JP3351434B2 - Resin composition for laminate and laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for a laminate used for manufacturing a printed wiring board, and more particularly to a resin composition having excellent crack resistance and heat resistance.

[0002]

2. Description of the Related Art As a material for printed wiring boards used for industrial electronic equipment such as computers, communication equipment, measuring equipment, etc., glass-base epoxy copper-clad laminates are most often used. Recently, miniaturization of circuit, reduction of diameter of sulfol,
With the rapid progress of multi-layering and higher multi-layering, the required performance for laminates has become even more severe. In particular, the occurrence of microcracks due to mechanical shock during small-diameter drilling is a serious problem as a cause of poor sulfor conduction and haloing. It is a task to be done.

As a method of improving the crack resistance, it is effective to make the epoxy resin, which is a raw material of the laminate, tough. As a method of toughening an epoxy resin, a method of blending an elastomer or a thermoplastic resin is known, and various attempts have been made for a long time. Among them, carboxyl group-terminated butadiene-acrylonitrile rubber (CTBN) is known as a typical compounding agent,
Widely used. However, when CTBN is blended, the heat resistance and moisture resistance of the resin are deteriorated, so that it has been difficult to apply it to laminates that require high solder heat resistance and high moisture absorption heat resistance. In the field of epoxy resins for semiconductor encapsulation, attempts have been made to mix polysiloxane compounds to reduce stress, but polysiloxane compounds are inherently poorly compatible with epoxy resins. When it was blended, it was difficult to prepare a varnish of a uniform solution or to prepare a uniform prepreg, and it was difficult to apply the varnish to a laminate.

[0004]

To date, no technique for producing a polysiloxane-containing epoxy resin laminate that can withstand practical use has been disclosed. The present inventors have found that by adding a specific polysiloxane compound to an epoxy resin by a specific method, crack resistance can be significantly improved without impairing the basic properties as a laminate material. The invention has been completed.

That is, the present invention relates to (A) an epoxy resin containing two or more epoxy groups in one molecule, (B) a curing agent and (C) a polysiloxane containing a carboxyl group in the molecule. The compound is an essential component, and all or part of (A) is preliminarily reacted with (C) in the presence of a catalyst until 90% or more of the carboxyl groups in (C) are reacted, and then compounded. A laminate obtained by laminating and molding a prepreg impregnated in a base material with the resin composition for a laminate, and in a preferred embodiment, the carboxyl equivalent of (C) is in the range of 500 to 5000, , The amount of which is 1 to 20 of the total amount of the resin composition
% By weight.

Hereinafter, the configuration of the present invention will be described. As the component (A) of the present invention, any polyfunctional epoxy resin may be used. Examples of the component commonly used in laminate applications include, for example, bisphenol A type epoxy resin,
Bisphenol A novolak type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, epoxy resin having diphenyl skeleton, epoxy resin having naphthalene skeleton, and triphenylmethane skeleton Preferred are epoxy resins having the same, and epoxy resins which are made flame-retardant by halogenating a part of hydrogen atoms in these epoxy resin structures. Two or more epoxy resins may be used in combination.

[0007] The curing agents of component (B) include bisphenol A, bisphenol F and polyvinyl phenol.
Phenol-novolak resin, cresol-novolak resin, bisphenol-A novolak resin, bisphenol-novolak resin
And polyfunctional phenols such as F-novolak resin, and halides, dicyandiamide, and other aromatic amines and acid anhydrides of these polyfunctional phenols. Among these, polyfunctional phenols or their halides are particularly desirable from the viewpoint of compatibility with the polysiloxane compound. As for the amount of the curing agent, the equivalent ratio of the reactive group of the curing agent to the epoxy group of the epoxy resin (reactive group / epoxy group) is 0.5 in dicyandiamide.
To 0.7, and others are preferably in the range of 0.7 to 1.2.

