(F-2) R-41 (manufactured by DIC Corporation)
<Solvent (F)>
(G-1) Propylene glycol monomethyl ether acetate (PGMEA)
(G-2) γ-butyrolactone (GBL)
(G-3) formamide

<Evaluation of surface tension of droplet>
For the obtained varnish-like photosensitive resin compositions according to each of Examples and Comparative Examples, the surface tension of droplets of the photosensitive resin composition was measured by the suspension method described in detail below. The unit is mN/m.
First, a varnish-like photosensitive resin composition is filled into a syringe with an 18G needle, and a fully automatic contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., DM-901) is used to measure the photosensitive resin composition. A 5 μL droplet was created. Next, by the young-Laplace method, the shape of the produced droplet was analyzed to measure the surface tension of the droplet.

<Evaluation of coatability to substrate>
(Applicability Evaluation 1: Examples 1 to 9 and Comparative Example 2)
An 8-inch silicon wafer was placed in an oven filled with hexamethyldisilazane vapor, treated at 120° C. for 1 minute, and then heated on a hot plate at 120° C. for 1 minute to obtain a silylated silicon wafer. got
The photosensitive resin composition was spin-coated on the silylated 8-inch silicon wafer obtained above so that the film thickness after drying was 5 μm, followed by heating at 120° C. for 3 minutes to form a coating film. Obtained. The appearance of the coating film was observed, and it was evaluated as ○ when the entire surface was coated, Δ when the shrinkage from the edge was 1 mm or more and 5 mm or less, and x when the shrinkage from the edge exceeded 5 mm. .

(Applicability Evaluation 2: Comparative Example 1)
Coatability was evaluated in the same manner as in Coatability Evaluation 1, except that a non-silylated silicon wafer was used instead of the silylated silicon wafer used in Coatability Evaluation 1.

<Glass transition temperature (Tg)>
(Preparation of test piece 1: Examples 1-5, 7-10 and Comparative Examples 1-2)
The obtained varnish-like photosensitive resin composition according to each of Examples and Comparative Examples was spin-coated onto an 8-inch silicon wafer obtained by silylating the photosensitive resin composition so that the film thickness after drying was 10 μm, Subsequently, heating was performed at 120° C. for 3 minutes to obtain a coating film. The resulting coating film was treated with a 2.38 wt% TMAH aqueous solution for 30 seconds, and then cured by heat treatment at 230°C for 90 minutes in a nitrogen atmosphere to obtain a cured product of the photosensitive resin composition. Strips (30 mm x 5 mm x 10 µm thick) were obtained.

(Preparation of test piece 2: Example 6)
Instead of immersing in the 2.38 wt% TMAH aqueous solution of test piece preparation 1 for 30 seconds, the photosensitive resin composition was exposed to 1000 mJ / cm ² with a high pressure mercury lamp, and then baked at 120 ° C. for 3 minutes after exposure. A sample was prepared in the same manner as in Preparation 1 of the test piece, except that it was immersed in cyclopentanone for 30 seconds.
(Measurement of glass transition temperature (Tg))
The coefficient of thermal expansion of the test piece obtained at a heating rate of 10° C./min was measured using a thermomechanical analyzer (manufactured by Seiko Instruments Inc., TMA/SS6000). Next, based on the obtained measurement results, the glass transition temperature (Tg) of the cured product was calculated from the inflection point of the coefficient of thermal expansion. The unit is °C.

<Tensile elongation>
Test pieces were prepared in the same manner as in Preparation 1 of Test Piece and Preparation 2 of Test Piece in <Measurement of Glass Transition Temperature (Tg)>.
For the obtained test piece, using a tensile tester (manufactured by Orientec, Tensilon RTC-1210A), under an atmosphere of 23 ° C., a tensile test was performed by a method conforming to JIS K7161, and the tensile elongation of the test piece was measured. bottom. The unit of tensile elongation is %. Moreover, the drawing speed in the tensile test was set to 5 mm/min.

<Tensile modulus>
Test pieces were prepared in the same manner as in Preparation 1 of Test Piece and Preparation 2 of Test Piece in <Measurement of Glass Transition Temperature (Tg)>.
For the obtained test piece, using a tensile tester (Tensilon RTC-1210A manufactured by Orientec Co., Ltd.), a tensile test was performed in a 23 ° C. atmosphere in accordance with JIS K7161, and based on the obtained measurement results. A stress-strain curve was generated. Next, the tensile modulus was calculated from the initial slope of the generated stress-strain curve. The unit of tensile modulus is GPa. Moreover, the drawing speed in the tensile test was set to 5 mm/min.

