JP2002114855A - Method for producing prepreg, lamination plate and metal-clad lamination plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a prepreg for printed wiring plates suppressed in resin flow during molding without reducing Tg, heat resistance and processability and provide a lamination plate having high accuracy in thickness. SOLUTION: This method for producing a prepreg is to impregnate a varnish obtained by blending (a) a straight chain high molecular epoxy resin having an epoxy group on the reaction terminal, 100-1000 epoxy equivalent and >=10000 weight average molecular weight, (b) a lower molecular epoxy resin having 100-1000 epoxy equivalent and <=5000 weight average molecular weight, (c) a curing agent and (d) a hardening accelerator as essential ingredients, to a glass woven fabric or a glass nonwoven fabric and heat the fabric to be in the B stage. In this case, good characteristics are obtained by blending 1-15 pts.wt. of (a) based on 100 pts.wt. of the total solid in the epoxy resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a prepreg used for an electrical insulating material such as a printed wiring board and a method for manufacturing a laminate.

[0002]

2. Description of the Related Art For example, a metal foil-clad laminate used for electric and electronic equipment is impregnated with a thermosetting resin varnish such as an epoxy resin composition on a substrate such as a glass cloth and then heated to a half. A prepreg is manufactured by curing, a required number of prepregs are stacked, and a metal foil such as a copper foil is arranged and laminated on one or both sides of the prepreg, and heated and pressed to perform molding. In general, a multilayer metal foil-clad laminate is generally formed by etching a metal foil on the surface of the metal foil-clad laminate obtained by the above-described method to form a conductor circuit, and then forming the conductor circuit on the front and back of the laminate. In addition, a required number of the same prepregs as described above are stacked, and a metal foil is arranged on one side or both sides thereof, laminated, and heated and pressed to perform molding. Further, in a prepreg using an epoxy resin composition as a main component of a thermosetting resin varnish, the epoxy equivalent is 100 to 1.
An epoxy resin composition comprising about 000 epoxy resins, an amine-based curing agent and a curing accelerator is generally used.

In recent years, as printed wiring boards have become denser, thinner, and have higher transmission speeds, printed wiring board materials are required to have a thickness accuracy and an interlayer thickness accuracy for controlling insulation reliability, high heat resistance, and impedance characteristics. Is required to be improved.

[0004]

In order to improve the thickness accuracy, it is effective to suppress the resin flow during molding by changing the molding pressure, heating conditions and auxiliary materials at the time of thermal molding. The thickness precision is improved by optimizing the resin flow and gel time of the prepreg depending on the heating conditions. However, in a resin varnish using a low molecular weight epoxy resin, it is difficult to suppress the resin flow during molding by optimizing the resin flow and the gel time, and it is not possible to obtain sufficient thickness accuracy. Therefore, blending a linear polymer component, a rubber component, and other fillers with the resin varnish is an effective means for suppressing resin flow of the prepreg. However, the blending of the filler tends to decrease the punching properties and drilling properties and heat resistance during the processing of the printed wiring board, and a straight-chain polymer component such as a polymer epoxy resin exemplified by a phenoxy resin, Alternatively, when a rubber component such as NBR is added, Tg and heat resistance are reduced,
Connection reliability decreases.

An object of the present invention is to provide a prepreg for a printed wiring board in which the resin flow during molding is improved without lowering the Tg, heat resistance and workability, and a high-precision laminated board formed using the same. Is to provide.

[0006]

Means for Solving the Problems The present invention relates to the following items. (1) (a) a linear high molecular weight epoxy resin having an epoxy equivalent of 200 to 1000 and a weight average molecular weight of 10,000 or more, and (b) a low molecular weight epoxy resin having an epoxy equivalent of 100 to 1000 and a weight average molecular weight of 5000 or less. A prepreg characterized by impregnating a base material with a varnish blended as an essential component. (2) The prepreg according to (1), wherein 1 to 15 parts by weight of a high molecular weight epoxy resin is blended with respect to 100 parts by weight of the total solid content in the varnish. (3) A laminate comprising the prepreg according to any one of (1) and (2). (4) A metal-clad laminate obtained by laminating the prepreg according to any one of (1) and (2) and a metal foil.

