JP6915340B2 - Photosensitive resin composition, cured film and electrical / electronic equipment - Google Patents

Description

The present invention relates to photosensitive resin compositions, cured films and electrical / electronic devices.

Various resin films are required in the manufacture of electrical and electronic equipment. For example, various resin films (cured film, permanent film) are required for applications such as insulation, lamination, and sealing, and the required properties also vary depending on the application. Therefore, a photosensitive resin composition for forming such a resin film has been actively studied. For example, in the examples of Patent Document 1, a highly stretchable photosensitive resin composition in which the elongation rate of the finally obtained cured film is 15% or more is described.

Japanese Unexamined Patent Publication No. 2009-098455

However, according to the studies by the present inventors, there is a problem when a highly stretchable photosensitive resin composition having a finally obtained cured film with an elongation rate of 15% or more is used in the manufacture of electrical and electronic equipment. I found that it may be. Specifically, the patterning property is poor, and the finally obtained cured film pattern may not have a desired shape.

The present invention has been made in view of the above circumstances. That is, one of the objects of the present invention is to enable good patterning in a highly stretchable photosensitive resin composition in which the elongation rate of the finally obtained cured film is 15% or more.

The present inventors have diligently studied to solve the above problems. As a result, in the highly stretchable photosensitive resin composition in which the elongation rate of the finally obtained cured film is 15% or more, the index of the glass transition temperature of the cured film formed by using the photosensitive resin composition is indexed. , It was found that it is closely related to the patterning property. Then, they have found that the above-mentioned problems can be solved by designing a photosensitive resin composition in which the glass transition temperature has a specific numerical value.

That is, according to the present invention.
A photosensitive resin composition for forming a cured film.
Contains a thermosetting resin (A), a photosensitizer (C), and an organic solvent (D).
The thermosetting resin (A) contains an epoxy resin (a).
The epoxy resin (a) contains a bifunctional epoxy resin (a1) containing a partial structure represented by —O—X—O— (where X represents an alkylene group having 2 to 12 carbon atoms).
After the organic solvent was dried under the condition of 120 ° C. for 5 minutes to obtain a resin film, the resin film was exposed to obtain an exposed resin film, and then the exposed resin film was subjected to a nitrogen atmosphere at 200 ° C. and 90 ° C. When a measurement sample with a thickness of 10 μm, a width of 6.5 mm, and a chuck-to-chuck distance of 20 mm, which is cut out from a cured film obtained by heat treatment under the condition of 1 minute, is measured under the condition of a tensile speed of 5 mm / min. Provided is a photosensitive resin composition having an elongation rate of 15 to 60% and a glass transition temperature of 100 to 250 ° C.

Further, according to the present invention, a cured film using the above-mentioned photosensitive resin composition is provided.

Further, according to the present invention, an electric / electronic device provided with the above-mentioned cured film is provided.

According to the present invention, a photosensitive resin composition having a good elongation rate and a good patterning property of the finally obtained cured film, a cured film using the photosensitive resin composition, and the cured film thereof. You can obtain the equipped electrical and electronic equipment.

Hereinafter, embodiments will be described.
The notation "a to b" indicates a or more and b or less unless otherwise specified. Further, in the notation of a group (atomic group) in the present specification, the notation that does not indicate whether it is substituted or unsubstituted includes both those having no substituent and those having a substituent. For example, the "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

The photosensitive resin composition of the present embodiment is
A photosensitive resin composition for forming a cured film.
Contains a thermosetting resin (A), a photosensitizer (C), and an organic solvent (D).
The organic solvent was dried under the condition of 120 ° C. for 5 minutes to obtain a resin film, and then the resin film was exposed to obtain an exposed resin film. The cured film obtained by heat treatment under the condition of minutes has an elongation rate of 15 to 60% and a glass transition temperature of 100 to 250 ° C. when measured under the condition of a tensile speed of 5 mm / min.

The reason why the above-mentioned problems can be solved by such a configuration is not necessarily clear, but based on the findings of the inventors, it is explained as follows.
The inventors examined from various viewpoints in order to investigate the cause of the poor patterning property of the highly stretchable photosensitive resin composition. According to the study, the highly stretchable photosensitive resin composition may have a specifically low glass transition temperature of the thermosetting resin contained in the composition, which leads to poor patterning property. Was estimated.
That is, the temperature of the resin film formed by the highly stretchable photosensitive resin composition of the prior art greatly exceeds the glass transition temperature of the resin film during the baking during the patterning process and the thermosetting process after the patterning. It softens and flows when heated with. It is considered that this deteriorates the patterning property.

Therefore, the present inventors can finally obtain a highly stretchable photosensitive resin composition in which the elongation rate of the finally obtained cured film is 15% or more (specifically, 15 to 60%). The patterning property was improved by setting the glass transition temperature of the cured film as an index and designing the composition so that the value was relatively high. Specifically, by designing a composition in which the glass transition temperature of the finally obtained cured film is in the range of 100 to 250 ° C., high extensibility and improvement in patterning property are balanced.

