JP6999459B2 - Dry films, cured products, and electronic components - Google Patents

Description

The present invention relates to dry films, cured products, and electronic components.

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 or an interlayer insulating layer provided on a printed wiring board used in an electronic device or the like (for example, a patent document). 1). The dry film has a resin layer obtained by applying a resin composition having desired properties on a carrier film and then performing a drying step, and generally for protecting the surface opposite to the carrier film. Protective film is distributed in the market in a laminated state. A printed wiring board having the above-mentioned protective film and insulating layer can be manufactured by applying a resin layer of a dry film to a substrate (hereinafter, also referred to as “laminate”) and then performing patterning and curing treatment. ..

Japanese Unexamined Patent Publication No. 2015-010179

When laminating a protective film in the dry film manufacturing process, if the tack on the surface of the resin layer is low, for example, when the amount of the inorganic filler contained in the resin layer is large, the adhesion to the protective film deteriorates. was there.

Further, when the amount of the inorganic filler contained in the resin layer is large, when the resin layer is formed, the resin composition is diluted and the viscosity is adjusted so that it can be easily applied with a solvent or the like. There is a problem that the filler tends to settle and the quality of the dry film becomes unstable.

Therefore, an object of the present invention is a dry film having good adhesion between the resin layer and the protective film and little precipitation of the inorganic filler contained in the resin layer, a cured product of the resin layer of the dry film, and the curing. The purpose is to provide electronic components with objects.

To achieve the above object, the inventors first considered improving the adhesion between the resin layer and the protective film by using a polyethylene (PE) film having a low glass transition point as a protective film. However, although the adhesion is improved, it has been noticed that there is a new problem that shrinkage wrinkles are generated on the surface of the resin layer during cooling after laminating the protective film.
On the other hand, it is difficult to laminate a protective film having a high glass transition point and low flexibility, such as polyethylene terephthalate (PET), with good adhesion.
Therefore, the inventors focused on a biaxially stretched polypropylene film (OPP) having less cooling shrinkage, that is, a glass transition temperature higher than that of polyethylene (PE) and good flexibility, and such a biaxially stretched polypropylene film (OPP). OPP) was used as a protective film for further study.
In this study, even with the biaxially stretched polypropylene film (OPP), the adhesion to the resin layer was still insufficient despite the embossing and corona treatment. Moreover, the precipitation of the inorganic filler, which was a problem when forming the resin layer, could not be eliminated even though it was constantly stirred before coating.

Therefore, in view of the above, the inventors have constructed a resin layer for the development of a dry film having good adhesion between the resin layer and the biaxially stretched polypropylene film (OPP) and less sedimentation of the inorganic filler contained in the resin layer. Further study was made on the resin composition to be used.
As a result, a polymer resin having a glass transition point of 20 ° C. or less and a weight average molecular weight of 30,000 or more and at least one of a semi-solid epoxy resin and a crystalline epoxy resin are used to form a resin layer. It has been found that the above-mentioned problems can be solved by blending the composition into the composition, and the present invention has been completed.

That is, the dry film of the present invention is a dry film including a carrier film, a resin layer, and a protective film, wherein the protective film is a biaxially stretched polypropylene film, and the resin layer is an inorganic filler and a glass transition. A polymer resin having a point of 20 ° C. or lower and a weight average molecular weight of 30,000 or more and an epoxy resin are contained, and the resin layer is at least one of a semi-solid epoxy resin and a crystalline epoxy resin as the epoxy resin. It is characterized by containing seeds.

In the dry film of the present invention, the resin layer contains at least one of a compound having a phenolic hydroxyl group, a compound having an active ester group, a compound having a cyanate ester group, and a compound having a maleimide group as a curing agent. Is preferable.

In the dry film of the present invention, the resin layer contains, as the inorganic filler, a mixture of an inorganic filler having an average particle size of 0.1 to 10 μm and an inorganic filler having an average particle size of 0.01 to 5 μm, and The difference between the peaks of the inorganic filler having an average particle diameter of 0.1 to 10 μm and the inorganic filler having an average particle diameter of 0.01 to 5 μm in the particle size distribution measurement is preferably 0.05 μm or more.

The dry film of the present invention preferably contains the inorganic filler in an amount of 50% by mass or more based on the total solid content of the resin layer.

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

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

According to the present invention, a dry film having good adhesion between the resin layer and the protective film and having less precipitation of the inorganic filler contained in the resin layer, a cured product of the resin layer of the dry film, and the cured product. It is possible to provide an electronic component having the above.

It is a schematic sectional drawing schematically showing one embodiment of the dry film of this invention.

<Dry film>
The dry film of the present invention is a dry film comprising a carrier film, a resin layer, and a protective film, wherein the protective film is a biaxially stretched polypropylene film, and the resin layer has an inorganic filler and a glass transition point. A polymer resin having a weight of 20 ° C. or lower and a weight average molecular weight of 30,000 or more and an epoxy resin are contained, and the resin layer comprises at least one of a semi-solid epoxy resin and a crystalline epoxy resin as the epoxy resin. It is characterized by including.

In the present invention, even when a biaxially stretched polypropylene film having a weak adhesion to a resin layer having a low tack is used as a protective film, the glass transition point is 20 ° C. or less and the weight average molecular weight is as high as 30,000 or more. By blending at least one of the molecular resin, the solid epoxy resin and the crystalline epoxy resin in the resin layer, the adhesion between the resin layer and the protective film is improved. Although the detailed mechanism is not clear, the adhesive force is stabilized by the matte surface of the resin layer due to the compounding of the polymer resin as described above, and the semi-solid epoxy resin or the crystalline epoxy resin is used as the epoxy resin. It is considered that by using the above, the protective film is softened or melted at the adhesion temperature, and as a result, the adhesion of the protective film is stable. Further, although the detailed mechanism is not clear, the precipitation of the inorganic filler is reduced by blending the above-mentioned polymer resin with the resin composition for forming the resin layer.

The problems of adhesion between the resin layer and the protective film and precipitation of the inorganic filler are both remarkable when the content of the inorganic filler is high, but according to the present invention, even when the content of the inorganic filler is high. It is possible to produce a dry film having good adhesion between the resin layer and the protective film and having less precipitation of the inorganic filler contained in the resin layer.

Further, when the content of the inorganic filler is high, if OPP is used as a protective film, the OPP is likely to be peeled off, cracked or powdered during slit processing, but according to the dry film of the present invention, peeling or peeling during slit processing is likely to occur. Cracking and powder falling can be suppressed.

The cured product of the resin layer of the dry film of the present invention is excellent in the flatness of the surface of the cured product even when the object to be bonded has irregularities, for example, when a component such as a circuit is embedded. Therefore, when a circuit or the like is further formed on the surface of the cured product, a fine pattern can be formed, so that the material can be suitably used as an interlayer insulating material.

Further, the cured product of the resin layer of the dry film of the present invention has excellent adhesion to the object to be bonded, and can also adhere well to a low-roughness wiring board, an etchout substrate, and a semiconductor.

The cured product of the resin layer of the dry film of the present invention is also excellent in warpage resistance.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the dry film of the present invention. The resin layer 12 is a dry film 11 having a three-layer structure formed on the carrier film 13 and laminated with the protective film 14. If necessary, another resin layer may be provided between the film and the resin layer. The resin layer of the dry film of the present invention may be one layer or two or more layers.

