JPH10120875A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtian a heat-resistant epoxy resin composition which can realize a low cost and very thin multilayer printed wiring board having by mixing an epoxy resin/acid anhydride adduct with an aromatic epoxy resin and a cure accelerator in a specified mixing ratio. SOLUTION: This composition is one having the ability to form a thermosetting insulation layer and comprising the three components: 20-75wt.% epoxy resin/acid anhydride adduct (A) represented by formula I (wherein R<1> and R<2> are each H, a 1-5C alkyl or a halogen; X is -SO2 -, -CH2 - or the like; 1 is 0 or 1; R<3> s are each H or a group represented by formula II (wherein Y is an acid anhydride residue; m is 1-3; and Z is a group represented by formula III or -R<3> ), provided that the rate of Rs which are hydrogen atoms is at most 85% based on the total R<3> s) and having a molecular weight of 10,000-200,000, a halogen content of 5-40wt.%, an epoxy/acid anhydride adduct having an acid value of 30-250mgKOH/g, an aromatic epoxy resin (B) and a cure accelerator (C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultra-thin glass plate which is excellent in embedding into an inner layer circuit, has excellent adhesion to a circuit board, and has excellent smoothness of an outer layer circuit after lamination. The present invention relates to a heat-resistant epoxy resin composition for a multilayer printed wiring board.

[0002]

2. Description of the Related Art Conventionally, a multilayer printed wiring board has a B-staged prepreg sheet formed by impregnating a glass cloth with an epoxy resin on an interior circuit board on which a circuit has been formed, and further laminating a copper foil thereon. A manufacturing method of performing pressure heating integral molding is employed. However, in this method, it takes time and equipment to prepare a prepreg by impregnating epoxy resin into a glass cloth and making it into a B-stage, and furthermore, it is necessary to add copper foil to form a multilayer and press-heat and integrally mold. It took a lot of equipment and time, and it was expensive. Further, the use of a glass cloth did not allow the interlayer thickness to be extremely thin.

[0003]

SUMMARY OF THE INVENTION The present invention provides a multi-layer printed wiring board with a low cost, which could not be achieved by the prior art.
Another object of the present invention is to provide a heat-resistant epoxy resin composition which can be made extremely thin.

[0004]

The present invention has solved the above-mentioned problems, and has a component (A) represented by the following formula (1) and a molecular weight range of 10,000 to 200,000 (gel). The weight average molecular weight in terms of permeation chromatography measurement and standard polystyrene conversion; hereinafter, the molecular weight means the weight average molecular weight by this measurement method), the halogen content is 5% by weight to 40% by weight, and the acid value is 30 mgK.
OH / g to 250 mgKOH / g epoxy resin-anhydride adduct, wherein component (B) has an epoxy equivalent of 4500
g / eq to 100 g / eq of an aromatic epoxy resin,
(C) an epoxy resin composition having a thermosetting insulating layer-forming ability, wherein the composition comprises a curing accelerator, and optionally contains an organic solvent for adjusting viscosity and an organic or inorganic filler. And the proportion of the component (A) is (A) +
An epoxy resin composition in an amount of 75% by weight to 20% by weight with respect to (B), and a copper foil with an adhesive for printed wiring boards obtained by applying the epoxy resin composition to a copper foil. The copper foil with the adhesive is used for ultra-thin, low-cost, heat-resistant multilayer printed wiring boards by laminating on an inner layer circuit board and heat-curing.

(Wherein R ¹ and R ² are a hydrogen atom and a carbon number of 1 to 5)
Is an alkyl group or a halogen atom, and X is-
SO ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —O—, and 1 represents 0 or 1. R ³ is a hydrogen atom or formula 2
Wherein the proportion of hydrogen atoms is any of R
³ or less than 85%.

Embedded image In Formula 2, Y represents an acid anhydride residue, and m is an integer of 1 to 3. Z represents any one of Formula 3 (Formula 3) and -R ³ .

Embedded image

The epoxy resin composition of the present invention, of course, satisfies various properties such as heat resistance, flame retardancy, and electrical insulation equivalent to glass epoxy circuit boards, and is applied to a copper foil. In such a case, it is necessary to prevent the copper foil from curling after the solvent is volatilized and the powder from dropping during cutting.
Also, when laminated on the inner layer circuit board, the inner layer circuit must be embedded.

