JPH07281437A - Photosetting resin laminated body - Google Patents

Abstract

PURPOSE:To obtain a photosetting resin laminated body useful for the production of a high-density printed circuit board having through holes of small dianaeter. CONSTITUTION:The photosetting resin layer of the photosetting resin laminated body has 20-95% transmittance for UV rays of 365nm wavelength. The thermoplastic polymer included in the photosetting resin layer contains a compd. expressed by the formula and has 110-150 deg.C glass transition temp. This laminated body is used for the production of a printed circuit board having small- diameter through holes. In the formula, R1 is a hydrogen atom or alkyl group of 1-3 carbon number, X is a halogen atom or alkyl group of 1-3 carbon number, (n) is 0 or an integer 1 to 3 and when n>2, plural X may be same or different from each other.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photocurable resin laminate. More specifically, the present invention relates to a novel photocurable resin laminate suitable for manufacturing a printed wiring board having a small diameter through hole.

[0002]

2. Description of the Related Art A method called a tenting method is often used for manufacturing printed wiring boards having through holes. The tenting method is performed using a so-called dry film resist (hereinafter abbreviated as DFR) including a support and a photocurable resin layer. The tenting method is DF
A photo-curable resin layer of R covers both end openings of each through hole of a metal-coated insulating plate (hereinafter abbreviated as a substrate), and then is exposed through a wiring pattern mask or the like to cure the through hole. (Tenting film) is formed, the photo-curable resin layer in the unexposed area is removed by a developer, and then the metal conductor layer on the substrate other than the cured resist image is etched to form a print having through holes. It is a method of manufacturing a wiring board.

The hardened resist layer formed so as to cover the through holes is held by being adhered to the surface of a conductor layer (hereinafter referred to as a land) formed around the through holes, so that the etching solution is contained in the through holes. It prevents you from getting in. Therefore, in the tenting method, it is indispensable in designing to make the land, and the width thereof is about 0.5 mm.

However, in recent years, the density of printed wiring boards has been increased, and small-diameter through-holes having a smaller diameter and narrower lands have been frequently used. The small diameter through hole has a diameter of 0.5 mm or less and a land width of 0.1 mm or less, preferably 0.05 mm or less.
If the land width is narrow, the cured resist film covering the small-diameter through-hole is not sufficiently adhered to the substrate, and defects often occur due to the etching solution soaking into the small-diameter through-hole, which makes production substantially impossible. Therefore, conventionally, the hole filling ink method and the plating method, which are more complicated and costly than the tenting method, have been used.

On the other hand, if the photo-curable resin layer of DFR is embedded in the small-diameter through hole to a certain depth and is sufficiently photo-cured, it is preferable even if the positions of the mask and the through hole deviate more than the land width. It is known that a printed wiring board having a small-diameter through-hole can be manufactured by a conventional tenting process in which a different tenting film is formed (JP-A-3-236956). This was put to practical use and spread as the "embedded tenting method".

The "embedded tenting method" is disclosed in Japanese Patent Laid-Open No. 3-
As disclosed in 236956, when the laminating speed is slowed down, the photocurable resin layer is deeply embedded in the through-hole, and the effect is more exerted. Therefore, the laminating is often performed at a slower speed. However, a part of the laminating apparatus is designed so as to be compatible with the normal laminating speed of the conventional tenting method, and thus there is a restriction that it cannot be used for the “embedded tenting method”. Also,
As the use of the "embedding tenting method" has expanded, it has been required to reduce the time required for the laminating process.

In the case of DFR, Japanese Patent Laid-Open No. 23695/1993
As disclosed in JP-A-6-
The photo-curable resin layer is more embedded in the through holes, which is more effective, but on the other hand, cold flow resistance, that is, the photo-curable resin layer does not exude from the roll end surface when the winding roll is stored. Is also required. The photocurable resin layer that exudes (called edge fuse) becomes a chip when laminating and contaminates the work environment, and further adheres to the surface of the substrate, causing the generation of a defective substrate, which is very practical. It becomes a big problem.

[0008]

In the production of a printed wiring board having a small diameter through hole, the photocurable resin layer penetrates to a depth where it is effective as the "embedding tenting method" even if the laminating speed condition is made higher. It is an object to develop a photo-curable resin laminate which is embedded in the holes and satisfies the cold flow resistance.