<Preparation of Adhesion Evaluation Substrate>
A sample for evaluating adhesiveness after bonding was prepared according to the following procedure.
<Preparation of Adhesion Evaluation Substrate 1 (Examples 1 to 5, 7 to 10 and Comparative Example 2)>
(1) Silylation treatment step A silicon wafer having a thickness of 0.725 mm was placed in an oven filled with hexamethyldisilazane vapor, treated at 120°C for 1 minute, and then placed on a hot plate at 120°C for 1 minute. Heating was performed to obtain a silylated silicon wafer.
(2) Film formation step On the silylated silicon wafer obtained in (1), the photosensitive resin composition was applied by spin coating so that the film thickness after drying was 3.0 µm, and the film was heated to 120°C on a hot plate. C. for 3 minutes to form a resin film with a thickness of 3.0 .mu.m.
(3) bleaching process (photosensitive agent decomposition process)
The resin film on the wafer prebaked in (2) was heat-treated at 100° C. for 30 minutes in an N ₂ atmosphere, followed by heat treatment at 130° C. for 30 minutes to obtain a substrate for adhesion evaluation.

<Preparation of Adhesion Evaluation Substrate 2 (Example 6)>
In place of the (3) bleaching step (photosensitive agent decomposition step) of <Preparation of Adhesion Evaluation Substrate 1>, the coating film obtained in the (2) film formation step was irradiated with ultraviolet light of 1000 mJ on the entire surface with a high-pressure mercury lamp. After the irradiation, additional heating was performed at 120° C. for 3 minutes to obtain a substrate for adhesion evaluation.

<Preparation of Adhesion Evaluation Substrate 3 (Comparative Example 1)>
A substrate for adhesion evaluation was obtained in the same manner as in Preparation 1 of substrate for adhesion evaluation, except that (1) silylation treatment of <Preparation of substrate for adhesion evaluation 1> was not performed.

<Adhesion process>
An adhesive structure was obtained by the following procedure.
First, the resin-coated wafer obtained in the preparation of the adhesion evaluation substrate was cut out using a dicing saw to prepare a 10 mm×10 mm square evaluation substrate.
Next, the substrate for evaluation was left still on the stage with the surface having the resin film facing upward. Next, a 5 mm×5 mm silicon wafer was placed on the evaluation substrate.
After that, the substrate for evaluation and the upper chip which were left standing were heated and pressed from above and below. At this time, the temperature of the lower stage was set at 30°C. Using a commercially available bonding tool for semiconductor assembly, heat and pressure were applied by pressing a heated bonding head against the upper chip. The temperature of the bonding head was set to 200° C., and the upper chip was bonded to the chip under conditions of a temperature of 200° C., a time of 10 seconds, and a pressure of 25 N so that the coated surfaces were in contact with each other to obtain a bonded sample. Thereafter, while maintaining the oxygen concentration at 1000 ppm or less, the composition was cured at 200° C. for 90 minutes to obtain a sample for adhesion evaluation after bonding.
Here, "25N" means that a force of 25N is applied to the upper chip of 5mm x 5mm, and the force per unit area (that is, pressure) is 1N/ ^mm2 , or 1MPa.

<Adhesion evaluation>
An Al pin with an epoxy resin (Φ5.2 mm, manufactured by Phototechnica Co., Ltd.) was placed on the upper chip of the adhesiveness evaluation sample obtained in <Preparation of adhesion evaluation sample> above, and heat-treated at 150 ° C. for 1 hour. , to obtain a bonded sample with Al pins.
The resulting adhesive sample with Al pins was subjected to a tensile test at 1 mm/min using a tensile tester (Tensilon RTC-1210A, manufactured by Orientec) to measure the breaking stress at break. This breaking stress was defined as adhesive strength (MPa). Table 1 shows the results. From the standpoint of reliability, the higher the breaking stress, the better.

<Evaluation of insulation reliability>
(Preparation of samples for insulation reliability 1: Examples 1 to 5, 7 to 10 and Comparative Examples 1 to 2)
A Cu wiring substrate was prepared by forming comb-shaped Cu wiring having a width of 5 μm, a pitch of 5 μm, and a height of 5 μm on a silicon wafer with an oxide film. The obtained photosensitive resin composition was applied onto a Cu wiring substrate by spin coating so that the film thickness after drying was 10 μm, and dried at 120° C. for 3 minutes to form a photosensitive resin film.
After the obtained photosensitive resin film was immersed in a 2.38 wt % TMAH aqueous solution for 30 seconds, the photosensitive resin film was cured at 200° C. for 90 minutes in a nitrogen atmosphere to obtain a sample for insulation reliability.
(Preparation of sample for insulation reliability 2: Example 6)
Instead of being immersed in the 2.38 wt% TMAH aqueous solution for 30 seconds in Preparation 1 of the insulation reliability sample, the photosensitive resin composition was exposed to 1000 mJ/cm ² with a high-pressure mercury lamp, and then exposed at 120 ° C. for 3 minutes. A sample was prepared in the same manner as in Preparation 1 of Sample for Insulation Reliability, except that it was post-baked and immersed in cyclopentanone for 30 seconds.