In the present embodiment, the photosensitive resin composition satisfying the above-mentioned parameters can be obtained by appropriately adjusting the type and blending ratio of each component contained in the photosensitive resin composition and the preparation method of the photosensitive resin composition. Obtainable.
Specifically, for example, for a thermosetting resin (A), its structure, type, type of reactive group contributing to curing (for example, epoxy group), number and density of the reactive group, and glass of the resin alone. The photosensitive resin composition of the present embodiment can be obtained by appropriately selecting the transition temperature, mass average molecular weight, prescription amount, and the like. It is also conceivable to use two or more kinds of resins.
As the photosensitizer (C), an appropriate photodegradable (photostability) material should be selected, and the type and acid strength of the acid generated by the decomposition, the content in the composition, etc. should be appropriately selected. That can be mentioned.
Further, use an appropriate curing agent (B) for the photosensitive resin composition, more specifically, use an appropriate phenol compound (b), and use an appropriate amount of the curing agent (B). And so on.
By comprehensively adjusting these, the photosensitive resin composition of the present embodiment can be obtained.

In the present specification, the elongation rate of the cured film refers to the elongation rate of the cured film formed by the following procedure.
(1) The composition is applied onto a substrate by spin coating so that the film thickness becomes 10 μm after drying, and dried at 120 ° C. for 5 minutes to form a photosensitive resin film.
(2) The photosensitive resin film obtained in (1) above is exposed to the entire surface at ^{250 mJ / cm 2 using an automatic exposure machine.}
(3) After the above (2), the substrate is heated on a hot plate at 120 ° C. for 5 minutes after exposure.
(4) After the above (3), it is cured at 200 ° C. for 90 minutes under nitrogen to obtain a cured film for evaluation.
In addition, the elongation rate is measured by cutting out a sample from the cured film for evaluation obtained above, and for a measurement sample having a film thickness of 10 μm, a width of 6.5 mm, and a chuck-to-chuck distance of 20 mm for fixing the sample, a tensile speed of 5 mm / Perform a tensile test under the condition of minutes. See also the description of the examples for details.
In the present embodiment, the elongation rate of the cured film is 15 to 60%, preferably 17 to 50%, and more preferably 20 to 40%. When the elongation rate is good, it is possible to follow the deformation of the members around the cured film, which can contribute to the improvement of the reliability of the electric / electronic device.

The photosensitive resin composition of the present embodiment enables good patterning due to the above-mentioned configuration, but at the same time, the coefficient of thermal expansion of the finally obtained cured film can be suppressed to a low level. The reason for this is considered to be that the higher glass transition temperature of the cured film limits the thermal motion of atoms and molecules in the cured film.
When the coefficient of thermal expansion is suppressed to a low level, the expansion and contraction of the cured film in the electric / electronic device becomes small, which can contribute to the improvement of the reliability of the electric / electronic device.
The coefficient of thermal expansion (ppm / K) of the finally obtained cured film is preferably 40 to 90, more preferably 45 to 90, and even more preferably 50 to 85. These numerical values are values at 50 to 100 ° C. With such a coefficient of thermal expansion, warpage of the substrate and the like can be suppressed, and the reliability of electrical and electronic devices can be improved.

In the present embodiment, the glass transition temperature of the cured film is 100 to 250 ° C, preferably 120 to 230 ° C, and more preferably 130 to 200 ° C. An appropriate value for the glass transition temperature means that the cured film can be used even in a high temperature environment, which can contribute to the improvement of reliability of electrical and electronic equipment.

Hereinafter, the components contained in or may be contained in the photosensitive resin composition of the present embodiment will be described.

<Thermosetting resin (A)>
The photosensitive resin composition of the present embodiment contains a thermosetting resin (A). Examples of the thermosetting resin (A) include phenol resin, polyimide resin, bismaleimide resin, epoxy resin, urea (urea) resin, melamine resin, polyurethane resin, cyanate ester resin, silicone resin, oxetane resin, and (meth). Examples thereof include acrylate resin, unsaturated polyester resin, diallyl phthalate resin, and benzoxazine resin.

The thermosetting resin (A) preferably contains an epoxy resin (a). As a result, it is possible to further improve the patterning property while obtaining high extensibility.

As the epoxy resin (a), for example, one having two or more epoxy groups in one molecule can be used. For example, phenol novolac type epoxy resin, cresol novolac type epoxy resin, cresol naphthol type epoxy resin, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, phenoxy resin, naphthalene skeleton type epoxy resin, 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 resin, aliphatic Examples thereof include epoxy resins, aliphatic polyfunctional epoxy resins, alicyclic epoxy resins, and polyfunctional alicyclic epoxy resins. The epoxy resin (a) may be used alone or in combination of two or more.

The epoxy resin (a) preferably contains a bifunctional epoxy resin (a1) containing a partial structure represented by —O—X—O— (where X represents an alkylene group having 2 to 12 carbon atoms). By including such an epoxy resin (a1), the extensibility of the cured film itself can be particularly improved. X is more preferably an alkylene group having 4 to 12 carbon atoms, and even more preferably an alkylene group having 6 to 12 carbon atoms. Further, X is preferably a linear alkylene group.

The epoxy resin (a1) ^{further, -O-Ar-X 1 -} (Ar) n -O- represented by partial structures ^{(X 1} represents a single bond or a divalent linking group, Ar is an aromatic It represents a group group, and n represents an integer of 0 or more). As a result, the durability of the cured film can be improved while obtaining the extensibility of the cured film. Further, by having such an aromatic ring-containing structure, a further low expansion coefficient can be achieved by the packing effect of the aromatic ring.
As the ^{divalent linking group of X 1} , a linear or branched alkylene group is preferable, and the alkylene group preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms.
Ar preferably has a benzene ring structure.
n is preferably 0 or 1, more preferably 1.
When n is 1 or more, the plurality of Ars may have the same structure or different structures.