[0009]

As a result of repeated studies to solve the above problems, among the photocurable resin layers having a specific ultraviolet transmittance, the thermoplastic polymer contained in the photocurable resin layer By selecting a specific polymer as, the normal laminating speed in the conventional tenting method (2-3 m / min)
However, the photo-curable resin layer is embedded to a depth that is effective as an "embedding tenting method", forming a good tenting film even when the position of the mask and the through hole of the substrate is deviated, and is cold flow resistant. It has been found to have properties.

That is, according to the present invention, the support layer and the ultraviolet ray having a wavelength of 365 nm, which is provided on one surface of the support layer, are applied to 20 times.
15% to 40% by weight of at least one first monomer selected from the group consisting of (a) α, β-unsaturated carboxylic acids and having a UV transmittance of At least one second monomer 5 selected from the compounds shown
~ 35% by weight,

[0011]

[Chemical 2]

(In the formula, R ₁ is a hydrogen atom or a carbon number of 1 to
3 alkyl group, X is a halogen atom or 1 to 3 carbon atoms
, An n is 0 or an integer of 1 to 3 and when n is 2 or more, a plurality of X may be the same or different from each other) and an alkyl group having 1 to 6 carbon atoms. (Meth) acrylate having a hydroxyalkyl group having 2 to 6 carbon atoms, (meth) acrylonitrile, (meth) acrylamide and hydrogen on the nitrogen thereof have 1 to 4 carbon atoms.
Obtained by vinyl copolymerizing a compound substituted with an alkyl group or an alkoxy group having 1 to 6 carbon atoms and 20 to 75% by weight of at least one third monomer selected from glycidyl methacrylate. Weight average molecular weight 30,
000 to 100,000 with a glass transition temperature of 110
One or two or more thermoplastic polymers at 150 ° C. 30 to
70 parts by weight, (b) one or more photopolymerizable compound 3 having one or more ethylenically unsaturated groups in one molecule
The present invention relates to a photocurable resin laminate comprising 0 to 70 parts by weight, and (c) a photocurable resin layer containing 0.01 to 20 parts by weight of one or more photopolymerization initiators as main components.

The photocurable resin laminate of the present invention is particularly useful as a resist film when manufacturing a printed wiring board having a small diameter through hole having a diameter of 0.5 mm or less and a land width of 0.1 mm or less. The photo-curable resin laminate of the present invention is laminated on both sides of a substrate having a small-diameter through hole at a speed of 3 m / min or less, and after exposure from both sides of the substrate, the cured resist layer obtained by etching is substantially affected by a mask shift Even in a portion where the land is not formed, a normal small-diameter through hole in which the etching solution is not soaked into the through hole can be obtained. Therefore, by using the photocurable resin laminate of the present invention, a printed wiring board having a small diameter through hole, which is difficult to manufacture with a good yield by the conventional tenting method, can be used as a usual laminate used in the conventional tenting method. Since it can be manufactured at a high speed, it can be manufactured without a laminator having a special specification, and the laminating time can be shortened.

The photo-curable resin layer constituting the photo-curable resin laminate of the present invention has an ultraviolet transmittance at a wavelength of 365 nm (hereinafter abbreviated as "365 nm transmittance") of 20 to 20.
It should be 95%. More preferably 25-
60%. If the 365 nm transmittance is lower than 20%, sufficient tenting film strength cannot be obtained in a portion where there is no land, so that the etching solution may be soaked.
On the other hand, if the 365 nm transmittance is higher than 95%, the exposure time becomes long, which is disadvantageous in terms of productivity.

When the photocurable resin layer contains a thermoplastic polymer made of a specific vinyl copolymer,
Even with a wide range of laminating speeds of less than 1 minute, a photo-curable resin laminate can be realized which is embedded in a small-diameter through hole to a predetermined depth. In the present invention, the photopolymerizable resin layer includes the thermoplastic polymer (a), one or more photopolymerizable compounds (b) having one or more ethylenically unsaturated groups in one molecule, And one or more photopolymerization initiator (c) as a main component.

As the thermoplastic polymer, those obtained by vinyl copolymerizing the following first to third monomers are used. As the first monomer, α, β-unsaturated carboxylic acid 15-4
0% by weight, preferably 20-30% by weight is used.
If it is less than 15% by weight, development with an aqueous alkali solution becomes difficult. If it is more than 40% by weight, it becomes insoluble in the solvent during the polymerization and the synthesis becomes impossible.

