JP2010059363A - Polyphenylene ether resin composition, prepreg, metal-clad laminate, and printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a PPE (polyphenylene ether) resin composition of which the cured product obtained therefrom scarcely has tack on the surface, and which has an epoxy compound and a cyanate compound compounded therein. <P>SOLUTION: The polyphenylene ether resin composition to be used is obtained by blending a polyphenylene ether (A) of which the number-average molecular weight is 1,000-5,000, the epoxy compound (B) having a naphthalene ring in the molecular structure, a cyanate ester compound (C), a phosphorus-based flame retardant (D), and a curing catalyst (E). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polyphenylene ether resin composition, a prepreg, a metal-clad laminate, and a printed wiring board that are preferably used as an insulating material for a printed wiring board.

  In electronic devices used in the field of information communication in recent years, signal capacity and speed have been increased. Therefore, there is a demand for a printed wiring board that has good high-frequency characteristics and can cope with a higher number of layers for increasing the number of wirings.

In a printed wiring board used for such an electronic device, a low dielectric constant (ε) and a low dielectric loss tangent (tan δ) are required in order to maintain reliability in a high frequency region from the MHz band to the GHz band. Conventionally, as a printed wiring board having such electrical characteristics, a PPE resin composition containing an epoxy resin or a cyanate compound as an essential component in polyphenylene ether (PPE) as an insulating layer has been disclosed (for example, Patent Documents). 1, 2). Such a PPE resin composition has high heat resistance and also has excellent dielectric properties.
JP-A-2005-290124 JP-A-10-279781

  However, when a fiber substrate is impregnated with a PPE resin composition containing an epoxy compound and a cyanate compound to produce a prepreg for use in the production of a printed wiring board, the surface of the prepreg is tacky (adhesive). There was a problem that remained. Such surface tackiness of the prepreg causes dust to adhere to the prepreg surface. And when a multilayer laminated body is manufactured in a state where dust adheres to the surface of the prepreg, reliability is impaired due to short circuit or migration of the printed wiring board. In particular, as the circuit width and circuit interval become narrower as the signal capacity increases and the speed increases, such a decrease in reliability due to dust adhering to the prepreg surface becomes a serious problem.

  In view of the above problems, an object of the present invention is to provide a PPE resin composition in which an epoxy compound and a cyanate compound are blended with less tack on the surface of the obtained cured product.

  The polyphenylene ether resin composition of the present invention comprises (A) a polyphenylene ether having a number average molecular weight of 1000 to 5000, (B) an epoxy compound having a naphthalene ring in the molecular structure, (C) a cyanate ester compound, (D) a phosphorus-based difficulty. A flame retardant and (E) a curing catalyst are blended. In a PPE resin composition in which an epoxy compound and a cyanate compound are blended, the use of an epoxy compound having a naphthalene ring in the molecular structure suppresses the tackiness of the resulting cured product. Therefore, such a PPE resin Since the prepreg obtained using the composition has a suppressed surface property, adhesion of dust can be suppressed. Thereby, a highly reliable multilayer printed wiring board can be manufactured.

（ｎは整数であり、エポキシ基数が平均２〜６個）
で表されるエポキシ化合物またはその誘導体であることが、タック性を充分に抑制できる点から好ましい。 Moreover, as an epoxy compound (B) which has a naphthalene ring in the said molecular structure, following formula (I):

(N is an integer, the average number of epoxy groups is 2-6)
It is preferable from the point which can fully suppress tackiness.

  Further, when the phosphorus flame retardant is a phosphazene compound or a phosphinate compound, it is possible to maintain the same flame resistance as when using a halogenated epoxy resin or the like while maintaining heat resistance. It is preferable from the point.

  The prepreg of the present invention is obtained by impregnating and drying a fibrous base material with any of the above polyphenylene ether resin compositions.

  In addition, the metal-clad laminate of the present invention is obtained by laminating a metal foil on the prepreg and molding by heating and pressing.

  The printed wiring board of the present invention is obtained by forming a circuit by partially removing the metal foil on the surface of the metal-clad laminate.

  According to the present invention, it is possible to provide a PPE resin composition in which an epoxy compound and a cyanate compound are blended so that no tack remains on the surface of the obtained prepreg.

  The polyphenylene ether resin composition of the present invention comprises (A) a polyphenylene ether (PPE) having a number average molecular weight of 1000 to 5000, (B) an epoxy compound having a naphthalene ring in the molecular structure, (C) a cyanate ester compound, (D) A phosphorus-based flame retardant and (E) a curing catalyst are blended.

