JP2002151812A - Pre-preg for printed wiring board - Google Patents

Abstract

(57) [Problem] To provide a prepreg for a printed wiring board having good plating property without a decrease in heat resistance of moisture-absorbing solder. SOLUTION: A varnish containing a silicone oligomer, a polyfunctional epoxy resin, a polyfunctional phenol resin, a flame retardant, and a curing accelerator is impregnated into a glass woven fabric or a glass nonwoven fabric, and heated to B-stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As electronic devices have become smaller and more sophisticated, the printed circuit boards mounted therein have an extremely large aspect ratio as the number of layers is increased, the thickness is reduced, and the size of through holes is reduced. Is coming. For this reason, prepregs for printed wiring boards have excellent workability, low water absorption, high heat resistance, and high Tg.
Is required.

[0003] From these demands, polyfunctional epoxy resins using a polyfunctional phenol resin as a curing agent have been widely used.

[0004] However, polyfunctional epoxy resins using a polyfunctional phenol resin as a curing agent are inexpensive, have high Tg, have high heat resistance, and have low water absorption. The nature also decreases. These problems can be dealt with by examining the liquid composition and conditions of desmear treatment and plating pretreatment.However, these desmear treatments and plating pretreatments are conventionally designed based on FR-4. Designing a unique line for a polyfunctional epoxy resin using a polyfunctional phenol resin as a curing agent is not preferable because of workability and space issues. To address this problem, various studies have been conducted on commercially available coupling agents, but when the blending amount is small, almost no improvement in plating is seen, and when the blending amount is large, plating improvement is seen, Heat resistance is greatly reduced.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a printed wiring having excellent high-temperature characteristics, excellent corrosion resistance and high Tg, excellent plating properties, and high reliability of through holes. It is intended to provide a board prepreg.

[0006]

That is, the present invention provides (a) 3
A functional siloxane unit (RSiO3 / 2) (where R is an organic group, and the R groups in the silicone oligomer may be the same or different from each other) and a tetrafunctional siloxane unit (RSiO4 / 2) contains at least one type of siloxane unit selected from the group consisting of
0 is a silicone oligomer having at least one functional group that reacts with a hydroxyl group at the terminal. (B) a polyfunctional epoxy resin (c) a polyfunctional phenolic resin (d) a flame retardant (e) a varnish containing a curing accelerator as an essential component is impregnated into a glass woven fabric or a glass nonwoven fabric, and heated to obtain B. An object of the present invention is to provide a method for producing a prepreg for a printed wiring board, which is characterized in that it is staged.

The molecular weight and structure of the silicone oligomer (a) used herein are not particularly limited as long as the silicone oligomer has at least one functional group which reacts with a hydroxyl group at the terminal. As the functional group which reacts with the hydroxyl group at the terminal of the silicone oligomer, usually, an alkoxyl group having 1 or 2 carbon atoms or a silanol group is preferable. As the silicone oligomer, a bifunctional siloxane unit (RSi
O2 / 2), trifunctional siloxane unit (RSiO3 / 2) (where R is an organic group such as methyl group, ethyl group having 1 carbon atom)
Or an annealed group having 6 to 12 carbon atoms, such as an alkyl group or a phenyl group, or a vinyl group, and the R groups in the silicone oligomer may be the same or different. ) And at least one type of siloxane unit selected from tetrafunctional siloxane units (SiO4 / 2), and preferably has a degree of polymerization of 2 to 70 (converted from the weight average molecular weight by GPC). When a silicone oligomer having a polymerization degree of more than 70 is used, heat resistance may be reduced. Here, RSiO2 / 2, RSiO3 / 2, and SiO4 / 2, which represent bifunctional, trifunctional, and tetrafunctional siloxane units, have the following structural formulas, respectively.