[Resin layer]
The resin layer of the dry film of the present invention is in a state generally referred to as a B stage state, and is obtained from a curable resin composition. Specifically, the resin layer of the dry film is obtained through a drying step after applying the curable resin composition to the film. As long as the curable resin composition contains the above components, the types and amounts of the other components are not particularly limited. The thickness of the resin layer is not particularly limited, and may be, for example, 1 to 200 μm. In the present invention, since the flatness is excellent when the thickness is large, for example, a thickness of 30 μm or more, further 50 μm or more, and further 100 μm or more can be preferably used. A plurality of resin layers of the dry film of the present invention may be laminated to form a resin layer having a thickness of more than 200 μm. In that case, a roll laminator or a vacuum laminator may be used.

[Polymer resin with a glass transition point of 20 ° C or less and a weight average molecular weight of 30,000 or more]
The resin layer contains a polymer resin having a glass transition point of 20 ° C. or lower and a weight average molecular weight of 30,000 or more. The glass transition point of the polymer resin is preferably −40 to 20 ° C., more preferably −15 to 15 ° C., and particularly preferably −5 to 15 ° C. When the temperature is −5 to 15 ° C., the warp of the cured product can be satisfactorily suppressed.
Further, the higher the weight average molecular weight of the polymer resin, the greater the effect of preventing the inorganic filler from settling. Therefore, it is preferably 100,000 or more, and more preferably 200,000 or more. The upper limit is, for example, 1 million or less.

Examples of the polymer resin include polymer resins having one or more 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. .. For example, a polymer resin having a butadiene skeleton ("G-1000", "G-3000", "GI-1000", "GI-3000" manufactured by Nippon Soda, "R-45EPI" manufactured by Idemitsu Petrochemical Co., Ltd., Daisel "PB3600", "Epofriend AT501" manufactured by Chemical Industry Co., Ltd., "Ricon130", "Ricon142", "Ricon150", "Ricon657", "Ricon130MA" manufactured by Clay Valley Co., Ltd.), a polymer resin having a butadiene skeleton and a polyimide skeleton ( Japanese Patent Laid-Open No. 2006-37083), polymer resin having an acrylic skeleton (“SG-P3”, “SG-600LB”, “SG-280”, “SG-790”, “SG-790” manufactured by Nagase ChemteX Corporation. "SG-K2", "SN-50" manufactured by Negami Kogyo Co., Ltd., "AS-3000E", "ME-2000") and the like.

The polymer resin is preferably an acrylic copolymer having a glass transition point of 20 ° C. or lower and a weight average molecular weight of 200,000 or more from the viewpoint of flatness of the cured product. In addition, from the viewpoint of adhesiveness to biaxially stretched polypropylene film (OPP) and adhesiveness to low-roughness substrates and circuits, the glass transition point is -5 to 15 ° C. and the weight average molecular weight is 200,000 to 500,000. It is preferably an acrylic copolymer.

The acrylic acid ester 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 acid ester copolymer preferably has an epoxy group, and more preferably has an epoxy group and an amide group. By having an epoxy group, it is possible to suppress the warp of the cured product.

Examples of the acrylic acid ester copolymer include Teisan Resin SG-70L, SG-708-6, WS-023 EK30, SG-P3, SG-80H, SG-280 EK23, SG-600TEA manufactured by Nagase ChemteX Corporation. SG-790 can be mentioned. The acrylic acid ester copolymer may be obtained by synthesis, and examples of the synthesis method include the synthesis method described in JP-A-2016-102200.

The polymer resin may be used alone or in combination of two or more. The blending amount of the polymer is preferably 0.5 to 10% by mass, more preferably 1.0 to 7.0% by mass, and 2.0 to 7 by mass based on the total solid content of the composition. It is more preferably 9.0% by mass, and particularly preferably 4.0 to 7.0% by mass.

In the present specification, the value of the weight average molecular weight (Mw) can be measured by the gel permeation chromatography (GPC) method (polystyrene standard) with the following measuring device and measuring conditions.
Measuring device: "Waters 2695" made by Waters
Detector: Waters 2414, RI (Differential Refractometer)
Column: Waters "HSPgel Colon, HR MB-L, 3 μm, 6 mm x 150 mm" x 2 + Waters "HSPgel Colon, HR 1, 3 μm, 6 mm x 150 mm" x 2
Measurement condition:
Column temperature: 40 ° C
RI detector set temperature: 35 ° C
Developing solvent: Tetrahydrofuran Flow rate: 0.5 ml / min Sample volume: 10 μl
Sample concentration: 0.7 wt%

[Epoxy resin]
The resin layer contains an epoxy resin. The epoxy resin is a resin having an epoxy group, and any conventionally known resin can be used. Examples thereof include a bifunctional epoxy resin having two epoxy groups in the molecule, a polyfunctional epoxy resin having three or more epoxy groups in the molecule, and the like. It may be a hydrogenated epoxy resin. The resin layer contains at least one of a semi-solid epoxy resin and a crystalline epoxy resin as the epoxy resin. As the semi-solid epoxy resin and the crystalline epoxy resin, one type may be used alone or two or more types may be used in combination. Further, the resin layer may contain a solid epoxy resin or a liquid epoxy resin. In the present specification, the solid epoxy resin refers to an epoxy resin that is solid at 40 ° C., and the semi-solid epoxy resin refers to an epoxy resin that is solid at 20 ° C. and liquid at 40 ° C., and is a liquid epoxy resin. Refers to an epoxy resin that is liquid at 20 ° C. Judgment of liquidity is carried out in accordance with the "Liquid confirmation method" of Attachment 2 of the Ministerial Ordinance on Dangerous Goods Testing and Properties (Ministerial Ordinance No. 1 of 1989). For example, the method described in paragraphs 23 to 25 of JP-A-2016-079384 is used. Further, the crystalline epoxy resin means an epoxy resin having strong crystallinity, and at a temperature below the melting point, the polymer chains are regularly arranged, and although it is a solid resin, it has a low viscosity comparable to that of a liquid resin when melted. A thermosetting epoxy resin.

Examples of the semi-solid epoxy resin include Epicron 860, Epicron 900-IM, Epicron EXA-4816, Epicron EXA-4822, Asahi Ciba Araldite AER280, Toto Kasei Epototo YD-134, and Mitsubishi Chemical jER834. Examples thereof include bisphenol A type epoxy resin such as jER872 and ELA-134 manufactured by Sumitomo Chemical Industries; naphthalene type epoxy resin such as Epicron HP-4032 manufactured by DIC; and phenol novolac type epoxy resin such as Epicron N-740 manufactured by DIC. ..
The semi-solid epoxy resin preferably contains at least one selected from the group consisting of bisphenol A type epoxy resin, naphthalene type epoxy resin and phenol novolac type epoxy resin. By containing 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.

