CN113614153A - Dry film, cured product, and electronic component - Google Patents

Abstract

The dry film (11) is provided with a curable resin layer (12) formed by a light-shielding curable resin composition, wherein the light-shielding curable resin composition comprises: a polymer resin having a glass transition point of 20 ℃ or lower and a weight-average molecular weight of 1 ten thousand or more, a colorant, and an inorganic filler. When the thickness of the curable resin layer (12) is X (μm), the maximum particle diameter of the aggregate particles of the inorganic filler is X/2(μm) or less. The dry film (11) has excellent light-shielding properties, can suppress warpage, and can suppress burrs and defects during dicing.

Description

Dry film, cured product, and electronic component

Technical Field

The invention relates to a dry film, a cured product and an electronic component.

Background

Conventionally, a dry film (laminated film) has been used as one of means for forming a protective film or an insulating layer such as a solder resist layer or an interlayer insulating layer provided on a printed circuit board used in an electronic device or the like (for example, patent document 1). Dry films have a resin layer obtained by applying a resin composition having desired characteristics onto a carrier film and then performing a drying process, and are generally distributed on the market in a state where a protective film for protecting the surface opposite to the carrier film is further laminated. The printed wiring board having the protective film and the insulating layer as described above can be manufactured by attaching (hereinafter, also referred to as "laminating") a resin layer of a dry film to a substrate, and then patterning and curing the resin layer.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2015-010179

Disclosure of Invention

Problems to be solved by the invention

Dry films are also used for sealing materials for semiconductor chips. After the dry film laminated on the semiconductor wafer is cured to form a sealing material, the sealing material is cut by, for example, a blade-type cutter to be divided into individual semiconductor chips. In this cutting, burrs may be generated at the cut end of the sealing material, or defects may be generated in the sealing material. In addition, after the semiconductor chip is sealed, the thickness of the sealing material on the chip becomes thin, but in such a case, light shielding properties for blocking light from the outside and protecting the semiconductor chip are also required.

Further, a resin having high light-shielding properties is required for a material disposed around each of the light-emitting elements of RGB in a partition wall in an optical sensor module and a display using a micro LED, but the light-shielding properties of the resins up to now are not necessarily sufficient. In addition, the dry film is sometimes required to have low light transmittance in other applications such as a black solder resist.

In addition, in the dry film, in order to sufficiently adhere the resin layer to the substrate, it is required that warpage is small when the resin layer is cured on the substrate.

Accordingly, an object of the present invention is to provide a dry film, a cured product, and an electronic component which have excellent light-shielding properties, can suppress warpage, and can further suppress burrs and defects during dicing.

Means for solving the problems

As a result of intensive studies to solve the above problems, the present inventors have found that a dry film including a curable resin layer formed from a light-shielding curable resin composition containing: a polymer resin having a glass transition point of 20 ℃ or lower and a weight average molecular weight of 1 ten thousand or more, a colorant, and an inorganic filler, and the maximum particle diameter of the aggregate particles of the inorganic filler is not more than half the thickness of the curable resin layer, whereby the dispersibility is excellent, sufficient light-shielding properties can be achieved, warpage can be suppressed, and burrs and defects at the time of cutting can be suppressed, and the present invention has been completed.

That is, the dry film of the present invention is characterized by comprising a curable resin layer formed from a light-shielding curable resin composition comprising: a polymer resin having a glass transition point of 20 ℃ or lower and a weight-average molecular weight of 1 ten thousand or more, a colorant, and an inorganic filler,

when the thickness of the curable resin layer is X (μm), the maximum particle diameter of the aggregate particles of the inorganic filler is X/2(μm) or less.

In the present invention, the light-shielding property means that the transmittance is less than 0.5% in all wavelength regions of light wavelengths 380-780nm at a film thickness of 40 μm of the curable resin layer.

In the dry film of the present invention, the maximum particle diameter of the aggregated particles of the inorganic filler is preferably 10 μm or less, the amount of the inorganic filler blended is preferably 0.1 to 70% by mass relative to the solid content of the light-shielding curable resin composition, the amount of the colorant blended is preferably 0.3 to 20% by mass relative to the solid content of the light-shielding curable resin composition, the amount of the polymer resin having a glass transition point of 20 ℃ or less and a weight average molecular weight of 1 ten thousand or more is preferably 1 to 35% by mass relative to the solid content of the light-shielding curable resin composition, and the curable resin layer preferably further contains a liquid epoxy resin.

The cured product of the present invention is obtained by curing the curable resin layer of the dry film.

The electronic component of the present invention is characterized by having the cured product.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a dry film, a cured product, and an electronic component which have excellent light-shielding properties, can suppress warpage, and can further suppress burrs and defects during dicing can be provided.

Drawings

Fig. 1 is a schematic sectional view schematically showing one embodiment of a dry film of the present invention.

Fig. 2 is a diagram showing colors of colorants with a and b values in the L x a b color system as coordinate axes.

Detailed Description

Hereinafter, the dry film, cured product and electronic component of the present invention will be described in more detail.

Fig. 1 is a schematic cross-sectional view of a dry film 11 according to an embodiment of the present invention. The dry film 11 shown in fig. 1 is a three-layer structure in which a curable resin layer 12 is formed on a carrier film 13 and a protective film 14 is laminated thereon. The dry film 11 may be provided with another resin layer between the protective film and the curable resin layer or between the support film and the curable resin layer as necessary.

< curable resin layer >

The dry film of the present invention includes a curable resin layer formed from a light-shielding curable resin composition including: a polymer resin having a glass transition point of 20 ℃ or lower and a weight-average molecular weight of 1 ten thousand or more, a colorant, and an inorganic filler, wherein the maximum particle diameter of the aggregate particles of the inorganic filler is X/2(μm) or less when the thickness of the curable resin layer is X (μm).

The inorganic filler can suppress curing shrinkage of the obtained cured product, and can improve various properties such as adhesion, hardness, and crack resistance due to matching of a conductor layer such as copper located around the insulating layer with a coefficient of linear expansion (CTE). Of course, the inorganic filler aggregates when the light-shielding curable resin composition is prepared into an ink. According to the study of the present inventors, it was clarified that: when the aggregate particles of the aggregated inorganic filler are large, burrs and defects are likely to occur during cutting. Further, the light-shielding property (low transmittance) of the cured product is improved by including a colorant such as carbon black in the curable resin composition. According to the study of the present inventors, it was clarified that: when the aggregate particles of the aggregated inorganic filler are large, the inorganic filler easily scatters light in the cured product, and the light-shielding property is not good. Therefore, when the thickness of the curable resin layer is X (μm), burrs and defects at the time of dicing can be suppressed by setting the maximum particle diameter of the aggregate particles of the inorganic filler to X/2(μm) or less, and the light shielding property of the thin film on the semiconductor chip can be improved.

Further, the curable resin layer contains a polymer resin having a glass transition point of 20 ℃ or lower and a weight average molecular weight of 1 ten thousand or more, whereby aggregation of the colorant and the inorganic filler can be suppressed, dispersibility of the colorant and the inorganic filler can be improved, sedimentation can be suppressed, and further, both light-shielding properties and long-term stability of the curable resin composition can be improved. Further, warpage of the cured product can be suppressed.

