JPH10147685A - Resin composition for insulation material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a material suitable for an insulating resin for printed circuit boards that can prevent the occurrence of cracking, when it has no glass cloth structure and uses an acrylic resin material, and has both of the resistances to shock and heat and the reliability in electric insulation. SOLUTION: This resin composition for insulating materials comprises (1) a carboxyl group-bearing alkali-soluble acrylic polymer and/or methacrylic polymer, (2) one or more C=C unsaturated double bonds-bearing polymerizable compound, (3) fine particles of crosslinked elastic polymer with an average particle size of <=5μm and (4) a polymerization initiator which can initiate the polymerization of the above C=C unsaturated double bonds with heat and/or by irradiation with active rays.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating material for printed wiring boards, and more particularly to a curable acrylic having excellent heat resistance, electrical insulation, adhesion to metal, water resistance and impact resistance. The present invention relates to a resin composition for a system insulating material (hereinafter, referred to as “resin composition of the present invention”).
Particularly, it is suitable for a resin composition as an interlayer insulating material of a multilayer printed wiring board.

[0002]

2. Description of the Related Art As electronic devices have become smaller and more multifunctional,
Currently, printed wiring boards are moving toward higher densities. For example, thinner conductor circuits, higher multilayers, smaller via holes including interstitial via holes such as through via holes, blind via holes, and buried via holes, and high-density mounting by surface mounting of small chip components. Therefore, various methods for manufacturing a multilayer printed wiring board excellent in large format and excellent in mass productivity are being developed. Further, a multi-chip module on which a plurality of bare chips are mounted is also formed by providing the via hole. However, a multi-chip module based on a resin substrate, which is superior in mass productivity to a conventional device base or ceramic base, is desired.

Conventionally, a conductor circuit pattern of an inner panel is formed by performing an etching process on both sides of a copper-clad laminate in which copper foil is laminated on both sides via one or more glass epoxy prepregs or glass polyimide prepregs. After the treatment, the prepreg and the copper foil are laid up as appropriate, laminated by heating and pressurizing with a press, and then the pattern is formed by performing processing such as drilling, plating, etching, etc. to form a multilayer printed wiring board. Being manufactured. However, in the conventional method, since a prepreg containing glass cloth is used as an interlayer insulating material, the weight is large, the thickness is restricted, and it has been difficult to reduce the thickness and weight required of an electronic device having a higher density. In addition, a material having a low dielectric constant required for high-speed operation is required, but there is a limit in a conventional prepreg using a glass cloth having a high dielectric constant.

In the conventional method of manufacturing a multilayer printed wiring board, since a hot press is generally used as described above, the inner layer panel and the prepreg 1 are prepared in preparation for the hot press.
It is necessary to lay-up two or more sheets, a copper foil, a release film, a mirror press plate, etc., heat-press them with a hot press or a vacuum hot press, and then take out and disassemble. Further lay-up, temperature rise during heating, heat compression, cooling,
There was a problem that dismantling etc. was a batch production, and required a large number of steps.

[0005] Further, in the case of drilling holes, the number of steps is increased in order to drill one hole at a time, so that a plurality of copper-clad laminates are generally stacked to increase the efficiency of drilling. However, as the density has increased recently, and small holes such as through via holes and blind via holes are required, it is necessary to drill the copper-clad laminates repeatedly due to problems such as processing accuracy and drill strength. In order to drill holes one by one with high precision, advanced processing technology is required, and there has been a problem such as a decrease in productivity.

In order to solve these problems, the present inventors disclosed in Japanese Patent Application Laid-Open No. 5-345810 a copper-clad insulating sheet obtained by applying an alkali-soluble insulating resin composition to a copper foil and having a conductor circuit pattern. Heat lamination on the inner layer plate, forming fine holes in the surface copper foil by etching, further dissolve the resin composition in alkali to form blind via holes,
A method of manufacturing a multilayer printed wiring board by curing an insulating resin layer and a copper-clad insulating sheet used for the method have been proposed. Also, JP-A-6-260771 and JP-A-6-263
No. 916 proposes the use of an acrylic resin as the insulating resin composition. Further, the present inventors have disclosed in
No. 226 proposes a flame-retardant resin composition for an interlayer insulating material using a flame-retardant acrylic resin.