  In the present invention, (A) PPE having a number average molecular weight of 1000 to 5000 is obtained by redistributing PPE having a number average molecular weight of 10,000 to 30,000 in a solvent in the presence of a phenol species and a radical initiator. And those obtained directly by polymerization reaction can be used without particular limitation. Specific examples of PPE include poly (2,6-dimethyl-1,4-phenylene oxide) or derivatives thereof.

  Further, the phenol species used in the redistribution reaction are not particularly limited. For example, polyfunctional phenolic compounds having two or more phenolic hydroxyl groups in the molecule such as bisphenol A, phenol novolak, cresol novolak, and the like Monofunctional phenolic compounds such as 2,6-xylenol are preferably used. These may be used alone or in combination of two or more.

  As PPE obtained by the above redistribution reaction, for example, those having hydroxyl groups contributing to curing at both ends of the molecular chain as shown by the following general formula (II) can maintain high heat resistance. To preferred.

（一般式（ＩＩ）中、ｘは２価の有機基であり、Ｒは何れも同じであっても異なっていても良い、水素又は炭素数１〜６のアルキル基であり、ｍ及びｎは整数を示す）

(In general formula (II), x is a divalent organic group, R is hydrogen which may be the same or different, or an alkyl group having 1 to 6 carbon atoms, and m and n are Indicates an integer)

  X is preferably an alkylene group having 1 to 3 carbon atoms or a group represented by the following general formula (III) or (IV).

（一般式（ＩＩＩ）、（Ｖ）中、Ｒは何れも同じであっても異なっていても良い、水素又は炭素数１〜６のアルキル基を示す）。

(In general formulas (III) and (V), R represents hydrogen or an alkyl group having 1 to 6 carbon atoms, which may be the same or different).

  The number average molecular weight of the polyphenylene ether (A) is 1000 to 5000, preferably 1500 to 3000. When the number average molecular weight is within such a range, the fluidity and the curing reactivity are excellent, and the compatibility with the epoxy compound and the cyanate ester compound is not lowered, so that excellent heat resistance and dielectric properties can be maintained. .

  As a blending ratio of the polyphenylene ether (A), 20 to 60% by mass, and further 30 to 50% by mass in the total amount of the (A) component, the (B) component, and the (C) component, This is preferable because sufficient heat resistance and excellent dielectric properties can be maintained.

  The epoxy compound (B) in the present invention can be used without particular limitation as long as it has a naphthalene ring in the molecular structure and two or more epoxy groups in one molecule. By using such an epoxy compound, tackiness of the prepreg surface can be suppressed.

（ｎは整数であり、エポキシ基数が平均２〜６個）
で表されるエポキシ化合物等のナフタレン含有ノボラック型エポキシ化合物またはその誘導体が特に好ましく用いられる。 The epoxy compound (B) having a naphthalene ring in the molecular structure has the following formula (I):

(N is an integer, the average number of epoxy groups is 2-6)
A naphthalene-containing novolak type epoxy compound such as an epoxy compound represented by the formula (1) or a derivative thereof is particularly preferably used.

  As a compounding ratio of the epoxy compound (B), it is sufficient to mix 20 to 60% by mass in the total amount of the component (A), the component (B) and the component (C). This is preferable because the characteristics can be maintained.

  You may mix | blend another epoxy compound with the polyphenylene ether resin composition of this invention in the range which does not impair the effect of this invention. Specific examples of such an epoxy compound include a dicyclopentadiene type epoxy compound, a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a phenol novolac type epoxy compound, and a biphenyl type epoxy compound.

  As the cyanate ester compound (C) in the present invention, a compound having two or more cyanate groups in one molecule is preferably used. Specific examples thereof include 2,2-bis (4-cyanatophenyl) propane, bis (3,5-dimethyl-4-cyanatophenyl) methane, and 2,2-bis (4-cyanatophenyl). And aromatic cyanate ester compounds such as ethane and derivatives thereof. These may be used alone or in combination of two or more.

  As a blending ratio of the cyanate ester compound (C), 20 to 60% by mass is blended in the total amount of the component (A), the component (B) and the component (C). It is preferable from the viewpoint that the dielectric characteristics can be maintained.

  The epoxy compound (B) and the cyanate ester compound (C) function as a component that imparts heat resistance and the like by forming a crosslinked structure or an IPN (Interpenetrating Polymer Network) structure with the polyphenylene ether (A) component.