As the crystalline epoxy resin, for example, a crystalline epoxy resin having a biphenyl structure, a sulfide structure, a phenylene structure, a naphthalene structure, or the like can be used. Biphenyl type epoxy resins are provided as, for example, jER YX4000, jER YX4000H, jER YL6121H, jER YL6640, jER YL6677 manufactured by Mitsubishi Chemical Corporation, and diphenyl sulfide type epoxy resins are provided as, for example, Epototo YSLV-120TE manufactured by Toto Kasei Co., Ltd. The phenylene type epoxy resin is provided as, for example, Epototo YDC-1312 manufactured by Toto Kasei Co., Ltd., and the naphthalene type epoxy resin is provided as, for example, EPICLON HP-4032, EPICLON HP-4032D, EPICLON manufactured by DIC Corporation. It is provided as HP-4700. Further, as the crystalline epoxy resin, Epototo YSLV-90C manufactured by Toto Kasei Co., Ltd. and TEPIC-S (triglycidyl isocyanurate) manufactured by Nissan Kasei Kogyo Co., Ltd. can also be used.

As the solid epoxy resin, HP-4700 (naphthalene type epoxy resin) manufactured by DIC, EXA4700 (tetrafunctional naphthalene type epoxy resin) manufactured by DIC, NC-7000 (polyfunctional solid epoxy resin containing naphthalene skeleton) manufactured by Nippon Kayaku Co., Ltd. Naphthalene type epoxy resin such as EPPN-502H (Trisphenol epoxy resin) manufactured by Nippon Kayaku Co., Ltd .; Epoxy product of a condensate of phenols such as EPPN-502H (Trisphenol epoxy resin) and aromatic aldehyde having a phenolic hydroxyl group (Trisphenol type epoxy resin); Dicyclopentadiene aralkyl type epoxy resin such as Epicron HP-7200H (dicyclopentadiene skeleton-containing polyfunctional solid epoxy resin); Biphenyl aralkyl such as Nippon Kayaku Co., Ltd. NC-3000H (biphenyl skeleton-containing polyfunctional solid epoxy resin) Type epoxy resin; Biphenyl / phenol novolac type epoxy resin such as NC-3000L manufactured by Nippon Kayaku Co., Ltd .; Novolak type epoxy resin such as Epicron N660, Epicron N690, N770 manufactured by DIC Co., Ltd .; EOCN-104S manufactured by Nippon Kayaku Co., Ltd .; Nippon Steel & Sumitomo Metal. Phosphorus-containing epoxy resin such as TX0712 manufactured by Kagaku Co., Ltd .; Tris (2,3-epoxypropyl) isocyanurate such as TEPIC manufactured by Nissan Kagaku Kogyo Co., Ltd. can be mentioned. By containing the solid epoxy resin, the glass transition temperature of the cured product becomes high and the heat resistance is excellent.

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, glycidylamine type epoxy resin, and aminophenol type epoxy resin. , Alicyclic epoxy resin and the like. By containing a liquid epoxy resin, the flexibility of the dry film is excellent.

The total amount of the semi-solid epoxy resin and the crystalline epoxy resin is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, based on the total amount of the epoxy resin. Within the above range, the resin layer of the dry film is excellent in tackiness and flexibility.

The thermosetting resin composition of the present invention may contain a thermosetting resin other than the (A) epoxy resin as long as the effects of the present invention are not impaired, and may contain, for example, an isocyanate compound, a blocked isocyanate compound, and an amino resin. , Benzoxazine resin, Carbodiimide resin, Cyclocarbonate compound, Polyfunctional oxetane compound, Episulfide resin and other known and commonly used thermosetting resins can be used.

[Inorganic filler]
The resin layer contains an inorganic filler. By blending an inorganic filler, the curing shrinkage of the obtained cured product is suppressed, and the thermal properties such as adhesion, hardness, and thermal properties such as crack resistance are improved by matching the thermal strength with the conductor layer such as copper around the insulating layer. Can be made to. Conventionally known inorganic fillers can be used as the inorganic fillers, and the inorganic fillers are not limited to specific ones. , Neuburg Silica particles, boehmite, magnesium carbonate, calcium carbonate, titanium oxide, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, calcium zirconate and other extender pigments, copper, tin, zinc, nickel, silver, palladium , Aluminum, iron, cobalt, gold, platinum and other metal powders. The inorganic filler is preferably spherical particles. Among them, silica is preferable, and it suppresses the curing shrinkage of the cured product of the curable composition, lowers the CTE, and improves the properties such as adhesion and hardness. Further, an inorganic filler having a large specific gravity such as alumina generally has a high sedimentation rate, but in the present invention, it can be suitably used because it can suppress sedimentation. The average particle size (median diameter, D50) of the inorganic filler is preferably 0.01 to 10 μm. The inorganic filler is preferably silica having an average particle size of 0.01 to 3 μm from the viewpoint of slit processability. In the present specification, the average particle size of the inorganic filler is the average particle size including not only the particle size of the primary particles but also the particle size of the secondary particles (aggregates). The average particle size can be obtained by a laser diffraction type particle size distribution measuring device. Examples of the measuring device by the laser diffraction method include Nanotrac wave manufactured by Nikkiso Co., Ltd.

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

The surface treatment of the inorganic filler is preferably a surface treatment with a coupling agent. As the coupling agent, a silane-based, titanate-based, aluminate-based, zircoaluminate-based, or other coupling agent can be used. Of these, a silane-based coupling agent is preferable. Examples of such silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminomethyl) -3-aminopropylmethyldimethoxysilane, and N- (2-aminoethyl) -3-amino. Propyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxy) Cyclohexyl) ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like can be mentioned, and these can be used alone or in combination. It is preferable that these silane-based coupling agents are previously immobilized on the surface of the inorganic filler by adsorption or reaction. Here, the treatment amount of the coupling agent with respect to 100 parts by mass of the inorganic filler is, for example, 0.5 to 10 parts by mass.

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. Can be mentioned. Of these, at least one of an amino group and an epoxy group is preferable. The surface-treated inorganic filler may have a photocurable reactive group in addition to the thermosetting reactive group.

The surface-treated inorganic filler may be contained in the resin layer in the surface-treated state, and the inorganic filler and the surface treatment agent are separately added to the curable resin composition forming the resin layer. The inorganic filler may be surface-treated in the composition by blending, but it is preferable to blend the inorganic filler which has been surface-treated in advance. By blending the inorganic fillers that have been surface-treated in advance, it is possible to prevent deterioration of crack resistance and the like due to the surface treatment agent that may remain in the surface treatment when they are blended separately. In the case of surface treatment in advance, it is preferable to mix a pre-dispersion liquid in which an inorganic filler is pre-dispersed in a solvent or a curable resin. Alternatively, it is more preferable to sufficiently surface-treat the surface-untreated inorganic filler when pre-dispersing it in a solvent, and then add the pre-dispersion liquid to the composition.

The inorganic filler may be blended with an epoxy resin or the like in a powder or solid state, or may be mixed with a solvent or a dispersant to form a slurry and then blended with the epoxy resin or the like.

The inorganic filler may be used alone or as a mixture of two or more. The blending amount of the inorganic filler is preferably 10 to 90% by mass, more preferably 50 to 90% by mass, and 60 to 90% by mass based on the total solid content of the resin layer of the dry film. Is even more preferable. When the blending amount of the inorganic filler is 10% by mass or more, thermal expansion is suppressed and the heat resistance is improved, while when it is 90% by mass or less, the generation of cracks can be suppressed.