Specific examples thereof include (meth) acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic acid half ester, etc., which may be used alone or in combination of two or more kinds. You may use. Methacrylic acid is particularly preferred. As the second monomer to be copolymerized, 5 to 35% by weight, preferably 15 to 30% by weight of the compound represented by the formula (1) is used. If it is less than 5% by weight, the cold flow resistance is deteriorated, the edge fuse is severe, and it becomes difficult to store the product as a product. When it is more than 35% by weight, the solubility in a solvent is lowered during the copolymerization, the polymerization is difficult to be completed, and the developing time of the photocurable resin layer is remarkably lengthened.

Specific examples thereof include styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene and the like, which may be used alone or in combination of two or more kinds. Particularly preferred is styrene. Further, as the third monomer to be copolymerized, an alkyl (meth) acrylate having an alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl (meth) acrylate having a hydroxyalkyl group having 2 to 6 carbon atoms, (meth) acrylonitrile At least one compound selected from the group consisting of (meth) acrylamide, a compound in which hydrogen on the nitrogen thereof is substituted with an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and glycidyl methacrylate. ~ 75 wt%, preferably 45-65 wt% is used. 20
When the content is less than the weight%, the flexibility of the photocurable resin layer decreases. If it exceeds 75% by weight, the cold flow resistance is deteriorated.

Specific examples include methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic acid-
n-propyl, (meth) acrylic acid-iso-propyl, (meth) acrylic acid-n-butyl, (meth) acrylic acid-sec-butyl, (meth) acrylic acid-tert
-Butyl, 2-ethylhexyl (meth) acrylate,
2-Hydroxyethyl (meth) acrylate, (meth)
2-hydroxypropyl acrylate, (meth) acrylamide, N-methylol acrylamide, N-butoxymethyl acrylamide, (meth) acrylonitrile,
Glycidyl (meth) acrylate and the like may be used alone or in combination of two or more kinds. Methyl methacrylate is particularly preferable.

The weight average molecular weight of the thermoplastic polymer is 3
000 to 100,000, preferably 3
It is 000 to 60,000. Weight average molecular weight is determined by gel permeation chromatography (GP
It is the value measured using the calibration curve of standard polystyrene according to C). When it is less than 30,000, the photocurable resin layer becomes brittle and fine cracks are generated around the cut portion during film cutting during lamination, which is not suitable for use. 100,
If it is larger than 000, the developability is deteriorated.

The glass transition temperature of the thermoplastic polymer is 11
Must be 0-150 ° C. Preferably 115-
It is 140 ° C. The glass transition temperature is the glass transition temperature (Tgn: F) of the homopolymer of the monomers contained in the copolymer.
Only in the equation of ox, the unit is determined by the following equation of Fox from the absolute temperature K) and the weight fraction (wn) of each monomer. 1 / Tg (copolymer) = w1 / Tg1 + w2 / Tg2 +
If the + wn / Tgn glass transition temperature is lower than 110 ° C., it is not possible to satisfy both the viscosity at 90 ° C. within the range of the present invention and the cold flow resistance. That is, when the viscosity at 90 ° C. is decreased, the cold flow is increased, and when the cold flow resistance is improved, the viscosity at 90 ° C. is increased and the embedding becomes small. Glass transition temperature is 150 ℃
If it is higher, the solubility is lowered, and a uniform photocurable resin composition cannot be obtained.

The amount of the thermoplastic polymer contained in the photocurable resin layer may be one kind or a mixture of two or more kinds, but the total amount is in the range of 30 to 70 parts by weight, preferably 40. -60 parts by weight. If it is less than 30 parts by weight, the cold flow resistance is deteriorated. If the amount is more than 70 parts by weight, the photocurable resin layer becomes brittle. The thermoplastic polymer is
Add a proper amount of radical polymerization initiator such as benzoyl peroxide or azobisisobutyronitrile to a solution obtained by diluting a mixture of the first to third monomers with a solvent such as acetone, methyl ethyl ketone, and isopropanol, and stir with heating. It is preferable to synthesize by. In some cases, a part of the mixture is added dropwise to the reaction solution for synthesis. Further, after the reaction is completed, a solvent may be further added to adjust the concentration to a desired value. In addition to solution polymerization, bulk polymerization, suspension polymerization and emulsion polymerization can also be used.