If the molecular weight of the component (A) is less than 10,000, the copper foil with the adhesive after the epoxy resin composition is applied to the copper foil and dried, may cause the copper foil to curl or to lose powder during cutting. Wake up and become defective. In addition, the molecular weight is 200,000
If it exceeds 70%, the solution viscosity is too high at a normal solvent amount of 70% by weight to 40% by weight even when diluted and dissolved with a solvent, and it is difficult to apply the solution to a copper foil. In order to obtain a solution viscosity that can be applied to a copper foil, a large amount of a less preferable solvent must be added, which is uneconomical and not good for the environment. The molecular weight of the component (A) is preferably 15,000.
~ 160,000, more preferably 20,000 ~ 10
It is 0000.

When the halogen content of the component (A) is less than 5% by weight, the epoxy resin composition of the present invention cannot provide sufficient flame retardancy, and when the halogen content is 40% by weight or less, it is not sufficiently flame retardant. It is not necessary for the content to exceed 40% by weight because the property can be imparted.

If the acid value of component (A) is less than 30 mg KOH / g, the crosslink density at the time of curing becomes low, and the desired heat resistance cannot be obtained. Further, when trying to synthesize a resin exceeding 250 mg KOH / g, a large amount of bifunctional or higher acid anhydride must be used, and addition polymerization is required during the synthesis of epoxy resin-acid anhydride (component (A)). It causes a reaction and gels, making synthesis very difficult.

In order to synthesize the resin of the component (A), the molecular weight of the acid anhydride must be taken into consideration, but an epoxy resin having a relatively high molecular weight must be used. Relatively high molecular weight epoxy resins can be obtained by the direct reaction of bisphenol A (BPA) or / and tetrabromobisphenol A (TBA) with epichlorohydrin, or by the diglycidyl ether of BPA or / and TBA and BPA or / and TB
A method by addition polymerization of A is known, but any method may be used. Further, both ends of the polymer epoxy resin are epoxy groups (in this case, the terminal group of the formula 1 is a group represented by the formula 3), or a part or all of the terminal groups are phenolic hydroxyl groups ( In this case, the modified polymer epoxy resin in which the terminal group of formula 1 is R ³ ) may be used.

The mixing ratio of component (A) to component (B) in the epoxy resin composition is most preferably 1: 1 in terms of the equivalent ratio of the carboxylic acid group of component (A) to the epoxy group of component (B). When the proportion of the component (A) in the components (A) and (B) exceeds 75% by weight, the usual solvent amount of 70% by weight to
At 40% by weight, the solution viscosity is too high and a large amount of a less preferable solvent must be added, which is uneconomical and not good for the environment. If the content is less than 20% by weight, the heat resistance when cured is insufficient, the coating performance of the copper foil with an adhesive is deteriorated, and phenomena such as curling of the copper foil and powder dropping during cutting may occur. become. Specifically, the epoxy resin for adding an acid anhydride is a single or each co-condensation type epoxy resin such as bisphenol A type, F type, and S type. Used are all halogenated.

Examples of the acid anhydride include maleic anhydride, succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride,
Hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, biphenylethertetracarboxylic dianhydride and the like are used.

The reaction between the epoxy resin and the acid anhydride is carried out by dissolving the epoxy resin in an inert solvent such as xylene, toluene, methyl ethyl ketone, diethyl cellosolve, methyl cellosolve acetate, methyl ethyl carbitol, or a mixture thereof. Anhydrous at once, or
Add and divide to react. At this time, when a catalyst is added, a general catalyst used for the synthesis of epoxy may be used, and a catalyst such as imidazole, triphenylphosphine, and phosphonium salt is used. The reaction temperature is 90 ° C
To 150 ° C, preferably 115 ° C to 125 ° C.

The epoxy resin-acid anhydride adduct (component (A)) synthesized in this manner alone is used. The resin flow during molding is small, the circuit embedding property is good, the flexibility and the flame retardancy are good. Although it is a substance with heat, its heat resistance is slightly insufficient. Therefore, in order to have heat resistance, it is necessary to further add an epoxy resin and heat and cure.

The epoxy resin as the component (B) includes:
It is intended to increase heat resistance without deteriorating physical properties such as flexibility after curing. It is aromatic and has an epoxy equivalent of 4500 g / eq.
It is preferable that the thickness is up to 100 g / eq. Epoxy equivalent is 450
If it exceeds 0 g / eq, the amount of the epoxy resin to be added will increase, and the physical properties of the epoxy resin-anhydride adduct (component (A)) will be impaired, and the crosslink density will be low, resulting in desirable heat resistance. A cured film may not be obtained. or,
An aliphatic epoxy resin may exhibit flexibility but not heat resistance. In addition, the epoxy equivalent is 100 g / eq.
If the amount is less than the above, the amount of the epoxy resin to be added becomes small, the crosslink density of the cured product becomes high, the material becomes hard and brittle, and the flexibility is lost. The epoxy equivalent of the component (B) is preferably 150 g / eq to 3500 g / eq, more preferably 200 g / eq to 2500 g / eq. Illustrating an epoxy resin suitable for the composition of the present invention,
Bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol A, F co-condensation type epoxy resin, novolak type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene-phenol type co-condensation type epoxy resin, and halogen substitution thereof Body and the like.