However, since these insulating resin layers do not have a reinforcing material made of glass cloth as in the prior art, when a hole or outer shape processing of a printed wiring board is performed by punching with a die, the resin may be finely divided at around room temperature. Since the cracks are easily formed and the reliability is lowered, it is necessary to heat the panel during the punching process. In addition, the resin cannot sufficiently follow the stress such as expansion and shrinkage of the resin generated during the curing or soldering of the resin, and due to the structure of the printed wiring board, the resin is soldered at the boundary where the thickness of the resin layer differs. In some cases, cracks may occur in the resin due to thermal shock at that time.

[0008]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the case of using an acrylic resin material in a structure without a glass cloth, and has an impact resistance, a heat resistance and an electrical insulation reliability. It is intended to provide a material suitable for an insulating resin for a printed wiring board.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and have arrived at the present invention. That is, the present invention provides (1) an alkali-soluble acrylic polymer and / or a methacrylic polymer having a carboxyl group, and (2) one CＣC unsaturated double bond.
(3) a particulate crosslinked elastic polymer having an average particle size of 5 μm or less, and (4) the above-mentioned C ＝ C by heating and / or irradiation with active energy rays.
Of a polymerization initiator capable of initiating the polymerization of unsaturated double bonds,
(1) A resin composition for an insulating material comprising the components (2), (3) and (4). Hereinafter, the present invention will be described in detail.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The alkali-soluble acrylic polymer and / or methacrylic polymer having a carboxyl group as the first component refers to acrylic acid and / or methacrylic acid (hereinafter referred to as “(meth) acrylic acid”). ) And a (meth) acrylic acid ester as main components, and a polymer in which a carboxyl group derived from (meth) acrylic acid, which is a constituent component thereof, is left.

A linear polymer containing (meth) acrylic acid and (meth) acrylic acid ester as main components (hereinafter referred to as “unmodified acrylic polymer”) is methyl acrylate and / or methyl methacrylate (hereinafter referred to as “methyl methacrylate”). “Acrylate and / or methacrylate” is referred to as “(meth) acrylate”), ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, hydroxyethyl (meth) acrylate,
(Meth) acrylic acid esters such as hydroxypropyl (meth) acrylate and tetrahydrofurfuryl (meth) acrylate and (meth) acrylic acid are mixed at an appropriate composition ratio with isopropyl alcohol, ethylene glycol monoethyl ether, propylene glycol monomethyl ether. And azobisisobutyronitrile, benzoyl peroxide or the like as an initiator.

The unmodified acrylic polymer can be copolymerized with a vinyl compound such as styrene or acrylonitrile as another component other than (meth) acrylic acid and (meth) acrylic acid ester. When water resistance is required, styrene is preferably copolymerized in a range of 5 to 30% by weight based on all monomers constituting the polymer.

In order to impart alkali solubility to the resin composition of the present invention before curing, the ratio of the (meth) acrylic acid and other components in the unmodified acrylic polymer is determined as the final composition. It is necessary to adjust the acid value in the range of 0.5 to 3.0 meq / g, and as described later, a part of the carboxyl group in the unmodified acrylic polymer is changed to a glycidyl group and a C ＝ C unsaturated diamine. Considering the case where the polymer is used for addition with a compound having a heavy bond, (meth) acrylic acid is used in an amount of 20 to 50 with respect to all monomers constituting the polymer.
% By weight.

The first component of the present invention is obtained by adding a compound having a glycidyl group and a C ＝ C unsaturated double bond in one molecule to a part of the carboxyl group of the unmodified acrylic polymer. preferable.

The compound is insoluble and infusibilized by heating or an active energy ray capable of polymerizing a C 線 C double bond such as an electron beam or an ultraviolet ray, and has sufficient mechanical properties as a wiring substrate. It has the effect of imparting physical properties. Specific examples of the compound include glycidyl (meth) acrylate, allyl glycidyl ether, vinylbenzyl glycidyl ether, 4-glycidyloxy-
Glycidyl (meth) acrylate is preferred in view of availability and easy addition reaction to a carboxyl group.

[0016] Further, Japanese Patent Application Laid-Open No. Hei 7-2 according to the invention of the present inventors.
Other glycidyl compounds, such as the brominated phenyl glycidyl ether disclosed in US Pat. No. 33226, may be used.

The molecular weight of the polymer of the first component is from 5,000 to
100,000 is preferred. If it is less than 5,000, the heat resistance is low, and furthermore, when the resin composition of the present invention is applied to a metal foil such as a copper foil and dried by heating and laminating a copper-clad insulating sheet to an inner layer panel, the resin flow is reduced. Control becomes difficult and oozes easily. On the other hand, if it exceeds 100,000, the alkali solubility becomes insufficient, and the above-mentioned Japanese Patent Application Laid-Open No.
In the method for manufacturing a multilayer printed wiring board described in Japanese Patent No. 345810, formation of minute blind via holes tends to be difficult, which is not preferable.

