Resin composition, prepreg, resin sheet, metal foil-clad laminate, and printed circuit board

Abstract

A resin composition that includes a maleimide compound, an alkenyl-substituted nadimide, a silane compound having a styrene skeleton and a hydrolyzable group or a hydroxy group, and an inorganic filler.

Claims

1. A resin composition, comprising: a maleimide compound, an alkenyl-substituted nadimide, a silane compound having a styrene skeleton and a hydrolyzable group or a hydroxy group, and an inorganic filler.

2. The resin composition according to claim 1, wherein the silane compound is a compound represented by the following formula (A): ##STR00019## where: R.sub.8 represents the hydrolyzable group or the hydroxy group; R.sub.9 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; when a plurality of R.sub.8 or R.sub.9 are present, the plurality of R.sub.8 or R.sub.9 are the same as or different from each other; and k represents an integer of 1 to 3.

3. The resin composition according to claim 1, wherein a ratio of a number of maleimide groups (β) in the maleimide compound and a number of alkenyl groups (α) in the nadimide ([β/α]) is 0.9 or more and 4.3 or less.

4. The resin composition according to claim 1, wherein the alkenyl-substituted nadimide is a compound represented by the following formula (1): ##STR00020## where: each R.sub.1 independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R.sub.2 represents an alkylene group having 1 to 6 carbon atoms, a phenylene group, a biphenylene group, a naphthylene group, or a group represented by the following formula (2) or (3): ##STR00021## where R.sub.3 represents a methylene group, an isopropylidene group, or a substituent represented by CO, O, S, or SO.sub.2, and ##STR00022## where each R.sub.4 independently represents an alkylene group having 1 to 4 carbon atoms, or a cycloalkylene group having 5 to 8 carbon atoms.

5. The resin composition according to claim 1, wherein the alkenyl-substituted nadimide is a compound represented by the following formula (4) and/or (5): ##STR00023##

6. The resin composition according to claim 1, wherein the resin composition comprises, as the maleimide compound, at least one compound selected from the group consisting of bis(4-maleimidophenyl)methane, 2,2-bis{4-(4-maleimidophenoxy)-phenyl}propane, bis(3-ethyl-5-methyl-4-maleimidophenyl)methane, and a maleimide compound represented by the following formula (6): ##STR00024## wherein each R.sub.5 independently represents a hydrogen atom or a methyl group, and n.sub.1 represents an integer of 1 or larger.

7. The resin composition according to claim 1, further comprising a cyanate ester compound.

8. The resin composition according to claim 7, wherein the resin composition comprises, as the cyanate ester compound, a compound represented by the following formula (7) and/or (8): ##STR00025## wherein each R.sub.6 independently represents a hydrogen atom or a methyl group, and n.sub.2 represents an integer of 1 or larger, and ##STR00026## wherein each R.sub.7 independently represents a hydrogen atom or a methyl group, and n.sub.3 represents an integer of 1 or larger.

9. The resin composition according to claim 1, wherein the inorganic filler is surface-treated in advance with the silane compound.

10. The resin composition according to claim 1, wherein the content of the silane compound is 0.1 to 15 parts by mass based on 100 parts by mass in total of resins and components that form resins by polymerization in the resin composition.

11. The resin composition according to claim 1, wherein the inorganic filler comprises at least one selected from the group consisting of silica, alumina, and aluminum nitride.

12. The resin composition according to claim 1, wherein the content of the inorganic filler is 100 to 1100 parts by mass based on 100 parts by mass in total of resins and components that form resins by polymerization in in the resin composition.

13. A metal foil-clad laminate comprising the resin composition according to claim 1, wherein the metal foil-clad laminate comprises: a metal foil disposed on one side or both sides of at least one of: a prepreg comprising a base material impregnated or coated with the resin composition, and a resin sheet comprising a support coated with the resin composition; wherein the metal foil-clad laminate comprises a cured product of the resin composition contained in at least one the prepreg and the resin sheet.