The epoxy resin (a) is preferably a compound represented by the following general formula (a1-1).

In the general formula (a1-1)
X, Ar, X ¹ , and n are each defined in the same manner as the atomic group defined in the above-mentioned partial structure. The same applies to the preferred embodiment.
m represents the number of repeating units. It is typically 1 to 100, preferably 1 to 50.

When the thermosetting resin (A) contains the epoxy resin (a1), the photosensitive resin composition further contains a trifunctional or higher functional epoxy resin (a2) (that is, three or more epoxy groups in one molecule). Epoxy resin) is preferably contained. As a result, a three-dimensional crosslinked structure is formed in the cured film, and it becomes easier to design the glass transition temperature of the cured film to a desired value. As a result, the patterning property is further improved and the expansion coefficient is further reduced. It becomes possible to do.

Specifically, as the epoxy resin (a2), a trifunctional or higher functional epoxy resin can be appropriately selected and used from those listed above as examples of the epoxy resin (a). Of these, a novolac type epoxy resin (phenol novolac epoxy resin, cresol novolac epoxy resin, etc.) trishydroxyphenylmethane type epoxy resin is preferable.

The lower limit of the content of the thermosetting resin (A) (or the total amount when a plurality of types of resins are contained) is, for example, 40% by mass or more with respect to the entire non-volatile components of the photosensitive resin composition. It is preferably 45% by mass or more, and more preferably 50% by mass or more. As a result, the heat resistance and mechanical strength of the finally obtained cured film can be improved. On the other hand, the upper limit of the content of the thermosetting resin (A) is, for example, 80% by mass or less, preferably 75% by mass or less, more preferably, with respect to the entire non-volatile component of the photosensitive resin composition. Is 70% by mass or less. Thereby, a sufficient amount of other components can be added, and the patterning property can be improved.
When the thermosetting resin (A) contains the epoxy resin (a1) and the epoxy resin (a2), the content of the epoxy resin (a1) is relative to the entire non-volatile component of the photosensitive resin composition. It is preferably 2 to 50% by mass, more preferably 3 to 45% by mass, and even more preferably 3 to 42% by mass.

<Curing agent (B)>
The photosensitive resin composition of the present embodiment preferably contains a curing agent (B). As a result, it is possible to further improve the patterning property while obtaining high extensibility. In addition, the effect of increasing the adhesive force of the cured film to the substrate can be expected. The curing agent (B) is not particularly limited as long as it promotes the polymerization / crosslinking reaction of the above-mentioned thermosetting resin (A) (preferably epoxy resin (a)).

The curing agent (B) preferably contains the phenol compound (b). As a result, the thermal expansion of the cured film can be further reduced, which is considered to contribute to the improvement of the reliability of the electronic device. Specifically, a phenol resin can be used as the phenol compound (b). The phenol resin can be appropriately selected from known ones, and for example, a novolak type phenol resin, a resol type phenol resin, a trisphenylmethane type phenol resin, and an arylalkylene type phenol resin can be used. From the viewpoint of good development characteristics, a novolak type phenol resin can be used. The weight average molecular weight of the phenol resin is preferably 200 to 20,000, more preferably 300 to 15,000, and even more preferably 350 to 13,000.

The phenol compound (b) is preferably trifunctional or higher, that is, a phenol compound having three or more phenolic hydroxyl groups in one molecule. The above-mentioned phenol resin corresponds to this. When the phenol compound (b) is a small molecule compound, it is preferably a compound having 3 to 10 functionalities. As a result, it is possible to further improve the patterning property while obtaining high extensibility.

The content of the curing agent (B) is, for example, 10 to 60% by mass, preferably 20 to 50% by mass, and more preferably 20 to 45% by mass with respect to the total non-volatile components in the composition. Within this range, the heat resistance and strength of the cured product are improved.

<Photosensitizer (C)>
The photosensitive resin composition of the present embodiment contains a photosensitive agent (C). As the photosensitizer (C), a photoacid generator can be used. The photoacid generator contains a photoacid generator that generates acid by irradiation with active light such as ultraviolet rays. Examples of the photoacid generator include onium salt compounds, for example, iodonium salts such as diazonium salt and diaryliodonium salt, sulfonium salts such as triarylsulfonium salt, triarylvirillium salt, benzylpyridinium thiocyanate and dialkylphenacyl. Cationic photopolymerization initiators such as sulfonium salts and dialkylhydroxyphenylphosphonium salts can be mentioned. In addition, a photosensitive diazoquinone compound can also be mentioned. The photosensitive diazoquinone compound is particularly preferably used when the photosensitive resin composition is of a positive type (the exposed portion dissolves when developed with an alkaline developer). As the photosensitizer, since the photosensitive composition comes into contact with a metal, those that do not generate hydrogen fluoride due to decomposition, such as methide salt type and borate salt type, are preferable.