BEST MODE FOR CARRYING OUT THE INVENTION

The high-molecular-weight epoxy resin (a) used in the present invention has an epoxy group at a reaction terminal, has an epoxy equivalent of 200 to 1,000 and a weight-average molecular weight of 10,000.
All that is required is the above. For example, a diglycidyl ether compound such as bisphenol A diglycidyl ether,
A polymer obtained by reacting with a chain extender such as an acid anhydride, a phenol compound or an amine compound to form a polymer is preferably used. In the present invention, the weight average molecular weight is measured by gel permeation chromatography using a standard polystyrene calibration curve. In addition, it is particularly preferable to use an epoxy resin having a Tg of 105 to 150 ° C. in terms of heat resistance.

The amount of the high molecular weight epoxy resin (a) is 1 to 100 parts by weight of the total solid content of the epoxy resin.
It is preferably 15 parts by weight, and particularly preferably 3 to 10 parts by weight. If the amount is less than 1 part by weight, the effect of blending the high molecular weight epoxy resin tends to be small, and it is difficult to sufficiently suppress the resin flow. On the other hand, when the amount exceeds 15 parts by weight, the resin flow tends to be too small, so that molding tends to be difficult, for example, the embedding property tends to deteriorate.

The type of the low molecular weight epoxy resin (b) used in the present invention may be any type as long as it has two or more epoxy groups in the molecule. For example, bisphenol A type epoxy resin, Bisphenol-type epoxy resin, bisphenol-type epoxy resin such as bisphenol S-type epoxy resin, phenol novolak-type epoxy resin, cresol novolak-type epoxy resin, novolak-type epoxy resin such as bisphenol-A novolak-type epoxy resin, dicyclopentadiene dioxide, etc. Epoxy resin comprising an alicyclic epoxy compound,
Epoxy resins composed of diglycidyl etherified diols of various diols such as naphthalene diol, and alkyl-substituted products and halides thereof can be used. These may be used in combination.

The curing agent for the epoxy resin is not particularly limited as long as it is generally used, and amine compounds, phenol compounds, acid anhydrides and the like are preferably used. Examples of the amine compound include diethylamine, diethylenetriamine, triethylenetetramine, diethylaminopropylamine, aminoethylpiperazine, mensendiamine, metaxylylenediamine, dicyandiamide, diaminodiphenylmethane, diaminodiphenylsulfone, methylenedianiline, and metaphenylenediamine. . Examples of the phenol compound include bisphenol compounds such as bisphenol A and bisphenol F, novolak compounds such as phenol novolak, cresol novolak, and bisphenol A novolak, and halides and alkyl group-substituted products thereof. As the acid anhydride, hexahydrophthalic anhydride (H
PA), tetrahydrophthalic anhydride (THPA), pyromellitic anhydride (PMDA), chlorendic anhydride (HE)
T), nadic anhydride (NA), methylnadic anhydride (MNA), dodecynylsuccinic anhydride (DDS)
A), phthalic anhydride (PA), methylhexahydrophthalic anhydride (MeHPA), maleic anhydride and the like. Some of these curing agents may be used in combination. The compounding amount is
It is preferably in the range of 0.5 to 1.5 equivalents to the epoxy group.

[0011] If necessary, a curing accelerator can be used. As the curing accelerator, any one may be used as long as it is used as a curing accelerator for an epoxy resin, and examples thereof include an imidazole compound, an organic phosphorus compound, a tertiary amine, and a quaternary amine.
Secondary ammonium salts and the like. It is preferable to use an imidazole compound in which the secondary amino group is masked with acrylonitrile, isocyanate, melamine, acrylate, or the like, since the prepreg has a pot life of twice or more and has excellent storage stability. Examples of the imidazole compound include imidazole, 2-methylimidazole,
Ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-
2-methylimidazole, 2-heptadecylimidazole, 4,5-diphenylimidazole, 2-methylimidazoline, 2-ethyl-4-methylimidazoline, 2-
Phenylimidazoline, 2-undecylimidazoline,
2-heptadecylimidazoline, 2-isopropylimidazole, 2,4-dimethylimidazole, 2-phenyl-4-methylimidazole, 2-methylimidazoline, 2-isopropylimidazoline, 2,4-dimethylimidazoline, 2-phenyl-4- Methyl imidazoline and the like, as a masking agent acrylonitrile,
Phenylene diisocyanate, toluene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, methylene bisphenyl isocyanate,
Melamine acrylate or the like can be used. These curing accelerators may be used in combination of several kinds, and the compounding amount is preferably 0.01 to 5 parts by weight based on 100 parts by weight of the epoxy resin. If the amount is less than 0.01 part by weight, the accelerating effect tends to decrease, and if it exceeds 5 parts by weight, the storage stability tends to deteriorate.