14. A printed circuit board comprising an insulating layer and a conductor layer formed on a surface of the insulating layer, wherein the insulating layer comprises a resin composition according to claim 1.

15. The resin composition according to claim 1, wherein a particle shape of the inorganic filler is spherical or substantially spherical.

16. The resin composition according to claim 1, wherein: the inorganic filler is one or more selected from the group consisting of silica, alumina, aluminum nitride, boron nitride, boehmite, molybdenum oxide, and titanium oxide; and a content of the inorganic filler is 100 to 1100 parts by mass based on 100 parts by mass of resins and components that form resins by polymerization in the resin composition.

Description

EXAMPLES

(1) Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not intended to be limited by these Examples.

Synthesis Example 1

Synthesis of α-naphthol aralkyl-based cyanate ester resin

(2) A reactor equipped with a thermometer, a stirrer, a dropping funnel, and a reflux condenser was cooled to 0 to 5° C. in advance using brine and charged with 7.47 g (0.122 mol) of cyanogen chloride, 9.75 g (0.0935 mol) of 35% hydrochloric acid, 76 mL of water, and 44 mL of methylene chloride. While the temperature and pH of this reactor were kept at −5 to +5° C. and 1 or lower, respectively, a solution containing 20 g (0.0935 mol) of an α-naphthol aralkyl-based phenol resin of the formula (9) wherein all of the R.sub.8 were hydrogen atoms (SN485, OH group equivalent: 214 g/eq., softening point: 86° C., manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), and 14.16 g (0.14 mol) of triethylamine dissolved in 92 mL of methylene chloride was added dropwise over 1 hour through the dropping funnel with stirring. After the completion of the dropwise addition, 4.72 g (0.047 mol) of triethylamine was further added dropwise thereto over 15 minutes. After the completion of the dropwise addition, the mixture was stirred at the same temperature as above for 15 minutes. Then, the reaction solution was separated into organic and aqueous layers, and the organic layer was separated. The obtained organic layer was washed with 100 mL of water twice. Then, methylene chloride was distilled off under reduced pressure with an evaporator, and the residue was finally concentrated to dryness at 80° C. for 1 hour to obtain 23.5 g of a cyanate ester product of the α-naphthol aralkyl-based phenol resin (α-naphthol aralkyl-based cyanate ester resin, functional group equivalent: 261 g/eq.).

Example 1

(3) 10 parts by mass of the α-naphthol aralkyl-based cyanate ester resin. obtained by Synthesis Example 1, 45 parts by mass of a novolac-based maleimide compound (BMI-2300, manufactured by Daiwa Fine Chemicals Co., Ltd., functional group equivalent: 186 g/eq.), and 45 parts by mass of bisallylnadimide (BANI-M, manufactured by Maruzen Petrochemical Co., Ltd., functional group equivalent: 286 glee.) were mixed with 150 parts by mass of spherical silica (SC-5050MOB, particle size: 1.6 μm, manufactured by Admatechs Co., Ltd.), 2.5 parts by mass of an epoxysilane compound 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.), 2.5 parts by mass of a styryl silane compound p-styryltrimethoxysilane (KBM-1403, manufactured by Shin-Etsu Chemical Co., Ltd.), and 1 part by mass of a wetting dispersant (DISPERBYK-161, manufactured by BYK Japan K.K.), and the mixture was diluted with methyl ethyl ketone to obtain varnish. An E glass woven fabric was impregnated and coated with this varnish, and dried by heating at 160° C. for 3 minutes to obtain a prepreg having a resin composition content of 49% by mass. In this respect, the ratio [β/α] was 1.54. In this context, the ratio [β/α] is represented by the following formula (the same holds true for the description below):
[β/α]=(Parts by mass of the maleimide compound/Functional group equivalent of the maleimide compound)/(Parts by mass of the alkenyl-substituted nadimide/Functional group equivalent of the alkenyl-substituted nadimide)