The polysiloxane compound component having a carboxyl group in the molecule (C) includes a compound having a carboxyl group at both ends of the molecule, a compound having a carboxyl group at only one end of the molecule, and a compound having a carboxyl group at one end of the molecule. Examples include those having a carboxyl group, those having a carboxyl group at the side chain and at the terminal of the molecule, and are represented by the following general formula. X-Si (R) ₂ O- [Si (R) ₂ O-] _m [Si (R) (X) O-] _n Si (R) ₂ -X where R is the same or different hydrocarbon Group (methyl group, ethyl group, phenyl group, etc.), X is R ₁ COOH or R (R
₁ is a hydrocarbon chain such as ethylene and propylene)
At least one or more X in the molecule is R ₁ COOH.

Of these, compounds having carboxyl groups at both ends of the molecule are particularly preferred. When the polysiloxane compound of the present invention is blended, in order to enhance the compatibility between the epoxy resin and the curing agent and the polysiloxane compound, all or part of the epoxy resin (A) and (C) It is desirable to carry out a preliminary reaction with the polysiloxane compound in the presence of a catalyst until at least 90% of the carboxyl groups of (C) have reacted.

When the polysiloxane compound having a carboxyl in the molecule of the present invention is blended without performing the preliminary reaction or at a stage where the preliminary reaction is insufficient, the compatibility is extremely poor, and the varnish becomes two layers. Since they are separated, they are practically unusable. The mixing ratio of (A) and (C) at the time of the preliminary reaction should be such that the equivalent ratio of the carboxyl group of (C) to the epoxy group of (A) (carboxyl group / epoxy group) is necessary for the reaction to proceed smoothly. It is desirably 0.5 or less, preferably 0.3 or less. If the equivalent ratio exceeds 0.5, gelation tends to occur during the reaction.

The catalyst components used in the preliminary reaction include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-ethyl -4-methylimidazole, 1-cyanoethyl-
Examples thereof include imidazole compounds such as 2-phenylimidazole, tertiary amines such as triethylamine and benzyldimethylamine, and phosphorus compounds such as triphenylphosphine. Any of these catalysts may be added at the time of the preliminary reaction, up to the amount finally required as a varnish component. Usually, the amount of the catalyst to be incorporated in the varnish is in the range of 0.03 to 0.5 part by weight based on 100 parts by weight of the epoxy resin.

The reaction is preferably carried out at a temperature of 100 to 160 ° C. for 0.5 to 20 hours with stirring while blowing nitrogen gas in the absence or presence of a solvent. In particular,
It is preferable to perform the reaction under reflux using methyl isobutyl ketone (= MIBK), toluene, xylene, dimethylformamide or the like as a solvent, since the reaction proceeds uniformly and the reaction is easily controlled. For example, using an imidazole catalyst,
When the entire amount required as a varnish component is finally added during the preliminary reaction, the reaction of the carboxyl group is completed in about 4 to 7 hours under reflux of MIBK and about 1 to 3 hours under reflux of xylene.

The carboxyl equivalent of the polysiloxane compound (C) is 500 to 5000, more preferably 700 to 3000.
Is desirably within the range. Carboxyl equivalent is 500
If it is less than 5, the heat resistance becomes poor, and if it exceeds 5,000, the compatibility with the epoxy resin or the curing agent becomes poor, so that it becomes difficult to prepare a uniform varnish solution, or various physical properties may be reduced. More often.

The compounding amount of the polysiloxane compound (C) is as follows:
It is desirable that the content be in the range of 1 to 20% by weight, more preferably 2 to 10% by weight. If the amount is less than 1% by weight, the effect of improving crack resistance is small, and if it exceeds 20% by weight, the compatibility with the epoxy resin or the curing agent becomes poor, or the physical properties are reduced. Increase.

The phase dispersion of the final cured product using the resin composition of the present invention depends on the type and amount of the polysiloxane compound, the type of the epoxy resin and the curing agent, and the curing conditions. Fig. 3 shows a phase structure in which the polysiloxane compound is finely dispersed with an average particle size of about 0.01 to 2 µm. The dispersion state of the polysiloxane compound is closely related to the physical properties of the cured product.
It is preferable to determine the blending amount and the curing conditions so as to be about 0.01 to 0.5 μm. In addition, the resin composition of the present invention, in addition to the above components, in a range that does not impair the spirit of the present invention,
Components such as other thermosetting resins, thermoplastic resins, elastomers, silane coupling agents, ultraviolet absorbers, and inorganic substances may be added.

