THERMOSETTING RESIN COMPOSITION, AND PREPREG AND METAL FOIL CLAD LAMINATE PREPARED FROM SAME

Abstract

Thermosetting resin composition, prepreg, and metal foil clad laminate prepared from same. The thermosetting resin composition comprises (A): a solvent-soluble polyfunctional vinyl aromatic copolymer, the copolymer being a polyfunctional vinyl aromatic copolymer having a structural unit derived from a monomer including a divinyl aromatic compound and an ethyl vinyl aromatic compound, and (B): selected from a polybutadiene resin having a number-average molecular weight of 500 to 10,000; the content of vinyl addition across 1, 2 positions in the molecule of the polybutadiene resin being 50% or more. The prepreg and the copper foil clad laminate prepared from the thermosetting resin composition of the present invention have a good toughness, maintain a high glass-transition temperature and a low water absorption, dielectric property and heat and humidity resistance, and are suitable for use in the field of high-frequency high-speed printed circuit boards and for processing of multilayer printed circuit boards.

Claims

1-10. (canceled)

11. A thermosetting resin composition, characterized in that the thermosetting resin composition comprises component (A) a solvent soluble polyfunctional vinyl aromatic copolymer having a structural unit derived from monomers comprising divinyl aromatic compound (a) and ethyl vinyl aromatic compound (b), comprising 20 mol. % or more of repeating units derived from divinyl aromatic compound (a), wherein the molar fraction of the vinyl group-containing structural unit derived from the divinyl aromatic compound (a) represented by the following formulae (a1) and (a2) satisfies (a1)/[(a1)+(a2)]0.5; the polystyrene-equivalent number average molecular weight Mn measured by gel permeation chromatography is 600 to 30,000; and the ratio of the weight average molecular weight Mw to the number average molecular weight Mn is 20.0 or less, ##STR00005## wherein R.sub.13 represents an aromatic hydrocarbon group having 6 to 30 carbon atoms; R.sub.14 represents an aromatic hydrocarbon group having 6 to 30 carbon atoms; and component (B) which is selected from polybutadiene resins having a number average molecular weight of 500-10,000, wherein the content of vinyl groups added at the 1,2 position in the molecular of the polybutadiene resins is 50% or more.

12. The thermosetting resin composition according to claim 11, characterized in that, in the thermosetting resin composition, the compounding amount of the component (A) is 10 to 98 wt. %, and the compounding amount of the component (B) is 2 to 90 wt. %, based on the total weight of the components (A) and (B).

13. The thermosetting resin composition according to claim 11, wherein the compounding amount of the component (A) is 30 to 90 wt. %, and the compounding amount of the component (B) is 10 to 70 wt. %, based on the total weight of the components (A) and (B).

14. The thermosetting resin composition according to claim 11, wherein the main chain skeleton of the soluble polyfunctional vinyl aromatic copolymer has an indane structure represented by the following formula (a.sub.3) ##STR00006## wherein W represents a saturated or unsaturated aliphatic hydrocarbon group or an aromatic hydrocarbon group, or an aromatic ring or a substituted aromatic ring fused to a benzene ring; Z is an integer of 0 to 4.

15. The thermosetting resin composition according to claim 11, wherein the soluble polyfunctional vinyl aromatic copolymer has a number average molecular weight M.sub.n of 600-10,000.

16. The thermosetting resin composition according to claim 11, wherein the soluble polyfunctional vinyl aromatic copolymer has a number average molecular weight distribution M.sub.w/M.sub.n value of less than or equivalent to 15.

17. The thermosetting resin composition according to claim 11, wherein the soluble polyfunctional vinyl aromatic copolymer has a metal ion content, i.e. the total content of various metal ions, of less than or equivalent to 500 ppm.

18. The thermosetting resin composition according to claim 11, characterized in that the component (A) is a soluble polyfunctional vinyl aromatic copolymer containing a structural unit of monovinyl aromatic compounds (c) other than the ethyl vinyl aromatic compounds (b).