Embedded image Further, the silicone oligomer used in the present invention is preferably three-dimensionally cross-linked in advance, so that the bifunctionality,
It is preferable that the siloxane unit comprises at least one siloxane unit selected from trifunctional and tetrafunctional siloxane units and has at least one siloxane unit selected from trifunctional and tetrafunctional siloxane units. For example, those composed of trifunctional siloxane units, those composed of tetrafunctional siloxane units, those composed of difunctional siloxane units and trifunctional siloxane units, those composed of difunctional siloxane units and tetrafunctional siloxane units, And desirably comprises a bifunctional siloxane unit, a trifunctional siloxane unit and a tetrafunctional siloxane unit. Further, it is preferable that the content of the tetrafunctional siloxane unit is 15 mol% or more, preferably 20 to 60% of the total siloxane unit. The silicone oligomer can be synthesized, for example, by condensing one or more chloro or alkoxylanes corresponding to a desired siloxane unit in the presence of water using an acid catalyst. The condensation reaction is performed to such an extent that a gel state is not obtained. For this purpose, the reaction temperature, the reaction time, the oligomer composition ratio, and the type and amount of the catalyst are changed and adjusted. As the catalyst, acetic acid, hydrochloric acid, maleic acid, phosphoric acid and the like are preferably used. The amount of oligomer is 10 resin solids.
It is preferably 0.1 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, based on 0. If the amount added is less than 0.1 part, there is almost no effect, and if it exceeds 20 parts by weight, the heat resistance decreases.

[0008] In addition to the silicone oligomer, additives including various coupling agents may be blended. Examples of the coupling agent include a silane coupling agent and a titanate coupling agent. Examples of the silane coupling agent include epoxysilanes such as γ-glycidoxypropyltrimethoxysilane and aminosilanes such as N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane and hydrochloride. Systems, cationic silane systems, vinyl silane systems, acryl silane systems, mercapto silane systems and composite systems thereof. Examples of the titanate coupling agent include isopropyl tris (dioctyl pyrophosphate) titanate. When such a coupling agent is blended, the amount thereof is not limited, but usually, the resin solid content is 100%.
0.001 to 50 parts by weight, preferably 0.00
It is preferable that the amount be 1 to 20 parts by weight.

As the polyfunctional epoxy resin (b),
Phenol novolak epoxy resin, cresol novolak epoxy resin, bisphenol A novolak epoxy resin, dicyclopentadiene epoxy resin,
There are a diglycidyl etherified product of a polyfunctional phenol, a diglycidyl etherified product of a polyfunctional alcohol, a halide thereof, a hydrogenated product thereof, and the like, and some of them can be used in combination.

Examples of the polyfunctional phenolic resin (c) include phenol novolak, cresol novolak, bisphenol A novolak, and halides and alkyl group-substituted products thereof. These curing agents are used in combination of several kinds. Is also good.

As the flame retardant (d), compounds called general flame retardants such as tetrabromobisphenol A, decabromodiphenyl ether, antimony trioxide and tetraphenyl phosphine are desirable. May be used in combination.

As the curing accelerator (e), an imidazole compound, an organic phosphorus compound, a tertiary amine, a quaternary ammonium salt or the like is used. When a masked imidazole compound is used, the conventional 2
It is possible to obtain a prepreg having a storage stability twice or more. Examples of the imidazole compound used herein include imidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole, and 2-heptadecyl Imidazole, 4,5-diphenylimidazole, 2-methylimidazoline, 2-ethyl-4-methylimidazoline, 2-phenylimidazoline, 2-undecylimidazoline, 2-heptadecylimidazoline, 2-isopropylimidazole, 2,4
-Dimethylimidazole, 2-phenyl-4-methylimidazole, 2-methylimidazoline, 2-isopropylimidazoline, 2,4-dimethylimidazoline, 2-
Phenyl-4-methylimidazoline and the like. Examples of the masking agent include acrylonitrile, phenylene diisocyanate, toluene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, methylene bisphenyl isocyanate, and melamine acrylate. Some of these curing accelerators may be used in combination.

The above (a), (b), (c), (d) and (e) are essential components. In addition, if necessary, a filler, a coloring agent, an antioxidant, a reducing agent, an ultraviolet ray A penetrant or the like may be added.

An epoxy resin varnish obtained by blending the above (a), (b), (c), (d) and (e) in a solvent is impregnated into a glass woven fabric or a glass nonwoven fabric and dried. To obtain a prepreg. The type of glass woven fabric or glass non-woven fabric used here is not particularly specified, and those having a thickness of 0.02 to 0.4 mm can be used according to the thickness of the target prepreg or laminate. . The drying conditions for producing the prepreg can be freely selected in accordance with the desired prepreg characteristics between a drying temperature of 60 to 200 ° C. and a drying time of 1 to 30 minutes.

[0015] The prepregs obtained according to the desired thickness of the laminated plate are laminated, and a metal foil is laminated on one or both sides thereof, and heated and pressed to produce a laminated plate. A copper foil or an aluminum foil is mainly used as the metal foil, but another metal foil may be used. The thickness of the metal foil is usually 5 to 200 μm.