The epoxy resin composition according to the present invention comprises:
A solvent may be used in order to maintain an appropriate viscosity when applying to a copper foil. As a solvent for adjusting viscosity, 100 ° C. to 15
It does not remain in the epoxy resin composition when the solvent is dried at 0 ° C., and examples thereof include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, dioxane, ethanol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, and cyclohexanone.

In the epoxy resin composition of the present invention, silica, calcium carbonate, talc, aluminum hydroxide, alumina, mica and the like are used for the purpose of imparting heat resistance, flame retardancy and low coefficient of linear expansion. In order to improve the adhesive strength, an epoxy silane coupling agent or a rubber component may be added to such an extent that the physical properties of the cured epoxy resin composition are not deteriorated.

The curing accelerator (component (C)) used in the present invention may be an accelerator generally used in epoxy resins, and may be an amine-based, imidazole-based, triphenylphosphonium, or phosphonium salt-based accelerator. Are used.
The amount of the component (C) used is preferably 50 ppm to 50,000 ppm, more preferably 100 ppm to 10,000 ppm, and more preferably 2 ppm, based on the component (A) + the component (B).
It is from 00 ppm to 5000 ppm. If the amount of the curing accelerator (component (C)) is less than 50 ppm, the heat curing time is too long, which is uneconomical. 50,000pp
If it is larger than m, the storage stability of the copper foil with the adhesive will be lost, and the commercial value will be lost.

The epoxy resin composition of the present invention is dissolved in the solvent as described above in a solvent of 15,000 cps or less, preferably 10,000 cps or less.
Adjusted to a viscosity of less than ps, varnished by adding an appropriate amount of a curing accelerator adjusted to have a certain curing time, applied to a copper foil, and evaporated at 90 ° C to 150 ° C to evaporate the solvent to form a copper foil with an adhesive. obtain. By laminating the obtained copper foil with adhesive on an inner circuit board with a dry laminator or the like and curing by heating, a multilayer printed wiring board having an outer copper foil can be prepared.

[0019]

Examples and Comparative Examples Hereinafter, the present invention will be specifically described based on Synthesis Examples, Examples and Comparative Examples. The following synthesis example,
In Examples and Comparative Examples, "parts" indicates "parts by weight". The catalysts used in Synthesis Examples 1 and 2 and Comparative Synthesis Example serve as curing accelerators in Examples and Comparative Examples as they are.

Synthesis Example 1 Brominated bisphenol A type epoxy resin which is a co-condensate of bisphenol A diglycidyl ether and tetrabromobisphenol A, specifically YPB-40A40
(Toto Kasei, hydroxyl equivalent 364.7 g / eq, epoxy equivalent 13500 g / eq, bromine content 25%, cyclohexanone solvent, solid content concentration 40.9%, hereinafter abbreviated as NV, weight average molecular weight 30,000) 600 parts , Methyl hexahydrophthalic anhydride (acid equivalent: 168 g / e
50 parts of q) and 0.7 parts of 2-ethyl 4-methylimidazole as a catalyst were charged into a 1 l separable flask, and the temperature was gradually raised to 110 ° C. while stirring. After stirring for 7 hours while maintaining the reaction temperature at 105 ° C to 125 ° C, 88.5 parts of cyclohexanone was added, and the acid value was 57.2 KOH.
mg / g, NV. 738.5 parts of cyclohexanone varnish of 40.0% epoxy resin-acid anhydride adduct was obtained.
This resin was designated as synthetic resin varnish I. Table 1 shows the properties of this resin.

Synthesis Example 2 Brominated bisphenol A type epoxy resin which is a cocondensate of bisphenol A diglycidyl ether and tetrabromobisphenol A, specifically YPB-40XM40
(Toho Kasei, hydroxyl equivalent 365.5 g / eq, epoxy equivalent 13000 g / eq, bromine content 25%, xylene, MEK solvent, NV 40.5%, weight average molecular weight 3
0000), 30 parts of methylhexahydrophthalic anhydride (acid equivalent: 168 g / eq), and 1.3 parts of n-butyltriphenylphosphonium bromide in a 1 l separable flask, and stirred. While 1
The temperature was gradually raised to 10 ° C. Reaction temperature 105 ° C ~
After stirring for 4 hours while maintaining 125 ° C., benzophenonetetracarboxylic dianhydride (acid anhydride equivalent: 225 g /
eq) was added, and the mixture was further stirred for 4 hours. 5 parts of water was added, and the mixture was further stirred for 1 hour.
Acid value 85.3 KOHmg / g, NV. 732.5 parts of 40.0% xylene of an epoxy resin-anhydride adduct and MEK varnish were obtained. This resin was designated as synthetic resin varnish II. Table 1 shows the properties of this resin.