According to the present invention, a polysiloxane compound having a carboxyl group in the molecule and having a carboxyl equivalent in the range of 500 to 5000 is compounded in the range of 1 to 20% by weight of the total amount of the resin composition, % Or more is reacted and then blended with the epoxy resin until the reaction is completed. As described above, the reactivity with the epoxy resin is extremely high, so that the preliminary reaction is completed in a short time, and the reactant is epoxy resin or the like. It is extremely suitable as a resin composition for laminates in that it has excellent compatibility with a curing agent and can prepare a uniform varnish solution. Further, the laminated plate produced by laminating and molding a prepreg impregnated with a resin composition of the present invention on a base material, together with a remarkable effect of improving crack resistance, improved adhesion to metals such as copper foil, and It has extremely excellent properties in that the glass transition temperature hardly decreases.

[0017]

EXAMPLES The present invention will be specifically described below with reference to examples. Parts and% in Examples and Comparative Examples are based on weight unless otherwise specified. Reaction Example 1 Carboxyl equivalent having carboxyl groups at both molecular ends
67 g of 1000 polydimethylsiloxane compound, 150 g of brominated bisphenol A type epoxy resin (bromine content: 21% by weight, epoxy equivalent: 480), 1 g of 2-ethyl-4-methylimidazole (= 2E4MZ) and methyl isobutyl ketone (= M
IBK) Put about 300 g in a separable flask, attach a cooling tube, stirrer, nitrogen introduction tube, thermometer, and put it on an oil bath
The reaction was performed at 115 ° C. for 5 hours. The conversion of carboxyl groups in the polysiloxane of the reactant was 98% or more.

EXAMPLE 1 560 g of the same brominated bisphenol A-type epoxy resin and tetrabromobisphenol A-type epoxy resin (bromine content) used in Reaction Example 1 48%, epoxy equivalent 400) 190 g, cresol novolak type epoxy resin (epoxy equivalent 215) 100 g and bisphenol A novolak resin (hydroxyl equivalent 118) 280 g
Was added and further diluted with acetone to prepare a varnish in which the polysiloxane compound was blended at 5% of the total resin.

The varnish was impregnated into a glass woven fabric having a thickness of 0.18 mm and dried to obtain a prepreg having a resin amount of 42%. Four prepregs were stacked, and a copper foil having a thickness of 35 μm was placed on both sides and pressed at a pressure of 30 kg / cm ² at 170 ° C. for 90 minutes to obtain a thickness of 0.8.
mm double-sided copper-clad laminate was obtained. Further, instead of woven glass fabric with a nonwoven glass fabric of 1 m ² per 100 g, similarly impregnated with the varnish and dried to give the resin amount 81% of the prepreg.
Eight sheets of this prepreg were stacked, release films were arranged on both sides, and pressed similarly to obtain a laminate having a thickness of 3.2 mm.

Further, using the double-sided copper-clad laminate having a thickness of 0.8 mm obtained above, an inner printed wiring pattern for testing was formed, black oxide treated, and then 0.18
2 mm prepreg using glass woven fabric, and 18μm thick copper foil on both sides, pressure 30kg / c
Pressing at m ² , 170 ° C. for 90 minutes gave a double-sided copper-clad four-layer plate. A 2,000 through-hole hole was drilled in this four-layer plate at a hole diameter of 0.4 mmφ and a pitch of 2.54 mm at a condition of 70,000 rpm and 20 μm / rotation by a drill, and a through-hole plating was performed to manufacture a through-hole four-layer plate.