Further, as described above, the problems of the adhesion between the resin layer and the protective film and the precipitation of the inorganic filler are remarkable especially when the content of the inorganic filler is high. In the present invention, a particularly excellent effect can be obtained when the blending amount of the inorganic filler is large, for example, when the solid content of the resin layer of the dry film is 50% by mass or more based on the total solid content. Further, when the content is 70% by mass or more, the sedimentation of the inorganic filler is particularly remarkable, but according to the present invention, it is excellent in suppressing the sedimentation of the inorganic filler.

Further, from the viewpoint of suppressing the sedimentation of the inorganic filler, the resin layer contains an inorganic filler having an average particle diameter of 0.1 to 10 μm (hereinafter, also referred to as “large diameter inorganic filler”) and an average particle diameter of 0.01. An inorganic filler having an average particle diameter of 0.1 to 10 μm and an inorganic filler having an average particle diameter of 0.01 to 5 μm and containing a mixture with an inorganic filler having an average particle diameter of up to 5 μm (hereinafter, also referred to as “small diameter inorganic filler”). It is preferable that the difference between the peaks of the particle size in the particle size distribution measurement of the filler is 0.05 μm or more. By blending such inorganic fillers having different average particle sizes and combining with a polymer resin having a glass transition point of 20 ° C. or less and a weight average molecular weight of 30,000 or more, sedimentation of the inorganic filler can be further prevented and coating can be performed. It is possible to suppress the settling of time. In addition, the surface of the cured product of the resin layer is excellent in smoothness, and the thickness of the resin layer can be maintained even after embedding the component. Further, it is easy to highly fill the inorganic filler, and a cured product having a high elastic modulus can be obtained by high filling. The peak value of the particle size can be obtained by a laser diffraction type particle size distribution measuring device. Examples of the measuring device by the laser diffraction method include Nanotrac wave manufactured by Nikkiso Co., Ltd. When three or more kinds of inorganic fillers are contained, the inorganic filler having the smallest diameter within the range of 0.01 to 5 μm is used as the small diameter inorganic filler, and the other inorganic fillers have an average particle diameter of 0.1. Anything within the range of ~ 10 μm and having a difference of 0.05 μm or more between peaks in the particle size distribution measurement with the minimum diameter inorganic filler shall be considered to correspond to the large diameter inorganic filler.

The inorganic filler having an average particle size of 0.1 to 10 μm preferably has an average particle size of 0.1 to 8 μm. The smaller the average particle size, the better the roughening of the surface of the cured product after desmear, and the more the silica can be suppressed from settling and agglomerating.

The inorganic filler having an average particle size of 0.01 to 5 μm preferably has an average particle size of 0.03 to 3 μm. The smaller the average particle size, the better the roughening of the surface of the cured product after desmear, and the more the silica can be suppressed from settling and agglomerating.

The maximum value of the difference between the peaks in the particle size distribution measurement of the inorganic filler having an average particle size of 0.1 to 10 μm and the inorganic filler having an average particle size of 0.01 to 5 μm is, for example, 5 μm.

The blending amount of the inorganic filler having an average particle size of 0.1 to 10 μm is preferably 5 to 80% by mass based on the total solid content of the composition.

The blending amount of the inorganic filler having an average particle size of 0.01 to 5 μm is preferably 5 to 15% by mass based on the total solid content of the composition.

[Curing agent]
The resin layer preferably contains a curing agent. Examples of the curing agent include compounds having a phenolic hydroxyl group, polycarboxylic acids and their acid anhydrides, compounds having a cyanate ester group, compounds having an active ester group, compounds having a maleimide group, and alicyclic olefin polymers. Be done. The curing agent may be used alone or in combination of two or more.

In the present invention, the resin layer preferably contains at least one of a compound having a phenolic hydroxyl group, a compound having an active ester group, a compound having a cyanate ester group, and a compound having a maleimide group. By using a compound having a phenolic hydroxyl group and a compound having an active ester group, a cured product having excellent adhesion to a low-roughness substrate or a circuit can be obtained. Further, by using the cyanate ester, the Tg of the cured product is increased and the heat resistance is improved, and by using the compound having a maleimide group, the Tg of the cured product is increased and the heat resistance is improved. CTE can be reduced.

Examples of the compound having a phenolic hydroxyl group include phenol novolac resin, alkylphenol volac resin, bisphenol A novolak resin, dicyclopentadiene type phenol resin, Xylok type phenol resin, terpene-modified phenol resin, cresol / naphthol resin, polyvinylphenols, and the like. Conventionally known materials such as phenol / naphthol resin, α-naphthol skeleton-containing phenol resin, triazine skeleton-containing cresol novolak resin, biphenyl aralkyl type phenol resin, and zylock type phenol novolak resin can be used.
Among the compounds having a phenolic hydroxyl group, the hydroxyl group equivalent is 100 g / eq. The above is preferable. The hydroxyl group equivalent is 100 g / eq. Examples of the compound having the above phenolic hydroxyl group include dicyclopentadiene skeleton phenol novolac resin (GDP series, manufactured by Gunei Chemical Co., Ltd.), zylock type phenol novolac resin (MEH-7800, manufactured by Meiwa Kasei Co., Ltd.), and biphenyl aralkyl type. Novolac resin (MEH-7851, manufactured by Meiwa Kasei Co., Ltd.), naphthol aralkyl type curing agent (SN series, manufactured by Nippon Steel & Sumitomo Metal Corporation), cresol novolak resin containing triazine skeleton (LA-3018-50P, manufactured by DIC), phenol containing triazine skeleton Examples thereof include novolak resin (LA-705N, manufactured by DIC).

The compound having a cyanate ester group is preferably a compound having two or more cyanate ester groups (-OCN) in one molecule. As the compound having a cyanate ester group, any conventionally known compound can be used. Examples of the compound having a cyanate ester group include phenol novolac type cyanate ester resin, alkylphenol novolak 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 can be mentioned. Further, it may be a prepolymer in which a part is triazine-ized.

Commercially available compounds having a cyanate ester group include a phenol novolac type polyfunctional cyanate ester resin (PT30S manufactured by Ronza Japan Co., Ltd.) and a prepolymer in which a part or all of bisphenol A dicyanate is triazined to form a trimer. (Lonza Japan Co., Ltd., BA230S75), dicyclopentadiene structure-containing cyanate ester resin (Lonza Japan Co., Ltd., DT-4000, DT-7000) and the like can be mentioned.

The compound having an active ester group is preferably a compound having two or more active ester groups in one molecule. A compound having an active ester group can generally be obtained by a condensation reaction between a carboxylic acid compound and a hydroxy compound. Among them, a compound having an active ester group obtained by using a phenol compound or a naphthol compound as the hydroxy compound is preferable. Examples of the phenol compound or naphthol compound include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, 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, fluoroglucin, benzenetriol , Dicyclopentadienyldiphenol, phenol novolac and the like. Further, the compound having an active ester group may be a naphthalenediol alkyl / benzoic acid type.