(insulation reliability evaluation)
The ends (Cu electrodes) of the Cu wirings of the substrates prepared in (Insulation Reliability Sample Preparation 1) and (Insulation Reliability Sample Preparation 2) were connected to the electrode wirings by soldering. Processing was performed at 130°C/85% with a bias of 5V. The insulation resistance value between the Cu wirings of the Cu wiring board is automatically measured at intervals of 6 minutes, and the insulation resistance value is defined as 1.0×10 4 Ω or less when the insulation resistance value is 1.0×10 ⁴ Ω or less. Time (h) was measured. When the time until dielectric breakdown was 200 hours or more, the evaluation was made as ◯. Comparative Example 1 could not be evaluated because it could not be applied normally due to shrinkage during application.

In the electronic device manufacturing methods of Examples 1 to 9, the adhesiveness between the photosensitive resin film and the substrate is excellent, and the surface tension of the droplets is 47 mN/m, compared to Comparative Example 1 in which no silylation treatment is performed. As compared with Comparative Example 2 of No. 2, excellent results were shown in the applicability of the photosensitive resin composition. Therefore, it was found that the electronic device manufacturing methods of Examples 1 to 9 are superior to Comparative Examples 1 and 2 in manufacturing stability. Further, by the manufacturing methods of Examples 1 to 9, an electronic device having excellent insulation reliability can be realized.

10 substrate 12 substrate 20 base film 22 base film 30 silylation treatment 50 photosensitive resin film 52 photosensitive resin film 60 electrode 70 bonding wire 100 electronic device 110 electronic device 120 electronic device

Claims (11)

preparing a substrate selected from the group consisting of a semiconductor substrate, a ceramic substrate, a metal substrate, and a resin substrate;
forming a base film on the substrate;
a step of silylating the surface of the underlying film;
applying a photosensitive resin composition on the surface of the silylated underlayer to form a photosensitive resin film;
patterning the photosensitive resin film;
obtaining an electronic device comprising the patterned photosensitive resin film as a permanent film;
In the photosensitive resin composition applied in the step of forming the photosensitive resin film, the surface tension of the droplets composed of the photosensitive resin composition measured by the hanging drop method is 20 mN/m or more and 42 mN/m or less. A method for manufacturing an electronic device (provided that the photosensitive resin composition is used with at least one selected from a polybenzoxazole precursor, a photoacid generator that generates an acid having a pKa of 3 or less, and a quinonediazide compound. , solvents, and photosensitive resin compositions containing) . A method for manufacturing an electronic device according to claim 1,
A method of manufacturing an electronic device, comprising the step of bonding another substrate through the patterned photosensitive resin film. A method for manufacturing an electronic device according to claim 1 or 2,
The silylation treatment step uses a method of exposing the surface of the underlying film to a vaporized silylating agent or a method of applying a liquid silylating agent to the surface of the underlying film. . A method for manufacturing an electronic device according to claim 3,
The method for manufacturing an electronic device, wherein the silylating agent includes a silylating agent having a Si—NH—Si structure. A method for manufacturing an electronic device according to claim 3 or 4,
The method for manufacturing an electronic device, wherein the silylating agent contains hexamethyldisilazane (HMDS). A method for manufacturing an electronic device according to any one of claims 1 to 5,
A method for producing an electronic device, wherein the photosensitive resin composition contains a polymer having a structural unit derived from a cyclic olefin in its molecule, and a photosensitive agent. A method for manufacturing an electronic device according to any one of claims 1 to 6,
A method of manufacturing an electronic device, wherein the base film includes an inorganic film. A method for manufacturing an electronic device according to claim 7,
A method of manufacturing an electronic device, wherein the inorganic film includes one or more selected from the group consisting of a silicon oxide film, a silicon nitride film, and an aluminum oxide film. A method for manufacturing an electronic device according to any one of claims 1 to 8,
A method of manufacturing an electronic device, comprising the step of heat-treating the patterned photosensitive resin film. A method for manufacturing an electronic device according to any one of claims 1 to 9,
A method of manufacturing an electronic device, wherein the substrate is composed of a silicon substrate. A method for manufacturing an electronic device according to any one of claims 1 to 10,
A method of manufacturing an electronic device, wherein the photosensitive resin film is used as an interlayer film, a surface protective film, a dam material, or an adhesive film.

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