Since the resin composition of the present invention contains the first component, which is a polymer having a large molecular weight, as a main component, it has the advantage that the resin flow can be controlled. That is, when the above-mentioned copper-clad insulating sheet manufactured using the resin composition of the present invention is stored in a roll shape, the effect of preventing seepage or winding deviation of the resin from the roll end can be obtained. Even when the copper-clad insulating sheet is heat-laminated on the inner layer panel, it flows into the recess but has fluidity enough to keep the distance between the inner layer panel and the surface copper foil. The temperature of the above-mentioned heating lamination is 60 to 120.
C is preferable, and more preferably 70 to 100C.

Further, the first component is an indispensable component for preventing cracking of the resin after coating and drying and preventing the resin from falling off the copper foil. The preferred amount is 10 to 60% by weight of the entire resin composition of the present invention.

Next, the polymerizable compound having at least one C ＝ C unsaturated double bond as the second component will be described. These are compounds having an acryloyl group, a methacryloyl group, an allyl group or a vinyl group. Specifically, compounds having one double bond include methyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and hydroxyethyl (meth) acrylate.
Acrylate, hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth)
Monofunctional (meth) acrylates such as acrylate; compounds having a vinyl group such as styrene and acrylonitrile; compounds having an allyl group such as allylphenol and eugenol; N-phenylmaleimide, p-hydroxy-N-phenylmaleimide and p-chloro- Compounds having a maleimide group such as N-phenylmaleimide are exemplified.

Compounds having two double bonds include 1,3
-Di (meth) acrylates such as butanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, di (meth) acrylate of bisphenol A type epoxy, and urethane acrylate; A) acrylates; vinyl compounds such as divinylbenzene; diallyl phthalate, bisphenol A
And allyl compounds such as diallyl ether. Compounds having three or more double bonds include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, phenol novolak type epoxy (meth) acrylate, Allyl isocyanurate and the like can be mentioned.

Among the above compounds, a compound such as polypropylene glycol di (meth) acrylate, which has a long crosslinking point and gives a soft cured product, and urethane (meth) acrylate, which is compatible with the first component, Preferred are polypropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate or pentaerythritol tri (meth) acrylate. The compounding amount of these compounds is 1 to 100 parts by weight of the first component.
The range of 0 to 200 parts by weight is preferable from the viewpoint of heat resistance.

The third component, the fine particle-like crosslinked elastic polymer, after curing the resin composition of the present invention, is uniformly dispersed in the cured product to form a structure corresponding to an island having a sea-island structure. And the impact resistance can be improved. Specific examples thereof include a crosslinked MBS resin having elasticity, a crosslinked acrylic rubber, a crosslinked NBR, a crosslinked AAS resin, and the like, which are easily available and have insulating properties when the resin composition of the present invention is cured and alkalis when it is not cured. Use of a crosslinked acrylic rubber is preferred because both have good solubility. These average particle diameters are set to 5 μm or less by the value based on the volume standard method. 5μ
If it exceeds m, the dispersibility of the third component in the resin varnish obtained by dissolving each component other than the third component in the solvent in the resin composition of the present invention becomes poor, so that stability cannot be obtained.

In the case where the resin composition of the present invention is mixed with a solvent to produce a resin varnish, if the third component is soluble in the solvent in the varnish, the component is difficult to be uniformly dispersed by agglomeration in the solvent. Become. In the case where the resin composition of the present invention is used as it is, the aggregates are likely to remain without dissolving during alkali dissolution. Further, when the third component is completely dissolved in the resin varnish, a crack is easily generated since a structure corresponding to the island having the above-mentioned sea-island structure is not formed. On the other hand, when the third component forms an islands-in-the-sea structure, even if an impact at normal temperature or a stress at the time of heating is applied, partial destruction of the resin stops at the interface of the third component, so that the destruction does not extend. .

When the third component is completely dissolved in the resin varnish, the unreacted carboxyl groups in the first component are uniformly covered with the third component, so that the acid content of the resin composition of the present invention is reduced. As a result, the alkali solubility is impaired. In contrast, the third component is
If the resin varnish is not dissolved in the solvent but is uniformly dispersed in the resin composition, only the surrounding resin components are dissolved when the alkali is dissolved, and the third component is not dissolved in the alkali. At the same time, the third component flows out and is removed. Therefore, the third component is preferably insoluble or hardly soluble in a solvent used for producing a resin varnish using the resin composition of the present invention. Specifically, the third component is preferably insoluble or hardly soluble by forming a crosslinked structure. It can be dissolved.