In addition, if necessary, additives such as a coloring agent, an antioxidant, a reducing agent, and an ultraviolet ray opaque agent may be added in such an amount range that the properties of the resin composition in the varnish used in the prepreg of the present invention are not impaired. May be added. In addition, a filler may be added to such an extent that punching workability and drill workability are not reduced.

A prepreg can be obtained by impregnating a substrate with a varnish obtained by blending the above resin composition in a solvent and drying. As the substrate, an inorganic fiber substrate, a chemical fiber substrate, a paper substrate, and the like can be used, and a glass woven fabric or a glass nonwoven fabric is preferably used. The thickness of the substrate is not particularly limited, but is usually 0.02 to
The one having a thickness of about 0.4 mm is used in accordance with the thickness of the target prepreg or laminate, and can be used in the present invention. The impregnation method can be applied as it is to a method usually used for the production of a prepreg. The resin can be impregnated by passing the liquid resin to the fiber base material by passing it under, and the amount of the resin applied can be controlled according to the purpose by a squeeze roll or a comma coater. The resin impregnation amount is usually determined according to the performance of the target prepreg and the thickness of the insulating layer after lamination, and is not particularly limited, but the resin content after the drying step is 30 to 90% by weight. Preferably 40
It is particularly preferred that the amount is from 80 to 80% by weight. Here, the resin content is a ratio of the total weight of the organic resin solid content and the additives used as required to the total weight of the prepreg. The drying conditions in the drying step when producing the prepreg are usually a drying temperature of 60 to 200 ° C. and a drying time of 1 to 3
It is performed for 0 minutes and can be freely selected according to the desired prepreg characteristics.

The prepreg obtained according to the desired thickness of the laminated plate is laminated with an inner layer material or the like by using an appropriate number of prepregs to produce a laminated plate. Alternatively, a prepreg is laminated, a metal foil is laminated on one side or both sides, and heated and pressed to produce a metal-clad laminate. A copper foil or an aluminum foil is generally used as the metal foil, but is not limited thereto, and a metal foil made of another metal or alloy may be used. The thickness of the metal foil is usually 5 to 200 μm, and this can be used in the present invention.

The heating temperature during production of the metal-clad laminate is preferably 130 to 200 ° C., more preferably 160 to 180.
C., the pressure is preferably 0.5 to 10 Mpa, more preferably 1 to 4 Mpa, usually prepreg properties,
It is determined by the capacity of the press machine, the thickness of the target laminate, and the like.

By performing circuit processing on the metal foil of the metal-clad laminate, a printed wiring board can be obtained. For circuit processing, for example, after forming a resist pattern on the metal foil surface, unnecessary portions of the foil are removed by etching, the resist pattern is peeled off, necessary through holes are formed by a drill, and a resist pattern is formed again, and a through hole is formed. The plating can be carried out by applying plating for electrical conduction and finally removing the resist pattern. On the surface of the printed wiring board thus obtained, the above metal foil-clad laminate is further laminated under the same conditions as described above, and further,
Circuit processing can be performed in the same manner as described above to obtain a multilayer printed wiring board. In this case, it is not necessary to form a through hole, and a via hole may be formed, or both may be formed. Such multilayering is performed for a required number of sheets.

[0017]

EXAMPLES Examples and comparative examples of the present invention will be described below. (Example 1)-High molecular weight epoxy resin (a): 5 parts by weight of XZ-92505 (trade name of Dow Chemical, epoxy equivalent: 800, weight average molecular weight: 10,000, Tg: 110 ° C)-Low molecular weight epoxy resin (b) : Epicoat 5046 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent: 480, weight average molecular weight: 1900) 95 parts by weight ・ Dicyandiamide 2.6 parts by weight ・ 2-ethyl-4-methylimidazole 0.2 part by weight Weight average molecular weight Was determined by gel permeation chromatography using a standard polystyrene calibration curve. The above composition was dissolved in methyl ethyl ketone to prepare a varnish having a nonvolatile content of 65%. This varnish was impregnated into a glass woven fabric (thickness 0.2 mm, basis weight 210 g / m ² ) and dried to obtain a prepreg having a resin content of 45%. Four prepregs were formed, copper foils of 18 μm were provided on both surfaces thereof, and pressed at 170 ° C. for 90 minutes at 4 MPa to obtain a 0.8 mm thick FR-4 laminate.