The lower limit of the content of the photosensitive agent (C) is, for example, 0.3% by mass or more, preferably 0.5% by mass or more, more preferably, with respect to the entire non-volatile component of the photosensitive resin composition. Is 0.7% by mass or more. Thereby, the patterning property can be improved in the photosensitive resin composition. On the other hand, the upper limit of the content of the photosensitive agent (C) is, for example, 5% by mass or less, preferably 4.5% by mass or less, based on the total non-volatile components of the photosensitive resin composition. It is preferably 4% by mass or less. Thereby, the long-term storage property of the photosensitive resin composition before curing can be improved.

<Organic solvent (D)>
The photosensitive resin composition of the present embodiment contains an organic solvent (D). The organic solvent (D) can be used without particular limitation as long as it can dissolve each component of the photosensitive resin composition and does not chemically react with each component. For example, 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 monobutyl ether acetate, benzyl alcohol, propylene carbonate, ethylene. Examples thereof include glycol diacetate, propylene glycol diacetate, propylene glycol monomethyl ether acetate, and benzyl alcohol. These can be appropriately selected depending on the desired film thickness. For example, benzyl alcohol is preferable when the film thickness is about 10 μm. Propylene glycol monomethyl ether acetate is preferable when the film thickness is about 90 μm.
As the organic solvent (D), only one kind may be used, or two or more kinds may be used in combination.

The organic solvent (D) is preferably used so that the concentration of the total amount of the non-volatile components in the photosensitive resin composition is 30 to 75% by mass. Within this range, each component can be sufficiently dissolved, and good coatability can be ensured.

<Surfactant (E)>
The photosensitive resin composition of the present embodiment preferably contains a surfactant (E). By containing the surfactant (E), a uniform resin film and a cured film can be obtained. In addition, it can be expected to prevent residues and patterns from floating during development. Examples of the surfactant include a fluorine-based surfactant, a silicon-based surfactant, an alkyl-based surfactant, an acrylic-based surfactant, and the like.

The surfactant (E) preferably contains a surfactant containing at least one of a fluorine atom and a silicon atom. As a result, a uniform resin film can be obtained (improvement of coatability), and in addition to improvement of developability, it also contributes to improvement of adhesive strength. As such a surfactant, for example, a nonionic surfactant containing at least one of a fluorine atom and a silicon atom is preferable. Commercially available products that can be used as the surfactant (e) include, for example, F-251, F-253, F-281, F-430, F-477, and F of the "Megafuck" series manufactured by DIC Co., Ltd. -551, 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 Fluorine-containing oligomeric surfactants such as, Fluorine-containing nonionic surfactants such as Futergent 250 manufactured by Neos Co., Ltd., Futergent 251 and the like, SILFOAM® series manufactured by Wacker Chemie (for example). Examples thereof include silicone-based surfactants such as SD 100 TS, SD 670, SD 850, SD 860, and SD 882).

The content of the surfactant (E) is usually 0.01 to 5% by mass, preferably 0.05 to 1% by mass, based on the total amount of the non-volatile components of the photosensitive resin composition.

<Adhesion aid (F)>
The photosensitive resin composition of the present embodiment preferably contains the adhesion aid (F). Thereby, the adhesion of the cured film can be further improved.

The adhesion aid (F) is not particularly limited, and for example, a silane coupling agent such as aminosilane, epoxysilane, acrylicsilane, mercaptosilane, vinylsilane, ureidosilane, or sulfidesilane can be used. One type of silane coupling agent may be used alone, or two or more types may be used in combination. Among these, it is more preferable to use epoxysilane (that is, a compound containing both an epoxy moiety and a group that generates a silanol group by hydrolysis in one molecule).
Examples of aminosilanes include bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, and γ-aminopropyl. Methyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N Examples thereof include −β (aminoethyl) γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-amino-propyltrimethoxysilane, and the like. Examples of the epoxy silane include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-glycidylpropyltrimethoxysilane. And so on. Examples of the acrylic silane include γ- (methacryloxypropyl) trimethoxysilane, γ- (methacryloxypropyl) methyldimethoxysilane, γ- (methacryloxypropyl) methyldiethoxysilane, and the like. Examples of the mercaptosilane include 3-mercaptopropyltrimethoxysilane. Examples of vinylsilane include vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, and the like. Examples of the ureidosilane include 3-ureidopropyltriethoxysilane and the like. Examples of the sulfide silane include bis (3- (triethoxysilyl) propyl) disulfide, bis (3- (triethoxysilyl) propyl) tetrasulfide, and the like.

The content of the adhesion aid (F) is preferably 1 to 10% by mass, more preferably 2 to 8% by mass, based on the total amount of the non-volatile components of the photosensitive resin composition.

<Other additives>
The photosensitive resin composition of the present embodiment may contain other additives, if necessary, in addition to the above-mentioned components. Examples of other additives include antioxidants, fillers such as silica, sensitizers, filming agents and the like.

<Combining of each ingredient>
In the photosensitive resin composition of the present embodiment, it is preferable to appropriately adjust the ratio of each component used from the viewpoint of further improving the patterning property while obtaining an elongation rate of 15% to 100%.
For example, when the photosensitive resin composition contains a curing agent (B) in addition to the thermosetting resin (A), the so-called "equivalent amount" is appropriate (that is, the thermosetting resin in the composition). It is preferable that the number of reactive functional groups of (A) and the number of reactive functional groups of the curing agent (B) are in an appropriate ratio).