Tables 1-1 and 1-2 show the results of the tests described below for the laminates produced above. -Copper foil peel strength (unit: kg / cm): Measured with a 0.8 mm thick copper-clad laminate based on JIS C 6481-Glass transition temperature (Tg, unit: ° C): Viscoelasticity (= DMA) , Measured on a 0.8 mm thick copper clad laminate ・ Izod impact test (IZ, unit kg cm / cm): Measured on a 3.2 mm thick glass nonwoven laminate with no notch based on JIS K 7110.・ Fracture toughness test K _IC : Fracture toughness value (MPa unit)
^1/2 ) G _IC : Breaking energy (unit: kJ / m ² ): Adopt the three-point bending method (= SENB test) based on ASTM E 399.
Measured on a 3.2 mm thick glass nonwoven substrate laminate. The G _IC was calculated based on the area surrounding the load-displacement curve leading to fracture. -Haloing and plating soak (unit: μm): Measured at 50 arbitrary through-holes on a 4-layer through-hole plate

Examples 2 to 4 In place of the polysiloxane compound in Reaction Example 1, a polydimethylsiloxane compound having a carboxyl group at both molecular terminals shown in Table 1 was used, in the same manner as in Reaction Example 1 and Example 1. Preliminary reaction, varnish preparation, prepreg preparation, and press molding were performed, and each polysiloxane compound was blended at 5% of the total resin. A nonwoven substrate laminate was obtained. Table 1 shows the results of evaluating the obtained laminate in the same manner as in Example 1.

Examples 5 and 6 The amount of the polysiloxane compound in Reaction Example 1 was 40 g.
Reaction Example 1 and Example 1 except that the amount was 143 g.
In the same manner as in the above, laminates containing 3% or 10% of the polysiloxane compound in the total resin were obtained. Table 1 shows the results of evaluating the obtained laminate in the same manner as in Example 1.

Example 7 Instead of the polysiloxane compound in Reaction Example 1, a carboxyl equivalent having a carboxyl group on the side chain of the molecule was used.
In the same manner as in Reaction Example 1 and Example 1 except that 40 g of 000 polydimethylsiloxane compound was blended, a laminated board containing 3% of the total resin with the polysiloxane compound was obtained. Table 1 shows the results of evaluating the obtained laminate in the same manner as in Example 1.

Comparative Example 1 710 g of brominated bisphenol A type epoxy resin, 190 g of tetrabromobisphenol A type epoxy resin, 100 g of cresol novolac type epoxy resin and bisphenol which are the same as those used in Example 1 A novolak resin 280
g and 2E4MZ1g were mixed, and acetone was added to prepare a varnish. Using this varnish, in the same manner as in Example 1, a laminate containing no polysiloxane compound was obtained. Table 1 shows the results of evaluating the obtained laminate in the same manner as in Example 1.

Example 8 The amount of the polysiloxane compound in Reaction Example 1 was 32 g.
A preliminary reaction was carried out in the same manner as in Reaction Example 1, except that To this reaction product, 750 g of the same brominated bisphenol A type epoxy resin as used in Example 1,
Lunovolak type epoxy resin 100g, dicyandiamide
A varnish was prepared by adding 25 g of dimethylformamide, methylcellosolve, and acetone as solvents. Using this varnish, in the same manner as in Example 1, a laminated board containing a polysiloxane compound in an amount of 3% of the total resin was obtained. Table 1 shows the results of evaluating the obtained laminate in the same manner as in Example 1.

Comparative Example 2 900 g of the same brominated bisphenol A type epoxy resin as used in Example 1, 100 g of cresol novolac type epoxy resin, 25 g of dicyandiamide, 1 g of 2E4MZ, dimethylformamide as solvent, methylcellosolve, And acetone were added to prepare a varnish. Using this varnish, in the same manner as in Example 1, a laminate containing no polysiloxane compound was obtained. Table 1 shows the results of evaluating the obtained laminate in the same manner as in Example 1.

