JP2011140661A - Resin composition, and prepreg and printed wiring board using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition which is free from halogen, is excellent in chargeability into through-holes and has a low dielectric constant and to provide a prepreg and a printed wiring board using the resin composition. <P>SOLUTION: The resin composition comprises: (a) an inorganic filler having a spherical particle shape and an average particle size of 0.1 to 5 μm; (b) a halogen-free thermosetting resin; (c) a halogen-free curing agent for the thermosetting resin; and (d) a halogen-free flame retardant, wherein a relative dielectric constant at frequency 1 GHz of the cured material of the resin composition is 2.5 to 3.5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resin composition, a prepreg using the resin composition, and a printed wiring board.

  In recent years, due to the increasing awareness of the environment, prepregs, metal-clad laminates, and printed wiring boards (hereinafter referred to as wiring board materials) used in electronic devices, etc., may generate harmful gases such as dioxins during incineration such as disposal. The introduction of halogen-free products that do not contain halogen compounds is progressing. In order to impart flame retardancy without containing a halogen compound, a method of adding a flame retardant containing no halogen and a relatively large amount of an inorganic filler in combination is generally performed. As the inorganic filler used here, aluminum hydroxide having a high flame retardant effect is often selected. Similarly, lead-free solder that does not contain lead is also being introduced, and in order to cope with the lead-free solder process performed at a higher temperature than before, wiring board materials are required to have high heat resistance and low thermal expansion. In order to satisfy these requirements, the addition of inorganic fillers to resin compositions used for wiring board materials has been further advanced.

  Furthermore, with the increase in speed and density of electronic devices, there is a demand for lower dielectric constants for wiring board materials and higher multilayers for printed wiring boards. However, the former halogen-free wiring board material has a large amount of aluminum hydroxide having a relatively high dielectric constant as described above, and thus it has been difficult to reduce the dielectric. Further, as a method for increasing the number of layers of the latter printed wiring board, two or more inner layer boards formed by forming a wiring pattern on one or both sides of a metal-clad laminate are used, and a prepreg is interposed in an intermediate layer between the inner layer boards. A sequential lamination method is generally known in which layers are laminated, heated and pressurized. In this method, the through-hole formed in the inner circuit board at the time of molding may be filled with the resin composition contained in the prepreg. When using a halogen-free prepreg containing aluminum hydroxide as the filler, aluminum hydroxide is used. Due to the irregular shape, the flow at the time of molding is insufficient, so that the through-holes of the inner circuit board may not be sufficiently filled.

  In order to impart flame retardancy without containing a halogen-based compound, a method such as adding a phosphorus-based flame retardant or an inorganic filler to the resin composition is performed. As phosphorus flame retardants, phosphate esters such as triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, condensed phosphate esters such as resorcinol diphosphate, etc. are widely used ( Patent Document 1). Moreover, as shown in Patent Document 2, a technique using phosphinate or diphosphinate as a flame retardant has been introduced.

  Furthermore, in recent years, in order to process a large amount of data at high speed, the frequency of signals has been increased in computers and information equipment terminals. As the frequency used increases, the transmission loss of electrical signals increases. In order to cope with this, there is a strong demand for the development of a printed wiring board having dielectric characteristics corresponding to higher frequencies.

  Transmission loss in high-frequency circuits is greatly affected by dielectric loss determined by the dielectric properties of the insulating layer (dielectric) around the wiring, and the dielectric constant and dielectric loss tangent (tan δ) of the printed wiring board substrate (especially insulating resin) are low. It is necessary to do. For example, in a device related to mobile communication, a substrate having a low dielectric loss tangent is strongly desired in order to reduce transmission loss in the quasi-microwave band (1 to 3 GHz) as the signal becomes higher in frequency.