Example 2 XZ-92505 (manufactured by Dow Chemical) 10 parts by weight Epicoat 5046 (manufactured by Yuka Shell Epoxy Co.) 90 parts by weight Dicyandiamide 2.5 parts by weight 2-Ethyl-4-methyl 0.2 parts by weight of imidazole Using the above composition, a prepreg having the same gel time as in Example 1 was prepared, and FR-
Four laminates were obtained.

(Example 3) XZ-92505 (manufactured by Dow Chemical) 15 parts by weight Epicoat 5046 (manufactured by Yuka Shell Epoxy Co., Ltd.) 85 parts by weight Dicyandiamide 2.4 parts by weight 2-ethyl-4-methyl 0.2 parts by weight of imidazole Using the above composition, a prepreg having a gel time similar to that of Example 1 was prepared, and FR-
Four laminates were obtained.

(Comparative Example 1) 2.6 parts by weight of dicyandiamide 100 parts by weight of Epicoat 5046 (manufactured by Yuka Shell Epoxy Co., Ltd.) 0.2 parts by weight of 2-ethyl-4-methylimidazole The above composition was used. A prepreg having a gel time similar to that of Example 1 was prepared, and the FR-
Four laminates were obtained.

(Comparative Example 2) 95 parts by weight of Epicoat 5046 (manufactured by Yuka Shell Epoxy Co., Ltd.) Phenoxy resin: Phenotote YP50 (trade name, manufactured by Tokasei Co., Ltd., epoxy equivalent 13,000, weight average molecular weight 29,000, Tg is 100 ° C.) 5 parts by weight ・ Dicyandiamide 2.5 parts by weight ・ 2-ethyl-4-methylimidazole 0.2 part by weight Using the above composition, a prepreg having the same gel time as in Example 1 was prepared. 0.8mm thick FR-
Four laminates were obtained.

(Comparative Example 3) 90 parts by weight of Epicoat 5046 (manufactured by Yuka Shell Epoxy) 10 parts by weight of phenotote YP50 (trade name of Tokasei Co., Ltd.) 2.4 parts by weight of dicyandiamide 2.4 parts by weight 2-ethyl 0.2 parts by weight of 4-methylimidazole Using the above composition, a prepreg having a gel time similar to that of Example 1 was prepared, and FR- having a thickness of 0.8 mm was used.
Four laminates were obtained.

The resin flow of the prepregs obtained in Examples 1 to 3 and Comparative Examples 1 to 3 was measured, and the thickness accuracy, Tg, and heat resistance of the laminate using the prepreg were measured. JIS-C-
It was measured according to 6521. JIS for thickness accuracy
The thickness was measured and the standard deviation was calculated according to -C-6481. Tg is also measured using TMA according to JIS-C-648.
1 was measured. Regarding heat resistance, the copper foil on the surface was removed by etching, immersed in a solder bath at 280 ° C. for 20 seconds, and the presence or absence of measling and blisters was visually evaluated. The evaluation criteria were as follows: は: no abnormality, Δ: occurrence of measling, ×: occurrence of blister.

As is clear from the results in Table 1, Examples 1 to
3 has a smaller resin flow of the prepreg than Comparative Example 1,
The plate thickness accuracy is improved, and there is no decrease in Tg or heat resistance as in Comparative Examples 2 and 3.

[0025]

[Table 1]

[0026]

According to the present invention, it is possible to manufacture a prepreg capable of suppressing the resin flow without deteriorating the laminate properties such as heat resistance and Tg. Can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 63:00 C08L 63:00 F term (Reference) 4F072 AB09 AB28 AD23 AD26 AD28 AD32 AE01 AE02 AF26 AF27 AF28 AF30 AF31 AG02 AG03 AG16 AG19 AH02 AL09 AL12 AL13 AL14 4F100 AB01B AB33B AK53A AK53K BA02 DH01A GB41 JA05 JA06 JJ03 YY00A 5G305 AA06 AA14 BA21 BA25 BA26 CA15

Claims (4)

[Claims] (1) An epoxy equivalent of 200 to 1000
The base material is impregnated with a varnish in which a high molecular weight epoxy resin having a weight average molecular weight of 10,000 or more and (b) a low molecular weight epoxy resin having an epoxy equivalent of 100 to 1,000 and a weight average molecular weight of 5,000 or less are essential components. A prepreg characterized by the following. 2. The prepreg according to claim 1, wherein 1 to 15 parts by weight of a high molecular weight epoxy resin is blended with respect to 100 parts by weight of the total solid content in the varnish. 3. A laminate comprising the prepreg according to claim 1 or 2. 4. A metal-clad laminate obtained by laminating the prepreg according to claim 1 and a metal foil.