The amount of the third component is preferably in the range of 5 to 40% by weight based on the total weight of the resin composition of the present invention so that the resin composition of the present invention can obtain sufficient impact resistance. . When the amount is more than 40% by weight, there is no problem in terms of impact resistance. However, when a resin varnish obtained by mixing the resin composition of the present invention with a solvent is produced, the third component is easily separated, It is not preferable because the stability of the varnish is lowered, and when coating and drying on the copper foil, coating unevenness and bubbles tend to occur.

As a method of dispersing the third component in the resin composition of the present invention, the third component is added in advance to a solvent such as methyl ethyl ketone and dispersed by a homomixer or the like. Preferably, the secondary aggregation of the fine particles is loosened by mixing other components, or dispersing the third component, other components and a solvent using a homomixer after mixing. Further, as another method, a three-roll, ball mill or the like is also suitable. If used without sufficiently coagulating the secondary coagulation, the third component is separated in the resin varnish, and the storage stability of the varnish is significantly reduced. Even if this varnish is applied to a copper foil, a uniform coating film is obtained. Because it is not possible, when laminating a copper-clad insulating sheet coated with the resin composition of the present invention on the inner layer panel having a conductor circuit pattern,
Bubbles are easily bitten, and insulation reliability decreases due to the interface between the bubbles and aggregated particles and other resin components. In addition, when the aggregated particles are large, the coated copper-clad insulation sheet is deformed during storage by stacking or winding, and thus the formation of a fine circuit by the etching method is significantly impaired. There is fear.

Among the polymerization initiators as the fourth component, examples of the initiator by heating include an organic peroxide type and an azobis type. Among these, dialkyl peroxides are preferred from the viewpoint of high storage stability due to a high decomposition initiation temperature and low generation of low molecular weight volatile components when decomposed. Specifically, dicumyl peroxide, t -Butylcumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane and 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne. Further, the amount is preferably 0.5 to 5 parts by weight based on 100 parts by weight of the resin composition of the present invention.
If the amount is less than 0.5 part by weight, the polymerization is insufficient. If the amount exceeds 5 parts by weight, the shelf life is shortened and the amount of the decomposition product of the initiator is increased, so that the heat resistance may be impaired.

Among the polymerization initiators as the fourth component, the initiators caused by ultraviolet light include aromatic ketones such as benzophenone, Michler's ketone, xanthone and thioxanthone.
2-ethylanthraquinone; acetophenones such as acetophenone, trichloroacetophenone, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexylphenyl ketone, benzoin isopropyl ether, benzoin isobutyl ether, and 2,2-diethoxyacetophenone; diketones And benzyl, methylbenzoyl formate and the like. The compounding amount is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the resin composition of the present invention. In the case where curing by an electron beam among the active energy rays is used, the polymerization initiator is not essential.

The resin composition of the present invention is cured by an active energy ray such as an electron beam or an ultraviolet ray or by heating, and is disclosed by the present inventors in JP-A-5-218651, JP-A-6-232563, and JP-A-6-232563. No. 250771 discloses a method for manufacturing a printed wiring board, that is, an uncured copper foil coated with the resin composition of the present invention is heat-laminated on a glass epoxy substrate or the like in which an inner layer circuit is formed in advance, and the resin is cured. When used in a method of manufacturing a multilayer printed wiring board by curing, the resin under the copper foil is cured, so that it is difficult to cure with ultraviolet light that does not pass through the copper foil. Therefore, in this case, curing is performed by electron beam and / or heating. Also when curing the resin composition of the present invention other than under the copper foil,
Since a sufficient effect cannot be obtained by ultraviolet curing, it is preferable to use electron beam and / or heating in combination. In each case, the effect of heat curing is greater than that of electron beam. Therefore, the use of an initiator by heating as the fourth component is more preferable.

The present invention is a resin composition comprising at least the above four components as essential components. To impart flame retardancy to the resin composition, a halogenated phenol is further added as a fifth component. A reaction product of a glycidyl ether of a compound with (meth) acrylic acid, and / or
It is preferable to add phosphorus or a phosphorus-based flame retardant as a component.