Commercially available compounds having an active ester group include dicyclopentadiene-type diphenol compounds such as HPC8000-65T (manufactured by DIC), HPC8100-65T (manufactured by DIC), and HPC8150-65T (manufactured by DIC). Can be 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 two or more maleimide skeletons, N, N'-1,3-phenylenedi maleimide, N, N'-1,4-phenylenedi maleimide, N, N'-4. , 4-Diphenylmethane bismaleimide, 1,2-bis (maleimide) ethane, 1,6-bismaleimide hexane, 1,6-bismaleimide- (2,2,4-trimethyl) hexane, 2,2'-bis- [4- (4-Maleimidephenoxy) phenyl] Propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, bis ( 3-Ethyl-5-methyl-4-maleimidephenyl) methane, bisphenol A diphenyl ether bismaleimide, polyphenylmethane maleimide, and oligomers thereof, and at least one of diamine condensates having a maleimide skeleton. Is more preferable. The oligomer is an oligomer obtained by condensing a compound having a maleimide group, which is a monomer among the above-mentioned compounds having a maleimide group.

Commercially available compounds having a maleimide group include BMI-1000 (4,4'-diphenylmethanebismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI-2300 (phenylmethanebismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI-. 3000 (m-phenylene bismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI-5100 (3,3'-dimethyl-5,5'-dimethyl-4,4'-diphenylmethanebismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI -7000 (4-methyl-1,3,-phenylene bismaleimide, manufactured by Daiwa Kasei Kogyo Co., Ltd.), BMI-TMH ((1,6-bismaleimide-2, 2,4-trimethyl) hexane, manufactured by Daiwa Kasei Kogyo Co., Ltd.) ) And so on.

The blending amount of the curing agent is preferably 20 to 100 parts by mass, more preferably 25 to 90 parts by mass with respect to 100 parts by mass of the epoxy resin.

Specific examples of the curable resin composition forming the resin layer include a thermosetting resin composition, a photocurable thermosetting resin composition, and a photocurable thermosetting resin composition containing a photopolymerization initiator. , A photocurable thermosetting resin composition containing a photobase generator, a photocurable thermosetting resin composition containing a photoacid generator, a negative photocurable thermosetting resin composition and a positive photosensitive Thermosetting resin composition, alkali-developed photocurable thermosetting resin composition, solvent-developed photocurable thermosetting resin composition, swelling peeling type thermosetting resin composition, dissolution peeling type thermosetting Examples thereof include, but are not limited to, resin compositions.

Hereinafter, as an example, in the case of forming a resin layer with a thermosetting resin composition containing no photocurable component, components that may be contained in addition to the above components will be described.

The resin layer may contain a thermosetting resin other than an epoxy resin, and may contain, for example, an isocyanate compound, a blocked isocyanate compound, an amino resin, a benzoxazine resin, a carbodiimide resin, a cyclocarbonate compound, a polyfunctional oxetane compound, or an episulfide resin. A known and commonly used thermosetting resin such as the above can be used.

The resin layer may further contain a thermoplastic resin in order to improve the mechanical strength of the obtained cured film. The thermoplastic resin is preferably soluble in a solvent. When it is soluble in a solvent, the flexibility of the dry film is improved, and the generation of cracks and the falling of powder can be suppressed. As the thermoplastic resin, various acid anhydrides or acid chlorides are used for the thermoplastic polyhydroxypolyether resin, the phenoxy resin which is a condensate of epichlorohydrin and various bifunctional phenol compounds, or the hydroxyl group of the hydroxyether portion present in the skeleton thereof. Examples thereof include a phenoxy resin, a polyvinyl acetal resin, a polyamide resin, a polyamide imide resin, and a block copolymer that have been esterified. The thermoplastic resin may be used alone or in combination of two or more.

The blending 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 resin layer. When the blending amount of the thermoplastic resin is within the above range, a uniform roughened surface state can be easily obtained.

Further, the resin layer can contain rubber-like particles, if 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 group-modified polybutadiene rubber, carboxyl group-modified or hydroxyl-modified acrylonitrile-butadiene rubber, and Examples thereof include crosslinked rubber particles and core-shell type rubber particles, and one type can be used alone or in combination of two or more types. These rubber-like particles are added to improve the flexibility of the obtained cured film, improve crack resistance, enable surface roughening treatment with an oxidizing agent, and improve the adhesion strength with copper foil and the like. Will be done.

The average particle size 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 size of the rubber-like particles in the present invention can be obtained by a laser diffraction type particle size distribution measuring device. For example, rubber-like particles are uniformly dispersed in an appropriate organic solvent by ultrasonic waves, etc., and the particle size distribution of the rubber-like particles is created on a mass basis using Nanotrac wave manufactured by Nikkiso Co., Ltd., and the median diameter is defined as the average particle diameter. It can be measured by doing.

The blending 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 resin layer. When it is 0.5% by mass or more, crack resistance can be obtained and the adhesion strength with the conductor pattern or the like can be improved. When it is 10% by mass or less, the coefficient of thermal expansion (CTE) decreases, the glass transition temperature (Tg) increases, and the curing characteristics are improved.

The resin layer can contain a curing accelerator. The curing accelerator promotes 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; diaminodiphenylmethane, m-phenylenediamine, m-xylenedamine, diaminodiphenylsulphon, dicyandiamide, urea and urea derivatives. Polyamines such as melamine, polybasic hydrazide; these organolates and / or epoxyadducts; amine complexes of boron trifluoride; ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4- Triazine derivatives such as diamino-6-xysilyl-S-triazine; trimethylamine, triethanolamine, N, N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholin, hexa (N-methyl) melamine, Amines such as 2,4,6-tris (dimethylaminophenol), tetramethylguanidine, m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolac, alkylphenol novolac; tributylphosphine, triphenylphosphine , Organic phosphines such as tris-2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide, hexadecyltributylphosphonium chloride; benzyltrimethylammonium chloride, phenyltributylammonium chloride and the like. Tertiary ammonium salts; the polybasic acid anhydrides; photocationic polymerization catalysts such as diphenyliodonium tetrafluoroboroate, triphenylsulfonium hexafluoroantimonate, 2,4,6-triphenylthiopyrilium hexafluorophosphate; styrene- Maleic anhydride resin; isomolar reactants of phenylisocyanate and dimethylamine, equimolar reactants of organic polyisocyanate such as tolylene diisocyanate and isophorone diisocyanate and dimethylamine, and conventionally known curing accelerators such as metal catalysts can be mentioned. .. Among the curing accelerators, phosphonium salts are preferable because BHAST resistance can be obtained.

As the curing accelerator, one kind may be used alone or two or more kinds may be mixed. The use of a curing accelerator is not essential, but when it is particularly desired to accelerate curing, it can be preferably used in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the epoxy resin. In the case of a metal catalyst, 10 to 550 ppm in terms of metal is preferable, and 25 to 200 ppm is more preferable with respect to 100 parts by mass of the compound having a cyanate ester 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. can. Specifically, ketones such as methyl ethyl ketone, cyclohexanone, methyl butyl ketone and methyl isobutyl ketone; aromatic hydrocarbons such as toluene, xylene and tetramethyl benzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, etc. Glycol ethers such as butyl carbitol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; acetic acid Esters such as ethyl, butyl acetate, isobutyl acetate, ethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol butyl ether acetate; ethanol, propanol, 2-methoxy Alcohols such as propanol, n-butanol, isobutyl alcohol, isopentyl alcohol, ethylene glycol, propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum-based such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, solvent naphtha, etc. In addition to solvents and the like, N, N-dimethylformamide (DMF), tetrachloroethylene, televisionn oil and the like can be mentioned. In addition, Maruzen Petrochemical Co., Ltd. Swazole 1000, Swazole 1500, Standard Petroleum Osaka Sales Office Co., Ltd. Solbesso 100, Solbesso 150, Sankyo Chemical Co., Ltd. Solvent # 100, Solvent # 150, Shell Chemicals Japan Co., Ltd. , Idemitsu Kosan Co., Ltd. Ipsol No. 100, Ipsol No. 150 and other organic solvents may be used. The organic solvent may be used alone or as a mixture of two or more.

