JPH09314758A - Prepreg and laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a prepreg and a laminated sheet, which are used as a printed wiring board material excellent in the reliability of electrical insulation under the condition of moisture absorption, by allowing an unwoven fabric, or a woven fabric, prepared from aramid fibers to contain resin and an ion scavenger. SOLUTION: An unwoven fabric, or a woven fabric, which is prepared from aramid fibers made of polyparaphenylene telephtalamide, or of copolyparaphenylene 3,4'-oxydiphenylene telephtalamide, is used as a base material. This base material is impregnated with varnish made of a resin such as an epoxy resin, a polyphenylene oxide resin, or the like, and with an ion scavenger of a type of exchanging both ions as an ion scavenger, and a prepreg is made by drying under heating the impregnated base material. Accordingly, even in the case of the aramid fibers which tend to absorb moisture, the occurrence of migration of ions is suppressed with the effect of the ion scavenger, and the conduction between circuits is prevented, thereby enhancing the reliability of electrical insulation under the condition of moisture absorption.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prepreg used as a material for a printed wiring board and a laminated board made of this prepreg.

[0002]

2. Description of the Related Art As a prepreg used as a material for producing a printed wiring board, a prepreg obtained by impregnating a glass cloth with a thermosetting resin and drying it has been widely used. However, in recent years, a printed wiring board using a prepreg having an organic fiber as a base material has been proposed in order to reduce the weight, reduce the dielectric constant, and perform laser processing. Aramid (wholly aromatic polyamide) fiber is used as a typical organic fiber. Because aramid fiber is lightweight and has a low dielectric constant, it is well suited to the needs of light, thin, short and small mobile devices such as mobile phones.

[0003]

As an aramid fiber, polyparaphenylene terephthalamide (P
PTA) and copolyparaphenylene 3,4 'oxydiphenylene terephthalamide (PPODTA) are used, but aramid fiber has higher hygroscopicity than glass fiber, and aramid fiber woven or non-woven fabric is used as a base material. A printed wiring board manufactured using a prepreg has a problem in reliability of electric insulation under moisture absorption.

Further, particularly in PPTA, a large amount of impure ions such as Na and Cl due to the manufacturing process thereof are present, and in combination with the above-mentioned high hygroscopicity, the electrical insulation reliability under hygroscopicity is greatly deteriorated. Met. That is, when the circuit of the printed wiring board is in an applied state under moisture absorption, CAF
(Conductive Anodic Film
nt) migration of impure ions occurs, and conduction occurs between circuits.

The present invention has been made in view of the above points, and an object of the present invention is to provide a prepreg and a laminated board which are materials of a printed wiring board having excellent electric insulation reliability under moisture absorption. is there.

[0006]

The prepreg according to the present invention is characterized by comprising a non-woven fabric or a woven fabric of aramid fibers containing a resin and an ion scavenger. According to the invention of claim 2, the aramid fiber has the following (1)
It is characterized by having a chemical structural formula.

[0007]

Embedded image

(M has a weight average of 30,000 to 70,000
The invention of claim 3 is characterized in that the aramid fiber has a chemical structural formula of the following formula (2).

[0009]

Embedded image

(M and n have a weight average of 30,000 to 700)
The numerical value is set to 00). The invention of claim 4 is characterized in that an epoxy resin or a polyphenylene oxide resin is used as the resin. The invention of claim 5 is characterized in that the ion trapping agent is contained in an amount of 0.3 to 4% by weight based on the resin.

The invention of claim 6 is characterized in that a dual ion exchange type is used as the ion trapping agent. The invention according to claim 7 is characterized in that an antimony-bismuth-based ion trapping agent is used as the ion trapping agent of both ion exchange type. The invention according to claim 8 is characterized in that, as the ion trapping agent, a cation exchange type and an anion exchange type are used in combination.

According to the invention of claim 9, a cation exchange type ion trapping agent selected from zirconium type and antimony type is used as an anion exchange type ion trapping agent, and bismuth type and magnesium-aluminum type. It is characterized in that each selected from the above is used. A laminated board according to the present invention is characterized by being obtained by laminating and molding the above prepreg and a metal foil.