The photopolymerizable compound having one or more ethylenically unsaturated groups in one molecule, which is one of the components of the photocurable resin layer, is used in an amount of 30 to 70 parts by weight, preferably 40 to 60 parts by weight. To be When the amount is less than 30 parts by weight, curing is insufficient and the strength as a resist is insufficient. When it is more than 70 parts by weight, the peeling time becomes long. Specific examples of this compound include 2-hydroxy-3-phenoxypropyl acrylate, phenoxytetraethylene glycol acrylate, β-hydroxypropyl-β ′-(acryloyloxy) propyl phthalate, 1,4-tetramethylene glycol di (meth). ) Acrylate, 1,6-hexanediol di (meth) acrylate, 1,4-cyclohexanediol di (meth) acrylate, octapropylene glycol di (meth) acrylate, glycerol (meth) acrylate, 2-di (p-hydroxyphenyl) )
Propane di (meth) acrylate, glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, polyoxypropyl trimethylolpropane tri (meth) acrylate, polyoxyethyl trimethylolpropane tri (meth) acrylate, dipentaerythritol penta (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane triglycidyl ether tri (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, diallyl phthalate, polyethylene glycol di (meth) acrylate,
There are polypropylene glycol di (meth) acrylate, bis (polyethylene glycol (meth) acrylate) polypropylene glycol, 4-normal octylphenoxypentapropylene glycol acrylate and the like. Further, with a polyvalent isocyanate compound such as hexamethylene diisocyanate and tolylene diisocyanate,
Examples thereof include urethane reaction products with a hydroxy acrylate compound such as 2-hydroxypropyl (meth) acrylate. Each may be used alone, or two or more kinds may be used in combination.

The photopolymerization initiator is 0.01 to 20 parts by weight,
It is preferably used in an amount of 1 to 10 parts by weight. If the amount is less than 0.01 parts by weight, the sensitivity is insufficient. If the amount is more than 20 parts by weight, it is difficult to set the 365 nm transmittance to 20% or more. The type and amount of the photopolymerization initiator is 36% of that of the photocurable resin layer.
The 5 nm transmission is chosen to be in the range of 20-95%. When a photopolymerization initiator having a large absorption for 365 nm ultraviolet light is used, the addition amount is reduced. On the contrary, when using a photopolymerization initiator having a small absorption, the addition amount is increased.

Examples of preferable photopolymerization initiators include compounds represented by the following formulas (2), (3) and (4).

[0026]

[Chemical 3]

[R ₂ and R ₃ each independently represent hydrogen, a hydroxyl group, an alkyl group, an alkoxy group or a phenoxy group, but R ₂ and R ₃ are not a hydroxyl group at the same time] Dimethyl ketal, benzyl diethyl ketal, benzyl dipropyl ketal, benzyl diphenyl ketal, benzoin methyl ether,
Examples thereof include benzoin ethyl ether, benzoin propyl ether and benzoin phenyl ether.

[0028]

[Chemical 4]

[In the formula, Y and Z are hydrogen, an alkyl group having 4 or less carbon atoms or halogen] Specific examples are thioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2-.
Isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diisopropylthioxanthone, 2
-Fluorothioxanthone, 4-fluorothioxanthone, 2-chlorothioxanthone, 4-chlorothioxanthone, 1-chloro-4-propoxythioxanthone and the like can be mentioned.

[0030]

[Chemical 5]

[Wherein R ₄ and R ₅ are alkyl groups having 3 or less carbon atoms, R ₆ is hydrogen or an alkyl group having 18 or less carbon atoms] Specific examples are p-dimethylaminobenzoic acid and p-diethylaminobenzoic acid. Examples thereof include acids and p-diisopropylaminobenzoic acid, and esterified products of these and the following alcohols. As alcohol, methyl alcohol,
Examples thereof include ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, n-amyl alcohol, isoamyl alcohol, hexyl alcohol and octyl alcohol.