The amount of residual solvent in the resin layer is preferably 0.5 to 7.0% by mass. When the residual solvent is 7.0% by mass or less, bumping during heat curing is suppressed and the flatness of the surface becomes better. In addition, it is possible to prevent the resin from flowing due to the melt viscosity being lowered too much, and the flatness is improved. When the residual solvent is 0.5% by mass or more, the fluidity at the time of laminating is good, and the flatness and the embedding property are better.

If necessary, the resin layer may further include conventionally known colorants such as phthalocyanine blue, phthalocyanine green, iodin green, disazo yellow, crystal violet, titanium oxide, carbon black, and naphthalene black, asbestos, orben, and benton. , Conventionally known thickeners such as fine powder silica, antifoaming agents such as silicone-based, fluorine-based, and polymer-based and / or leveling agents, thiazole-based, triazole-based, adhesion-imparting agents such as silane coupling agents, Conventionally known additives such as flame retardants, titanates, and aluminum can be used.

As a method for manufacturing a printed wiring board using the dry film of the present invention, a conventionally known method may be used. For example, in the case where the resin layer is made of a thermosetting resin composition and the resin layer is sandwiched between the carrier film and the protective film as shown in FIG. 1, the following method is used. A printed wiring board can be manufactured at. Either the carrier film or the protective film is peeled off from the dry film, heat-laminated on the circuit board on which the circuit pattern is formed, and then thermoset. The thermosetting may be cured in an oven or may be cured by a hot plate press. When laminating or hot plate pressing the substrate on which the circuit is formed and the dry film of the present invention, the copper foil or the substrate on which the circuit is formed can be laminated at the same time. A printed wiring board can be manufactured by forming a pattern or a via hole at a position corresponding to a predetermined position on a substrate on which a circuit pattern is formed by laser irradiation or a drill to expose the circuit wiring. At this time, if there is a residual component (smear) that cannot be completely removed on the pattern or the circuit wiring in the via hole, the desmear process is performed. The remaining carrier film or protective film may be peeled off either after laminating, after thermosetting, after laser processing, or after desmear treatment. The layer circuit may be connected by a copper pillar.

[Carrier film]
The carrier film has a role of supporting the resin layer of the dry film, and is a film to which the curable resin composition is applied when the resin layer is formed. Examples of the carrier film include polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyimide films, polyamideimide films, polyethylene films, polytetrafluoroethylene films, polypropylene films, and films made of thermoplastic resins such as polystyrene films, and Surface-treated paper or the like can be used. Among these, a polyester film can be preferably used from the viewpoints of heat resistance, mechanical strength, handleability and the like. The thickness of the carrier film is not particularly limited, but is appropriately selected depending on the intended use in the range of approximately 10 to 150 μm. The surface of the carrier film on which the resin layer is provided may be subjected to a mold release treatment. Further, sputter or ultrathin copper foil may be formed on the surface of the carrier film on which the resin layer is provided.

[Protective film]
The protective film is provided on the surface opposite to the carrier film of the resin layer for the purpose of preventing dust and the like from adhering to the surface of the resin layer of the dry film and improving handleability. In the present invention, a biaxially stretched polypropylene film is used as the protective film. By using the biaxially stretched polypropylene film, it is possible to reduce the cooling shrinkage after laminating on the resin layer. The thickness of the protective film is not particularly limited, but is appropriately selected depending on the application in the range of approximately 10 to 100 μm. It is preferable that the surface of the protective film on which the resin layer is provided is subjected to a treatment for improving adhesion such as embossing, corona treatment, and slight adhesive treatment, and a mold release treatment.

The dry film of the present invention can be preferably used for forming a permanent protective film for electronic components, particularly a printed wiring board, and particularly preferably for forming a coverlay for a solder resist layer, an interlayer insulating layer, and a flexible printed wiring board. can. In particular, the dry film of the present invention can be preferably used for forming a cured product having a high content of inorganic filler. A wiring board may be formed by bonding wirings using the dry film of the present invention. It can also be used as a sealing material for semiconductor chips.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples of the present invention, but it goes without saying that the present invention is not limited to the following examples. In the following, "part" and "%" are all based on mass unless otherwise specified.

<Production Example 1 of a polymer compound having a glass transition point of 20 ° C. or less and a weight average molecular weight of 30,000 or more>
[Manufacturing of Polymer Resin A and Polymer Resin B]
In a reaction vessel, 50 g of bifunctional hydroxyl group-terminated polybutadiene G-3000 (hydroxyl group equivalent = 1800 g / eq., Solid content 100 wt%: manufactured by Nippon Soda Co., Ltd.) and Ipsol 150 (aromatic hydrocarbon mixed solvent: Idemitsu Petroleum) (Chemical Co., Ltd.) 100 g and 0.005 g of dibutyltin laurate were mixed and uniformly dissolved. When it became uniform, the temperature was raised to 50 ° C., and 3.08 g of isophorone diisocyanate (IPDI, Mw = 222, isocyanate group equivalent = 111 g / eq.) Was added with stirring for about 3 hours and about 12 hours. The reaction was carried out in two ways. Each of the obtained reaction solutions was added dropwise to the n-hexane solution to precipitate a white precipitate. Then, the white precipitate was recovered by filtration and dried at 100 ° C. for 2 hours to obtain a polymer of polybutadiene and IPDI having a ratio of about 1: 1.
The obtained polymer was subjected to GPC measurement (Waters, 2695 polystyrene conversion) and DSC measurement ((DSC-6100, Seiko Instruments, temperature rise rate 5 ° C.)), and the molecular weight Mw and the glass transition temperature Tg, respectively. As a result, it was confirmed that the one having a short reaction time (hereinafter referred to as polymer resin A) had a weight average molecular weight of Mw = 50,000 and Tg = −10 ° C., while the reaction was carried out. It was confirmed that the one having a long time (hereinafter referred to as polymer resin B) had a weight average molecular weight of Mw = 250,000 and Tg = -12 ° C.

<Preparation of curable resin composition>
The solvents described in Examples and Comparative Examples were placed in a container, stirred while heating at 50 ° C., and then each component other than the filler was added. After confirming that those components were dissolved, a filler was added and the mixture was sufficiently stirred. Then, it was kneaded with a three-roll mill to prepare a curable resin composition. The numerical values in the table indicate parts by mass, and indicate the amount of solid content other than the solvent.

<Precipitation after stirring and standing>
The prepared curable resin composition was placed in a transparent glass screw tube and stored in a constant temperature bath set at 23 ° C. for 12 hours for aging treatment. The curable resin composition was charged 50 mm from the bottom of the screw tube. After aging, the curable resin composition was taken out and visually observed from the side surface to confirm the sedimentation state of the curable resin composition. The judgment criteria are as follows.
◎ ◎: No sedimentation is observed.
⊚: A transparent supernatant liquid of less than 1 mm was confirmed from the upper part of the composition.
〇: A transparent supernatant liquid of 1 mm or more and less than 3 mm was confirmed from the upper part of the composition.
Δ: A transparent supernatant liquid of 3 mm or more and less than 5 mm was confirmed from the upper part of the composition.
X: A transparent supernatant liquid of 5 mm or more was confirmed from the upper part of the composition. When the sediment was confirmed with a grind meter, aggregated particles were confirmed.