19. The thermosetting resin composition according to claim 11, characterized in that the polybutadiene resins having a number average molecular weight of 1,000-8,000; preferably, the content of vinyl groups added at the 1,2 position in the polybutadiene resins is greater than or equivalent to 70%.

20. The thermosetting resin composition according to claim 11, characterized in that there further contains an initiator as the component (C) in addition to the components (A) and (B); the component (C) is used in an amount of 0.1 to 10 by weight based on 100 parts by weight of the component (A) and the component (B).

21. The thermosetting resin composition according to claim 11, wherein the component (C) initiator has a half-life temperature t.sub.1/2 of not less than 130 C.; the initiator is a radical initiator.

22. The thermosetting resin composition according to claim 11, wherein the thermosetting resin composition further comprises a filler, wherein the filler comprises an organic filler and/or an inorganic filler.

23. The thermosetting resin composition according to claim 11, wherein the thermosetting resin composition further comprises a flame retardant, wherein the flame retardant may be a bromine-containing flame retardant or a halogen-free flame retardant.

24. The thermosetting resin composition according to claim 11, wherein the thermosetting resin composition further comprises an antioxidant, a heat stabilizer, a light stabilizer, a plasticizer, a lubricant, a flow modifier, an anti-drip agent, an anti-blocking agent, an antistatic agent, a flow promoter, a processing aid, a substrate binder, a mold release agent, a toughening agent, a low shrinkage additive and a stress relief additive, or a combination of at least two selected therefrom.

25. A resin varnish, characterized in that it is obtained by dissolving or dispersing the thermosetting resin composition in claim 11 in a solvent.

26. A prepreg, characterized in that the prepreg comprises a substrate and the thermosetting resin composition in claim 11 adhered to the substrate by impregnation and drying.

27. A prepreg according to claim 26, wherein, the substrate is woven or non-woven fabrics prepared from organic fibers, carbon fibers or inorganic fibers.

28. A laminate, characterized in that the laminate comprises at least one prepreg according to claim 27.

29. A metal foil-clad laminate, comprising one or at least two laminated prepregs according to claim 27, and metal foils on one side or both sides of the laminated prepreg.

30. A high-frequency high-speed circuit board comprising one or at least two laminated prepregs according to claim 27.

Description

EMBODIMENTS

[0092] The technical solution of the present invention will be further described below by way of specific embodiments. It should be understood by those skilled in the art that the present invention is not to be construed as limited.

Preparation Example 1

[0093] 0.481 mol (68.4 mL) of vinylbenzene, 0.0362 mol (5.16 mL) of ethylvinylbenzene, 63 mL of a dichloroethane solution of 1-chlorovinylbenzene (40 mmol) (having a concentration of 0.634 mmol/mL), 11 mL of a dichloroethane solution of brominated tetra-n-butylammonium (1.5 mmol) (having a concentration of 0.135 mmol/mL), and 500 mL of dichloroethane were placed in a 1000 mL flask. 1.5 mL of a dichloroethane solution of 1.5 mmol SnCl.sub.4 was added at 70 C. (having a concentration of 0.068 mmol/mL), and the reaction lasts 1 hour. After the polymerization reaction of a small amount of methanol which was foamed with nitrogen, the reaction mixture was poured into a large amount of methanol at room temperature to precipitate a polymer. The obtained polymer was washed with methanol, filtered, dried, and weighed to obtain 54.6 g of copolymer (49.8 wt. % yield)

[0094] The obtained polymer VOD-A had a Mw of 4,180, a Mn of 2560, and a Mw/Mn of 1.6. It was detected by using a JNM-LA600 type nuclear magnetic resonance spectroscopic device manufactured by JEOL that the polymer VOD-A was found to contain 52 mol. % of structural units derived from divinylbenzene and 48 mol. % of structural units derived from ethylvinylbenzene. Further, it is understood that there was an indane structure in the copolymer VOD-A. The indane structure was present in an amount of 7.5 mol. % relative to the structural units of all monomers. Moreover, the molar fraction of the structural unit represented by the formula (a.sub.1) was 0.99 with respect to the total amount of the structural units represented by the above formulae (a.sub.1) and (a.sub.2).