The abbreviations and the like in Tables 1-1 and 1-2 are as described below in addition to the description in Example 1. * 1) Total amount at the time of preliminary reaction and at the time of mixing varnish: brominated bisphenol A type epoxy resin (bromine content: 21% by weight, epoxy equivalent: 480) * 2) TBA-EP: tetrabromobisphenol A Epoxy resin (bromine content 48%, epoxy equivalent 400) * 3) CN-EP: Cresol novolak epoxy resin (epoxy equivalent 215) * 4) BPA-N: Bisphenol A novolak resin (hydroxyl equivalent 118) * 5) 2E4MZ: 2-ethyl-4-methylimidazole

[0029]

TABLE 1 TABLE 1-1 units real 1 real 2 real 3 real 4 real five components policy: - position of (COOH) ends at both ends across both ends across Rokisa: (- COOH) equivalent g / mol 1000 750 1700 2700 1000 emissions: Compounded amount g 67 67 67 67 40: Compounded amount% 5 5 5 5 3 Brominated epoxy resin * 1 g 710 710 710 710 710 710: TBA-EP * 2 g 190 190 190 190 190 CN-EP * 3 g 100 100 100 100 100 BPA-N * 4 g 280 280 280 280 280 Dicyandiamide g 2E4MZ * 5 g 1 1 1 1 1 Physical properties Copper foil peel strength kg / cm 1.8 1.8 1.9 1.7 1.8 Glass transition temperature ° C 153 153 154 154 154 153 IZ (Notch None ) kg cm / cm 33 31 38 34 28 K _IC (fracture toughness) MPa m ^1/2 3.6 3.5 3.7 3.6 3.4 G _IC (fracture energy) kJ / m ² 4.5 4.2 4.6 4.5 3.6 Hello average μm 80 100 70 90 90 Max μm 150 230 160 170 160 Plating average μm 12 14 11 14 12 Max μm 30 38 31 32 33

[0030]

[Table 2] Table 1-2 Unit Actual 6 Actual 7 Actual 8 Ratio 1 Ratio 2 component policy : Position of (-COOH) Both ends Side chain Both ends Loxa : (-COOH) equivalent g / mol 1000 4000 1000 N : Compounding amount g 143 40 32: Blended amount% 10 3 3 Brominated epoxy resin * 1 g 710 710 900 710 900: TBA-EP * 2 g 190 190 190 CN-EP * 3 g 100 100 100 100 100 BPA-N * 4 g 280 280 280 Dicyandiamide g 25 25 2E4MZ * 5 g 1 1 1 1 1 Physical properties Copper foil peel strength kg / cm 1.7 1.7 2.1 1.7 2.0 Glass transition temperature ℃ 151 153 152 153 152 IZ (Notch pear) kg cm / cm 44 29 30 20 25 K _IC (fracture toughness) MPa m ^1/2 3.7 3.4 3.6 3.1 3.3 G _IC (fracture energy) kJ / m ² 4.8 3.5 4.0 2.8 3.3 Haloing average μm 90 110 120 160 150 Maximum μm 150 220 230 310 300 Plating Penetration average μm 11 18 16 23 21 Maximum μm 35 40 35 47 50

[0031]

As is clear from the above Examples and Comparative Examples, the laminates produced from the resin composition of the present invention are extremely excellent in impact resistance, crack resistance, copper foil adhesion and heat resistance. Therefore, it can sufficiently withstand the mechanical impact during small diameter drilling.

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁷ Identification code FI H05K 1/03 630 H05K 1/03 630B (56) References JP-A-62-98793 (JP, A) JP-A-62-96521 (JP, A) JP-A-4-103615 (JP, A) JP-A-4-108851 (JP, A) JP-A-3-197529 (JP, A) JP-A-3-177415 (JP, A) JP-A-3-95214 (JP, A) JP-A-2-86148 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 63/00-63/10 C08L 83/06 B23B 27/38 C08G 59/14 C08J 5/24 H05K 1/03

Claims (3)

(57) [Claims] 1. Essential components are (A) an epoxy resin containing two or more epoxy groups in one molecule, (B) a curing agent and (C) a polysiloxane compound containing a carboxyl group in the molecule. A laminate prepared by preliminarily reacting all or part of (A) with (C) in the presence of a catalyst until 90% or more of the carboxyl groups in (C) are reacted, and then blending A laminate obtained by laminating a prepreg obtained by impregnating a base material with a resin composition for use. 2. The laminate according to claim 1, wherein the carboxyl equivalent of (C) is in the range of 500 to 5,000. 3. The compounding amount of (C) is 1 to 20 of the total amount of the resin composition.
The laminate according to claim 1, which is in weight%.