<Making a dry film and evaluating its appearance>
Adjust the amount of the solvent so that the prepared curable resin composition has a viscosity of 0.5 to 20 dPa · s (rotational viscometer 5 rpm, 25 ° C.), and use a bar coater to adjust the thickness of the resin layer. Was applied to a carrier film (PET film; Toray Industries, Inc. Lumirror 38R75, thickness 38 μm, size 30 cm × 30 cm) so as to be 40 μm after drying. Next, in a hot air circulation type drying oven, the resin layer is dried at 70 to 120 ° C. (average 100 ° C.) for 5 to 10 minutes so that the residual solvent in the resin layer is 0.5 to 2.5% by mass, and is placed on a carrier film. A resin layer was formed. The surface state of the resin layer was visually classified into the following three under a white light source.
Matte: No light reflection is seen on the resin surface even under a white light source.
Semi-matte: There is a slight reflection of the white light source.
Gross: Reflections from a white light source can be seen.

<Adhesion with biaxially stretched polypropylene film (OPP)>
OPP (Alfan FG-201, Fish Aires, Oji F-Tex) was adhered to the surface of the resin layer of the produced dry film using a roll laminator. The conditions of the roll laminator were two ways, the surface temperature was 80 ° C. or 110 ° C., the linear pressure was 0.3 MPa, and the feed rate was 5 cm / sec. A strip having a width of 1 cm and a length of 10 cm was prepared from the obtained dry film having a three-layer structure, and the peeling weight of OPP was measured by the peel strength measuring method (90 ° direction, tensile speed 50 mm) described in JIS-C-6481. / Min) was measured. The evaluation criteria are as follows.
⊚: Maximum peel strength 3 N / cm or more.
〇: Maximum peel strength 1 N / cm or more and less than 3 N / cm.
Δ: Maximum peel strength less than 1 N / cm.
X: Not in close contact.

<Slit processing>
A dry film having a three-layer structure having a size of 30 × 30 cm in which OPP was adhered was cut into a size of 25 × 25 cm at the end using a cutter knife, and the state was confirmed. The evaluation criteria are as follows.
⊚: No floating of OPP and no cracking of resin.
〇: Floating of OPP (maximum part less than 1 mm) was confirmed in the cut portion.
Δ: OPP floated and the resin end was cracked (maximum portion 1 mm or more and less than 5 mm) at the cut portion.
X: OPP floated and the resin end was cracked (maximum portion 5 mm or more) at the cut portion.

<Glass transition point (Tg)>
After peeling off the OPP of the produced three-layer structure dry film, dry using the vacuum laminator MVLP-500 (manufactured by Meiki Co., Ltd.) on the glossy surface (GTS-MP-18, Furukawa Circuit Foil) of the electrolytic copper foil. The resin layers of the film were bonded together. The conditions were a temperature of 80 to 110 ° C. and a pressure of 0.5 MPa. Then, the carrier film was peeled off and the material was cured in a hot air circulation type drying oven. The conditions were 100 ° C. × 30 min + 180 ° C. × 30 min + 200 ° C. × 60 min. Subsequently, the obtained cured product was peeled off from the copper foil to obtain a cured product. Then, a sample was cut out to a measurement size (size of 3 mm × 10 mm), and measurement was performed using TMA6100 manufactured by Seiko Instruments Inc. In the TMA measurement, the sample was heated from room temperature to 280 ° C. at a heating rate of 10 ° C./min with a test load of 5 g, then air-cooled to room temperature, and measured twice in succession. The pole change point of the second temperature raising step in the second time was evaluated as Tg. The evaluation criteria are as follows.
⊚: Tg = 190 ° C. or higher.
〇: Tg = less than 190 ° C.

<CTE>
TMA measurement was carried out by the same method as the Tg measurement method. The average thermal expansion rate between 30 ° C. and 100 ° C. in the second time was defined as CTE (unit: ppm).

<Warp on copper foil>
After peeling off the OPP from the produced dry film, a vacuum laminator MVLP-500 (manufactured by Meiki Co., Ltd.) was placed on the glossy surface of an electrolytic copper foil (GTS-MP-18 μm, manufactured by Furukawa Circuit Foil, size 20 x 20 cm). ) Was used to bond the dry films. The conditions were a temperature of 80 to 110 ° C. and a pressure of 0.5 MPa. Then, the carrier film was peeled off and the material was cured in a hot air circulation type drying oven. The conditions were 100 ° C. × 30 min + 180 ° C. × 30 min + 200 ° C. × 60 min. Immediately after cooling to room temperature, the warped state of the four corners of the copper foil (warped shapes are all smiles) was measured with a caliper. The evaluation criteria are as follows.
◎: No warp.
〇: Of the four corners, the amount of warpage of the part with the largest warp is less than 3 mm.
Δ: Of the four corners, the amount of warpage of the portion with the largest warp is 3 mm or more and less than 10 mm.
X: Of the four corners, the amount of warpage of the part with the largest warp is 10 mm or more.

<Adhesion with base material (low roughness electrolytic copper)>
A solid copper substrate (MCL-E-770G, manufactured by Hitachi Kasei Kogyo) with a copper thickness of 12 μm and a plate thickness of 0.2 mm is treated with electrolytic copper plating (manufactured by Atotech, with a surface roughness of 100 nm or less after plating) to reduce the copper thickness. The total length was 20 μm. Then, as a pretreatment, a flat bond treatment (surface roughness after the treatment of 100 nm or less, manufactured by MEC) was performed. Then, the dry film from which the OPP was peeled off was bonded to the front and back surfaces of the substrate using a 2-chamber vacuum laminator CVP-600 (manufactured by Nichigo Morton). The conditions were laminating and pressing at a temperature of 80 to 110 ° C. and a pressure of 0.5 MPa, respectively. Then, the carrier film was peeled off, and the resin layer was cured in a hot air circulation type drying oven. The conditions were 100 ° C. × 30 min + 180 ° C. × 30 min + 200 ° C. × 60 min. Then, a cutter knife was used on the surface of the obtained cured film to prepare a 100-square grid with a size of 1 mm × 1 mm (based on JIS-K5400, grid test). After that, a polyester tape ((1) product number 8422B: adhesive strength 5.1 N / cm and (2) product number 879: adhesive strength 15 N / cm, both manufactured by 3M) is attached to the surface of the cut cured film, and the tape is immediately taped. The tape was momentarily peeled off by holding the edge of the tape and keeping it perpendicular to the cured film surface. The state of the coating film after peeling was judged according to the following criteria.
◎ ◎: Mass 0 peeled off with tape (2).
⊚: With tape (2), one or more and less than five peeled masses. In the tape (1), the peeled mass is 0.
〇: With tape (1), 1 or more and less than 5 stripped masses.
Δ: 5 or more and less than 20 stripped masses on the tape (1).
X: 20 or more squares peeled off with the tape (1).