A multilayer laminate according to the present invention is characterized by being obtained by laminating and molding the above prepreg and the above laminate.

[0014]

Embodiments of the present invention will be described below. In the present invention, the aramid fiber (wholly aromatic polyamide fiber) is not particularly limited, but may be polyparaphenylene terephthalamide (PPTA) represented by the chemical structural formula (1) above, or (2) above. ) Copolyparaphenylene 3, represented by the chemical structural formula
4'oxydiphenylene terephthalamide (PPODT
A) can be used. In the present invention, a non-woven fabric or woven fabric made of this aramid fiber is used as a substrate.

Thermosetting resins and thermoplastic resins in general can be used as the resin to be contained in the base material. Among them, an epoxy resin having a low cost and good adhesiveness, and a polyphenylene oxide having a small dielectric constant can be used. It is preferable to use a resin. Then, a prepreg can be prepared by impregnating a base material with a resin varnish such as an epoxy resin or a polyphenylene oxide resin and heating and drying, but in the present invention, an ion trapping agent is further contained.

As the ion trapping agent, there are ion exchange resins and inorganic ion exchangers, but it is preferable to use inorganic ion exchangers in consideration of heat resistance and chemical resistance. Also, since the ions to be captured include cations and anions,
It is desirable to use both ion exchange type inorganic ion exchangers, or to use a cation exchange type inorganic ion exchanger and an anion exchange type inorganic ion exchanger together.

As the both ion exchange type inorganic ion exchangers, antimony-bismuth type ones can be used. For example, "IXE-" from Toa Gosei Kagaku Kogyo Co., Ltd. can be used.
It is possible to use those provided as "600", "IXE-633", and "IXE-680". As the cation exchange type inorganic ion exchanger, a zirconium-based one or an antimony-based one can be used. For example, the former are "IXE-100" and "IXE-150" from Toa Gosei Chemical Industry Co., Ltd. , The latter provided by Toa Gosei Kagaku Kogyo Co., Ltd. as "IXE-300" can be used. As the anion-exchange type inorganic ion exchanger, a bismuth-based one or a magnesia-aluminum-based one can be used. For example, the former is “IXE-5” from Toa Gosei Chemical Industry Co., Ltd.
00 ”and“ IXE-550 ”, the latter is“ IXE-7 ”from Toa Gosei Chemical Industry Co., Ltd.
The one provided as "00" can be used.

The method of introducing the ion scavenger is most preferably a method of scraping the ion scavenger at the stage of making a nonwoven fabric from aramid fibers, but it is recommended to coat the aramid fiber nonwoven fabric or woven fabric with the ion scavenger. Alternatively, it may be carried out by applying a resin containing an ion scavenger to a non-woven fabric or woven fabric of aramid fibers and impregnating the resin.

The larger the amount of the ion trapping agent, the higher the ion trapping effect can be expected. However, when the amount of the ion scavenger is large, the heat resistance and chemical resistance of the printed wiring board may be deteriorated. Therefore, in the present invention, the amount of the ion scavenger is in the range of 0.3 to 4% by weight with respect to the resin. It is preferable to set so that When both the cation exchange type and the anion exchange type are used together, the ratio of the cation exchange type and the anion exchange type ion trapping agents is in the range of 2: 8 to 5: 5 by weight. It is preferable to set.

As described above, a prepreg containing a non-woven fabric or woven fabric of aramid fiber as a base material and containing a resin and an ion scavenger can be obtained. The prepreg has a resin content of 53 to 56% by weight. It is preferable to prepare so that. Then, a plurality of the prepregs are stacked, a metal foil such as a copper foil is further stacked on one side or both sides of the prepreg, and this is heat-pressed to obtain a metal foil-clad laminate. The heating and pressurizing conditions vary depending on the type of resin compounded on the substrate, but the temperature is 180 to 1
90 ° C., pressure 30 to 50 kg / cm ² , time 90 to 10
It is preferably set to 0 minutes.