[0095] The copolymer VOD-A was soluble in toluene, xylene, THF, dichloromethane, dichloroethane, chloroform, and no gel formation was observed.

Preparation Example 2

[0096] 0.481 mol (68 mL) of vinylbenzene, 0.362 mol (52 mL) of ethylvinylbenzene, 47 mL of a dichloroethane solution of 1-chlorovinylbenzene (30 mmol) (having a concentration of 0.634 mmol/mL), 65 mL of a dichloroethane solution of chlorinated tetra-n-butylammonium (2.25 mmol) (having a concentration of 0.035 mmol/mL), and 500 mL of dichloroethane were placed in a 1000 mL flask. 22 mL of a dichloroethane solution of 1.5 mmol SnCl.sub.4 was added at 70 C. (having a concentration of 0.068 mmol/mL), and the reaction lasts 1 hour. After the polymerization reaction of a small amount of methanol which was foamed with nitrogen, the reaction mixture was poured into a large amount of methanol at room temperature to precipitate a polymer. The obtained polymer was washed with methanol, filtered, dried, and weighed to obtain 67.4 g of copolymer VOD-B (61.4 wt. % yield)

[0097] The obtained polymer VOD-B had a Mw of 7,670, a Mn of 3680, and a Mw/Mn of 2.1. It was detected by using a JNM-LA600 type nuclear magnetic resonance spectroscopic device manufactured by JEOL that the polymer VOD-B was found to contain 51 mol. % of structural units derived from divinylbenzene and 49 mol. % of structural units derived from ethylvinylbenzene. Further, it is understood that there was an indane structure in the copolymer VOD-B. The indane structure was present in an amount of 7.5 mol. % relative to the structural units of all monomers. Moreover, the molar fraction of the structural unit represented by the formula (a.sub.1) was 0.99 with respect to the total amount of the structural units represented by the above formulae (a.sub.1) and (a.sub.2).

[0098] The copolymer VOD-B was soluble in toluene, xylene, THF, dichloromethane, dichloroethane, chloroform, and no gel formation was observed.

Preparation Example 3

[0099] 0.0481 mol (6.84 mL) of vinylbenzene, 0.0362 mol (5.16 mL) of ethylvinylbenzene, 12.0 mg of a cobalt chain transferring agent having the following formula (as)

##STR00004##

[0100] wherein R.sub.30 is an isopropyl group; Py is pyridyl group

and 150 ml of tetrahydrofuran were placed in a 300 ml flask, then 2,2-azobis(2,4-dimethylvaleronitrile) was added at 50 C., and reacted for 72 hours. The reaction mixture was poured into a large amount of methanol at room temperature to precipitate a polymer. The obtained polymer was washed with methanol, filtered, dried, and weighed to obtain 3.15 g of copolymer VOD-C (28.7 wt. % yield)

[0101] The obtained polymer VOD-c contained Gel, so it is soluble only in THF solvent. It had a Mw of 94,600, a Mn of 12,800, and a Mw/Mn of 7.4. It was detected by using a JNM-LA600 type nuclear magnetic resonance spectroscopic device manufactured by JEOL that the polymer VOD-C was found to contain 58 mol. % of structural units derived from divinylbenzene and 42 mol. % of structural units derived from ethylvinylbenzene. Further, it is understood that there was no indane structure in the copolymer VOD-C. Moreover, the molar fraction of the structural unit represented by the formula (a.sub.1) was 0.25 with respect to the total amount of the structural units represented by the above formulae (a.sub.1) and (a.sub.2).