Specifically, in the photosensitive resin composition of the present embodiment, when the thermosetting resin (A) contains the epoxy resin (a) and the curing agent (B) contains the phenol compound (b), The equivalent ratio of phenolic hydroxyl groups in the total amount of the phenol compound (b) to the epoxy groups in the total amount of the epoxy resin (a) (that is, the number of epoxy groups in the total amount of the epoxy resin (a) is M, phenol. The value of N / M when the number of phenolic hydroxyl groups in the total amount of the compound (b) is N) is preferably 0.5 to 1.2, more preferably 0.60 to 1.05. More preferably, it is 0.8 to 0.98. As a result, the curing reaction in the film is appropriately controlled, and a cured film having higher extensibility can be obtained.
In determining the above equivalent ratio, especially when a commercially available product is used as the epoxy resin (a) or the phenol compound (b), it is described in a catalog, a data sheet, or the like. By using values such as "epoxy equivalent" and "hydroxyl equivalent", the equivalent ratio can be easily obtained.

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

<Cured film and its formation method>
The method for obtaining the cured film of the photosensitive resin composition of the present embodiment is not particularly limited. For example, the following steps:
Step of applying the photosensitive resin composition on the substrate (step 1),
Step of heating and drying the photosensitive resin composition to obtain a photosensitive resin film (step 2),
Step of exposing the photosensitive resin film with active light (step 3),
A step of developing the exposed photosensitive resin film to obtain a patterned resin film (step 4), and
Step of heating the patterned resin film to obtain a cured film (step 5),
Therefore, a cured film of the photosensitive resin composition of the present embodiment can be obtained.

In step 1, the substrate is not particularly limited, and examples thereof include a silicon wafer, a ceramic substrate, an aluminum substrate, a SiC wafer, and a GaN wafer. The substrate includes, for example, a substrate on which a semiconductor element or a display element is formed on the surface, in addition to the raw substrate. Further, it may be a printed wiring board or the like. In order to improve the adhesiveness, the surface of the substrate may be treated with an adhesive aid such as a silane coupling agent. The method of applying the photosensitive resin composition on the substrate can be performed by spin coating, spray coating, dipping, printing, roll coating, inkjet method or the like.

In step 2, the temperature of heat drying is usually 80 to 140 ° C., preferably 90 to 120 ° C. The heating and drying time is usually about 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 performed on a hot plate, oven, or the like. The thickness of the photosensitive resin film is preferably 1 to 500 μm.

In step 3, as the active light beam for exposure, for example, X-ray, electron beam, ultraviolet ray, visible light and the like can be used. In terms of wavelength, active light rays having a wavelength of 200 to 500 nm are preferable. In terms of pattern resolution and handleability, the light source is preferably the g-line, h-line or i-line of the mercury lamp. Further, two or more light rays may be mixed and used. As the exposure apparatus, a contact aligner, a mirror projection or a stepper is preferable. After the exposure, the photosensitive resin film may be heated again if necessary, and the temperature and time thereof are, for example, about 80 to 140 ° C. and 10 to 300 seconds.

In step 4, development can be carried out using an appropriate developer, for example, by a method such as a dipping method, a paddle method, or a rotary spray method. Thereby, a patterned resin film can be obtained.

The developer that can be used is not particularly limited, but in the present embodiment, it is preferable that the developer is a developer containing an organic solvent as a main component (a developer in which 95% by mass or more of the components is an organic solvent). Specific examples thereof include a ketone solvent such as cyclopentanone, an ester solvent such as propylene glycol monomethyl ether acetate and butyl acetate, and an ether solvent such as propylene glycol monomethyl ether. Other developing solutions include 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 and tetrabutylammonium hydroxy. An aqueous solution of a quaternary ammonium salt such as do (preferably 1 to 5% by mass) can also be used.

After the developing step, the developing solution may be removed by washing with a rinsing solution. Examples of the rinsing solution 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.

In step 5, a cured film can be obtained by heating the patterned resin film. In this embodiment, the heating temperature is preferably 160 to 300 ° C, more preferably 180 to 200 ° C. By setting this temperature range, the rate of the cross-linking reaction and the uniform curing of the entire film can be achieved at the same time. The heating time is not particularly limited, but is, for example, in the range of 15 to 300 minutes. This heat treatment can be performed by a hot plate, an oven, a temperature-increasing oven in which a temperature program can be set, or the like. The atmospheric gas for the heat treatment may be air or an inert gas such as nitrogen or argon. Further, it may be heated under reduced pressure.

Further, as a method of obtaining a cured film, a laminating method, that is, a method of first forming a photosensitive resin film on a carrier substrate and then attaching the photosensitive resin film to an appropriate substrate may be applied.

As a method for forming the photosensitive resin film on the carrier base material, a method in which the photosensitive resin composition is applied to the carrier base material and then dried is preferable.

As the carrier base material, for example, a polymer film or a metal foil can be used. The polymer film is not particularly limited, but for example, heat resistance of polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, release papers such as polycarbonate and silicone sheets, fluororesins and polyimide resins. Examples thereof include a thermoplastic resin sheet having the above. The metal foil is not particularly limited, and is, for example, copper and / or copper-based alloy, aluminum and / or aluminum-based alloy, iron and / or iron-based alloy, silver and / or silver-based alloy, gold and gold-based alloy. , Zinc and zinc alloys, nickel and nickel alloys, tin and tin alloys and the like. Of these, a sheet made of polyethylene terephthalate is most preferable because it is inexpensive and the peel strength can be easily adjusted.