Specific examples of the reaction product of the glycidyl ether of the halogenated phenol compound, which is the fifth component, with (meth) acrylic acid include a reaction product of tetrabromobisphenol A diglycidyl ether with (meth) acrylic acid.
A reaction product of an epoxy resin (for example, DER514 manufactured by Dow) containing both a tetrabromobisphenol A skeleton and bisphenol A containing no bromine and (meth) acrylic acid can be used. If desired, two or more kinds can be used. . Further, compounds having a different number of bromine substitutions per bisphenol A skeleton, such as a monobromo compound and a dibromo compound, which are contained as by-products of tetrabromobisphenol A, may be present. Further, a reaction product of a monofunctional brominated epoxy resin (eg, BROC series manufactured by Nippon Kayaku Co., Ltd.) and (meth) acrylic acid or a polyfunctional brominated epoxy resin (eg, BREN series manufactured by Nippon Kayaku Co., Ltd.) A reaction product of (meth) acrylic acid and (meth) acrylic acid can also be used. Among these, when blended in the resin composition of the present invention,
Bifunctional compounds capable of having both strength and appropriate flexibility are preferred, and bromine is particularly preferred as a halogen type because of its excellent flame retardancy. The compounding amount of the fifth component is such that the bromine content is 5 to 2 in the resin composition of the present invention.
It is preferable that the content be 5% by weight.

When the bromine content is less than 5% by weight, the flame retardancy of the cured product of the resin composition of the present invention cannot be sufficiently obtained unless 2% by weight or more of phosphorus derived from the sixth component described below is added. It is not preferable to mix a large amount of phosphorus because the insulating property is reduced. When the amount of bromine is more than 25% by weight, flame retardancy can be obtained, but the halogen compound is easily desorbed upon heating, and solder heat resistance and long-term reliability are unfavorably reduced.

Specific examples of the sixth component phosphate ester include tricresyl phosphate, tri (2,6-dimethylphenyl) phosphate (PX130 manufactured by Daihachi Chemical Industry Co., Ltd.), and triaryl phosphate (Ajinomoto ( And the like, and two or more of them can be blended if desired. Red phosphorus, which is a simple substance of phosphorus, also has a high flame-retardant effect, and its fine powder such as Hishigard CP manufactured by Nippon Chemical Industry Co., Ltd. can be used.

The compounding amount of the sixth component is preferably such that the phosphorus content in the resin composition of the present invention is in the range of 0.1 to 2% by weight. When the phosphorus content is less than 0.1% by weight, flame retardancy cannot be obtained unless a larger amount of a bromine compound is added, so that a large amount of halide decomposed products are generated during soldering, and heat resistance is reduced. If it is not sufficient, and if it exceeds 2% by weight, electrical insulation tends to deteriorate.

The resin composition of the present invention further requires an inorganic filler such as talc, calcium carbonate or silica, which is usually used, or an additive such as a leveling agent, an antifoaming agent, a pigment or an ion scavenger. May be added according to

As a solvent for forming a resin varnish,
While dissolving each component other than the components and applying the resin composition of the present invention to a copper foil, those which volatilize by heating and time to such an extent that the resin composition is not polymerized, specifically, methyl ethyl ketone, ethanol And those having a boiling point of less than 100 ° C. such as isopropyl alcohol. The solvent is preferably blended so that the solid content of the resin varnish is 30 to 80% by weight.

The resin composition of the present invention is described in JP-A-5-218651 and JP-A-6-2325 by the present inventors.
63 and JP-A-6-250771 are suitable for the method of manufacturing a printed wiring board. That is, the resin composition of the present invention has no resin flow before curing, has good adhesion to the inner layer plate, and can be used as a heat-resistant insulating material after curing. Furthermore, when this method is used, the formation of blind via holes for making electrical connection between the inner layer circuit and the outer layer circuit has conventionally been drilled one hole at a time, but the resin composition of the present invention has an alkali-soluble property. Since it is provided, the copper foil at a predetermined position is removed by an etching method, and the exposed resin is dissolved and removed with an alkaline aqueous solution, so that a large number of blind via holes can be formed at once, further increasing the production efficiency. it can.

The dielectric constant of a conventional glass epoxy laminate is 1
It is 4.7-5.0 in MHz. The epoxy resin alone has a dielectric constant of 3.7, but it is known that the dielectric constant increases when glass cloth is used as a reinforcing material. Since the resin composition of the insulating material of the present invention has no glass cloth and the properties of the resin, the dielectric constant is 2.9 to 3.0 at 1 MHz, and when used as an interlayer insulating material, the signal transmission speed is increased. It will be advantageous.