TABLE-US-00001 TABLE 1 Materials in the examples and comparison examples Product Manu- name facturer or brand Material description Self-made Copolymer Polyfunctional vinyl aromatic copolymer VOD-A Self-made Copolymer Polyfunctional vinyl aromatic copolymer VOD-B Self-made Copolymer Polyfunctional vinyl aromatic copolymer VOD-C Sartomer Ricon 130 Polybutadiene having a low vinyl content (having a molecular weight of about 2,500 and 1,2-vinyl content of 28%) Sartomer Ricon 142 Polybutadiene having a medium vinyl content (having a molecular weight of about 3,900 and 1,2-vinyl content of 55%) Sartomer Ricon 154 Polybutadiene having a high vinyl content (having a molecular weight of about 1,400 and 1,2-vinyl content of 70%) Sartomer Ricon 153 Polybutadiene having a high vinyl content (having a molecular weight of about 5,200 and 1,2-vinyl content of 90%) Nippon B-1000 Polybutadiene having a high vinyl content Soda (having a molecular weight of about 1,200 and 1,2-vinyl content of higher than 85%) Nippon B-3000 Polybutadiene having a high vinyl content Soda (having a molecular weight of about 3,200 and 1,2-vinyl content of higher than 90%) Nippon GI-3000 Hydroxyl-terminated polybutadiene (having Soda a molecular weight of about 3,100 and containing no 1,2-vinyl) Albemarle BT-93W Ethylene bis-tetrabromophthalimide Mitsubishi OPE-2ST-1 Vinyl modified polyphenylene ether resin Gas Asahi H1041 Hydrogenated styrene butadiene block Kasei copolymer Xinqiao DCP Dicumyl peroxide Chemical Admatechs S0-C2 D50: 0.5 um spherical silicon Nittobo 2116NE NE-glass fiberglass cloth

Example 1

[0102] 80.0 parts by weight of the polyfunctional vinyl aromatic copolymer VOD-A, 20.0 parts by weight of polybutadiene Ricon 142 (from Sartomer) having a medium vinyl content, 3.0 parts by weight of a radical initiator DCP, 25 parts by weight of a bromine flame retardant BT-93 W, and 60 parts by weight of the silica fine powder S0-C2 were dissolved in a toluene solvent, and adjusted to a suitable viscosity. NE-glass fiber cloth (Nittobo, model 2116NE) was impregnated with the resin varnish, controlled to be suitable for piece weight by a clamping axis, and dried in an oven to remove the toluene solvent, so as to prepare a 2116 prepreg. 6 sheets of 2116 prepregs and 12 sheets of 2116 prepregs were respectively overlapped, and were coated with a copper foil having a thickness of 1 OZ on both the upper and lower sides, vacuum laminated and cured for 120 min in a press at a curing pressure of 50 kg/cm.sup.2, and a curing temperature of 200 C., to prepare high-speed circuit boards with two thickness specifications (6*2116-0.76 mm plates for testing comprehensive performance, 12*2116-1.52 mm thick plates for testing mechanical properties). The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 2 in detail.

Example 2

[0103] It was the same as in the process of Example 1, except for that the polybutadiene resin was replaced by polybutadiene Ricon 154 having a high vinyl content. The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 2 in detail.

Example 3

[0104] It was the same as in the process of Example 1, except for that the polybutadiene resin was replaced by polybutadiene Ricon 153 having a high vinyl content. The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 2 in detail.

Example 4

[0105] It was the same as in the process of Example 1, except for that the polybutadiene resin was replaced by polybutadiene B-1000 having a high vinyl content. The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 2 in detail.

Example 5

[0106] It was the same as in the process of Example 1, except for that the polybutadiene resin was replaced by polybutadiene B-3000 having a high vinyl content. The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 2 in detail.