  Furthermore, electronic information devices such as computers have been equipped with high-speed microprocessors with operating frequencies exceeding 1 GHz, and delays in high-speed pulse signals on printed wiring boards have become a problem. In a printed wiring board, the signal delay time becomes longer in proportion to the square root of the relative dielectric constant εr of the insulator around the wiring. Therefore, a high-speed computer or the like requires a low dielectric constant wiring board material.

JP 2003-206392 A JP 2002-284963 A

  The present invention solves the above-mentioned problems of the prior art, and provides a low-dielectric-constant resin composition that is halogen-free and excellent in filling through holes, and a prepreg and printed wiring board using the same. .

That is, the present invention is as follows.
(1) (a) an inorganic filler having a spherical particle shape and an average particle diameter of 0.1 to 5 μm, (b) a thermosetting resin containing no halogen, and (c) the thermosetting containing no halogen. A resin composition comprising a curing agent for a functional resin, (d) a flame retardant containing no halogen, and having a relative dielectric constant of 2.5 to 3.5 at a frequency of 1 GHz in the cured product.
(2) A prepreg obtained by impregnating a substrate with the resin composition according to item (1) and drying it.
(3) A printed wiring board obtained by laminating, heating and pressing between two or more inner layer boards formed with a wiring pattern on one side or both sides via the prepreg according to item (2).

  It has become possible to provide a resin composition having a low dielectric constant that is halogen-free and excellent in filling through holes, and a prepreg and printed wiring board using the resin composition.

Hereinafter, the present invention will be described in detail.
The component (a) of the present invention is an inorganic filler having a spherical particle shape and an average particle size of 0.1 to 5 μm. When the average particle size is less than 0.1 μm, the peel strength of the metal foil may be inferior, and when it exceeds 5 μm, the resin composition may be easily precipitated when an organic solvent is added to the resin composition. Moreover, in this invention, it is preferable that the maximum particle size of an inorganic filler is 20 micrometers or less. If the maximum particle size exceeds 20 μm, the electrical characteristics may be inferior in reliability when the thickness of the prepreg is thin or the wiring pattern formed on the metal-clad laminate is fine. The inorganic filler used in the present invention is not particularly limited as long as the particle shape is spherical and the average particle diameter is 0.1 to 5 μm, but silica is preferable because of its low dielectric constant. Examples of commercially available products include SP-3B (trade name, manufactured by Fuso Chemical Industry Co., Ltd., average particle size: 3.0 μm), SO-25R (trade name manufactured by Admatechs Co., Ltd., average particle size: 0.5 μm), and the like.

  The amount of the inorganic filler used in the present invention is preferably 5 to 100 parts by weight based on 100 parts by weight of the resin solid content of the resin composition. If the amount is less than 5 parts by weight, the effect of the inorganic filler cannot be obtained. If the amount exceeds 100 parts by weight, the inorganic filler may settle or agglomerate when an organic solvent is added to the resin composition to form a varnish. When adding an inorganic filler in this invention, you may add various surface treating agents as needed.

  The component (b) of the present invention is not particularly limited as long as it is a thermosetting resin containing no halogen, and examples thereof include an epoxy resin, a polyimide resin, a triazine resin, a melamine resin, a phenol resin, and a cyanate compound. These can be used alone or in combination of two or more. Among these, epoxy resins are exemplified as follows: bisphenol A type epoxy resin, bisphenol AD type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, phenol Novolac epoxy resin, cresol novolac epoxy resin, biphenyl epoxy resin, phenol biphenylene novolac epoxy resin, bisphenol A novolac epoxy resin, diglycidyl etherified product of biphenol, diglycidyl etherified product of naphthalenediol, diglycidyl phenolic compound Etherified products, diglycidyl etherified products of alcohols, alkyl-substituted products thereof, hydrogenated products, and the like can be used. Among these, alone or in combination of two or more. It can be.