The curable resin layer of the dry film is usually in a state called a B-stage state, and is obtained from a light-shielding curable resin composition. Hereinafter, each component will be described.

[ Polymer resin having a glass transition point of 20 ℃ or lower and a weight-average molecular weight of 1 ten thousand or more ]

The glass transition point of the polymer resin having a glass transition point of 20 ℃ or less and a weight average molecular weight of 1 ten thousand or more is preferably-40 to 20 ℃, more preferably-15 to 15 ℃, and particularly preferably-5 to 15 ℃. When the temperature is-5 to 15 ℃, the warpage of the cured product can be well inhibited.

The higher the weight average molecular weight of the polymer resin, the greater the effect of preventing sedimentation of the colorant and the inorganic filler, and therefore, it is preferably 10 ten thousand or more, more preferably 20 ten thousand or more. The upper limit value is, for example, 100 ten thousand or less, and preferably 50 ten thousand or less.

Examples of the polymer resin include polymer resins having 1 or more kinds of skeletons selected from a butadiene skeleton, an amide skeleton, an imide skeleton, an acetal skeleton, a carbonate skeleton, an ester skeleton, a urethane skeleton, an acrylic skeleton, and a siloxane skeleton. Examples thereof include: examples of the polymer resin having a butadiene skeleton include polymer resins having a butadiene skeleton (G-1000, G-3000, GI-1000, GI-3000, R-45EPI, manufactured by shinko Corporation, "PB 3600, EPFD AT501, manufactured by Clay Valley Corporation," Ricon130 "," Ricon142 "," Ricon150 "," Ricon657 and "Ricon 130 MA"), polymer resins having a butadiene skeleton and a polyimide skeleton (described in Japanese patent laid-open publication No. 2006 37083), and polymer resins having an acrylic skeleton (SG-P3, SG-600LB, SG-280, SG-790 and SG-K2, SN-50, AS-3000E, and ME-2000, manufactured by Nagase mtcheex Corporation).

The polymer resin is preferably an acrylic copolymer having a glass transition point of 20 ℃ or less and a weight average molecular weight of 1 ten thousand or more, from the viewpoint of flatness of a cured product. Further, from the viewpoint of suppressing dispersibility of the colorant and the inorganic filler and suppressing sedimentation of the composition, an acrylic copolymer having a glass transition point of 20 ℃ or less and a weight average molecular weight of 10 to 100 ten thousand is preferable, and an acrylic copolymer having a glass transition point of-5 to 15 ℃ and a weight average molecular weight of 20 to 50 ten thousand is preferable.

The acrylic copolymer may have a functional group, and examples of the functional group include a carboxyl group, a hydroxyl group, an epoxy group, and an amide group.

The acrylic copolymer preferably has an epoxy group, and more preferably has an epoxy group and an amide group. The epoxy group can suppress warpage of the cured product.

Examples of the acrylate copolymer include TEISANRESIN SG-70L, SG-708-6, WS-023EK30, SG-P3, SG-80H, SG-280EK23, SG-600TEA and SG-790 manufactured by Nagase ChemteX Corporation. The acrylic acid ester copolymer can be synthesized, and examples of the synthesis method include the synthesis method described in Japanese patent application laid-open No. 2016-102200.

The polymer resin may be used alone in 1 kind or in combination of 2 or more kinds. The amount of the polymer resin is preferably 1 to 35% by mass, more preferably 1 to 30% by mass, based on the total solid content of the composition. When the content is within the above range, the dispersibility of the inorganic filler or the like and the long-term stability of the composition can be improved. In particular, when the amount of the polymer resin is 5% by mass or more, a cured film having a low transmittance and suppressed warpage of the substrate can be obtained.

In the present specification, the value of the weight average molecular weight (Mw) can be measured by a Gel Permeation Chromatography (GPC) method (polystyrene standard) using, for example, the following measurement apparatus and measurement conditions.

A measuring device: waters system "Waters 2695"

A detector: waters ` Waters2414 `, RI (differential refractometer)

Column: HSPgel Column, HRMB-L, 3 μm, 6 mm. times.150 mm ". times.2 + HSPgel Column, HR1, 3 μm, 6 mm. times.150 mm". times.2 manufactured by Waters

The measurement conditions were as follows:

column temperature: 40 deg.C

RI detector set temperature: 35 deg.C

Developing solvent: tetrahydrofuran (THF)

Flow rate: 0.5 mL/min

Sample amount: 10 μ L

Sample concentration: 0.7% by mass

[ coloring agent ]

The colorant is not particularly limited as long as it can give a light-shielding curable resin composition, and a known and conventional black colorant can be used. Specific examples thereof include carbon black, titanium black, iron oxide, cobalt oxide, perylene black colorants, and the like, and these colorants may be used alone or in combination of a plurality of kinds.

The colorant may be a combination of a perylene colorant and a colorant having a complementary color relationship with the perylene colorant, and the combination may exhibit light-shielding properties.

Perylene colorants include colorants showing colors such as green, yellow, orange, red, violet, and black, and there are numbers given by The color index (c.i.; issued by The Society of Dyers and Colourists company).

-green: solvent Green 5

-orange color: solvent orange 55

-red: solvent Red 135, 179, pigment Red 123, 149, 178, 179, 190, 194, 224

-purple: pigment Violet 29

-black: pigment black 31, 32

Other perylene colorants than those described above may be used, and examples thereof include Lumogen (registered trademark) Black FK4280, Lumogen Black FK4281, known as a near infrared ray transmitting Black organic pigment from BASF, which has no color index, Lumogen FYellow 083, Lumogen F Orange 240, Lumogen F Red305, Lumogen F Green850, known as a light-collecting fluorescent dye, and the like, and are suitably used because absorption in the ultraviolet region is small and coloring power is high, as with other perylene compounds.

In the present invention, the following describes complementary color colorants that can be used in combination with perylene colorants. First, the complementary color relationship in the present invention will be described.

Since the coloring agent also has a hue which does not show a color index color, the external hue of the cured coating film of the resin composition is measured and expressed by the method specified in JIS Z8729, and the coloring agent for making (a, b) of the obtained cured coating film infinitely close to (0, 0) by combining with the perylene-based coloring agent is selected as the coloring agent having a complementary color relationship, by confirming that a value and b value indicating the hue in the L a b color system are coordinate axes (see fig. 2). The thickness of the cured coating film is not particularly limited, and is, for example, 40 μm.

Further, the values a and b are in the range of-5 to +5, preferably in the range of-2 to +2, as the values (a, b) infinitely close to (0, 0). The colorant having a complementary color relationship may be a perylene colorant, or a colorant other than a perylene colorant.

The colorant having a complementary color relationship with the perylene-based colorant may be any colorant as long as the color system a and b of the colorants are close to 0, respectively, by the combination with the perylene-based colorant.