Synthesis Example 3 Brominated bisphenol A type epoxy resin which is a cocondensate of bisphenol A diglycidyl ether and tetrabromobisphenol A, specifically YPB-40XM40
600 parts (described above), 51 parts of trimellitic anhydride (acid anhydride equivalent: 192 g / eq) and 0.5 parts of triethylenediamine were charged into a 1-liter separable flask, and the temperature was gradually raised to 110 ° C. while stirring. It began to. Reaction temperature 1
After stirring for 5 hours while maintaining the temperature between 05 ° C and 125 ° C, MEK
, And an acid value of 102 KOH mg / g, NV. 4
0.0% of an epoxy resin-anhydride adduct xylene,
735 parts of MEK varnish were obtained. This resin was designated as synthetic resin varnish III. Table 1 shows the properties of this resin.

Comparative Synthesis Example A brominated bisphenol A type epoxy resin which is a cocondensate of bisphenol A diglycidyl ether and tetrabromobisphenol A, specifically YPB-40XM40
600 parts of the above (described above), 23 parts of methylhexahydrophthalic anhydride (acid equivalent: 168 g / eq), and 0.7 parts of 2-ethyl-4-methylimidazole as a catalyst were charged into a 1-liter separable flask and stirred. The temperature was gradually raised to 110 ° C. After stirring for 7 hours while maintaining the reaction temperature at 105 ° C. to 125 ° C., 42 parts of MEK was added, and the acid value was 2.
8.6 KOH mg / g, NV. Xylene of 40.0% epoxy resin-acid anhydride adduct, MEK varnish was 665
I got a copy. This resin was designated as synthetic resin varnish IV. Table 1 shows the properties of this resin.

[0024]

[Table 1]

Example 1 227.5 parts of the synthetic resin varnish I obtained in Synthesis Example 1 was
YD-014 (Toto Kasei, epoxy equivalent 954 g / e
q, softening point 98 ° C, bisphenol A type epoxy resin)
50 parts, YDB-400 (manufactured by Toto Kasei, epoxy equivalent 405 g / eq, softening point 70 ° C., bromine content 48.5)
%, Brominated bisphenol A type epoxy resin).
3 parts were added and uniformly stirred and mixed to obtain an epoxy resin composition varnish. This varnish is applied to the anchor surface of a copper foil having a thickness of 35 μm using a roller coater so that the resin thickness after solvent drying is 60 μm, and the solvent is dried at 130 ° C. to 140 ° C. for 15 minutes to form a copper with adhesive. A foil was obtained. On the other hand, a glass-epoxy-copper-clad double-sided laminated board having a copper blackening treatment with a pitch of 200 μm was used as a simulated inner-layer circuit board. The copper foil with the adhesive was laminated on both sides of the simulated inner layer circuit board with a dry laminator, and heated and cured at 175 ° C. for 1 hour to obtain a four-layer printed wiring board.

Example 2 227.5 parts of the synthetic resin varnish I obtained in Synthesis Example 1 was
YDB-500EK80 (Toto Kasei, epoxy equivalent 5
15g / eq, bromine content 20.5%, MEK varnish,
NV. (80%) was uniformly mixed with stirring to obtain an epoxy resin composition varnish. Apply this varnish to a thickness of 35
Resin thickness after solvent drying is 60 μm on anchor surface of copper foil of μm.
A printed wiring board was obtained in exactly the same manner as in Example 1 except that the coating was performed with a roller coater so as to have a thickness of μm, and the solvent was dried to obtain a copper foil with an adhesive.

Example 3 227.5 parts of the synthetic resin varnish I obtained in Synthesis Example 1 was
50 parts of YD-014 (described above), 16.3 parts of YDB-400 (described above), fused silica (FD-2 manufactured by Denki Kagaku)
01S) was added and uniformly stirred and mixed to obtain a printed wiring board in exactly the same manner as in Example 1 except that an epoxy resin composition varnish was obtained.