In addition to these initiators, any known compound can be used. For example, aromatic ketones such as benzophenone, 4,4′-bis (dimethylamino) benzophenone [Michler's ketone], 4,4′-bis (diethylamino) benzophenone, 2-
(O-chlorophenyl) -4,5-diphenylimidazolyl dimer and other biimidazole compounds, 9-phenylacridine and other acridines, α, α-dimethoxy-α-
Morpholino-methylthiophenylacetophenone, 2,
4,6-Trimethylbenzoylphosphine oxide, phenylglycine, 1-phenyl-1,2-propanedione-2-o-benzoyloxime, ethyl 2,3-dioxo-3-phenylpropionate-2- (o- There are oxime esters such as benzoylcarbonyl) -oxime.

In order to improve the thermal stability and storage stability of the photocurable resin, it is preferable to add a radical polymerization inhibitor to the photocurable resin layer. For example, p-
Methoxyphenol, hydroquinone, pyrogallol,
Naphthylamine, tert-butylcatechol, cuprous chloride, 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis (4-ethyl-6-ter).
t-butylphenol), 2,2'-methylenebis (4
-Methyl-6-tert-butylphenol) and the like.

The photocurable resin layer may contain coloring substances such as dyes and pigments. For example, fuchsin, phthalocyanine green, auramine base, chalcoxide green S, paramagenta, crystal violet, methyl orange, Nile blue 2B, Victoria blue, malachite green, basic blue 20, diamond green and the like.

Further, a color-forming dye that develops color upon irradiation with light may be contained. As a color-forming dye, a combination of a leuco dye and a halogen compound is well known. Examples of leuco dyes include tris (4-dimethylamino-2)
-Methylphenyl) methane [leuco crystal violet], tris (4-dimethylamino-2-methylphenyl) methane [leucomalachite green] and the like. On the other hand, as the halogen compound, amyl bromide, isoamyl bromide, isobutylene bromide, ethylene bromide, diphenylmethyl bromide, benzal bromide, methylene bromide, tribromomethylphenyl sulfone, carbon tetrabromide, tris (2,
3-dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,
1-trichloro-2,2-bis (p-chlorophenyl)
Examples include ethane and hexachloroethane.

Further, the photocurable resin layer may contain additives such as a plasticizer, if necessary. Examples thereof include phthalates such as diethyl phthalate. The photocurable resin layer has a viscosity at 90 ° C. of 5 × 10 ² to 5 × 10 ^2.
It is preferably ⁵ poise, more preferably 10 poise.
³ to 10 ⁵ poise, most preferably 10 ³ to 10 ⁴ poise. 3 because of low viscosity at 90 ° C
Even in a wide range of laminating speed of m / min or less, it is possible to embed a small-diameter through hole to a predetermined depth. Viscosity is 5 ×
If it is larger than 10 ⁵ poise, the embedding property of the photocurable resin layer into the small-diameter through hole is deteriorated. On the other hand, as the viscosity becomes lower, the photo-curable resin layer is more likely to be embedded in the small-diameter through hole, but the cold flow resistance deteriorates. 5x
If it is less than 10 ² poise, the roll shape of the product cannot be maintained for a long time.

The thickness of the photocurable resin layer is 30 to 100 μm.
However, the preferable range is 35 to 70 μm.
Is. When the thickness is less than 30 μm, the tenting film of the photocurable resin layer in the opening of the through hole is likely to swell or break during development, and the depth of the photocurable resin layer embedded in the through hole is sufficient. Not reliable. On the other hand, if the thickness is more than 100 μm, it is difficult to keep the transmittance at a wavelength of 365 nm at 20% or more, and the resolution is deteriorated, which is not preferable.

As the supporting layer of the photocurable resin laminate, a transparent layer which transmits active light is desirable. For example, polyethylene terephthalate film, polyvinyl alcohol film, polyvinyl chloride film, vinyl chloride copolymer film, polyvinylidene chloride film, vinylidene chloride copolymer film, polymethyl methacrylate copolymer film, polystyrene film, polyacrylonitrile film, Examples thereof include a styrene copolymer film, a polyamide film and a cellulose derivative film.
These films may be stretched if necessary.

After laminating the photocurable resin layer on one surface of the support layer, a protective layer is laminated on the surface of the photocurable resin layer as required. An important characteristic of this protective layer is that the protective layer is sufficiently smaller than the support layer in terms of adhesion to the photocurable resin layer and can be easily peeled off. For example, there are polyethylene film, polypropylene film and the like. Further, a film having excellent releasability disclosed in JP-A-59-202457 can be used.