Further, as a method of applying the photosensitive resin composition to the carrier base material, a resin varnish is applied to the carrier base material using various coater devices such as a spin coater, a comma coater, and a die coater, and then this is applied. The drying method is preferred. As a result, it is possible to obtain a photosensitive resin film (photosensitive resin film) with a carrier base material having no voids and having a uniform thickness. The photosensitive resin film with a carrier base material (photosensitive resin film) may have a sheet shape or a roll shape that can be wound up.

The film thickness of the photosensitive resin film on the carrier substrate can be appropriately designed according to the film thickness of the final cured film. It is typically 5 to 500 μm (unit), preferably 10 to 250 μm (unit).

A known laminating method can be used in the step of attaching the photosensitive resin film on the carrier substrate to an appropriate substrate. For example, a vacuum laminator can be used. For example, in a vacuum chamber having a predetermined vacuum degree, laminating can be performed on a table having a predetermined temperature using a sticking roll having a predetermined pressure.

The pressure to be pressurized is not particularly limited, but is preferably 0.2 to 5 MPa or less, more preferably 0.4 to 1 MPa or less, for example. The heat treatment time can be appropriately set depending on the type of resin used and the like, and can be, for example, 10 to 60 seconds.

The lower limit of the temperature in this laminating step is, for example, 40 ° C. or higher, preferably 50 ° C. or higher, and more preferably 60 ° C. or higher. The upper limit of the temperature in the laminating step is, for example, 150 ° C. or lower, preferably 140 ° C. or lower, and more preferably 130 ° C. or lower.

<Electrical / electronic equipment>
The electric / electronic device provided with the cured film of the photosensitive resin composition of the present embodiment has high reliability because the cured film has good elongation characteristics and a low coefficient of thermal expansion.
Here, "electrical / electronic equipment" refers to electronic devices such as semiconductor chips, semiconductor elements, printed wiring boards, electric circuits, display devices such as television receivers and monitors, information and communication terminals, light emitting diodes, physical batteries, and chemical batteries. It refers to elements, devices, final products, and other electrical equipment in general that apply engineering technology.
The cured film of the photosensitive resin composition of the present embodiment is used in electrical and electronic equipment as, for example, a permanent film, a protective film, an insulating film, a rewiring material, and the like.

Examples will be shown below, but the present invention is not limited to the examples.
<Preparation of photosensitive resin composition>
The following components were uniformly mixed and dissolved in the amounts shown in Table 1 (unit: parts by mass), and then filtered through a polypropylene filter having a pore size of 0.2 μm to obtain a photosensitive resin composition. Details of each component in the table are as follows. The amount of the surfactant is the amount of propylene glycol as a 20% by mass solution of methyl ether acetate.

-Thermosetting resin (A)
A-1: Polyfunctional epoxy resin represented by the following structure (EPICLON N-740 manufactured by DIC Corporation, phenol novolac type epoxy resin)

A-2, A-3: Bifunctional epoxy resin represented by the following structural formula (A-2 and A-3 have different weight average molecular weights. The number average molecular weight of A-2 is around 1900, and the number of A-3s. The average molecular weight is around 3700 (both are polystyrene-equivalent values).

A-4: Bisphenol F type epoxy resin represented by the following structural formula (EPICLON 830CRP, manufactured by DIC Corporation)

・ Hardener (B)
B-1: Novolac type phenol resin represented by the following structure (PR-55617, manufactured by Sumitomo Bakelite Co., Ltd.)

・ Photosensitizer (C)
CPI-310B (manufactured by Sun Appro Co., Ltd., triarylsulfonium salt)
-Organic solvent (D)
Benzyl alcohol / surfactant (E)
Megafuck R41 (manufactured by DIC Corporation, fluorine-based), propylene glycol monomethyl ether acetate 20% by mass solution, adhesion aid (F)
KBM-403E (manufactured by Shin-Etsu Chemical Co., Ltd., epoxy group-containing silane coupling agent)

In addition, A-2 and A-3 were synthesized by the following method.

-Synthesis of A-2 100 parts by mass of 1,6-hexanediol diglycidyl ether, 55.2 parts by mass of bisphenol F, and 0.40 parts by mass of a 50% by mass tetramethylammonium chloride aqueous solution (catalyst) were prepared. These were mixed with a cyclohexanone solvent, placed in a pressure resistant reaction vessel, and subjected to a polymerization reaction at 180 ° C. for 5 hours in a nitrogen gas atmosphere to obtain A-2.
-Synthesis of A-3 100 parts by mass of 1,6-hexanediol diglycidyl ether, 69.3 parts by mass of bisphenol F, and 0.15 parts by mass of triphenylphosphine (catalyst) were prepared. These were mixed with a cyclohexanone solvent, placed in a pressure resistant reaction vessel, and subjected to a polymerization reaction at 180 ° C. for 5 hours in a nitrogen gas atmosphere to obtain A-3.