Example 2

(4) Varnish was obtained in the same way as in Example 1, and a prepreg was obtained in the same way as in Example 1, except that 5 parts by mass of the styryl silane compound p-styryltrimethoxysilane (KBM-1403, manufactured by Shin-Etsu Chemical Co., Ltd.) were used instead of 2.5 parts by mass of the epoxysilane compound 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) and 2.5 parts by mass of the styryl silane compound p-styryltrimethoxysilane (KBM-1403, manufactured by Shin-Etsu Chemical Co., Ltd.).

Comparative Example 1

(5) Varnish was obtained in the same way as in Example 1, and a prepreg was obtained in the same way as in Example 1, except that 5 parts by mass of the epoxysilane compound 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) were used instead of 2.5 parts by mass of the epoxysilane compound 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) and 2.5 parts by mass of the styryl silane compound p-styryltrimethoxysilane (KBM-1403, manufactured by Shin-Etsu Chemical Co., Ltd.).

Comparative Example 2

(6) Varnish was obtained in the same way as in Example 1, and a prepreg was obtained in the same way as in Example 1, except that 5 parts by mass of an acrylic silane compound 3-acryloxypropyltrimethoxysilane (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.) were used instead of 2.5 parts by mass of the epoxysilane compound 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) and 2.5 parts by mass of the styryl silane compound p-styryltrimethoxysilane (KBM-1403, manufactured by Shin-Etsu Chemical Co., Ltd.).

Comparative Example 3

(7) Varnish was obtained in the same way as in Example 1, and a prepreg was obtained in the same way as in Example 1, except that 2.5 parts by mass of the epoxysilane compound 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) and 2.5 parts by mass of an acrylic silane compound 3-acryloxypropyltrimethoxysilane (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.) were used instead of 2.5 parts by mass of the epoxysilane compound 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) and 2.5 parts by mass of the styryl silane compound p-styryltrimethoxysilane (KBM-1403, manufactured by Shin-Etsu Chemical Co., Ltd.).

Comparative Example 4

(8) Varnish was obtained in the same way as in Example 1, and a prepreg was obtained in the same way as in Example 1, except that 5 parts by mass of an olefin silane compound octenyltrimethoxysilane (KBM-1083, manufactured by Shin-Etsu Chemical Co., Ltd.) were used instead of 2.5 parts by mass of the epoxysilane compound 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) and 2.5 parts by mass of the styryl silane compound p-styryltrimethoxysilane (KBM-1403, manufactured by Shin-Etsu Chemical Co., Ltd.).

Comparative Example 5

(9) Varnish was obtained in the same way as in Example 1, and a prepreg was obtained in the same way as in Example 1, except that 5 parts by mass of an acrylic silane compound methacryloxyoctyltrimethoxysilane (KBM-5803, manufactured by Shin-Etsu Chemical Co., Ltd.) were used instead of 2.5 parts by mass of the epoxysilane compound 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) and 2.5 parts by mass of the styryl silane compound p-styryltrimethoxysilane (KBM-1403, manufactured by Shin-Etsu Chemical Co., Ltd.).

Preparation of Metal Foil-Clad Laminate

(10) Electrolytic copper foils having a thickness of 12 μm (3EC-III, manufactured by Mitsui Mining & Smelting Co., Ltd.) were disposed on the upper and lower sides of 1 layer, 4 layers, or 8 lavers of the prepreg thus obtained, and laminate molding of the resultant was carried out at a pressure of 30 kgf/cm.sup.2 and a temperature of 220° C. for 120 minutes to obtain a copper-clad laminate having an insulating layer thickness of 0.1 mm, 0.4 mm, or 0.8 mm as a metal foil-clad laminate.