More preferred combinations of perylene colorants and colorants having complementary color relationships are combinations of pigment red 149, 178, 179 and green anthraquinone colorants (solvent green 3, solvent green 20, solvent green 28, etc.), and in the case of color mixing (combination) of perylene colorants with each other, combinations of red perylene colorants (pigment red 149, 178, 179) and black perylene colorants (pigment black 31, 32), and combinations of black perylene colorants (pigment black 31, 32) and the same black perylene colorants (Lumogen (registered trademark) BlackFK4280, 4281).

In addition, the colorant may be any combination selected from the group consisting of a combination of a yellow colorant and a violet colorant, a combination of a yellow colorant and a blue colorant and a red colorant, a combination of a green colorant and a violet colorant, a combination of a green colorant and a red colorant, a combination of a yellow colorant and a violet colorant and a blue colorant, and a combination of a green colorant and a red colorant and a blue colorant, as long as the resin composition has light-shielding properties due to the combination. Further, a violet colorant, an orange colorant, a brown colorant, and the like may also be combined.

Examples of the blue colorant include phthalocyanine-based colorants, anthraquinone-based colorants, and the like, and include compounds classified into pigments (pigments) and solvents (solvents). In addition, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

Examples of the red colorant include monoazo colorants, disazo colorants, azo lakes, benzimidazolone colorants, perylene colorants, pyrrolopyrroledione colorants, condensed azo colorants, anthraquinone colorants, quinacridone colorants, and the like.

Examples of the yellow coloring agent include monoazo-based, disazo-based, condensed azo-based, benzimidazolone-based, isoindolinone-based and anthraquinone-based coloring agents.

Examples of the green colorant include phthalocyanine-based colorants and anthraquinone-based colorants. In addition, metal substituted or unsubstituted phthalocyanine compounds can also be used.

Specific examples of the violet colorant, orange colorant and brown colorant include pigment violet 19, 23, 29, 32, 36, 38 and 42; solvent violet 13, 36; c.i. pigment orange 1, c.i. pigment orange 5, c.i. pigment orange 13, c.i. pigment orange 14, c.i. pigment orange 16, c.i. pigment orange 17, c.i. pigment orange 24, c.i. pigment orange 34, c.i. pigment orange 36, c.i. pigment orange 38, c.i. pigment orange 40, c.i. pigment orange 43, c.i. pigment orange 46, c.i. pigment orange 49, c.i. pigment orange 51, c.i. pigment orange 61, c.i. pigment orange 63, c.i. pigment orange 64, c.i. pigment orange 71, c.i. pigment orange 73; c.i. pigment brown 23, c.i. pigment brown 25; c.i. pigment black 1, c.i. pigment black 7, and the like.

The amount of the colorant is not particularly limited, and is preferably 0.3 to 20 parts by mass based on the total solid content of the composition. By setting the amount to 0.3 part by mass or more, the light-shielding property can be improved. On the other hand, by setting the blending amount to 20 parts by mass or less, a composition having excellent dispersibility can be obtained.

The carbon black is dispersed in a resin to obtain light-shielding properties. Carbon black used for a colorant of a general black color can be used. As the carbon black, 1 or 2 or more kinds of known carbon blacks such as channel black, furnace black, thermal black and lamp black can be used. In addition, carbon black coated with a resin may also be used. Further, carbon nanofibers and carbon nanotubes may be used.

When carbon black is blended in the resin composition, carbon black powder may be added, or a carbon black dispersion may be added.

The average particle diameter of the carbon black is preferably 10nm or more and 500nm or less, more preferably 10nm or more and 300nm or less, and particularly preferably 10nm or more and 100nm or less. The average particle diameter is an arithmetic average diameter obtained by observing the particles with an electron microscope.

The amount of carbon black blended is preferably 0.1 to 20% by mass based on the total solid content of the light-shielding curable resin composition. When the amount of carbon black is 0.1% by mass or more, sufficient light-shielding properties can be obtained, and when the amount is 20% by mass or less, the occurrence of cracks can be suppressed.

Further, the more the amount of carbon black compounded, the more easily the carbon black is sedimented, but by including the above-mentioned polymer resin having a glass transition point of 20 ℃ or lower and a weight average molecular weight of 1 ten thousand or more, sedimentation of the carbon black is suppressed. Wherein the compounding amount of the polymer resin having a glass transition point of 20 ℃ or less and a weight average molecular weight of 1 ten thousand or more and the compounding amount of the carbon black are preferably 1: 1-100: 1.

[ inorganic Filler ]

The curable resin layer contains an inorganic filler. By adding the inorganic filler, it is possible to suppress curing shrinkage of the obtained cured product, improve adhesion and hardness, and improve thermal characteristics such as crack resistance due to CTE matching of a conductor layer such as copper located around the insulating layer. As the inorganic filler, conventionally known inorganic fillers can be used, and examples thereof include, but are not limited to, metal powders such as barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica and the like, talc, clay, nougat silica particles, boehmite, magnesium carbonate, calcium carbonate, titanium oxide, alumina, aluminum hydroxide, silicon nitride, aluminum nitride, calcium zirconate, copper, tin, zinc, nickel, silver, palladium, aluminum, iron, cobalt, gold, platinum and the like. The inorganic filler is preferably spherical particles. Among these, silica is preferable, and suppresses curing shrinkage of a cured product of the curable composition, resulting in a lower CTE, and also in improvement of properties such as adhesion and hardness.

The inorganic filler may be surface-treated. As the surface treatment, surface treatment without introducing an organic group such as surface treatment with a coupling agent, alumina treatment, or the like may be performed. The surface treatment method of the inorganic filler is not particularly limited, and a known conventional method may be used, and the surface of the inorganic filler may be treated with a surface treatment agent having a curable reactive group, for example, a coupling agent having a curable reactive group as an organic group.

The surface treatment of the inorganic filler is preferably a surface treatment using a coupling agent. As the coupling agent, silane-based, titanate-based, aluminate-based, or zircoaluminate-based coupling agents can be used. Among them, silane coupling agents are preferable. Examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminomethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like, and they may be used alone or in combination. These silane coupling agents are preferably immobilized on the surface of the inorganic filler by adsorption or reaction in advance. The amount of the coupling agent to be treated is, for example, 0.5 to 10 parts by mass per 100 parts by mass of the inorganic filler.

As the curable reactive group, a thermosetting reactive group is preferable. Examples of the thermosetting reactive group include a hydroxyl group, a carboxyl group, an isocyanate group, an amino group, an imino group, an epoxy group, an oxetanyl group, a mercapto group, a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group, and an oxazoline group. Among them, at least 1 of an amino group and an epoxy group is preferable. The inorganic filler subjected to surface treatment may have a photocurable reactive group in addition to the thermosetting reactive group.