<Flatness>
A die bonding sheet FH-900 (thickness 10 μm, manufactured by Hitachi Kasei Kogyo Co., Ltd.) was heated at 60 ° C. and bonded to the back surface of a silicon dummy chip having a thickness of 150 μm and a size of 10 × 10 mm. After that, on soda glass (thickness 1.1 mm, size 60 x 60 mm, manufactured by Hiraoka Special Glass Co., Ltd.), vacuum laminator MVLP-500 (manufactured by Meiki Co., Ltd .; conditions are 100 ° C., 0.5 MPa, time 1 minute). Was used and bonded at a pitch of 5 mm. After that, a dry film from which OPP was peeled off was placed on a glass substrate on which dummy chips were arranged, and a 2-chamber vacuum laminator CVP-600 (manufactured by Nichigo Morton) was used to form a resin layer under the condition that the surface of the resin became flat. They were laminated so that the total thickness was 200 μm. Each condition was performed at a temperature of 80 to 110 ° C. and a pressure of 0.5 MPa for each of the laminating and pressing. Then, the carrier film was peeled off and the material was cured in a hot air circulation type drying oven. The conditions were 100 ° C. × 30 min + 180 ° C. × 30 min + 200 ° C. × 60 min. As the flatness evaluation on the dummy chip of the obtained substrate, the surface roughness measuring instrument Surfcoder SE-600 was used to evaluate the unevenness on the chip and the portion of the cured product only. The judgment criteria are as follows.
◎: No unevenness.
〇: Unevenness less than 5 μm.
Δ: Concavo-convexness of 5 μm or more and less than 10 μm.
X: Concavo-convexness of 10 μm or more.

* 1: Mitsubishi Chemical's jER828, bisphenol A type epoxy resin, epoxy equivalent 189 g / eq, liquid

* 2: DIC Epicron N-740, phenol novolac type epoxy resin, epoxy equivalent 182 g / eq, semi-solid * 3: Mitsubishi Chemical Epicoat YX4000H, 3,3'5,5'-tetramethyl-4,4 -Biphenol diglycidyl ether, epoxy equivalent 192 g / eq, crystalline * 4: NC-3000H manufactured by Nippon Kayaku Co., Ltd., biphenyl novolac type epoxy compound, epoxy equivalent 290 g / eq,
* 5: Ronza Japan Primaset PT-30, novolak type cyanate resin, cyanate equivalent 124 g / eq, solid * 6: DIC Epicron HPC-8000, active ester resin, active equivalent 223 g / eq, solid * 7: LA-3018 manufactured by DIC, ATN-containing cresol novolac resin, hydroxyl group equivalent 151 g / eq, solid * 8: Meiwa Kasei HF-1M, phenol novolac resin, hydroxyl group equivalent 106 g / eq,
* 9: Daiwa Kasei Kogyo BMI-2300, phenylmethanebismaleimide, maleimide equivalent 187 g / eq, solid * 10: Shikoku Kasei Co., Ltd. 2E4MZ, 2-ethyl-4-methylimidazole * 11: Tokyo Kasei Kogyo Co., Ltd. CO ( II) Cobalt (II) acetylacetonate, powder * 12: Teisan Resin SG-80H MEK cut product manufactured by Nagase ChemteX, solid content 18% by mass, acrylic acid ester copolymer (functional group: epoxy group, amide group)
* 13: Teisan Resin SG-P3 MEK cut product manufactured by Nagase ChemteX, solid content 15% by mass, acrylic acid ester copolymer (functional group: epoxy group)
* 14: Teisan Resin SG-280 MEK cut product manufactured by Nagase Chemtex Co., Ltd., solid content 23% by mass, acrylic acid ester copolymer (functional group: carboxyl group)
* 15: Teisan Resin WS-023 MEK cut product manufactured by Nagase ChemteX, solid content 30% by mass, acrylic acid ester copolymer (functional group: carboxyl group, hydroxyl group)
* 16: Polymer of polybutadiene and IPDI synthesized above (polymer resin A)
* 17: Polymer of polybutadiene and IPDI synthesized above (polymer resin B)
* 18: Mitsubishi Chemical Corporation YX6954, phenoxy resin, Mw = 38000, Tg = 130 ° C.
* 19: SO-C2 manufactured by Admatex, spherical silica, average particle size (D50) = 0.5 μm (same as the peak value in particle size distribution measurement).
* 20: SO-C1, spherical silica manufactured by Admatex, average particle size (D50) = 200 nm (same as the peak value in particle size distribution measurement)
* 21: YA050SV2 manufactured by Admatex, spherical silica treated with vinylsilane KBM-1003 at 1% by mass, average particle size (D50) = 50 nm (same as the peak value in particle size distribution measurement).
* 22: MUF-1BV manufactured by Ryumori Co., Ltd., spherical silica, average particle size (D50) = 3 μm (same as the peak value in particle size distribution measurement).
* 23: MSS-T72 manufactured by Ryumori Co., Ltd., spherical silica, average particle size (D50) = 5 μm (same as the peak value in particle size distribution measurement)
* 24: SO-C5 manufactured by Admatex, spherical silica, average particle size (D50) = 1.5 μm (same as the peak value in particle size distribution measurement)
* 25: Denka ASUS P-20, alumina, average particle size (D50) = 0.3 μm (same as the peak value in particle size distribution measurement)
* 26: KBM-403 manufactured by Shin-Etsu Silicone Co., Ltd., epoxy silane coupling agent * 27: Methyl ethyl ketone

From the results shown in the above table, it can be seen that in the case of the dry film of the example, the adhesion between the resin layer and the protective film is good, and the precipitation of the inorganic filler contained in the resin layer is small. Further, in the case of the dry film of the example, it can be seen that it is excellent in suppressing peeling, cracking and powder falling during slit processing, warpage resistance, adhesion to a substrate, and flatness of the surface of a cured product.

11 Three-layer structure dry film 12 Resin layer 13 Carrier film 14 Protective film

Claims (6)

In a dry film comprising a carrier film, a resin layer, and a protective film,
The protective film is a biaxially stretched polypropylene film.
The resin layer contains an inorganic filler, a polymer resin having a glass transition point of 20 ° C. or less and a weight average molecular weight of 30,000 or more, and an epoxy resin.
A dry film, wherein the resin layer contains at least one of a semi-solid epoxy resin and a crystalline epoxy resin as the epoxy resin. The present invention is characterized in that the resin layer contains at least one of a compound having a phenolic hydroxyl group, a compound having an active ester group, a compound having a cyanate ester group, and a compound having a maleimide group as a curing agent. 1 The dry film according to 1. The resin layer contains a mixture of an inorganic filler having an average particle size of 0.1 to 10 μm and an inorganic filler having an average particle size of 0.01 to 5 μm, and the average particle size is 0.1 to 10 μm. The dry film according to claim 1 or 2, wherein the difference between the peaks of the inorganic filler and the inorganic filler having an average particle diameter of 0.01 to 5 μm in the particle size distribution measurement is 0.05 μm or more. The dry film according to any one of claims 1 to 3, wherein the inorganic filler is contained in an amount of 50% by mass or more based on the total solid content of the resin layer. A cured product obtained by curing the resin layer of the dry film according to any one of claims 1 to 4. An electronic component comprising the cured product according to claim 5.

Images