Example 6

[0107] It was the same as in the process of Example 1, except for that the ratio of the polyfunctional vinyl aromatic copolymer VOD-A and polybutadiene B-3000 having a high vinyl content had changed from the original weight ratio of 80:20 to 50:50. The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 2 in detail.

Example 7

[0108] It was the same as in the process of Example 6, except for that the ratio of the polyfunctional vinyl aromatic copolymer VOD-A and polybutadiene B-3000 having a high vinyl content had changed from the original weight ratio of 80:20 to 13:87 The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 2 in detail.

Example 8

[0109] It was the same as in the process of Example 6, except for that the ratio of the polyfunctional vinyl aromatic copolymer VOD-A and polybutadiene B-3000 having a high vinyl content had changed from the original weight ratio of 80:20 to 93:7 The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 2 in detail.

Example 9

[0110] It was the same as in the process of Example 1, except for that the polyfunctional vinyl aromatic copolymer VOD-A was replaced with the polyfunctional vinyl aromatic copolymer VOD-B. The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 2 in detail.

Comparison Example 1

[0111] 100 parts by weight of the polyfunctional vinyl aromatic copolymer VOD-A, 3.0 parts by weight of a radical initiator DCP, 25 parts by weight of a bromine flame retardant BT-93 W, and 60 parts by weight of the silica fine powder S0-C2 were dissolved in a toluene solvent, and adjusted to a suitable viscosity. NE-glass fiber cloth (Nittobo, model 2116NE) was impregnated with the resin varnish, controlled to be suitable for piece weight by a clamping axis, and dried in an oven to remove the toluene solvent, so as to prepare a 2116 prepreg. 6 sheets of 2116 prepregs and 12 sheets of 2116 prepregs were respectively overlapped, and were coated with a copper foil having a thickness of 1 OZ on both the upper and lower sides, vacuum laminated and cured for 120 min in a press at a curing pressure of 50 kg/cm.sup.2, and a curing temperature of 200 C., to prepare high-speed circuit boards with two thickness specifications (6*2116-0.76 mm plates for testing comprehensive performance, 12*2116-1.52 mm thick plates for testing mechanical properties). The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 3 in detail.

Comparison Example 2

[0112] 80.0 parts by weight of the polyfunctional vinyl aromatic copolymer VOD-A, 20.0 parts by weight of polybutadiene Ricon 154 (Sartomer) having a high vinyl content, 3.0 parts by weight of a radical initiator DCP, 25 parts by weight of a bromine flame retardant BT-93 W, and 60 parts by weight of the silica fine powder S0-C2 were dissolved in a toluene solvent, and adjusted to a suitable viscosity. NE-glass fiber cloth (Nittobo, model 2116NE) was impregnated with the resin varnish, controlled to be suitable for piece weight by a clamping axis, and dried in an oven to remove the toluene solvent, so as to prepare a 2116 prepreg. 6 sheets of 2116 prepregs and 12 sheets of 2116 prepregs were respectively overlapped, and were coated with a copper foil having a thickness of 1 OZ on both the upper and lower sides, vacuum laminated and cured for 120 min in a press at a curing pressure of 50 kg/cm.sup.2, and a curing temperature of 200 C., to prepare high-speed circuit boards with two thickness specifications (6*2116-0.76 mm plates for testing comprehensive performance, 12*2116-1.52 mm thick plates for testing mechanical properties). The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 3 in detail.