The photocurable resin laminate of the present invention can be used in the "embedding tenting method" in manufacturing a printed wiring board having a small diameter through hole. That is, the photocurable resin laminate of the present invention is manufactured by laminating a photocurable resin laminate on a metal-coated insulating plate having a through hole, and exposing, developing, and etching the printed wiring board having a small diameter through hole. In the method, when laminating the photocurable resin laminate, the depth of embedding of the photocurable resin layer extending from the inner peripheral edge of the through hole along the inner wall of the through hole to the inner wall is When used in a method in which the thickness of the metal conductor layer on each surface of the metal-coated insulating plate is 0.3 or more, an excellent effect is exhibited.

In the step of laminating the photocurable resin laminate of the present invention on both sides of the metal-coated insulating plate and embedding it inside the through hole, it extends from the inner peripheral edge of the through hole to the inner wall surface along the inner wall of the through hole. The embedding depth of the photocurable resin layer is 0.3 or more with respect to the thickness of the metal conductor layer on each surface of the metal-coated insulating plate having the depth, in FIG. 1 from the inner peripheral edge of the through hole to the inner wall. It means that a value obtained by dividing the depth d of the photo-curable resin layer extending to the area by the thickness t of the conductor layer formed on both surfaces of the insulating plate is 0.3 or more. 0.5 or more is more preferable, and 1.1 or more is most preferable. The larger this value is, the more likely it is that defects will not occur even with a large deviation width, but if it is 2 or more, no further increase in the effect will be observed, and the peeling time of the cured resist layer after etching will be long, and the productivity will be increased. Is reduced. When it is less than 0.3, there is no significant difference from the conventional tenting method.

As a method for laminating the photocurable resin laminate of the present invention on a substrate, a hot roll laminator or a vacuum laminator used in the conventional tenting method can be used. In order to embed it on top, it is necessary to properly set the roll temperature, pressure, laminating speed, etc. of the laminator. Typically,
In order to embed the photocurable resin layer deeper, it is effective to raise the roll temperature and pressure and slow the laminating speed. Furthermore, it is more preferable to use a two-stage hot roll laminator as disclosed in JP-A-3-236956.

The exposure is carried out by using an ultraviolet ray such as an ultra-high pressure mercury lamp through a mask having a high transparency which is transparent in the portion to be left as a wiring and the portion to be left as a coating of the opening of the conductive through hole. In development, the unexposed portion is removed by development using an alkaline aqueous solution. As the alkaline aqueous solution, an aqueous solution of sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide or the like is used. Most commonly 0.5-3%
Aqueous sodium carbonate solution is used.

The etching can be carried out by a method suitable for the DFR used, such as acid etching or alkali etching. Peeling of the photocurable resist after etching is peeled by an alkaline aqueous solution which is stronger than the alkaline aqueous solution used in the development. For example, an aqueous solution of 1 to 5% sodium hydroxide or potassium hydroxide is used.

[0045]

The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the examples. All "parts" in the following examples are "parts by weight". Various properties in the examples were measured by the following methods. 1) Molecular weight It was determined as a polystyrene-equivalent weight average molecular weight by gel permeation chromatography manufactured by JASCO Corporation. 2) Viscosity A flow tester CFT-500 manufactured by Shimadzu Corporation was used. 3) Ultraviolet Transmittance Using a UV spectrometer UV-240 manufactured by Shimadzu Corporation, a laminate of a polyethylene terephthalate film and a photocurable resin layer was placed on the measurement side, a polyethylene terephthalate film was placed on the reference side, and measurement was performed in T% mode. 4) Glass transition temperature (Tg) It was calculated by applying it to the Fox equation. 5) Evaluation of cold flow property [Press flow test] 2.5c of photocurable resin layer laminate
Cut into m square, peel off the protective film (polyethylene film), polyethylene terephthalate film 10cm
A force of 100 kg was applied for 5 minutes by a hydraulic press heated to 40 ° C. at the center of the corner, the protrusion width in four directions of the resist was measured, and the average value was obtained.