Generally, the resin composition for insulating material is 0.6 mm
When used as an interlayer insulating material for the following thin printed wiring boards, the printed wiring board is liable to warp when heated to a high temperature such as soldering or solder reflow, and contains no third component and has no glass cloth or inorganic filler. In addition to the above-described generation of warpage due to heating, stress cannot be dispersed, and cracks may occur in the resin, and blisters may occur in the resin layer sandwiched between the inner and outer copper foils. However, in the resin composition of the present invention, the deformation stress is applied to the resin layer, but the third component absorbs the above-mentioned stress, so that the above-described crack and swelling hardly occur.

[0041]

The present invention will be described in detail below with reference to examples.

Example 1 (Synthesis of the first component) From 26.8 parts by weight of n-butyl acrylate, 5.2 parts by weight of styrene, 26.8 parts by weight of acrylic acid, and 0.25 parts by weight of azobisisobutyronitrile The resulting mixture was dropped into 100 parts by weight of a mixed solvent of methyl ethyl ketone and ethanol (mixing ratio: 7: 3) maintained at a temperature of 75 ° C. over 5 hours under a nitrogen gas atmosphere. Thereafter, the mixture was aged for 0.5 hour, and 0.3 part by weight of azobisisobutyronitrile was further added and aged for 4 hours to synthesize an unmodified acrylic polymer. Next, while adding 0.23 parts by weight of hydroquinone as a polymerization inhibitor and blowing a small amount of air, 1.5 parts by weight of N, N-dimethylbenzylamine and glycidyl methacrylate 1 were added.
After adding 4.7 parts by weight, the mixture is reacted at a temperature of 77 ° C. for 10 hours, and has a molecular weight of 15,000 to 50,000 and an acid value of 2.2.
A first component having a carboxyl group of 5 meq / g and an unsaturated group content of 0.9 mol / kg (hereinafter referred to as "base resin") was synthesized.

(Preparation of Resin Composition) A cross-linked MBS resin having an average particle size of 0.2 μm (25 parts by weight of the base resin synthesized as described above, 10 parts by weight of polyethylene glycol diacrylate in terms of solid component) (Kureha Chemical Co., Ltd.) BTA manufactured by
751) 25 parts by weight, brominated bisphenol A-epoxy methacrylate (bromine content in solid content is about 38%)
, 40 parts by weight in terms of solid content, 6.7 parts by weight of a phosphate ester (Leophos manufactured by Ajinomoto Co., Inc., phosphorus content: 8%),
1.0 part by weight of dicumyl peroxide (Parkmill D manufactured by NOF CORPORATION) and 75 parts by weight of methyl ethyl ketone are mixed well using a homodisper to prepare a resin composition, and methyl ethyl ketone is added to increase the viscosity to about 700 cp.
s, and then filtered through a 300th filter cloth, and the hole diameter is 5 μm.
The mixture was subjected to pressure filtration using a filter of No. 1 to prepare a resin varnish.

Example 2 (Preparation of Resin Composition) A crosslinked MBS resin (40 parts by weight in terms of solid component), 10 parts by weight of polypropylene glycol diacrylate, and an average particle diameter of 0.2 μm was prepared from the base resin synthesized in Example 1. Kureha Chemical Co., Ltd. Paraloid EXL265
5) 10 parts by weight, brominated bisphenol A-epoxy methacrylate 40 parts by weight, Leophos 6.7 parts by weight,
Using 1.0 part by weight of Park Mill D and 30 parts by weight of methyl ethyl ketone, a resin composition was prepared by mixing well as in Example 1, and then having a viscosity of about 7 as in Example 1.
A 00 cps resin varnish was prepared.

Example 3 (Preparation of resin composition) The base resin synthesized in Example 1 was 35 parts by weight in terms of solid component, 5 parts by weight of polypropylene glycol diacrylate, and a crosslinked acrylic rubber having an average particle size of 0.2 μm ( Kanebuchi Chemical Industry Co., Ltd. Kaneace FM21)
20 parts by weight, 40 parts by weight of brominated bisphenol A-epoxy methacrylate, 6.7 parts by weight of Leophos, 1.0 part by weight of Parkmill D and 6 parts of methyl ethyl ketone
Using 0 parts by weight, a resin composition was prepared by mixing well as in Example 1, and then having a viscosity of about 70 as in Example 1.
A resin varnish of 0 cps was prepared.