<Preparation of cured film>
(1) Each composition shown in the table below was applied onto a substrate by spin coating so as to have a film thickness of 10 μm, and dried at 120 ° C. for 5 minutes to form a photosensitive resin film.
(2) The photosensitive resin film obtained in (1) above was exposed to the entire surface at ^{250 mJ / cm 2 using an automatic exposure machine.}
(3) After the above (2), the substrate was heated on a hot plate at 120 ° C. for 5 minutes after exposure.
(4) After the above (3), the mixture was cured at 200 ° C. for 90 minutes under nitrogen to obtain a cured film for evaluation.

<Measurement of elongation rate>
A sample is cut out from the cured film for evaluation obtained above, and the measurement sample having a film thickness of 10 μm, a width of 6.5 mm, and a chuck-to-chuck distance of 20 mm for fixing the sample is a Tencilon universal material measuring machine RTA-100 (A & D Co., Ltd.). -Day) was measured using a load cell of 100 N under the condition of a tensile speed of 5 mm / min.
In each example, 10 samples were measured and the average value (%) for 6 samples excluding the 4 samples with the best elongation, the second best elongation, the worst elongation and the second worst elongation. Are listed in the table below.

<Measurement of glass transition temperature of cured film>
The following measurement data of the coefficient of thermal expansion was analyzed, and the position of the inflection point of the coefficient of thermal expansion was defined as the glass transition temperature. The measurement results (° C) are shown in the table below.

<Evaluation of workability (patternability)>
After drying, the wafer was coated with a spin coat so that the film thickness was 90 μm, and dried at 120 ° C. for 5 minutes to obtain a photosensitive resin film. Subsequently, the photosensitive resin film was subjected to pattern exposure of a 50 μm width line ^{at 250 mJ / cm 2 with an i-line stepper.} Then, on a hot plate, heat treatment (PEB) was performed after exposure at 120 ° C. for 5 minutes. Subsequently, the unexposed portion was dissolved and removed by spray developing with PGMEA (propylene glycol monomethyl ether acetate) for 90 seconds. Subsequently, it was cured at 200 ° C. for 90 minutes to obtain a cured product of the photosensitive resin composition on which a negative pattern was formed. In the obtained line patterns, those in which the width of the line was within 40 to 60 μm were marked with ◯, those in which the width of the line was not completely fit but almost fit were marked with Δ, and those in which the width was not fit were marked with x.

<Evaluation of coefficient of thermal expansion (CTE)>
From the cured film obtained in the above <Preparation of cured film>, a sample having a width of 4 mm and a measurement length of 10 mm was obtained.
This was measured using a thermomechanical analyzer SS6000 (manufactured by Hitachi High-Tech Science Corporation) under the condition of a tension of 30 N. The conditions for raising and lowering the temperature were as follows.
1st time: 30 ° C → 250 ° C → 10 ° C (hold for 15 minutes) at a rate of temperature increase / decrease of 10 ° C / min
Second time: 10 ° C → 250 ° C (5 ° C / min heating rate)
The data obtained in the region of 50 to 100 ° C. for the second time was analyzed to determine the coefficient of thermal expansion. The obtained coefficient of thermal expansion (ppm / K) is shown in the table below.

As shown in the examples, the highly stretchable photosensitive resin composition of the present embodiment has a good elongation rate, a good patterning performance (that is, a good processability), and further thermally expands. I was able to keep the rate low.

Hereinafter, an example of the reference form will be added.
<1>
A photosensitive resin composition for forming a cured film.
A photosensitive resin composition containing a thermosetting resin (A), a photosensitive agent (C), and an organic solvent (D).
<2>
The photosensitive resin composition according to <1>.
A photosensitive resin composition in which the thermosetting resin (A) contains an epoxy resin (a).
<3>
The photosensitive resin composition according to <2>.
Photosensitive resin composition in which the epoxy resin (a) contains a bifunctional epoxy resin (a1) containing a partial structure represented by —O—X—O— (X represents an alkylene group having 2 to 12 carbon atoms). thing.
<4>
The photosensitive resin composition according to <3>.
A photosensitive resin composition in which X is an alkylene group having 4 to 12 carbon atoms.
<5>
The photosensitive resin composition according to <3> or <4>.
The bifunctional epoxy resin (a1) is further represented by a partial structure represented by ^{-O-Ar-X 1-} (Ar) _n- ^{O- (X 1} represents a single bond or a divalent linking group, and Ar is aroma. A photosensitive resin composition which is a bifunctional epoxy resin containing (representing a group group and n represents an integer of 0 or more).
<6>
The photosensitive resin composition according to any one of <3> to <5>.
A photosensitive resin composition in which the epoxy resin (a) further contains a trifunctional or higher functional epoxy resin (a2).
<7>
The photosensitive resin composition according to any one of <1> to <6>.
Further, a photosensitive resin composition containing a curing agent (B).
<8>
The photosensitive resin composition according to <7>.
A photosensitive resin composition in which the curing agent (B) contains a phenol compound (b).
<9>
The photosensitive resin composition according to <8>.
The thermosetting resin (A) contains an epoxy resin (a) and contains
A photosensitive resin composition in which the equivalent ratio of phenolic hydroxyl groups in the total amount of the phenol compound (b) to the epoxy group in the total amount of the epoxy resin (a) is 0.5 to 1.2.
<10>
The cured film of the photosensitive resin composition according to any one of <1> to <9>.
<11>
An electrical / electronic device provided with a cured film of <10>.