  The component (c) of the present invention is not particularly limited as long as it is a curing agent for the thermosetting resin containing no halogen. Examples of the curing agent in the case of using an epoxy resin as the thermosetting resin include amine compounds, polyfunctional phenol compounds, acid anhydride compounds, and the like, and these are selected singly or in combination. Although the compounding quantity of a hardening | curing agent is not restrict | limited in particular, 0.01-5.0 equivalent is preferable with respect to the functional group of the main material of a thermosetting resin. Even when any thermosetting resin is used, a curing accelerator may be used. The curing accelerator in this case is not particularly limited. For example, imidazole compounds, organophosphorus compounds, secondary amines, tertiary amines, quaternary ammonium salts, and the like are used. These are selected. The blending amount of the curing accelerator is not particularly limited, but is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the total solid content of the organic component in the resin composition.

  The component (d) of the present invention is not particularly limited as long as it is a halogen-free flame retardant. For example, phosphinic acid metal salt-based, phosphazene-based, phosphate ester-based, condensed phosphate ester-based, ammonium phosphate-based, phosphorus An acid melamine type, a cyclic ester type, etc. are mentioned, Among these, it can use individually or 2 types or more.

  In addition, the resin composition used in the present invention may contain a catalyst, a flexible agent, and the like as needed. Further, the cured product of the resin composition of the present invention has a relative dielectric constant of 2.5 to 3.5 at a frequency of 1 GHz. When the relative dielectric constant exceeds 3.5, when a printed wiring board is used, the delay of the high-speed pulse signal becomes a problem. A resin composition having a relative dielectric constant of less than 2.5 is difficult to produce.

  The varnish of the resin composition of the present invention can be obtained by adding an organic solvent to the above compounded material as necessary and mixing them. The organic solvent used in the present invention is not particularly limited, but alcohol solvents such as methanol, ethanol, isopropyl alcohol and n-butanol, ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone, and aromatic carbonization such as toluene and xylene. Hydrogen solvents, sulfur compound solvents such as dimethyl sulfoxide, amide solvents such as N-methylpyrrolidone, N-methylformaldehyde, N, N-dimethylformamide, cellosolv solvents such as methyl cellosolve, ethyl cellosolve, cellosolve acetate, etc. They can be used and are selected from these alone or in combination.

  The base material is impregnated with the varnish of the resin composition of the present invention, and further dried to produce a prepreg. Although it does not restrict | limit especially as a base material used for this invention, Usually, a woven fabric, a nonwoven fabric, etc. are used. The material of the substrate is not particularly limited, but inorganic fibers such as glass, alumina, silica alumina glass, silica glass, silicon carbide, and zirconia, and organic fibers such as aramid, polyetherimide, carbon, and cellulose are used. .

  The printed wiring board of the present invention comprises two or more inner layer boards formed by forming a wiring pattern on one side or both sides of a metal-clad laminate or the like, laminated between the inner layer boards via the prepreg of the present invention, and heated and heated. Obtained by pressing. The conditions at the time of heat and pressure molding depend on the reactivity between the thermosetting resin and the curing agent, and therefore are selected according to the resin material used, and are usually in the range of 130 to 250 ° C., preferably 150 to 200 ° C. In general, a pressure in the range of 0.5 to 20 MPa, preferably 1 to 8 MPa, a heating and pressing time in the range of 10 to 200 minutes, preferably 30 to 120 minutes is selected.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

(Examples 1-3, Comparative Examples 1-2)
The resin composition and methyl ethyl ketone of the compounding quantity (solid weight part) shown in following Table 1 were mix | blended, and it stirred for 60 minutes at 80 degreeC, and obtained the varnish of the resin composition. Methyl ethyl ketone was blended so that the varnish had a solid content of 50% by weight. The prepared varnish was impregnated into a 0.1 mm thick glass cloth (2116, manufactured by Asahi Sebel Co., Ltd., trade name), heated at 160 ° C. for 5 minutes and dried to obtain a prepreg having a resin content of 50% by weight. Through holes with a diameter of 0.1 mm are drilled at intervals of 10 mm perpendicular to a copper-clad laminate (MCL-E-67: manufactured by Hitachi Chemical Co., Ltd., trade name) with a thickness of 0.8 mm cut into 250 mm × 250 mm. 576 pieces were formed, one prepreg was sandwiched between the two copper-clad laminates, and a copper foil (GTS-18: manufactured by Furukawa Circuit Foil Co., Ltd., trade name) on both sides of the copper-clad laminates. ) Was placed, and a test substrate was prepared by heating and pressing under vacuum at 180 ° C., 3 MPa for 60 minutes. About the test board | substrate obtained by the Example and the comparative example, it evaluated by confirming the filling property to a through-hole for every hole. Fillability was calculated by the following equation (1), assuming that the resin composition was filled in the through-holes without voids. The results are shown in Table 1.