The surface-treated inorganic filler may be contained in the curable resin layer in a surface-treated state, and the inorganic filler may be mixed with each of the inorganic filler and the surface treatment agent in the curable resin composition for forming the curable resin layer to perform the surface treatment of the inorganic filler in the composition. By blending the inorganic filler subjected to the surface treatment in advance, it is possible to prevent a reduction in crack resistance and the like due to the surface treatment agent which may remain unconsumed by the surface treatment in the case of blending separately. When the surface treatment is performed in advance, a predispersion solution in which an inorganic filler is predispersed in a solvent or a curable resin is preferably blended, and more preferably: predispersing the surface-treated inorganic filler in a solvent, compounding the predispersion in a composition; or the surface treatment may be sufficiently performed when the inorganic filler having an untreated surface is predispersed in a solvent, and then the predispersion liquid is mixed into the composition.

The inorganic filler may be mixed in a powder or solid state with other components of the curable resin composition, or may be mixed with a solvent or a dispersant to prepare a slurry and then mixed with other components.

The maximum particle diameter of the aggregated particles of the inorganic filler is X/2(μm) or less when the thickness of the curable resin layer is X (μm). By setting the maximum particle diameter of the aggregate particles to be equal to or less than half the thickness of the curable resin layer, scattering of light by the inorganic filler in the curable resin layer can be suppressed, and sufficient light-shielding properties can be obtained. In addition, when the inorganic filler is contained, it is advantageous for suppressing burrs at the time of cutting, but burrs are likely to be generated when the particle diameter of the largest particle of the aggregated particles is large, and defects are likely to be generated at the time of cutting.

The maximum particle diameter of the aggregate particles of the inorganic filler is preferably 10 μm or less in satisfying the relationship with the film thickness of the curable resin layer. By setting the maximum particle diameter of the aggregated particles of the inorganic filler to 10 μm or less, burrs and defects at the time of cutting can be more effectively suppressed. The polymer resin having a glass transition point of 20 ℃ or lower and a weight average molecular weight of 1 ten thousand or more can improve the dispersibility of the inorganic filler. Therefore, the curable resin composition containing a polymer resin having a glass transition point of 20 ℃ or less and a weight average molecular weight of 1 ten thousand or more is excellent in dispersion stability in the state of ink, and can suppress aggregation of the inorganic filler. Therefore, even after the curable resin composition as an ink is stored for a long period of time, the maximum particle diameter of the aggregated particles of the inorganic filler can be maintained at 10 μm or less.

The inorganic filler may be used alone in 1 kind, or may be used in the form of a mixture of 2 or more kinds. The amount of the inorganic filler is preferably 0.1 to 70% by mass based on the total solid content of the curable resin layer of the dry film. When the amount of the inorganic filler is 0.1% by mass or more, the thermal expansion can be suppressed to improve the heat resistance, while when the amount is 70% by mass or less, the occurrence of cracks can be suppressed. Further, when the amount of the inorganic filler is 20% by mass or more, the cut resistance is improved, and therefore, it is preferable.

[ epoxy resin ]

The light-blocking curable resin composition may contain an epoxy resin. The epoxy resin is a resin having an epoxy group, and any of conventionally known epoxy resins can be used. Examples thereof include a 2-functional epoxy resin having 2 epoxy groups in the molecule, a polyfunctional epoxy resin having 3 or more epoxy groups in the molecule, and the like. The epoxy resin may be hydrogenated. The epoxy resin includes solid epoxy resin, liquid epoxy resin, semisolid epoxy resin, and crystallized epoxy resin, and preferably includes at least liquid epoxy resin. The solid epoxy resin and the liquid epoxy resin may be used alone in 1 kind, or may be used in combination in 2 or more kinds. In the present specification, a solid epoxy resin means an epoxy resin that is solid at 40 ℃, a semisolid epoxy resin means an epoxy resin that is solid at 20 ℃ and liquid at 40 ℃, and a liquid epoxy resin means an epoxy resin that is liquid at 20 ℃. The determination of the liquid state is performed according to the "method for confirming the liquid state" in the attached page 2 of the provincial command for testing and properties of dangerous objects (the "national annual self-government command No. 1"). For example, the method is described in paragraphs 23 to 25 of Japanese patent application laid-open No. 2016-079384. The crystalline epoxy resin is a highly crystalline epoxy resin, and is a low-viscosity thermosetting epoxy resin in which polymer chains are regularly arranged at a temperature not higher than the melting point and which is a solid resin but becomes a liquid resin arrangement when melted.

Examples of the liquid epoxy resin include bisphenol a type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, phenol novolac type epoxy resin, tert-butyl catechol type epoxy resin, glycidyl amine type epoxy resin, aminophenol type epoxy resin, and alicyclic epoxy resin. By including the liquid epoxy resin, the flexibility of the dry film is excellent.

Examples of the solid epoxy resin include naphthalene type epoxy resins such as HP-4700 (naphthalene type epoxy resin) manufactured by DIC corporation and NC-7000 (naphthalene skeleton-containing multifunctional solid epoxy resin) manufactured by Nippon Kabushiki Kaisha; an epoxide (trisphenol type epoxy resin) of a condensate of a phenol such as EPPN-502H (trisphenol epoxy resin) manufactured by Nippon Kagaku K.K. and an aromatic aldehyde having a phenolic hydroxyl group; dicyclopentadiene aralkyl type epoxy resins such as EPICLON HP-7200H (dicyclopentadiene skeleton-containing polyfunctional solid epoxy resin) manufactured by DIC; biphenyl aralkyl type epoxy resins such as NC-3000H (biphenyl skeleton-containing multifunctional solid epoxy resin) manufactured by Nippon Chemicals corporation; biphenyl/phenol novolac type epoxy resins such as NC-3000L manufactured by Nippon Chemicals; novolac type epoxy resins such as EPICLON 660, EPICLON 690 and N770 manufactured by DIC corporation and EOCN-104S manufactured by Nippon Kabushiki Kaisha; phosphorus-containing epoxy resins such as NIPPON STEEL Chemical & Material Co., Ltd., TX0712 manufactured by Ltd.; tris (2, 3-epoxypropyl) isocyanurate such as TEPIC manufactured by Nissan chemical Co. By containing the solid epoxy resin, the glass transition temperature of the cured product becomes high and the heat resistance is excellent.

As the semi-solid epoxy resin, at least 1 selected from the group consisting of a bisphenol a type epoxy resin, a naphthalene type epoxy resin, and a phenol novolac type epoxy resin is preferably contained. By including the semi-solid epoxy resin, the glass transition temperature (Tg) of the cured product is high, the CTE is low, and the crack resistance is excellent.

Examples of the semisolid epoxy resin include bisphenol A type epoxy resins such as EPICLON 860, EPICLON 900-IM, EPICLON EXA-4816, EPICLON EXA-4822, NIPPON STEEL Chemical & Material Co., Ltd., Epotohto YD-134, Mitsubishi Chemical Corporation jER 834, jER 872, and Sumitomo Chemical Corporation ELA-134; naphthalene epoxy resins such as EPICLON HP-4032 available from DIC; phenol novolac epoxy resins such as EPICLON-740 manufactured by DIC corporation.