Insulation Reliability

(11) The insulation reliability was evaluated by the interwinding insulation reliability test based on HAST (highly accelerated temperature and humidity stress test). First, a printed circuit board (L/S=100/100 μm) was formed by the subtractive method from the copper-clad laminate (thickness: 0.1 mm) thus obtained. Next, a power was connected to the wiring, and continuous humidity insulation resistance was evaluated under conditions involving a temperature of 130° C., a humidity of 85%, and an applied voltage of 5 VDC. A resistance value equal to or lower than 1.0×10.sup.8 Ω was regarded as a breakdown. The evaluation criteria are as described below. ◯: No breakdown occurred for 500 hours or longer ×: A breakdown occurred in less than 500 hours.

(12) The results are shown in Table 1.

Chemical Resistance

(13) The copper-clad laminate (50 mm×50 mm×0.4 mm) was dipped for 2 hours in an aqueous sodium hydroxide solution of 70° C. adjusted to 1 N. The amount of decrease in weight (% by mass) was calculated from the masses of the copper-clad laminate before and after the dipping. A lower absolute value means better chemical resistance (alkali resistance). The results are shown in Table 1.

Desmear Resistance

(14) The copper foils were removed from both sides of the copper-clad laminate (50 mm×50 mm×0.4 mm) by etching. The resulting sample was dipped in Swelling Dip Securiganth P manufactured by Atotech Japan K.K. as a swelling solution at 80° C. for 10 minutes, then dipped in Concentrate Compact CP manufactured by Atotech Japan K.K. as a roughening solution at 80° C. for 5 minutes, and finally dipped in Reduction Conditioner Securiganth P500 manufactured by Atotech Japan K.K. as a neutralizing solution at 45° C. for 10 minutes. This treatment was repetitively carried out three times. Then, the amount of decrease in mass (% by mass) was determined from the masses of the copper-clad laminate before and after the treatment. A lower absolute value means better desmear resistance. The results are shown in Table 1.

Rate of Elastic Modulus Maintenance

(15) The copper foils were removed from both sides of the copper-clad laminate (50 mm×25 mm×0.8 mm). The flexural modulus of the resulting sample was measured at each of 25° C. and 250° C. using an autograph (AG-Xplus manufactured by Shimadzu Corp.) according to JIS C6481. From the flexural modulus at 25° C. (a) and the flexural modulus at 250° C. (b) measured by this approach, the rate of elastic modulus maintenance was calculated according to the following formula:
Rate of elastic modulus maintenance=(b)/(a)×100

Heat Resistance

(16) The copper-clad laminate (50 mm×25 mm×0.4 mm) was floated on solder of 280° C. for 30 minutes, and the presence or absence of delamination was visually confirmed to evaluate heat resistance. The evaluation criteria are as described below. ∘: abnormalities. ×: Delamination occurred while the sample was floated for 0 to 30 minutes.

(17) TABLE-US-00001 TABLE 1 Example Example Comparative Comparative Comparative Comparative Comparative 1 2 Example 1 Example 2 Example 3 Example 4 Example 5 Insulation reliability ◯ ◯ X ◯ ◯ X X Chemical resistance −0.45 −0.59 −0.63 −1.48 −0.17 −1.31 −1.72 (% by mass) Desmear resistance −0.77 −0.83 −1.34 −1.23 −1.17 −2.17 −1.34 (% by mass) Rate of elastic 91 88 93 92 93 88 88 modulus maintenance (%) Heat resistance ◯ ◯ ◯ ◯ ◯ ◯ ◯

(18) The present application is based on Japanese Patent Application No. 2015-135212 filed on Jul. 6, 2015, the contents of which are incorporated herein by reference.

INDUSTRIAL APPLICABILITY

(19) The present invention can provide an insulating layer for printed circuit boards not only excellent in chemical resistance, desmear resistance, and insulation reliability but excellent in heat resistance and the rate of elastic modulus loss, and is therefore industrially applicable to fields such as printed circuit boards for use in semiconductor plastic packages.