  Also, a cured product (30 mm × 30 mm, 1 mm thickness) of the resin composition was prepared, and the relative permittivity at 1 GHz of the cured product was measured at 25 ° C. at 25 ° C. using RF Impedance / Material Analyzer (manufactured by Hewlett Packard, 4291B). did. The results are shown in Table 1.

Moreover, the detail of the compounding material (resin composition) in the said Table 1 was shown below.
1 *: Spherical silica, average particle size 3.0 μm (trade name: SP-3B, manufactured by Fuso Chemical Industry Co., Ltd.)
2 *: Spherical silica, average particle size 0.5 μm (trade name: SO-25R, manufactured by Admatechs Co., Ltd.)
3 *: Silica (irregular shape), average particle size 1.1 μm (trade name: FLB-1, manufactured by Kashimori)
4 *: Aluminum hydroxide (irregular shape), average particle diameter 3.0 μm (manufactured by Nacalai Tex)
5 *: Cresol novolac type epoxy resin (trade name: ESCN-195, manufactured by Sumitomo Chemical Co., Ltd., epoxy equivalent: 195)
6 *: phenol biphenylene novolac type epoxy resin (trade name: NC-3000-H, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 288)
7 *: Phosphorus-modified epoxy resin (trade name: FX289, manufactured by Tohto Kasei Co., Ltd., epoxy equivalent: 308)
8 *: 2,2-bis (4-cyanatephenyl) propane prepolymer (trade name: AroCy B-30, manufactured by Asahi Ciba Co., Ltd., trimerization rate 30%, cyanate equivalent: 200)
9 *: Melamine-modified phenol novolak resin (trade name: Epicure YLH828, manufactured by Japan Epoxy Resin Co., Ltd., hydroxyl equivalent: 146)
10 *: 2-ethyl-4-methylimidazole (trade name: EpiCure EMI24, manufactured by Japan Epoxy Resin Co., Ltd.)
11 *: Zinc 2-ethylhexanoate (Wako Pure Chemical Industries, Ltd.)
12 *: Dialkylphosphinic acid aluminum salt (trade name: OP930, manufactured by Clariant)

  As is apparent from Table 1, Examples 1 to 3 of the present invention have a small relative dielectric constant and through-holes as compared with Comparative Examples 1 and 2 by using a spherical silica inorganic filler as the inorganic filler. Excellent filling properties. On the other hand, Comparative Example 1 is inferior in filling ability to the through-hole because it uses amorphous silica, and Comparative Example 2 is filling in the through-hole because it uses amorphous aluminum hydroxide. In addition, the relative dielectric constant is also large.

Claims (3)

  (A) an inorganic filler having a spherical particle shape and an average particle size of 0.1 to 5 μm, (b) a thermosetting resin containing no halogen, and (c) the thermosetting resin containing no halogen. A resin composition comprising a curing agent, (d) a flame retardant containing no halogen, and having a relative dielectric constant of 2.5 to 3.5 at a frequency of 1 GHz in the cured product.   A prepreg obtained by impregnating a substrate with the resin composition according to claim 1 and drying it.   A printed wiring board obtained by laminating, heating and pressing the prepreg according to claim 2 between two or more inner layer boards formed by forming a wiring pattern on one side or both sides.