As the crystalline epoxy resin, for example, a crystalline epoxy resin having a biphenyl structure, a thioether structure, a phenylene structure, a naphthalene structure, or the like can be used. Examples of the biphenyl type epoxy resin include jER YX4000, jER YX4000H, jER YL6121H, jER YL6640 and jER YL6677 manufactured by Mitsubishi Chemical Corporation. Diphenyl thioether type epoxy resins are exemplified by two-dimensional NIPPON STEEL Chemical & Material Co., Ltd., Epotohto YSLV-120TE manufactured by Ltd. Examples of the phenylene-based epoxy resin include NIPPON STEEL Chemical & Material Co., Ltd., Epotohto YDC-1312 manufactured by Ltd. Examples of the naphthalene epoxy resin include EPICLON HP-4032, EPICLON HP-4032D and EPICLON HP-4700 manufactured by DIC corporation. Further, as the crystalline epoxy resin, NIPPON STEEL Chemical & Material Co., Ltd., Epotohto YSLV-90C manufactured by Ltd., and TEPIC-S (triglycidyl isocyanurate) manufactured by Nissan Chemical Co., Ltd., can be used.

The amount of the epoxy resin is preferably 1 to 70% by mass in total based on the total solid content of the composition. When the amount is within the above range, the cured product is excellent in heat resistance, flexibility and crack resistance. The amount of the liquid epoxy resin is preferably 5 to 60% by mass based on the total solid content of the epoxy resin, the curing agent, the curing accelerator and the polymer resin. When the amount is within the above range, the flexibility of the dry film is excellent.

The light-shielding curable resin composition may contain a curable resin component other than an epoxy resin within a range not impairing the effects of the present invention, and for example, a known and conventional thermosetting resin such as an isocyanate compound, a blocked isocyanate compound, an amino resin, a benzoxazine resin, a carbodiimide resin, a cyclic carbonate compound, a polyfunctional oxetane compound, an episulfide resin, or the like can be used.

[ curing agent ]

The light-shielding curable resin composition preferably contains a curing agent. Examples of the curing agent include compounds having a phenolic hydroxyl group, polycarboxylic acids and anhydrides thereof, compounds having a cyanate group, compounds having an active ester group, compounds having a maleimide group, alicyclic olefin polymers, and the like. The curing agent may be used alone in 1 kind or in combination of 2 or more kinds.

As the resin having a phenolic hydroxyl group, there can be used: conventionally known phenol novolac resins, such as phenol novolac resins, alkylphenol novolac resins, bisphenol a novolac resins, dicyclopentadiene type phenol resins, Xylok type phenol resins, terpene modified phenol resins, cresol/naphthol resins, polyvinyl phenols, phenol/naphthol resins, α -naphthol skeleton-containing phenol resins, triazine skeleton-containing cresol novolac resins, biphenyl aralkyl type phenol resins, and Xylok type phenol novolac resins.

Examples of the resin having a phenolic hydroxyl group include: dicyclopentadiene skeleton phenol novolak resin (GDP series, available from Kyoho Chemical Co., Ltd.), Xylok type phenol novolak resin (MEH-7800 available from Kyoho Chemical Co., Ltd.), biphenyl aralkyl type phenol novolak resin (MEH-7851 available from Kyoho Chemical Co., Ltd.), naphthol aralkyl type curing agent (SN series, NIPPON STEEL Chemical & Material Co., Ltd.), cresol novolak resin having a triazine skeleton (LA-3018-50P, DIC available from Kyoho Chemical Co., Ltd.), phenol novolak resin having a triazine skeleton (LA-705N, DIC available from Ltd.), and the like.

The compound having an isocyanate group is preferably a compound having 2 or more isocyanate groups (-OCN) in one molecule. Any conventionally known compound can be used as the compound having a cyanate group. Examples of the compound having a cyanate group include phenol novolac type cyanate ester resin, alkylphenol novolac type cyanate ester resin, dicyclopentadiene type cyanate ester resin, bisphenol a type cyanate ester resin, bisphenol F type cyanate ester resin, and bisphenol S type cyanate ester resin. In addition, a prepolymer in which a part of the prepolymer is triazinated may be used.

Examples of commercially available compounds having a cyanate group include: phenol novolak type polyfunctional cyanate ester resins (manufactured by Lonza Japan Ltd., PT30S), prepolymers in which a part or all of bisphenol A dicyanate ester is converted to a trimer by triazinization (manufactured by Lonza Japan Ltd., BA230S75), and cyanate ester resins containing a dicyclopentadiene structure (manufactured by Lonza Japan Ltd., DT-4000, DT-7000), and the like.

The compound having an active ester group is preferably a compound having 2 or more active ester groups in one molecule. The compound having an active ester group can be usually obtained by a condensation reaction of a carboxylic acid compound and a hydroxyl compound. Among them, a compound having an active ester group obtained by using a phenol compound or a naphthol compound as a hydroxyl compound is preferable. Examples of the phenol compound or naphthol compound include hydroquinone, resorcinol, bisphenol a, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol a, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α -naphthol, β -naphthol, 1, 5-dihydroxynaphthalene, 1, 6-dihydroxynaphthalene, 2, 6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzenetriol, dicyclopentadienyl diphenol, and phenol novolak. The compound having an active ester group may be a naphthalene diol alkyl/benzoic acid type.

As commercially available compounds having an active ester group, dicyclopentadiene type diphenol compounds, for example, HPC8000-65T (available from DIC Co., Ltd.), HPC8100-65T (available from DIC Co., Ltd.), and HPC8150-65T (available from DIC Co., Ltd.), are mentioned.

The compound having a maleimide group is a compound having a maleimide skeleton, and any conventionally known compound can be used. The compound having a maleimide group preferably has 2 or more maleimide skeletons, more preferably N, N ' -1, 3-phenylenedimaleimide, N ' -1, 4-phenylenedimaleimide, N ' -4, 4-diphenylmethane bismaleimide, 1, 2-bis (maleimide) ethane, 1, 6-bismaleimide hexane, 1, 6-bismaleimide- (2,2, 4-trimethyl) hexane, 2 ' -bis- [4- (4-maleimidophenoxy) phenyl ] propane, 3 ' -dimethyl-5, 5 ' -diethyl-4, 4 ' -diphenylmethane bismaleimide, 4-methyl-1, 3-phenylenebismaleimide, bis (3-ethyl-5-methyl-4-maleimidophenyl) methane, bisphenol A diphenyl ether bismaleimide, polyphenylmethane maleimide, and oligomers thereof, and a diamine condensate having a maleimide skeleton. The oligomer is obtained by condensing a compound having a maleimide group as a monomer among the compounds having a maleimide group.

Examples of commercially available compounds having a maleimide group include BMI-1000(4,4 '-diphenylmethane bismaleimide, manufactured by Daihu Kasei Kogyo Co., Ltd.), BMI-2300 (phenylmethane bismaleimide, manufactured by Daihu Kasei Kogyo Co., Ltd.), BMI-3000 (m-phenylene bismaleimide, manufactured by Daihu Kasei Kogyo Co., Ltd.), BMI-5100(3, 3' -dimethyl-5, 5 '-dimethyl-4, 4' -diphenylmethane bismaleimide, manufactured by Daihu Kasei Kogyo Co., Ltd.), BMI-7000 (4-methyl-1, 3-phenylene bismaleimide, manufactured by Daihu Kasei Kogyo Co., Ltd.), BMI-TMH ((1, 6-bismaleimide-2, 2, 4-trimethyl) hexane, Manufactured by Dazai chemical industry Co., Ltd.) and the like.