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

[0017]

[Function] A laminated board composed of a multifunctional epoxy, a multifunctional phenol, a flame retardant, and a curing accelerator is excellent in chemical resistance, and as a result, the wall surface of the hole is not roughened by desmear treatment after drilling. Of the plating is poor. As a result of various studies on this problem, it has been found that, by blending an oligomer in a resin, P which is a nucleus of plating can be obtained.
The adhesion of d is increased, and the plating property is improved.

[0018]

EXAMPLE 1 40 g of tetramethoxysilane and 93 g of methanol were blended, then 0.47 g of acetic acid and 18.9 g of distilled water were added, and the mixture was stirred at 50 ° C. for 8 hours. Twenty (calculated from the weight average molecular weight by GPC, the same applies hereinafter) silicone oligomers were synthesized. The obtained silicone oligomer had a methoxy group and / or a silanol group as a terminal functional group. Methanol was added to the obtained silicone oligomer solution to prepare an oligomer solution having a solid content of 20% by weight. 100 parts by weight of a cresol novolak type epoxy resin (Dai Nippon Ink Chemical Industry Co., Ltd. product name: Epicron N-673), 35 parts by weight of a phenol novolak resin (Denippon Ink and Chemicals, Inc. Fenolite TD-2131), 45 parts by weight of tetrabromobisphenol A 0.10 parts by weight of 2-phenylimidazole, 10 parts by weight of the silicone oligomer prepared above, and a mixed solvent of methyl ethyl ketone and ethylene glycol monomethyl ether (10: 1 by weight) were dissolved to give a resin solid content of 65%. Varnish was obtained. This varnish was impregnated into a 200 μm glass woven fabric (MIL part number 7628 type) and dried in a dryer at 150 ° C. for 4 minutes to obtain a prepreg in a B-stage state. The obtained four prepregs are stacked, and a thickness of 18 μm is formed on both sides thereof.
Was heated and pressed at a pressure of 2 Mpa and a temperature of 170 ° C. for 90 minutes to obtain a double-sided copper-clad laminate. Example 2 40 g of trimethoxysilane and 93 g of methanol were blended, then 0.53 g of acetic acid and 15.8 g of distilled water were added, and the mixture was stirred at 50 ° C. for 8 hours to synthesize a silicone oligomer having a siloxane unit polymerization degree of 15. . The obtained silicone oligomer had a methoxy group and / or a silanol group as a terminal functional group. Methanol was added to the obtained silicone oligomer solution to prepare an oligomer solution having a solid content of 20% by weight, and 20 parts by weight of the silicone oligomer was blended. Otherwise, a double-sided copper-clad laminate was obtained in the same manner as in Example 1. . Example 3 20 g of trimethoxysilane and 22 of tetramethoxysilane
g and 98 g of methanol, then 0.52 g of acetic acid
And 18.3 g of distilled water, and the mixture was stirred at 50 ° C. for 8 hours to synthesize a silicone oligomer having a siloxane unit polymerization degree of 25. The obtained silicone oligomer had a methoxy group and / or a silanol group as a terminal functional group. Methanol was added to the obtained silicone oligomer solution to prepare an oligomer solution having a solid content of 20% by weight. A double-sided copper-clad laminate was obtained in the same manner as in Example 1 except that 20 parts by weight of the silicone oligomer was blended. Example 4 To the silicone oligomer solution obtained in Example 1 were added γ-glycidoxypropyltrimethoxysilane (trade name: A-187 Nippon Unicar Co., Ltd.) as a silane coupling agent and methanol, and the solid content was 20%. A solution having a weight% (silicone oligomer: A-187 = 4: 1 weight ratio) was prepared. A double-sided copper-clad laminate was obtained in the same manner as in Example 1 except that 20 parts by weight of the silicone oligomer was blended. Comparative Example 1 A double-sided copper-clad laminate was obtained in the same manner as in Example 1 except that no oligomer was blended. Comparative Example 2 20 parts by weight of A-187 was blended in place of the oligomer,
Otherwise in the same manner as in Example 1, a double-sided copper-clad laminate was obtained. The double-sided copper-clad laminate obtained as described above is 50 × 50 m
m in a normal state and in a PCT (121 ° C. 12
After treatment at 25.7 hPa) for 5 hours, the plate was immersed in a solder at 260 ° C. for 20 seconds, and the appearance was visually evaluated. Further, holes were drilled with a φ0.3 mm drill. Next, KMnO
4, a conditioner (CLC501 manufactured by Hitachi Chemical Co., Ltd.), a pre-dip (PD-301 manufactured by Hitachi Chemical Co., Ltd.), a seeder (HS202B manufactured by Hitachi Chemical Co., Ltd.), an accelerator (Hitachi Plating pretreatment is performed by CLC 601 manufactured by Kasei Kogyo Co., Ltd., followed by chemical copper plating (CUS manufactured by Hitachi Chemical Co., Ltd.).
T-201). Thereafter, copper on the surface of the base material was removed, Pd in the holes was removed with aqua regia, the amount of Pd was quantified by atomic absorption, and the amount of Pd in the area of the through hole was measured. Further, the plating properties were visually observed.