The metal foil of the metal foil-clad laminate obtained as described above can be processed into a printed wiring board by exposing, developing, etching, etc. to form a circuit. Then, using the printed wiring board thus formed with a circuit as an inner layer material, stacking a plurality of the above prepregs and further stacking a metal foil such as a copper foil on the prepreg, and heat-pressing under the same conditions as above. Thus, a multi-layer laminated board can be obtained. Further, a metal foil on the surface of the multi-layer laminate is exposed, developed, and etched to form a circuit, which can be processed into a multi-layer printed wiring board.

In the printed wiring board manufactured as described above, since the base material is made of aramid fiber, it easily absorbs moisture. When copper foil is used as the metal foil, copper absorbs moisture.
Under the applied conditions, it becomes ions and migration easily occurs, and when an epoxy resin is used as the resin,
Similarly, anions represented by hydrolyzable chlorine easily migrate, and as an aramid fiber, PPT
When A is used, ions contained in a large amount due to the manufacturing process also easily migrate. However, in the present invention, since the ion trapping agent is contained, it is possible to prevent these ions from being trapped by the ion trapping agent and causing the migration of ions, and to prevent conduction between circuits due to migration. It is possible to prevent and improve the reliability of electrical insulation under moisture absorption.

[0023]

EXAMPLES Next, the present invention will be specifically described with reference to examples. (Example 1) 10 parts by weight of cresol novolac type epoxy resin ("YDCN-220" manufactured by Tohto Kasei Co., Ltd.),
Epoxy resin with 3 parts by weight of brominated bisphenol A type epoxy resin ("YDB-500K" manufactured by Tohto Kasei Co., Ltd.), 0.9 parts by weight of dicyandiamide as a curing agent, and 0.2 parts by weight of benzyldimethylamine as a curing accelerator. Both ion-exchange type inorganic ion exchangers (“IXE-600” manufactured by Toagosei Kagaku Kogyo Co., Ltd.) were added to the composition in an amount of 1% by weight based on the solid content of the epoxy resin composition, and 50% by weight of methyl ethyl ketone as a solvent was added to the composition. An epoxy resin varnish was prepared by adding and mixing parts.

A PPTA type aramid fiber non-woven fabric ("Amount" manufactured by DuPont) was coated with the above epoxy resin varnish to impregnate it and heated at 160 ° C for 7 minutes to give a resin amount of 55% by weight. I got a prepreg. Next, 8 sheets of this prepreg were stacked, and copper foil having a thickness of 35 μm was stacked on each side of the prepreg, and this was placed at 180 ° C. for 4 hours.
A double-sided copper-clad laminate having a thickness of 0.8 mm was obtained by heat-press molding under conditions of 0 kg / cm ² and 90 minutes.

(Example 2) Instead of "IXE-600", a cation exchange type inorganic ion exchanger ("IXE-300" manufactured by Toa Gosei Chemical Industry Co., Ltd.) and an anion exchange type inorganic ion exchanger (Toa). Synthetic Chemical Industry Co., Ltd. "IXE-800") was added in an amount of 0.5% by weight (1.0% by weight in total) based on the solid content of the epoxy resin composition. A prepreg having a resin content of 55% by weight was produced in the same manner as in 1. and a double-sided copper-clad laminate was obtained in the same manner as in Example 1 using this prepreg.

(Example 3) A prepreg having a resin amount of 55% by weight was prepared in the same manner as in Example 1 except that a PPDODTA type aramid fiber non-woven fabric ("Technora Part No. TP-72" manufactured by Teijin Limited) was used as the base material. Was prepared, and using this prepreg, a double-sided copper-clad laminate was obtained in the same manner as in Example 1.

(Example 4) 30 parts by weight of polyphenylene oxide ("Noryl PX9701" manufactured by Japan GE Co., Ltd.), 5 parts by weight of styrene-butadiene block copolymer ("Sorprene T406" manufactured by Asahi Kasei Kogyo Co., Ltd.), as a crosslinkable monomer 35 parts by weight of triallyl isocyanurate (“TAIC” manufactured by Nippon Kasei Co., Ltd.), 2,5-dimethyl-2,5-di (t-butylperoxy) hexane as a reaction initiator (“P” manufactured by NOF Corporation)
H25B ") 1 part by weight of the polyphenylene oxide resin composition was mixed with 1 wt% of the same ion-exchange type inorganic ion exchanger as in Example 1 based on the polyphenylene oxide resin composition, and trichloroethylene was added as a solvent to the polyphenylene oxide resin composition. By adding 70 parts by weight and mixing,
A polyphenylene oxide resin varnish was prepared.