The amount of the curing agent is preferably 20 to 500 parts by mass, and more preferably 25 to 500 parts by mass, per 100 parts by mass of the epoxy resin.

Hereinafter, as an example, a description will be given of components that can be contained in addition to the above-described components when a light-shielding curable resin composition is formed from a thermosetting resin composition containing no photocurable component.

The light-shielding curable resin composition may further contain a thermoplastic resin in order to improve the mechanical strength of the resulting cured film. The thermoplastic resin is preferably soluble in a solvent. When the resin is soluble in a solvent, the flexibility of the dry film is improved, and the generation of cracks and powder falling can be inhibited. Examples of the thermoplastic resin include a thermoplastic polyhydroxypolyether resin, a phenoxy resin which is a condensate of epichlorohydrin and various 2-functional phenol compounds, a phenoxy resin in which the hydroxyl group of a hydroxyether moiety present in the skeleton thereof is esterified with various acid anhydrides and/or acid halides, a polyvinyl acetal resin, a polyamide resin, a polyamideimide resin, and a block copolymer. The thermoplastic resin may be used alone in 1 kind or in combination of 2 or more kinds.

The amount of the thermoplastic resin is preferably 0.5 to 20% by mass, more preferably 0.5 to 10% by mass, based on the total solid content of the light-shielding curable resin composition. When the amount of the thermoplastic resin is within the above range, a uniform rough surface state can be easily obtained.

Further, the light-shielding curable resin composition may contain rubber-like particles as necessary. Examples of such rubber-like particles include polybutadiene rubber, polyisopropylene rubber, urethane-modified polybutadiene rubber, epoxy-modified polybutadiene rubber, acrylonitrile-modified polybutadiene rubber, carboxyl-modified polybutadiene rubber, acrylonitrile-butadiene rubber modified with a carboxyl group or a hydroxyl group, and crosslinked rubber particles and core-shell rubber particles thereof, and 1 or more may be used alone or 2 or more may be used in combination. These rubber-like particles are added for the purpose of improving flexibility of the obtained cured film, improving crack resistance, or making it possible to improve adhesion strength to a copper foil or the like by surface roughening treatment with an oxidizing agent.

The average particle diameter of the rubber-like particles is preferably in the range of 0.005 to 1 μm, more preferably in the range of 0.2 to 1 μm. The average particle diameter of the rubber-like particles can be determined by a laser diffraction type particle diameter distribution measuring apparatus or a measuring apparatus based on a dynamic light scattering method. The measurement device by the laser diffraction method includes Microtrac MT3300EXII manufactured by MicrotracBEL Corp. and the measurement device by the dynamic light scattering method includes Nanotrac Wave II UT151 manufactured by MicrotracBEL Corp.

The amount of the rubber-like particles is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass, based on the total solid content of the light-shielding curable resin composition. When the amount is 0.5% by mass or more, crack resistance can be obtained, and the adhesion strength to a conductor pattern or the like can be improved. When the amount is 10% by mass or less, the Coefficient of Thermal Expansion (CTE) decreases, the glass transition temperature (Tg) increases, and the curing properties improve.

The light-shielding curable resin composition may contain a curing accelerator. The curing accelerator is a substance that accelerates a thermosetting reaction, and is used to further improve properties such as adhesion, chemical resistance, and heat resistance. Specific examples of such a curing accelerator include imidazole and its derivatives; guanamines such as acetoguanamine and benzoguanamine; polyamines such as diaminodiphenylmethane, m-phenylenediamine, m-xylylenediamine, diaminodiphenylsulfone, dicyandiamide, urea derivatives, melamine, and polyhydrazide; organic acid salts and/or epoxy adducts thereof; an amine complex of boron trifluoride; triazine derivatives such as ethyldiamino-s-triazine, 2, 4-diamino-s-triazine, and 2, 4-diamino-6-xylyl-s-triazine; amines such as trimethylamine, triethanolamine, N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa (N-methyl) melamine, 2,4, 6-tris (dimethylaminophenol), tetramethylguanidine, and m-aminophenol; polyphenols such as polyvinyl phenol, polyvinyl phenol bromide, phenol novolac, and alkylphenol novolac; organic phosphines such as tributylphosphine, triphenylphosphine, and tris-2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl (2, 5-dihydroxyphenyl) phosphonium bromide and hexadecyltributylphosphonium chloride; quaternary ammonium salts such as benzyltrimethylammonium chloride and phenyltributylammonium chloride; the foregoing polybasic acid anhydrides; photocationic polymerization catalysts such as diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, 2,4, 6-triphenylthiopyrylium hexafluorophosphate and the like; styrene-maleic anhydride resin; an equimolar reaction product of phenyl isocyanate and dimethylamine, an equimolar reaction product of organic polyisocyanate such as toluene diisocyanate or isophorone diisocyanate and dimethylamine, and a conventionally known curing accelerator such as a metal catalyst. Among the curing accelerators, phosphonium salts are preferred in view of obtaining the resistance to BHAST.

The curing accelerator may be used singly or in combination of 2 or more. The curing accelerator is not essential, but may be used in an amount of preferably 0.01 to 5 parts by mass per 100 parts by mass of the epoxy resin when it is particularly desired to accelerate curing. In the case of the metal catalyst, the amount is preferably 10 to 550ppm, more preferably 25 to 200ppm in terms of metal, per 100 parts by mass of the compound having an isocyanate group.

The organic solvent is not particularly limited, and examples thereof include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents, and the like. Specific examples thereof include ketones such as methyl ethyl ketone, cyclohexanone, methyl butyl ketone, and methyl isobutyl ketone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, isobutyl acetate, ethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, and propylene glycol butyl ether acetate; alcohols such as ethanol, propanol, 2-methoxypropanol, n-butanol, isobutanol, isoamyl alcohol, ethylene glycol and propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, naphtha, hydrogenated naphtha and solvent naphtha, and N, N-Dimethylformamide (DMF), tetrachloroethylene and turpentine. Further, organic solvents such as SWASOL1000, SWASOL1500, Solvent #100, Solvent #150, SHELLSOL A100, SHELLSOL A150, IPSOL No. 100, IPSOL No. 150, available from Kashin corporation, and the like available from Maruzen petrochemical Co., Ltd can be used. The organic solvent may be used alone in 1 kind, or may be used in the form of a mixture of 2 or more kinds.

The amount of the residual solvent in the light-shielding curable resin composition is preferably 0.5 to 7.0 mass%. When the residual solvent is 7.0 mass% or less, bumping during thermal curing is suppressed, and the surface flatness becomes better. Further, excessive decrease in melt viscosity and resin flow can be suppressed, and flatness can be improved. When the residual solvent is 0.5% by mass or more, the fluidity at the time of lamination is good, and the flatness and embeddability become better.