Each configuration in these reference forms, for example, specific embodiments of a thermosetting resin (A), a curing agent (B), a photosensitizer (C), an organic solvent (D), etc., is for carrying out the invention. As described in the form.
An example of yet another reference form is added. For carrying out the invention, each configuration in the following reference forms, for example, specific aspects such as a thermosetting resin (A), a curing agent (B), a photosensitizer (C), and an organic solvent (D), is also used. As described in the form.
1. 1.
A photosensitive resin composition for forming a cured film.
Contains a thermosetting resin (A), a photosensitizer (C), and an organic solvent (D).
The organic solvent was dried under the condition of 120 ° C. for 5 minutes to obtain a resin film, and then the resin film was exposed to obtain an exposed resin film. A photosensitive resin having an elongation rate of 15 to 60% and a glass transition temperature of 100 to 250 ° C. when measured under a tensile speed of 5 mm / min for a cured film obtained by heat treatment under the condition of minutes. Composition.
2.
1. 1. The photosensitive resin composition according to the above.
A photosensitive resin composition in which the thermosetting resin (A) contains an epoxy resin (a).
3. 3.
2. The photosensitive resin composition according to the above.
The epoxy resin (a) is a photosensitive resin containing a bifunctional epoxy resin (a1) containing a partial structure represented by —O—X—O— (X represents an alkylene group having 2 to 12 carbon atoms). Composition.
4.
3. 3. The photosensitive resin composition according to the above.
A photosensitive resin composition in which X is an alkylene group having 4 to 12 carbon atoms.
5.
3. 3. Or 4. The photosensitive resin composition according to the above.
The bifunctional epoxy resin (a1) further has a partial structure represented by ^{-O-Ar-X 1-} (Ar) _n- ^{O- (X 1} represents a single bond or a divalent linking group, and Ar is A photosensitive resin composition which is a bifunctional epoxy resin containing an aromatic group (where n represents an integer of 0 or more).
6.
3. 3. ~ 5. The photosensitive resin composition according to any one of the above.
A photosensitive resin composition in which the epoxy resin (a) further contains a trifunctional or higher functional epoxy resin (a2).
7.
1. 1. ~ 6. The photosensitive resin composition according to any one of the above.
Further, a photosensitive resin composition containing a curing agent (B).
8.
7. The photosensitive resin composition according to the above.
A photosensitive resin composition in which the curing agent (B) contains a phenol compound (b).
9.
8. The photosensitive resin composition according to the above.
The thermosetting resin (A) contains an epoxy resin (a).
A photosensitive resin composition in which the equivalent ratio of phenolic hydroxyl groups in the total amount of the phenol compound (b) to the epoxy group in the total amount of the epoxy resin (a) is 0.5 to 1.2.
10.
1. 1. ~ 9. The cured film of the photosensitive resin composition according to any one of.
11.
10. Electrical and electronic equipment with a hardened film.

Claims (9)

A photosensitive resin composition for forming a cured film.
Contains a thermosetting resin (A), a photosensitizer (C), and an organic solvent (D).
The thermosetting resin (A) contains an epoxy resin (a).
The epoxy resin (a) contains a bifunctional epoxy resin (a1) containing a partial structure represented by —O—X—O— (where X represents an alkylene group having 2 to 12 carbon atoms).
After drying the organic solvent at 120 ° C. for 5 minutes to obtain a resin film, the resin film is exposed to obtain an exposed resin film, and then the exposed resin film is subjected to a nitrogen atmosphere at 200 ° C. and 90 ° C. When a measurement sample with a thickness of 10 μm, a width of 6.5 mm, and a chuck-to-chuck distance of 20 mm, which is cut out from a cured film obtained by heat treatment under the condition of 1 minute, is measured under the condition of a tensile speed of 5 mm / min. A photosensitive resin composition having an elongation rate of 15 to 60% and a glass transition temperature of 100 to 250 ° C. The photosensitive resin composition according to claim 1.
A photosensitive resin composition in which X is an alkylene group having 4 to 12 carbon atoms. The photosensitive resin composition according to claim 1 or 2.
The bifunctional epoxy resin (a1) further has a partial structure represented by ^{-O-Ar-X 1-} (Ar) _n- ^{O- (X 1} represents a single bond or a divalent linking group, and Ar is A photosensitive resin composition which is a bifunctional epoxy resin containing an aromatic group (where n represents an integer of 0 or more). The photosensitive resin composition according to any one of claims 1 to 3.
A photosensitive resin composition in which the epoxy resin (a) further contains a trifunctional or higher functional epoxy resin (a2). The photosensitive resin composition according to any one of claims 1 to 4.
Further, a photosensitive resin composition containing a curing agent (B). The photosensitive resin composition according to claim 5.
A photosensitive resin composition in which the curing agent (B) contains a phenol compound (b). The photosensitive resin composition according to claim 6.
The thermosetting resin (A) contains an epoxy resin (a).
A photosensitive resin composition in which the equivalent ratio of phenolic hydroxyl groups in the total amount of the phenol compound (b) to the epoxy group in the total amount of the epoxy resin (a) is 0.5 to 1.2. The cured film of the photosensitive resin composition according to any one of claims 1 to 7. An electrical / electronic device provided with the cured film according to claim 8.