Comparison Example 3

[0113] 48 parts by weight of the polyfunctional vinyl aromatic copolymer VOD-A, 12 parts by weight of vinyl modified polyphenylene ether resin OPE-2ST-1, 40 parts by weight of hydrogenated styrene butadiene block copolymer H1041, 3.0 parts by weight of a radical initiator DCP, 25 parts by weight of a bromine flame retardant BT-93 W, and 60 parts by weight of the silica fine powder S0-C2 were dissolved in a toluene solvent, and adjusted to a suitable viscosity. NE-glass fiber cloth (Nittobo, model 2116NE) was impregnated with the resin varnish, controlled to be suitable for piece weight by a clamping axis, and dried in an oven to remove the toluene solvent, so as to prepare a 2116 prepreg. 6 sheets of 2116 prepregs and 12 sheets of 2116 prepregs were respectively overlapped, and were coated with a copper foil having a thickness of 1 OZ on both the upper and lower sides, vacuum laminated and cured for 120 min in a press at a curing pressure of 50 kg/cm.sup.2, and a curing temperature of 200 C., to prepare high-speed circuit boards with two thickness specifications (6*2116-0.76 mm plates for testing comprehensive performance, 12*2116-1.52 mm thick plates for testing mechanical properties). The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 3 in detail.

Comparison Example 4

[0114] 80.0 parts by weight of the polyfunctional vinyl aromatic copolymer VOD-A, 20 parts by weight of methyl-terminated acryloyl cage silsesquioxane A, 3.0 parts by weight of a radical initiator DCP, 25 parts by weight of a bromine flame retardant BT-93 W, and 60 parts by weight of the silica fine powder S0-C2 were dissolved in a toluene solvent, and adjusted to a suitable viscosity. NE-glass fiber cloth (Nittobo, model 2116NE) was impregnated with the resin varnish, controlled to be suitable for piece weight by a clamping axis, and dried in an oven to remove the toluene solvent, so as to prepare a 2116 prepreg. 6 sheets of 2116 prepregs and 12 sheets of 2116 prepregs were respectively overlapped, and were coated with a copper foil having a thickness of 1 OZ on both the upper and lower sides, vacuum laminated and cured for 120 min in a press at a curing pressure of 50 kg/cm.sup.2, and a curing temperature of 200 C., to prepare high-speed circuit boards with two thickness specifications (6*2116-0.76 mm plates for testing comprehensive performance, 12*2116-1.52 mm thick plates for testing mechanical properties). The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 3 in detail.

Comparison Example 5

[0115] 80.0 parts by weight of the polyfunctional vinyl aromatic copolymer VOD-A, 20.0 parts by weight of polybutadiene Ricon 130 (Sartomer) having a low vinyl content, 3.0 parts by weight of a radical initiator DCP, 25 parts by weight of a bromine flame retardant BT-93 W, and 60 parts by weight of the silica fine powder S0-C2 were dissolved in a toluene solvent, and adjusted to a suitable viscosity. NE-glass fiber cloth (Nittobo, model 2116NE) was impregnated with the resin varnish, controlled to be suitable for piece weight by a clamping axis, and dried in an oven to remove the toluene solvent, so as to prepare a 2116 prepreg. 6 sheets of 2116 prepregs and 12 sheets of 2116 prepregs were respectively overlapped, and were coated with a copper foil having a thickness of 1 OZ on both the upper and lower sides, vacuum laminated and cured for 120 min in a press at a curing pressure of 50 kg/cm.sup.2, and a curing temperature of 200 C., to prepare high-speed circuit boards with two thickness specifications (6*2116-0.76 mm plates for testing comprehensive performance, 12*2116-1.52 mm thick plates for testing mechanical properties). The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 3 in detail.

Comparison Example 6

[0116] 80.0 parts by weight of the polyfunctional vinyl aromatic copolymer VOD-A, 20 parts by weight of the hydroxyl-terminated polybutadiene resin GI-3000 (Nippon Soda), 3.0 parts by weight of a radical initiator DCP, 25 parts by weight of a bromine flame retardant BT-93 W, and 60 parts by weight of the silica fine powder S0-C2 were dissolved in a toluene solvent, and adjusted to a suitable viscosity. NE-glass fiber cloth (Nittobo, model 2116NE) was impregnated with the resin varnish, controlled to be suitable for piece weight by a clamping axis, and dried in an oven to remove the toluene solvent, so as to prepare a 2116 prepreg. 6 sheets of 2116 prepregs and 12 sheets of 2116 prepregs were respectively overlapped, and were coated with a copper foil having a thickness of 1 OZ on both the upper and lower sides, vacuum laminated and cured for 120 min in a press at a curing pressure of 50 kg/cm.sup.2, and a curing temperature of 200 C., to prepare high-speed circuit boards with two thickness specifications (6*2116-0.76 mm plates for testing comprehensive performance, 12*2116-1.52 mm thick plates for testing mechanical properties). The physical properties of the prepared copper foil substrate were tested, and the results are shown in Table 3 in detail.