Then, a PPTA type aramid fiber woven fabric (“Kevlar” manufactured by DuPont) was coated with the above epoxy resin varnish to impregnate it and heated at 130 ° C. for 10 minutes to give a resin amount of 55% by weight. I got a prepreg. Next, 8 pieces of this prepreg were piled up, and copper foil having a thickness of 35 μm was piled up on each side of the prepreg, and this was placed at 180 ° C.
A double-sided copper-clad laminate having a thickness of 0.8 mm was obtained by heat-press molding under conditions of kg / cm ² and 90 minutes.

Comparative Example 1 A prepreg was produced in the same manner as in Example 1 except that the inorganic ion exchanger was not used, and a double-sided copper-clad laminate was obtained in the same manner as in Example 1. (Comparative Example 2) The cation exchange type inorganic ion exchanger ("IXE-300") and the anion exchange type inorganic ion exchanger ("IXE-800") were compounded in 0.05 wt% increments (total of 0. 1% by weight), except that the prepreg was manufactured in the same manner as in Example 2 and further in the same manner as in Example 2 to obtain a double-sided copper-clad laminate.

COMPARATIVE EXAMPLE 3 A cation-exchange type inorganic ion exchanger ("IXE-300") and an anion-exchange type inorganic ion exchanger ("IXE-800") were added in an amount of 2.0% by weight ( A prepreg was produced in the same manner as in Example 2 except that the total amount was changed to 4.0% by weight, and a double-sided copper-clad laminate was obtained in the same manner as in Example 2.

COMPARATIVE EXAMPLE 4 Without using the anion exchange type inorganic ion exchanger ("IXE-800"), only the cation exchange type inorganic ion exchanger ("IXE-300") was 1.0% by weight. Except that it was mixed with the blending amount of
A prepreg was prepared in the same manner as in Example 2, and a double-sided copper-clad laminate was obtained in the same manner as in Example 2.

With respect to the double-sided copper-clad laminates A of Examples 1 to 4 and Comparative Examples 1 to 4 obtained as described above, the copper foil on one side was etched to form a 150 μm wide line of 150 μm.
A pair of comb-shaped circuits 1 and 1 having a pattern as shown in FIG. 2 arranged in parallel through an m-width space are provided, and the copper foil on the other surface is entirely removed by etching (FIG. 1 (a)). One prepreg 2 (the same prepreg used for manufacturing the laminated plate A) is provided on the surface provided with the comb-shaped circuit 1 of FIG. 1B.
As shown in the above, and this is 180 ° C, 40 kg / cm ² , 9
As shown in FIG.
A hygroscopic insulation evaluation sample B having a thickness of 0.2 mm as shown in (c) was prepared.

The terminal portion 1a is exposed so that electricity can be applied to the comb-shaped circuits 1 and 1 of the moisture absorption / insulation evaluation sample B, and the moisture absorption / insulation evaluation sample B is subjected to moisture absorption conditions of a humidity of 85% RH and a temperature of 85 ° C. Application of 30 V to the comb-shaped circuits 1 and 1 was continuously performed for the time shown in Table 1, and the moisture absorption insulation resistance between the comb-shaped circuits 1 and 1 was measured with an insulation resistance meter. The results are shown in the column of moisture absorption insulation resistance in Table 1.

Further, the above moisture absorption / insulation evaluation sample B was made to absorb moisture under the conditions of humidity 85% RH and temperature 85 ° C. for the time shown in Table 1, and then immersed in a solder bath at 260 ° C. for 20 seconds to obtain the moisture absorption insulation evaluation sample B. Was observed. The results are shown in the column of solder heat resistance in Table 1 as "x" indicating the occurrence of blisters and "○" indicating the absence of blistering.