The light-shielding curable resin composition may further contain conventionally known coloring agents such as phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide and naphthalene black, conventionally known thickeners such as asbestos, ORBEN, BENTON and fine silica, antifoaming agents and/or leveling agents such as silicone-based, fluorine-based and polymer-based agents, adhesion imparting agents such as thiazole-based, triazole-based and silane coupling agents, flame retardants, and conventionally known additives such as titanate-based and aluminum-based agents, as required.

The thickness of the curable resin layer of the dry film formed from the light-shielding curable resin composition may be, for example, 1 to 200 μm. Within the above thickness range, the maximum diameter of the aggregated particles of the inorganic filler in the light-shielding curable resin composition is not more than one-half the thickness of the curable resin layer. For example, those having a thickness of 30 μm or more, more preferably 50 μm or more, and still more preferably 100 μm or more may be suitably used, because of the more excellent flatness when the thickness of the curable resin layer is large. The curable resin layer may be formed to have a thickness of more than 200 μm by stacking a plurality of curable resin layers. In this case, a roll laminator or a vacuum laminator can be used.

[ Carrier film ]

The curable resin layer of the carrier film-supported dry film is a thin film coated with a light-shielding curable resin composition when the curable resin layer is formed. As the carrier film, for example, a polyester film such as polyethylene terephthalate or polyethylene naphthalate, a film made of a thermoplastic resin such as a polyimide film, a polyamideimide film, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film or a polystyrene film, a surface-treated paper, or the like can be used. Among them, a polyester film can be suitably used from the viewpoint of heat resistance, mechanical strength, handling property, and the like. The thickness of the carrier film is not particularly limited, and is appropriately selected within a range of approximately 10 to 150 μm depending on the application. The surface of the carrier film on which the curable resin layer is provided may be subjected to release treatment. Further, a sputtered or ultra-thin copper foil may be formed on the surface of the carrier film on which the curable resin layer is provided.

[ protective film ]

The protective film is provided on the surface of the curable resin layer of the dry film, which is opposite to the carrier film, for the purpose of preventing adhesion of dust and the like to the surface of the curable resin layer and improving handling properties. As the protective film, a biaxially oriented polypropylene film (OPP) is preferably used. By using the biaxially oriented polypropylene film, the shrinkage upon cooling after lamination to the curable resin layer can be reduced. Of course, the protective film is not limited to the biaxially oriented polypropylene film. The thickness of the protective film is not particularly limited, and is suitably selected within a range of about 10 to 100 μm depending on the application. The surface of the protective film on which the curable resin layer is provided is preferably subjected to a treatment for improving adhesion such as embossing, corona treatment, or micro-adhesion treatment, or a release treatment.

The dry film of the present invention is preferably used for forming a sealing material or a permanent protective film for electronic parts, particularly semiconductor devices, printed circuit boards, and optical sensor modules, by laminating the dry film on a semiconductor wafer or the like and curing a curable resin layer to form a cured product. Among them, the sealing material is suitable for semiconductor chips. A wiring board can also be formed by using the dry film of the present invention and attaching wiring.

Examples of the cured product of the light-shielding curable resin composition of the present invention or an electronic component using the cured product of the dry film of the present invention include a semiconductor device, a printed circuit board, and an optical sensor module. As the method for manufacturing the electronic component, a conventionally known method can be used.

Examples

The present invention will be specifically described below by way of examples and comparative examples of the present invention, but the present invention is not limited to the examples. In the following description, unless otherwise specified, all the terms "part" and "%" are based on mass.

< preparation of light-blocking curable resin composition >

The solvents described in examples and comparative examples were placed in a vessel, stirred while being heated to 50 ℃ so that the solvents did not volatilize, and then the respective resin components and the coupling agent were added. After confirming the dissolution of the resin component, the inorganic filler and the colorant described in examples were added and sufficiently stirred. Then, the resultant was kneaded by a bead mill filled with zirconia beads to prepare a light-blocking curable resin composition. As a bead mill, a conical type K-8 (manufactured by Buhler Group) was used, and kneading was carried out at a rotation speed of 1200rpm, a discharge rate of 20%, a bead diameter of 0.65mm, and a filling rate of 88%. The numerical values in the table represent parts by mass unless otherwise specified, and the amounts of solid components other than the solvent, the polymer resin, and the nanosilica represent the amounts of solid components.

< dispersibility >

The dispersibility of the light-shielding curable resin composition was confirmed by a method of dispersing it in accordance with JIS K5600-2-5 using a 0-50 μm grind gauge. The evaluation criteria are as follows. The maximum particle size of the aggregated particles obtained using the grinding gauge is shown in the table.

Good: the dispersion degree is 20 μm or less when judged by 5 particle values

And (delta): the dispersion degree is more than 20 μm and less than 30 μm determined by 5 particle values

X: the dispersion degree judged by 5 particle values is more than 30 mu m

< inhibition of sedimentation of composition (ink) >

The light-shielding curable resin composition thus prepared was placed in a transparent glass screw tube, and subjected to a storage aging treatment in a thermostat set at 23 ℃ for 12 hours. The light-shielding curable resin composition was charged to a position 50mm from the bottom of the threaded pipe. After the curing, the light-shielding curable resin composition was taken out and observed from the side by visual observation to confirm the state of sedimentation of the light-shielding curable resin composition. The criteria for determination are as follows.

Good: no sedimentation was observed.

And (delta): a clear supernatant of less than 1mm was confirmed from the upper part of the composition.

X: a clear supernatant of 20mm or more was observed from the upper part of the composition.

< preparation of Dry film >

The amount of the solvent was adjusted so that the viscosity of the light-shielding curable resin composition was 0.5 to 20dPa · s (rotational viscometer: 5rpm, 25 ℃), and the film thickness of the curable resin layer was dried and then applied to a carrier film (PET film; TN-200 manufactured by Toyo Co., Ltd., thickness: 38 μm, size: 30 cm. times.30 cm) by using a bar coater. Then, the resin layer is dried in a hot air circulation drying furnace at 70 to 120 ℃ (average 100 ℃) for 5 to 10 minutes so that the residual solvent of the curable resin layer is 0.5 to 2.5 mass%, and the curable resin layer is formed on the carrier film. Then, a biaxially oriented polypropylene film (OPP, ALPHAN FG-201, Fish air es, ojif-tex) was laminated on the surface of the dry film thus produced using a roll laminator set at a temperature of 80 ℃ to produce a dry film having a 3-layer structure.

< transmittance >

The protective film of the resulting dry film having a 3-layer structure was peeled off, and the resultant was stuck to a glass slide having a thickness of 1mm by means of a vacuum laminator MVLP-500 (manufactured by Minn machine Co., Ltd.). The conditions are such that the laminating temperature is 80 to 110 ℃ and the pressure is 0.5 MPa. Next, the carrier film was peeled off, and the resin layer was cured in a hot air circulation drying oven at 100 ° c. × 30 minutes and 200 ° c. × 60 minutes. The transmittance at 380nm to 780nm of the obtained cured product was measured by an ultraviolet-visible near-infrared spectrophotometer V-700 (manufactured by Nissan Spectroscopy). The evaluation criteria are as follows.