When this value is 0.8 mm or more, an edge fuse is generated on the end face of the roll when it is stored in the form of a roll, and it becomes substantially impossible to stably laminate on the substrate by the laminator. I know. 6) Embedding depth from the inner peripheral edge of the through hole of the photocurable resin layer to the inner wall (hereinafter, simply referred to as "embedding depth") The substrate after development is embedded and hardened with an epoxy resin, and the through hole appears. And the length d extending from the substrate surface to the inner wall was measured with an optical microscope. (Fig. 1) 7) Opening coverage of small diameter through hole After etching, the opening coverage is observed with an optical microscope.
The presence or absence of tearing was confirmed.

A: The number of holes in which the tenting film completely covers the openings of the small-diameter through holes, and the etching solution does not soak into the through holes. B: The total number of observation holes. (A / B) x 100

[0048]

[Synthesis example] 2 equipped with stirrer, reflux condenser, thermometer
In a liter separable flask, 350 g of methyl ethyl ketone (MEK) was put, and 100 g of methacrylic acid as a monomer, 100 g of styrene, 160 g of methyl methacrylate, 40 g of 2-hydroxyethyl methacrylate, 40 g, while stirring at 80 ° C. under a nitrogen stream. A homogeneous mixture of 4 g of azobisisobutyronitrile was added dropwise as a polymerization initiator over 4 hours. After heating and stirring for 8 hours, 3 g of azobisisobutyronitrile was added as a MEK solution, and further 12
Heated and stirred for hours. Finally, add 400 g of MEK,
The solution concentration was adjusted to about 35% to obtain the desired thermoplastic polymer (P-1). Molecular weight is 48,000, Tg is 130 ℃
Met.

The above-mentioned method was repeated using the monomer composition (total amount of monomers: 400 g) shown in Tables 1 and 2 and the polymerization initiator (azobisisobutyronitrile) to prepare various thermoplastic polymers. Was synthesized.

[0050]

[Example 1] Thermoplastic polymer solution P- polymerized in the synthesis example
1, the photopolymerizable compound, the photopolymerization initiator and other components were stirred for 12 hours at the following component ratios. P-1 (36% MEK solution) 144 parts by weight Nonaethylene glycol diacrylate (M-1) 10 parts by weight Urethane reaction product of hexamethylene diisocyanate and oligopropylene glycol monomethacrylate (M-2) 22 parts by weight Anhydrous phthalate Reaction product of half-esterified product of acid and 2-hydroxypropyl acrylate and propylene oxide (M-3: OE-A200 manufactured by Nippon Shokubai Kagaku Co., Ltd.) 10 parts by weight Benzyl dimethyl ketal (I-1) 5 parts by weight 2, 4-Diethylthioxanthone (I-2) 0.3 parts by weight Ethyl p-dimethylaminobenzoate (I-3) 3 parts by weight Malachite Green (D-1) 0.04 parts by weight Leuco Crystal Violet (D-2) 0 0.4 parts by weight tribromophenyl sulfone (D-3) 0.5 parts by weight MEK 11 Next, this mixed solution is uniformly applied to a polyethylene terephthalate film (PET film) having a thickness of 20 μm using a bar coater and dried in a dryer at 90 ° C. for 5 minutes to form a photocurable resin layer having a thickness of A 50 μm thick laminate was obtained. Then, a 28 μm polyethylene film (PE film) was attached to the side of the photocurable resin layer on which the PET film was not laminated to obtain a desired photocurable resin laminate.
The viscosity of this photocurable resin layer at 90 ° C. is 7 × 10 ³
It was a poise and the 365 nm transmittance was 38%.

While peeling off the PE film of this photocurable resin laminate, a photocurable resin layer was formed on the surface of 330 × 330 × 1.
Use a two-stage hot roll laminator ("AL-700" manufactured by Asahi Kasei Kogyo) on a copper-clad laminate with a size of 6 mm.
Laminated at 0/160 ° C. Pressure was applied using an air cylinder having an inner diameter of 4 cm, the air pressure applied to the air cylinder was 6.8 kg / cm ² gauge, and the laminating speed was 1.0 m / min. The copper-clad laminate used was 18 μm copper foil laminated on both sides of a glass fiber epoxy base material to form a through hole with a diameter of 0.35 mm, and plating was performed to further reduce the thickness to about 2
It was assumed that copper of 5 μm was deposited to achieve conduction on both sides. The embedded depth of the photocurable resin layer was 100 μm.