  The phosphorus flame retardant (D) used in the present invention is not particularly limited as long as it is a known phosphorus flame retardant containing a phosphorus atom. In the present invention, by using a phosphorus-based flame retardant, a high flame retardant effect can be exhibited while suppressing the tackiness of the obtained prepreg.

  Specific examples of such phosphorus flame retardants (D) include, for example, phosphazene compounds such as phosphinate compounds, cyclophosphazene oligomers, triphenyl phosphate, tricresyl phosphate, xylenyl diphenyl. Examples thereof include phosphate compounds such as phosphate and cresyl diphenyl phosphate, condensed phosphate ester compounds, cyclic phosphate ester compounds, and derivatives thereof. These may be used alone or in combination of two or more. Among these, phosphazene compounds are preferably used because they are excellent in electrical characteristics and heat resistance.

  As a compounding quantity of the said phosphorus flame retardant (D), it is heat resistance to mix | blend 2-30 mass parts with respect to 100 mass parts of total amounts of (A) component, (B) component, and (C) component. And from the viewpoint of providing a sufficient flame retardant effect without deteriorating the dielectric properties.

  The polyphenylene ether resin composition in the present invention is blended with a curing catalyst for promoting the curing reaction. Specific examples of such a curing catalyst include, for example, organic metal salts of organic acids such as octanoic acid, stearic acid, acetylacetonate, naphthenic acid, and salicylic acid, such as Zn, Cu, and Fe, triethylamine, and triethanolamine. Examples thereof include tertiary amines, imidazoles such as 2-ethyl-4-imidazole and 4-methylimidazole. These may be used alone or in combination of two or more. Among these, an organic metal salt, particularly zinc octoate, is particularly preferably used because high heat resistance can be obtained.

  The blending ratio of the curing catalyst is not particularly limited. For example, when an organic metal salt is used, 0.005 to 0.005 parts by mass of the total amount of the component (A), the component (B), and the component (C). The amount is preferably about 5 parts by mass. When imidazoles are used, the amount is preferably about 0.01 to 5 parts by mass.

  The polyphenylene ether resin composition of the present invention may further contain an inorganic filler as necessary for the purpose of enhancing dimensional stability during heating or enhancing flame retardancy.

  Specific examples of the inorganic filler include silica, alumina, talc, aluminum hydroxide, magnesium hydroxide, titanium oxide, mica, aluminum borate, barium sulfate, calcium carbonate, and the like.

  Further, as the inorganic filler, those which are surface-treated with an epoxy silane type or amino silane type silane coupling agent are particularly preferable. A metal-clad laminate obtained by using a polyphenylene ether resin composition containing an inorganic filler surface-treated with a silane coupling agent as described above has high heat resistance during moisture absorption and also has an interlayer peel strength. Tend to be higher.

  In addition, the polyphenylene ether resin composition of the present invention may contain additives such as, for example, heat stabilizers, antistatic agents, ultraviolet absorbers, dyes, pigments, and lubricants, as long as the effects of the present invention are not impaired. May be blended.

  The polyphenylene ether resin composition of the present invention is prepared in a varnish form. Such a varnish is prepared as follows, for example.

  First, an epoxy compound (B) and a cyanate ester compound (C) are blended and dissolved in a resin solution of a polyphenylene ether (A) having a number average molecular weight of 1000 to 5000. At this time, heating may be performed as necessary.

  Then, a phosphorus-based flame retardant (D), a curing catalyst (E) and other components used as necessary are added, and a predetermined dispersion state is obtained using a ball mill, a bead mill, a planetary mixer, a roll mill, or the like. The varnish-like thermosetting resin composition is prepared.

  Examples of a method for producing a prepreg using the obtained polyphenylene ether resin composition include a method in which a fibrous base material is impregnated with a polyphenylene ether resin composition and then dried.

  Examples of the fibrous base material include glass cloth, aramid cloth, polyester cloth, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, linter paper and the like. When a glass cloth is used, a laminate having excellent mechanical strength can be obtained, and a flat glass processed glass cloth is particularly preferable. The flattening can be performed, for example, by continuously pressing the glass cloth with a press roll at an appropriate pressure and compressing the yarn flatly. In addition, as a thickness of a base material, the thing of 0.04-0.3 mm can generally be used.