Very good: the transmittance in the whole wavelength region is less than 0.1%

O: a transmittance of 0.1% or more and less than 0.5% in the entire wavelength region

X: a transmittance of 0.5% or more over the entire wavelength region

< cut resistance >

The protective film of the resulting 3-layer structured dry film was peeled off and attached to an 8-inch wafer having a thickness of 700 μm using a vacuum laminator MVLP-500 (manufactured by Minn machine Co., Ltd.). The conditions are such that the laminating temperature is 80 to 110 ℃ and the pressure is 0.5 MPa. Next, the carrier film was peeled off, and the resin layer was cured in a hot air circulation drying oven at 100 ° c. × 30 minutes and 200 ° c. × 60 minutes. Next, the cured film was evaluated for cut resistance using a cutting machine DFD6240 (manufactured by DISCO inc., ceramic blade mounted). The cutting was carried out at 10000rpm for the cutting conditions and at a feed rate of 1 mm/min. The evaluation criteria are as follows.

Very good: no burr and resin defect on the surface of the cured film

Good: the length of burrs and resin defects generated on the surface of the cured film is less than 1.0mm

X: the length of burrs and resin defects generated on the surface of the cured film is 1.0mm or more

< warpage of substrate >

A copper-clad laminate (MCL-E-770G, manufactured by Hitachi chemical Co., Ltd., size 10X 10cm) having a copper thickness of 12 μm and a thickness of 0.1mm was subjected to electrolytic copper plating (Atotech Co., Ltd., surface roughness after plating was 100nm or less) so that the total copper thickness was 20 μm. Next, CZ-8101(1 μm etching, MEC co., ltd. system) was performed as a pretreatment. Then, the OPP-peeled dry film was attached to one surface of the substrate by a double chamber vacuum laminator CVP-600(Nichigo-Morton Co., Ltd.). As for the conditions, the lamination and the pressing are respectively carried out at a temperature of 80-110 ℃ and a pressure of 0.5 MPa. Next, the carrier film was peeled off, and the resin layer was cured in a hot air circulation drying oven at 100 ° c. × 30 minutes and 200 ° c. × 60 minutes.

Next, 5 cycles of reflow treatment were performed with an exposure time of 10 seconds or more set to a peak temperature of 280 ℃ or 275 ℃ or more, and the warpage state of the substrate at 4 corners was measured with a caliper (all warpage shapes were smile). The evaluation criteria are as follows.

Very good: no warp

Good: the warpage amount of the most warped part in 4 corners is less than 10mm

And (delta): the maximum warpage amount of the 4 corners is 10mm or more and less than 30mm

X: the maximum warpage amount of the 4 corners is more than 30mm

Table 1 shows the compounding ratio of each ingredient and the evaluation results.

[ Table 1]

The comments 1 to 17 in table 1 are as follows.

*1: JeR 828 made by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin, epoxy equivalent 189g/eq, liquid

*2: NC-3000H manufactured by Nippon chemical Co., Ltd., epoxy compound in the form of a diphenol varnish, epoxy equivalent of 290g/eq, and,

*3: primaset PT-30 manufactured by Lonza Japan Ltd, novolak type cyanate ester resin, cyanate ester equivalent 124g/eq, solid

*4: EPICLON HPC-8000, available from DIC corporation, active ester resin, active equivalent of 223g/eq, and solid

*5: phenol novolac resin, HF-1M, manufactured by Minghe chemical Co., Ltd

*6: 2E4MZ, 2-ethyl-4-methylimidazole manufactured by Siguohiniji Kabushiki Kaisha

*7: tokyo chemical industry Co Ltd, cobalt acetylacetonate (II)

*8: is a polymer resin having a glass transition point of 20 ℃ or lower and a weight-average molecular weight of 1 ten thousand or more, TEISAN RESIN SG-80HMEK cut product manufactured by Nagase ChemteX Corporation, a solid content of 18 mass%, and an acrylate copolymer resin (functional group: epoxy group, amide group)

*9: MA77 charcoal Black powder manufactured by Mitsubishi Chemical Corporation (average particle diameter 23nm)

*10: paliogen Red K3580 pigment Red 149, product of BASF corporation, perylene colorants

*11: solvent Green 3, a Green anthraquinone-based colorant manufactured by Tokyo chemical industry Co., Ltd

*12: fastogen Blue 5380 Phthalocyanine Blue available from DIC Co., Ltd

*13: cromophtal (registered trademark) RedA2BN manufactured by BASF corporation, red anthraquinone-based colorant

*14: fine silica particles FB-3SDC manufactured by electrochemical Co., Ltd. (D50 ═ 3.1 μm)

*15: ADMATECHS co., ltd. silica fine particles SO-E1(D50 ═ 0.2 μm)

*16: ADMATECHS co., ltd. nano silica (D50-50 nm), solid content 30 mass%

*17: KBM-403 epoxy silane coupling agent manufactured by shin-Etsu chemical Co., Ltd

From the results shown in table 1, it is understood that the curable resin layer including the light-shielding curable resin composition shown in each example is excellent in dispersibility of a dry film, ink sedimentation inhibition, light transmission inhibition (in other words, light-shielding property), cut resistance, and warpage inhibition of a substrate.

Description of the reference numerals

11 Dry film

12 curable resin layer

13 Carrier film

14 protective film

Claims (8)

1. A dry film comprising a curable resin layer formed from a light-shielding curable resin composition, the light-shielding curable resin composition comprising: a polymer resin having a glass transition point of 20 ℃ or lower and a weight-average molecular weight of 1 ten thousand or more, a colorant, and an inorganic filler,

when the thickness of the curable resin layer is X (μm), the maximum particle diameter of the aggregated particles of the inorganic filler is X/2(μm) or less.

2. The dry film according to claim 1, wherein the maximum particle diameter of the aggregated particles of the inorganic filler is 10 μm or less.

3. The dry film according to claim 1 or 2, wherein the inorganic filler is added in an amount of 0.1 to 70% by mass based on the solid content of the light-shielding curable resin composition.

4. The dry film according to any one of claims 1 to 3, wherein a blending amount of the colorant is 0.3 to 20% by mass with respect to a solid content of the light-shielding curable resin composition.

5. The dry film according to any one of claims 1 to 4, wherein a compounding amount of the polymer resin having a glass transition point of 20 ℃ or less and a weight average molecular weight of 1 ten thousand or more is 1 to 35% by mass with respect to a solid content of the light-shielding curable resin composition.

6. The dry film according to any one of claims 1 to 5, wherein the curable resin layer further comprises a liquid epoxy resin.

7. A cured product obtained by curing the curable resin layer of the dry film according to any one of claims 1 to 6.

8. An electronic component comprising the cured product according to claim 7.

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