Comparative Example 1 (Preparation of Resin Composition) 50 parts by weight of the base resin synthesized in Example 1 in terms of solid content, 10 parts by weight of polyethylene glycol diacrylate, and 40 parts by weight of brominated bisphenol A-epoxy methacrylate , Leofos 6.
7 parts by weight and 1.0 part by weight of Park Mill D
A resin composition was prepared by mixing well as described above, and the viscosity was adjusted to about 700 cps by adding methyl ethyl ketone.

Comparative Example 2 (Preparation of Resin Composition) The base resin synthesized in Example 1 was converted to a solid component in an amount of 40 parts by weight, 20 parts by weight of polyethylene glycol diacrylate, 40 parts by weight of brominated bisphenol A-epoxy methacrylate, Leofos 6.7
1 part by weight and Park Mill D 1.0 part by weight were mixed well as in Example 1 to prepare a resin composition, and methyl ethyl ketone was added to adjust the viscosity to about 700 cps.

Comparative Example 3 (Preparation of Resin Composition) 35 parts by weight of the base resin synthesized in Example 1 in terms of solid component, 5 parts by weight of polypropylene glycol diacrylate, carboxyl group-terminated liquid NB
R (HydraCTBN 1300 x 13 manufactured by BF Goodrich, USA) 2
0 parts by weight, 40 parts by weight of brominated bisphenol A-epoxy methacrylate, 6.7 parts by weight of Reophos and 1.0 part by weight of Parkmill D were mixed well as in Example 1 to prepare a resin composition, and methyl ethyl ketone was added. In addition, the viscosity was about 700 cps.

(Preparation of Test Piece and Measurement of Physical Properties) The compositions of all the resin compositions of Examples and Comparative Examples are summarized in Table 1. Using these resin compositions, test pieces were prepared by the following methods, and physical properties were measured. Table 1 also shows the evaluation results of the following characteristics.

[0050]

[Table 1]

The above resin composition was applied to a roughened surface of a copper foil having a thickness of 18 μm using a bar coater, and was applied at 70 ° C. for 10 minutes.
After drying for 1 minute, it was further dried at 110 ° C. for 5 minutes to evaporate and remove the solvent to form a resin layer having a thickness of about 80 μm, thereby producing a copper-clad insulating sheet having a two-layer structure including a copper foil and a resin. This copper-clad insulating sheet was used before the lamination described below in order to prevent the adhesion of dust and the like, with a protective film made of polyethylene adhered to the resin surface, and this film was peeled off if necessary.

The copper foil of the single-sided copper-clad glass epoxy board having a thickness of 1 mm is blackened, the resin surface of the above-mentioned copper-clad insulating sheet is aligned with the blackened surface, and bonded using a hot roll laminator. After irradiating an electron beam with an accelerating voltage of 175 kV by an apparatus at 20 Mrad, the resin layer is cured by heating at 170 ° C. for 30 minutes to produce a copper-clad laminated panel having an inner layer plate (hereinafter simply referred to as “laminated panel”). did.

(Adhesion of Copper Foil)
-Cut to a size of 10 cm x 2.5 cm according to C6481 and 1 cm along the longitudinal center line by etching.
A copper foil pattern having a width was formed and used as a test piece for measuring copper foil peel strength.

The prepared test piece for measuring the peeling strength of the conductor was directly coated with a copper foil by 50 in accordance with JIS-C6481.
The film was peeled at a speed of mm / min, and the peel strength was measured.

(Solder Heat Resistance) A copper plating layer having a thickness of about 20 μm was formed on the surface copper foil of the laminated panel, cut into a size of 4 cm square, and 2.5 cm × 2.5 cm by an etching method.
Was formed at the center to prepare a test piece for a solder heat resistance test.

The test piece was floated in a molten solder bath at a bath temperature of 260 ° C. with the copper foil side down, and the time required for the copper foil to expand was measured.

(Insulation Resistance Between Layers) An M pattern of a test pattern for a multilayer printed wiring board specified in JIS-C5012 is formed on the outer layer copper foil of the laminated panel by an etching method, and the resin layer away from the pattern is removed. By shaving off, the copper foil of the inner layer was partially exposed so that the insulation resistance between the outer layer and the inner layer could be measured. Using the prepared test piece for measuring interlayer insulation resistance, the insulation resistance value at DC 100 V was measured.

(Punching resistance) The copper foil of a glass epoxy substrate having a thickness of 1 mm was removed by etching, and the copper-clad insulating sheet was adhered to one surface of this panel using a hot roll laminator, and was irradiated with an electron beam. Acceleration voltage 175
After irradiation with an electron beam of 20 kV at kV, the resin layer was cured by heating at 170 ° C. for 30 minutes. Thereafter, the copper foil on the bonded sheet side was also removed by etching to obtain a test piece for a punching test.