Example 4 224 parts of the synthetic resin varnish II obtained in Synthesis Example 2, Y
50 parts of D-014 (described above), YDB-400 (described above)
, 20 parts of YDF-170 (manufactured by Toto Kasei Co., Ltd., epoxy equivalent 173 g / eq, bisphenol F type epoxy resin), and 0.7 parts of triphenylphosphine, and uniformly stirred and mixed to obtain an epoxy resin composition varnish. A printed wiring board was obtained in exactly the same manner as in Example 1 except for obtaining the printed wiring board.

Example 5 224 parts of the synthetic resin varnish II obtained in Synthesis Example 2, Y
87.8 parts of DB-500EK80 (described above) and 0.5 part of triphenylphosphine were added and uniformly stirred and mixed to obtain a printed wiring board in exactly the same manner as in Example 1 except that an epoxy resin composition varnish was obtained. Obtained.

Example 6 226 parts of the synthetic resin varnish III obtained in Synthesis Example 3 was used.
105.8 parts of YDB-500EK80 (described above) was added and uniformly stirred and mixed to obtain a printed wiring board in exactly the same manner as in Example 1 except that an epoxy resin composition varnish was obtained.

Example 7 226 parts of the synthetic resin varnish III obtained in Synthesis Example 3 was used,
25 parts of YDB-400 (described above), 19 parts of YD-128 (manufactured by Toto Kasei, epoxy equivalent: 185 g / eq, bisphenol A type epoxy resin) and 50 parts of MEK were added, and the mixture was uniformly stirred and mixed. A printed wiring board was obtained in exactly the same manner as in Example 1 except that the above was obtained.

Comparative Example 1 214 parts of the synthetic resin varnish IV obtained in the Comparative Synthesis Example
A printed wiring board was obtained in exactly the same manner as in Example 1 except that 28.1 parts of YDB-500EK80 (described above) was added and uniformly stirred and mixed to obtain an epoxy resin composition varnish.

Comparative Example 2 227.5 parts of the synthetic resin varnish I obtained in Synthesis Example 1 was
YD-020 (Toto Kasei, epoxy equivalent 4850 g /
eq, softening point 143 ° C, bisphenol A epoxy resin). A printed wiring board was obtained in exactly the same manner as in Example 1 except that 750 parts of a 60% MEK solution was added and uniformly stirred and mixed to obtain an epoxy resin composition varnish.

Table 2 shows the characteristic values of the multilayer printed wiring board prepared as described above.

[0035]

[Table 2]

(Test Method) Solder heat resistance test: A sample after boiling at 100 ° C. for 2 hours was immersed in a solder bath at 260 ° C. at n = 5, and all samples that did not swell or peel for 20 seconds or more were evaluated. And Circuit embedding: In the inner layer circuit after peeling the outer layer copper foil,
The one in which the resin was embedded was evaluated as ○. Glass transition temperature: heat-cured without laminating copper foil with adhesive, and peeled copper foil for TM
A measurement was performed.

[0037]

By using the epoxy resin composition according to the present invention, a prepreg using a glass cloth can be prepared without using a prepreg.
By simply laminating a copper foil with an adhesive, a heat-resistant multilayer printed wiring board having an outer copper foil can be produced, and the manufacturing process can be simplified and the manufacturing cost can be reduced. On the other hand, since no glass cloth is used, an extremely thin multilayer printed wiring board can be produced.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // C08G 65/28 C08G 65/28

Claims (3)

[Claims] (1) The component (A) is represented by the following formula (1), has a molecular weight of 10,000 to 200,000, a halogen content of 5 to 40% by weight, and an acid value of 30 m
an epoxy resin-anhydride anhydride adduct of gKOH / g to 250 mgKOH / g, wherein the component (B) is an epoxy resin,
An epoxy resin composition having a thermosetting insulating layer-forming ability, wherein the component (C) is a composition comprising a curing accelerator, and the content of the component (A) is 20 to 75% by weight. Embedded image (In Formula 1, R ¹ and R ² are any of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and a halogen atom, and X is —SO
_{2 -, - CH 2 -,} - C (CH 3) 2 -, - a O-, l represents 0 or 1. R ³ is a hydrogen atom or formula 2
Wherein the proportion of hydrogen atoms is any of R
³ or less than 85%. Embedded image In Formula 2, Y represents an acid anhydride residue, and m is an integer of 1 to 3. Z represents any one of Formula 3 (Formula 3) and -R ³ . Embedded image ) 2. The epoxy resin according to claim 1, wherein the epoxy resin as the component (B) is an aromatic epoxy resin having an epoxy equivalent of 4500 g / eq to 100 g / eq. 2. The epoxy resin composition according to claim 1. 3. A copper foil with an adhesive for printed wiring boards, wherein the epoxy resin composition according to claim 1 is applied to the copper foil.