  Impregnation is performed by dipping or coating. The impregnation can be repeated a plurality of times as necessary. In this case, it is also possible to repeat the impregnation using a plurality of solutions having different compositions and concentrations, and finally adjust to a desired composition and resin amount.

  The base material impregnated with the polyphenylene ether resin composition is heated at a desired heating condition, for example, at 80 to 170 ° C. for 1 to 10 minutes, whereby a semi-cured (B stage) prepreg is obtained.

  The thus obtained prepreg using the polyphenylene ether resin composition of the present invention has a suppressed surface tackiness. Therefore, when laminating the metal-clad laminate described below, dust or the like is difficult to adhere to the surface. Therefore, an electric circuit board having excellent reliability can be obtained.

  As a method for producing a metal-clad laminate using the prepreg thus obtained, one or a plurality of the prepregs are stacked, and a metal foil such as a copper foil is stacked on both upper and lower surfaces or one surface thereof. By heating and pressing to laminate and integrate, a double-sided metal foil-clad laminate or a single-sided metal foil-clad laminate can be produced. The heating and pressing conditions can be appropriately set depending on the thickness of the laminate to be manufactured, the type of the resin composition of the prepreg, etc. For example, the temperature is 170 to 210 ° C., the pressure is 3.5 to 4.0 Pa, and the time For 60 to 150 minutes.

  And the printed wiring board which provided the conductor pattern as a circuit on the surface of a laminated body can be obtained by carrying out the etching process etc. on the metal foil of the surface of the produced laminated body.

  The present invention will be described more specifically with reference to the following examples. However, the scope of the present invention is not limited to these examples.

(Production Example 1: Production of a solution of polyphenylene ether (PPE1) having a number average molecular weight of 2500 by redistribution reaction)
250 parts by mass of toluene was placed in a flask equipped with a stirrer and a stirring blade. While controlling the flask at an internal temperature of 90 ° C., 90 parts by mass of PPE having a number average molecular weight of 25000 (“Noryl 640-111” manufactured by SABIC Japan), 7 parts by mass of bisphenol A, and 7 parts by mass of benzoyl peroxide were added. By continuing the reaction for 2 hours, a solution of polyphenylene ether (PPE1) having a number average molecular weight of 2500 (solid content concentration 29%) was prepared. The number average molecular weight is a value in terms of styrene measured by gel permeation chromatograph (GPC).

(Production Example 2: Production of a solution of polyphenylene ether (PPE2) having a number average molecular weight of 4000 by redistribution reaction)
By reacting in the same manner as in Production Example 1 except that 7 parts by mass of bisphenol A and 7 parts by mass of benzoyl peroxide were used, 3.6 parts by mass of bisphenol A and 3.6 parts by mass of benzoyl peroxide were used. A solution of polyphenylene ether (PPE2) having a number average molecular weight of 4000 was prepared.

(Examples 1-8, Comparative Examples 1-4)
First, the raw materials used in this example are shown together.
<Epoxy compound>
Epicon HP5000 (manufactured by DIC Corporation), which is a condensed polycyclic epoxy compound having a structure represented by the above formula (I) and having an average number of epoxy groups of 2 to 3
Epicon EXA9900 (manufactured by DIC Corporation), which is a condensed polycyclic epoxy compound having a structure represented by the above formula (I) and having an average number of epoxy groups of 4 to 6
・ Epicron HP7200 (manufactured by DIC Corporation), which is a dicyclopentadiene type epoxy compound
・ Epicron 840 (made by DIC Corporation) which is a bisphenol A type epoxy compound
-Epicron N-740 (manufactured by DIC Corporation), which is a phenol novolac type epoxy compound
<Cyanate ester compound>
2,2-bis (4-cyanatophenyl) propane (BADCy manufactured by Lonza Japan)
<Flame retardants>
Phosphorus flame retardant (SPB-100 manufactured by Otsuka Pharmaceutical Co., Ltd., phosphazene compound)
・ Phosphorus flame retardant (OP935 manufactured by Clariant Japan, phosphinate compound)
<Curing catalyst>
・ Zinc octanoate (DIC Corporation, zinc concentration 18%)
[Preparation of resin varnish]
The toluene solution of polyphenylene ether was heated to 90 ° C., and the epoxy compound and the cyanate ester compound were added so as to have the blending ratio shown in Table 1, followed by stirring for 30 minutes for complete dissolution. Further, a curing catalyst, a flame retardant, and an inorganic filler were added and dispersed with a ball mill to obtain a varnish.