[0035]

[Table 1]

As shown in Table 1, in Comparative Example 1 in which the ion scavenger was not mixed, the moisture absorption insulation resistance was drastically reduced.
Continuity occurred after 00 hours, but in each of the examples containing an ion scavenger, the decrease in moisture absorption insulation resistance was small. In Comparative Example 2 in which the amount of the ion scavenger is small, the effect of preventing a decrease in insulation resistance due to moisture absorption is insufficient, and the amount of the ion scavenger is too large in Comparative Example 3
It is confirmed that the heat resistance of the above-mentioned ones is lowered. Furthermore, when only a cation-exchange type ion-trapping agent is used as in Comparative Example 4, the effect of preventing a decrease in moisture absorption insulation resistance is insufficient, and as in Example 2, anion-exchange type It is confirmed that it is necessary to use the ones together.

[0037]

As described above, according to the present invention, the non-woven fabric or woven fabric of aramid fibers is made to contain the resin and the ion trapping agent, so that the aramid fiber easily absorbs moisture, but the ions are trapped by the ion trapping agent. Therefore, the migration of ions can be suppressed, and the conduction between circuits due to the migration can be prevented to improve the reliability of electrical insulation under moisture absorption.

Further, in the present invention, since the epoxy resin or the polyphenylene oxide resin is used as the resin, the prepreg excellent in cost and adhesiveness can be produced by the epoxy resin, and the polyphenylene oxide resin is used. A prepreg having a low dielectric constant can be produced. Further, in the present invention, since the ion trapping agent is contained in an amount of 0.3 to 4% by weight based on the resin, it is possible to sufficiently trap the ions without lowering the heat resistance.

Further, in the present invention, the ion trapping agent is of the double ion exchange type, so that both cations and anions can be trapped, and the effect of trapping ions can be enhanced. It is possible. Further, in the present invention, as the ion trapping agent, a cation exchange type and an anion exchange type are used in combination, so that both cations and anions can be trapped.
It is possible to obtain a high ion trapping effect.

[Brief description of drawings]

FIG. 1 shows a moisture absorption insulation evaluation sample,
(A), (b), (c) is a schematic sectional drawing, respectively.

FIG. 2 is a schematic plan view showing a comb-shaped circuit of a moisture absorption insulating evaluation sample.

[Explanation of symbols]

 1 comb-shaped circuit 2 prepreg A laminated board B moisture absorption insulation evaluation sample

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location C08K 3:10 C08L 63:00 71:12 (72) Inventor Tomoyuki Fujiki 1048 Kadoma, Kadoma, Osaka Prefecture Address Matsushita Electric Works Co., Ltd. (72) Inventor Koichi Ito 1048, Kadoma, Kadoma-shi, Osaka Address Matsushita Electric Works Co., Ltd.

Claims (11)

[Claims] 1. A prepreg characterized by comprising a non-woven fabric or a woven fabric of aramid fibers and containing a resin and an ion scavenger. 2. The prepreg according to claim 1, wherein the aramid fiber has the following chemical structural formula. Embedded image (M is set to a value such that the weight average is 30,000 to 70,000) 3. The prepreg according to claim 1, wherein the aramid fiber has the following chemical structural formula. Embedded image (M and n are set to numerical values such that the weight average is 30,000 to 70,000) 4. The prepreg according to claim 1, wherein an epoxy resin or a polyphenylene oxide resin is used as the resin. 5. An ion scavenger is added to the resin in an amount of 0.3-4.
The prepreg according to any one of claims 1 to 4, wherein the prepreg is contained in a weight percentage. 6. The prepreg according to any one of claims 1 to 5, wherein a dual ion exchange type is used as the ion scavenger. 7. The prepreg according to claim 6, wherein an antimony-bismuth-based ion scavenger is used as the both ion exchange type ion trap. 8. The prepreg according to claim 1, wherein a cation exchange type and an anion exchange type are used together as the ion scavenger. 9. A cation exchange type ion scavenger selected from zirconium type and antimony type, and an anion exchange type ion scavenger selected from bismuth type and magnesium-aluminum type. The prepreg according to claim 8, which is used respectively. 10. A laminated plate obtained by laminating and molding a prepreg according to any one of claims 1 to 9 and a metal foil. 11. A multi-layer laminate obtained by laminating and molding the prepreg according to any one of claims 1 to 9 and the laminate according to claim 9.