A negative film made of 1000 circular conductive portions having a diameter of 0.4 mm was formed in the photo-curable resin layer in accordance with the positions of the through holes, and passed through a super-high pressure mercury lamp (HMW-201KB manufactured by Oak Manufacturing Co., Ltd.) at 100 mJ. Exposure was performed at / cm ² . At this time, one surface has a mask shift width of 80 μm.
Alternatively, the exposure was performed so that the thickness was 10 μm, and the other surface was not displaced. When the mask is shifted, the length from the inner wall surface of the through hole to the upper surface of the cured resist image covering the through hole on the line passing through the center of the through hole and the center of the cured resist image covering the through hole is defined as the mask shift width. did.

Then, after peeling off the PET film, 30
An unexposed portion was dissolved and removed by spraying a 1% aqueous sodium carbonate solution at 60 ° C. for 60 seconds. Further, a cupric chloride solution at 50 ° C. was sprayed for 115 seconds to etch the copper in the portion without the cured resist. The through-hole opening coverage ratio (hereinafter, abbreviated as displacement retention ratio) was 100% when the mask displacement was 10 μm.

Next, a 3% aqueous solution of sodium hydroxide at 50 ° C. was sprayed for 120 seconds to peel off the cured resin film used as the resist, and then the inside of the through hole was examined with a tester. Is 0
There were 0 (0.0%) breaks in the substrate with a mask shift of 10 μm. In the same manner, when laminating at a laminating speed of 3.0 m / min,
The embedded depth was 30 μm, and the shift retention rate after etching was 100%. Further, the conduction after the resist is peeled off is 10 (1.0
%), And when the mask shift is 10 μm, it is 0 (0.
It was 0%).

[0055]

Examples 2 to 9 and Comparative Examples 1 to 7 Laminated boards and wiring boards were obtained in the same manner as in Example 1 except that the compositions shown in Tables 3 to 6 were used. The composition abbreviations shown in Tables 3 to 6 are as follows:
The thermoplastic polymers are shown in Tables 1-2, and the other components are shown in Example 1 and below.

I-4: Michler's ketone

[0057]

[Table 1]

[0058]

[Table 2]

[0059]

[Table 3]

[0060]

[Table 4]

[0061]

[Table 5]

[0062]

[Table 6]

[0063]

The photocurable resin laminate of the present invention forms a good tenting film even when the positions of the mask and the through holes are deviated, prevents the etchant from entering the through holes, and Since it has good sensitivity and resolution, it can be advantageously used for manufacturing a high-density printed wiring board using a small-diameter through hole in recent years.

[Brief description of drawings]

FIG. 1 is a schematic enlarged cross-sectional view showing a state in which a resin layer is formed on an inner wall from an inner peripheral edge portion of a through hole.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating plate 2 Conductor layers formed on both sides of an insulating plate 3 Through holes 4 Photocurable resin layers laminated on both sides of an insulating plate

Claims (1)

[Claims] 1. A support layer and a surface provided on one surface thereof,
It has an ultraviolet transmittance of 20 to 95% with respect to an ultraviolet ray having a wavelength of 365 nm, and (a) is at least one first monomer 15 to 40 selected from α, β-unsaturated carboxylic acids.
%, At least 5 to 35% by weight of at least one second monomer selected from the compounds represented by the following formula (1): (In the formula, R ₁ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X is a halogen atom or an alkyl group having 1 to 3 carbon atoms, n is 0 or an integer of 1 to 3, and n is 2 or more. In this case, a plurality of X may be the same or different from each other), and an alkyl (meth) acrylate having an alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl having a hydroxyalkyl group having 2 to 6 carbon atoms Among (meth) acrylate, (meth) acrylonitrile, (meth) acrylamide and compounds in which hydrogen on the nitrogen thereof is substituted with an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and glycidyl methacrylate 20 to 75% by weight of at least one third monomer selected from the group consisting of 30,000 to 1 weight average molecular weight obtained by vinyl copolymerization
1 with a glass transition temperature of 110 to 150 ° C at 000
30 to 70 parts by weight of one or more thermoplastic polymers,
(B) 30 to 70 parts by weight of one or more photopolymerizable compounds having one or more ethylenically unsaturated groups in one molecule, and (c) one or more photopolymerization initiators. A photocurable resin laminate comprising a photocurable resin layer whose main component is 0.01 to 20 parts by weight.