TABLE-US-00002 TABLE 2 Materials and Example Example Example Example Example Example Example Example Example performances 1 2 3 4 5 6 7 8 9 Copolymer 80 80 80 80 80 50 13 93 VOD-A Copolymer 80 VOD-B Copolymer VOD-C Ricon 130 Ricon 142 20 Ricon 154 20 Ricon 153 20 B-1000 20 B-3000 20 50 87 7 20 GI-3000 OPE-2ST-1 H1041 Cage silsesquioxane A DCP 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 BT-93W 25 25 25 25 25 25 25 25 25 S0-C2 60 60 60 60 60 60 60 60 60 Tg-DMA( C.) 260.6 283.3 290.2 286.1 292.0 272.2 212.2 292.6 291.2 Td-5% loss 416.2 415.3 416.3 413.2 416.3 417.3 416.5 414.2 413.5 ( C.) PCT water 0.15 0.15 0.14 0.14 0.14 0.15 0.15 0.14 0.14 absorption rate (%) Dielectric 3.41 3.40 3.41 3.40 3.41 3.40 3.41 3.40 3.40 constant (10 GHz) Dielectric 0.0021 0.0020 0.0020 0.0020 0.0021 0.0020 0.0020 0.0020 0.0020 loss factor (10 GHz) Pendulum 65.368 64.589 64.201 65.365 64.201 65.365 66.135 62.451 64.547 Impact strength (kJ/m.sup.2) Drop hammer impact toughness PCT >300 s >300 s >300 s >300 s >300 s >300 s >300 s >300 s >300 s

TABLE-US-00003 TABLE 3 Materials and Comp. Comp. Comp. Comp. Comp. Comp. performances Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Copolymer 100 48 80 80 80 VOD-A Copolymer VOD-B Copolymer 80 VOD-C Ricon 130 20 Ricon 142 Ricon 154 20 Ricon 153 B-1000 B-3000 GI-3000 20 OPE-2ST-1 12 H1041 40 Cage 20 silsesquioxane A DCP 3.0 3.0 3.0 3.0 3.0 3.0 BT-93W 25 25 25 25 25 25 S0-C2 60 60 60 60 60 60 Tg-DMA( C.) 291.6 211.2 202.6 289.3 246.3 203.4 Td-5% loss 416.2 360.2 412.3 414.2 412.6 414.3 ( C.) PCT water 0.14 0.15 0.25 0.15 0.16 0.23 absorption rate (%) Dielectric 3.40 3.40 3.43 3.55 3.40 3.80 constant (10 GHz) Dielectric loss 0.0020 0.0020 0.0030 0.0050 0.0020 0.0052 factor (10 GHz) Pendulum 45.687 58.234 55.501 54.632 65.547 50.321 Impact strength (kJ/m.sup.2) Drop hammer impact toughness PCT >300 s 10 s; 2 s; >300 s >300 s 3 s; delamination delamination delamination

[0117] The test methods for the above characteristics are as follows.