  Next, the obtained resin varnish was impregnated into glass cloth (“WEA116E” manufactured by Nitto Boseki Co., Ltd.), and then heated and dried at 150 ° C. for 3 to 5 minutes to obtain a prepreg.

  Next, 6 sheets of the obtained prepregs were stacked and laminated, and copper foils (F2-WS 18 μm manufactured by Furukawa Circuit Foil Co., Ltd.) were disposed on both outer layers, respectively, under conditions of a temperature of 220 ° C. and a pressure of 3 MPa. By heating and pressing, a copper-clad laminate having a thickness of 0.75 mm was obtained.

  The following evaluation was performed using the obtained prepreg and copper clad laminate.

<Finger touch tackiness>
A test piece of 10 × 10 cm prepreg was prepared, an index finger was pressed against the surface, and the tactile sensation was determined according to the following criteria.

Tack "No": I do not feel a tuck.
Tack “Yes”: Feels tacky.

<Ball tackiness>
The test was carried out using a ball tack tester (manufactured by Yasuda Seiki Seisakusho) based on the tilting ball tack method (J. Dow method) based on JIS-Z-0237. The test was carried out in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50%, and 32 types of balls represented by 32 times the value of “Nominal Ball” in accordance with JISB 1501 were used. The test result was expressed by the maximum ball number found and obtained from the average value of the three test times. Samples with no tack were written as 0.

<Circuit fillability>
A core material having a length of 150 mm, a width of 100 mm, and a thickness of 0.8 mm, in which 1000 communication holes having a hole diameter of 0.3 mm were formed at a pitch of 2 mm, was prepared. And the obtained prepreg and copper foil were laminated | stacked in that order on the single side | surface of the said core material, and only copper foil was laminated | stacked on the other single side | surface. And the said laminated body was shape | molded with the hot press on the conditions of 220 degreeC x 2 hours, and the pressure of 3 MPa. Then, the number of holes that were completely filled out of 1000 holes was counted, and the ratio was determined.

<Glass-transition temperature>
The glass transition temperature (Tg) of the copper-clad laminate was measured using a viscoelastic spectrometer “DMS100” manufactured by Seiko Instruments Inc. At this time, measurement was performed with a bending module at a frequency of 10 Hz, and the temperature at which tan δ reached a maximum when the temperature was raised from room temperature to 280 ° C. under a temperature rising rate of 5 ° C./min was defined as the glass transition temperature (Tg).

<Dielectric properties>
In accordance with the standard of JIS C 6481, the dielectric constant and dielectric loss tangent of the copper-clad laminate at 1 MHz were determined.

<Flame retardance>
The flame retardancy of the copper clad laminate cut out to a predetermined size was determined by performing a combustion test according to the UL 94 combustion test method.

<Oven heat resistance>
In accordance with the standard of JIS C 6481, the copper-clad laminate cut out to a predetermined size was left in a thermostat set at a predetermined temperature for 1 hour and then taken out. And the processed test piece was observed visually and the highest temperature when the swelling did not generate | occur | produce was calculated | required.

  The B stage prepreg obtained from the PPE resin composition containing an epoxy compound having a naphthalene ring in the molecular structure of Examples 1 to 8 had no tack. On the other hand, as shown in Comparative Examples 1 to 4, when an epoxy compound other than an epoxy compound having a naphthalene ring was blended, a clear tack was observed on the surface.

Claims (6)

  (A) polyphenylene ether having a number average molecular weight of 1000 to 5000, (B) an epoxy compound having a naphthalene ring in the molecular structure, (C) a cyanate ester compound, (D) a phosphorus flame retardant, and (E) a curing catalyst The polyphenylene ether resin composition characterized by the above-mentioned. The epoxy compound (B) having a naphthalene ring in the molecular structure is represented by the following formula (I):

(N is an integer, the average number of epoxy groups is 2-6)
The polyphenylene ether resin composition according to claim 1, which is an epoxy compound represented by the formula:   The polyphenylene ether resin composition according to claim 1 or 2, wherein the phosphorus flame retardant is a phosphazene compound or a phosphinate compound.   A prepreg obtained by impregnating and drying a fibrous base material with the polyphenylene ether resin composition according to any one of claims 1 to 3.   A metal-clad laminate obtained by laminating a metal foil on the prepreg according to claim 4 and heating and pressing.   A printed wiring board obtained by forming a circuit by partially removing the metal foil on the surface of the metal-clad laminate according to claim 5.