[0019]

[Table 1] Evaluation of plating ○: 100% plating is applied. Δ: 80% or more plating is applied. X: Less than 80% plating is applied.

[0020]

According to the present invention, it is possible to obtain a prepreg having a large plating amount and a good plating property without reducing the heat resistance of the moisture-absorbing solder.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 3/00 C08K 3/00 5/00 5/00 7/14 7/14 C08L 63/00 C08L 63 / 00 C 83/04 83/04 F term (reference) 4F072 AA01 AA04 AA06 AA07 AB09 AB28 AB29 AD13 AD23 AD47 AE02 AE07 AG03 AH02 AH22 AJ04 AJ22 AK05 AK14 AL13 4J002 CC03 CD05 CD06 CD07 CD09 DE126 EB136 EN007 EU117 FD007 EW00 4J036 AA01 AD08 AF06 AJ08 AK09 AK10 DC40 DD07 FA03 FA09 FB07 FB16 JA08

Claims (8)

[Claims] (1) (a) a trifunctional siloxane unit (RSiO
3/2) (wherein R is an organic group, and the R groups in the silicone oligomer may be the same or different from each other) and a tetrafunctional siloxane unit (RSiO4 /
A silicone oligomer containing at least one type of siloxane unit selected from 2), having a degree of polymerization of 2 to 70, and having at least one functional group that reacts with a hydroxyl group at a terminal.
(B) a polyfunctional epoxy resin (c) a polyfunctional phenolic resin (d) a flame retardant (e) a varnish containing a curing accelerator as an essential component is impregnated into a glass woven fabric or a glass nonwoven fabric, and heated to obtain B. A prepreg for a printed wiring board characterized by being staged. 2. The printed wiring board according to claim 1, wherein the silicone oligomer comprises a bifunctional siloxane unit (RSiO2 / 2) and a tetrafunctional siloxane unit (RSiO4 / 2) and has a degree of polymerization of 6 to 70. Of manufacturing prepreg for garments. 3. The printed wiring board according to claim 1, wherein the silicone oligomer comprises trifunctional siloxane units (RSiO3 / 2) and tetrafunctional siloxane units (RSiO4 / 2), and has a degree of polymerization of 6 to 70. Of manufacturing prepreg for garments. 4. The printed wiring board according to claim 1, wherein the silicone oligomer comprises a bifunctional siloxane unit (RSiO2 / 2) and a trifunctional siloxane unit (RSiO3 / 2) and has a degree of polymerization of 6 to 70. Of manufacturing prepreg for garments. 5. The silicone oligomer comprises a bifunctional siloxane unit (RSiO2 / 2), a trifunctional siloxane unit (RSiO3 / 2) and a tetrafunctional siloxane unit (RSi2).
2. The method for producing a prepreg for a printed wiring board according to claim 1, wherein the prepreg comprises O4 / 2) and has a degree of polymerization of 6 to 70. 6. The method for producing a prepreg for a printed wiring board according to claim 2, wherein the proportion of the tetrafunctional siloxane unit (RSiO4 / 2) in all the siloxane units of the silicone oligomer is 15 mol% or more. 7. The silicone oligomer comprises tetrafunctional siloxane units (RSiO4 / 2) and has a degree of polymerization of 6 to 70.
The method for producing a prepreg for a printed wiring board according to claim 1. 8. The silicone oligomer comprises trifunctional siloxane units (RSiO3 / 2) and has a degree of polymerization of 6 to 70.
The method for producing a prepreg for a printed wiring board according to claim 1.