The test piece for the punching test was set on a mini desk press manufactured by Kamekura Seiki so that the male mold hit the cured resin of the present invention first, and the test piece was punched out with a 2 cm square punching die, and the substrate (2 cm square) ) Was observed to check for cracks.

(Thermal shock resistance) 1 mm thick glass epoxy board with 35 μm copper foil on both sides (size 10 cm × 10 cm)
Eight copper foils having a width of 1 mm were formed on one surface only at one-cm intervals by a usual etching method. This pattern was usually subjected to a blackening treatment to enhance the adhesion between the inner layer and the resin. Next, the copper-clad insulating sheet was adhered to the pattern forming surface using a hot roll laminator, and irradiated with an electron beam of 175 kV by an electron beam irradiation device at 20 Mrad.
The resin layer was cured by heating at 70 ° C. for 30 minutes. Further, a copper plating having a thickness of 20 μm is formed on the outer layer copper foil of the obtained panel, and the inner layer pattern is parallel to the inner layer pattern in a reverse pattern corresponding to the inner layer pattern immediately above every other end of the inner layer pattern at intervals of 1 cm width. A 1 cm wide pattern was formed by an etching method. This substrate was aged at 150 ° C. for 30 minutes to obtain a test piece for a thermal shock test.

The test piece for the thermal shock test was previously
After floating in a solder bath kept at 60 ° C. in a normal state for 20 seconds, it is immediately immersed in water at 25 ° C. and rapidly cooled. This is performed twice for each test piece, the outer layer is removed by etching, and cracks in the insulating layer are formed. Was observed.

(Burning Test) A 0.4 mm thick glass epoxy substrate (NEMA) from which all copper foil was removed by etching
Standard: FR-4) The above-mentioned copper-clad insulating sheet was hot-roll laminated on both sides, and each side was irradiated with an electron beam of 175 kV at an acceleration voltage of 175 kV by an electron beam irradiation apparatus, and then heated at 170 ° C. for 30 minutes to obtain a resin. The layer was cured. Further, the entire surface copper foil of the substrate was removed by etching, and the product was manufactured by Underwriters Laboratories Inc., USA. The samples were cut and tested based on the safety standard for flame retardancy (UL94) set forth in. UL which is the highest grade of this standard
When it was considered to be equivalent to 94V-0, it was set to V-0.

(Alkali solubility test) A copper-clad insulating sheet was cut into a size of 30 mm × 20 mm, and was adhered to a plastic plate with a cellophane tape so that the resin surface of the copper-clad insulating sheet was exposed at 20 mm × 20 mm. Then, a test sample was prepared. 2.5 liters of a 1% sodium carbonate solution at 40 ° C. was placed in a 3 liter beaker, and the test sample was immersed while stirring the solution, and the dissolution time was measured.

[0064]

According to the resin composition of the present invention, it has a structure without a reinforcing material such as glass cloth, and has impact resistance, heat resistance, flame retardancy, and the like which cannot be obtained with a conventional acrylic resin.
It is possible to obtain an insulating material having insulation reliability, and by using this, it is possible to manufacture a multilayer printed wiring board that is suitable for thinning and weight reduction, high-speed transmission, and excellent mass productivity.

Continuation of the front page (72) Inventor Hiroshi Hibino 1 in Funamicho, Minato-ku, Nagoya, Aichi Prefecture Inside Nagoya Research Institute, Toagosei Co., Ltd. (72) Inventor Kaoru Kimura 1 in Funamicho, Minato-ku, Nagoya-shi, Aichi 1 Toagosei Co., Ltd. Nagoya Research Laboratory

Claims (2)

[Claims] (1) an alkali-soluble acrylic polymer and / or methacrylic polymer having a carboxyl group; (2) a polymerizable compound having at least one CＣC unsaturated double bond; (3) A finely divided crosslinked elastic polymer having an average particle diameter of 5 μm or less, and (4) a polymerization initiator capable of initiating polymerization of the CＣC unsaturated double bond by heating and / or irradiation of active energy rays are blended. And a resin composition for an insulating material. (1) An alkali-soluble acrylic polymer and / or methacrylic polymer having a carboxyl group comprises acrylic acid and / or methacrylic acid,
A linear polymer mainly composed of an acrylic ester and / or a methacrylic acrylic ester, wherein a glycidyl group and a CＣC
The resin composition for an insulating material according to claim 1, which is a linear polymer to which a compound having an unsaturated double bond is added.