1) Glass transition temperature (Tg): The Tg of the laminate was measured according to the dynamic thermal mechanical analysis (DMA) method specified in IPC-TM-650 2.4.24.4.
2) Thermal decomposition temperature (Td-5% loss): According to the thermogravimetric analysis (TGA), the temperature Td at 5% weight loss of the laminate was measured according to the TGA method specified in IPC-TM-650 2.4.24.6.
3) PCT water absorption rate: After etching the copper foil on the surface of the copper clad laminate, the substrate was dried to weigh the original weight, and then placed in a pressure cooker, treated at 120 C. and 150 KPa for two hours, taken out with a dry cloth, wiped to dry and to weigh the sample after water absorption. PCT water absorption (weight after cooking-weight before cooking)/weight before cooking.
4) Dielectric constant Dk and dielectric loss factor Df: Tested according to the SPDR (Split Post Dielectric Resonator) method at a test frequency of 10 GHz.
5) Pendulum impact strength: Using a simple-supported beam non-metallic material pendulum impact tester. A laminate of about 1.6 mm was made into several 120 mm*10 mm notched samples (notch depth 2 mm). The pendulum was used to impact the sample at a speed of 3.8 m/s. After the sample broke, the absorption work of the pendulum impact tester was read. Finally, the pendulum impact strength was calculated.
6) Drop hammer impact toughness: using the drop hammer impact tester. The drop hammer of the impact tester had a drop height of 100 cm and a weight of 1 Kg. Toughness evaluation: the clearer the cross was, the better the toughness of the product was, represented by the character . If the cross was blurred, it showed that the product had poor toughness and brittleness, which was represented by the character . If the clarity of the cross was between clarity and blur, it indicated that the product had a general toughness, which was represented by the character .
7) PCT: After etching the copper foil on the surface of the copper clad plate, the substrate was placed in a pressure cooker, treated at 120 C. and 150 KPa for two hours, and then immersed in a tin furnace at 288 C. When the substrate was layered, the corresponding time was recorded. The evaluation could be ended if bubbles or delamination did not appear after the substrate was in the tin furnace for more than 5 minutes.

Physical Property Analysis

[0118] It can be seen from the physical property data in Tables 2 and 3 that Comparison Example 1 discloses that the substrate has a higher glass transition temperature, better electrical properties, lower water absorption ratio, but extremely worst toughness after the polyfunctional vinyl aromatic copolymer VOD-A was used for self-curing. In Comparison Example 3, after the addition of the hydrogenated styrene butadiene block copolymer, the toughness of the substrate was improved, but the glass transition temperature was significantly reduced. Moreover, the delamination and plate blasting appeared, and it had a poor heat and humidity resistance. In Comparison Example 4, the terminal (meth)acryloyl cage-type silsesquioxane A was introduced as a crosslinking agent. It was inferior in dielectric properties due to its high polarity. In Comparison Example 5, the content of vinyl group added at 1,2-position in the polybutadiene used was less than 50%; the heat resistance of the substrate was remarkably lowered, and the PCT water absorption rate was increased. In Comparison Example 6, polybutadiene resin containing no 1,2-vinyl group was used; the heat resistance of the substrate was remarkably lowered; the PCT water absorption rate was increased; the dielectric properties were deteriorated; and the toughness was also lowered. In Examples 1 to 9, polybutadiene resin was used as the polyfunctional vinyl aromatic copolymer VOD-A or VOD-B. The cured substrate had good toughness and maintained its high glass transition temperature, low water absorption, excellent dielectric properties and heat and humidity resistance.

[0119] As described above, the circuit substrate of the present invention has good toughness as compared with general laminates, and maintains its high glass transition temperature, low water absorption, excellent dielectric properties, and moist heat resistance.

[0120] The applicant claims that the thermosetting resin composition of the present invention, prepregs and metal foil-clad laminate prepared therefrom are described by the above embodiments. However, the present invention is not limited to the above embodiments, i.e. it does not mean that the present invention cannot be carried out unless the above embodiments are applied. Those skilled in the art shall know that any modifications of the present invention, equivalent substitutions of the materials selected for use in the present invention, and addition of the auxiliary ingredients, and specific manner in which they are selected, all are within the protection scope and disclosure of the present invention.