JPH0734497B2 - Method for manufacturing high frequency laminated plate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a high frequency laminated plate. More specifically, the present invention relates to a method for producing a laminated board which is useful as a laminated board for high frequencies, which is excellent in high frequency characteristics, interlayer adhesion and metal foil adhesion.

(Prior Art) Wiring laminates for electrical and electronic equipment such as precision equipment, electronic calculators, and communication equipment are required to have large interlaminar adhesive strength and metal foil adhesive strength as basic properties. With high-density mounting and higher speed, excellent high-frequency performance (dielectric constant ε, dielectric tangent tan δ) is also required.

Conventionally, as a resin substrate for a laminated board having a large interlayer adhesive force and a metal foil adhesive force, a resin substrate using an epoxy resin or an imide resin is known, and a resin substrate excellent in high frequency performance is poly-4-fluorine. Those using a chlorinated ethylene resin are known.

Furthermore, the inventor of the present invention has found that polyphenylene oxide resin, a crosslinkable polymer, and / or a crosslinkable polymer can be used as a resin substrate for a new laminated board that has excellent dielectric properties even in an ultrahigh frequency region and has excellent dimensional stability. A substrate produced from a composition containing a crosslinkable monomer and an inorganic filler has also been proposed (JP-A-62-149728).

(Problems to be Solved by the Invention) However, a resin substrate using an epoxy resin or an imide resin has excellent interlayer adhesiveness and metal foil adhesiveness and can secure sufficient moldability, but is inferior in high frequency performance. Have a point. On the other hand, the one using poly-4-fluoroethylene resin has a drawback that it is extremely expensive although it has excellent high frequency performance.

Compared to these resins, the laminated board produced from the polyphenylene oxide resin composition as described above is excellent in high frequency characteristics, has less dimensional change during molding, and is very practical in terms of good dimensional stability. It is useful. Therefore, this polyphenylene oxide resin is highly expected to provide a laminate having excellent high frequency performance.

However, in the case of this polyphenylene oxide-based resin laminate, there is a problem that the interlayer adhesive force and the metal foil adhesive force are poor, and this point has been a major problem to be solved practically.

The present invention has been made in view of the above circumstances, solves the problem of the conventional resin substrate, while utilizing the characteristics of the resin substrate for the polyphenylene oxide-based laminate, the interlayer adhesion and metal It is an object of the present invention to provide a laminated board using a new resin substrate that has a large foil adhesive force, is excellent in high frequency performance, and can be manufactured at low cost.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a resin composition containing polyphenylene oxide, a crosslinkable polymer and / or a monomer, and a crosslinkable prepolymer.
Provided is a method for producing a laminated plate for high frequency, which is characterized in that it is formed or impregnated into a base material while being kept at 40 ° C. or higher and laminated and integrated with a metal foil.

Polyphenylene oxide used as a resin substrate in the high-frequency laminate of the present invention is a thermosetting resin having a relatively high glass transition point, a low dielectric constant and a low dielectric loss, and has been attracting attention in recent years because it is inexpensive. It is a thing. This polyphenylene oxide has, for example, the following general formula (1): (R represents hydrogen or a hydrocarbon group having 1 to 3 carbon atoms,
Each R may be the same or different. ), One example of which is poly (2,6
-Dimethyl-1,4-phenylene oxide) can be mentioned.

The molecular weight is not particularly limited, for example,
Weight average molecular weight (Mw) 10,000 to 80,000, molecular weight distribution Mw
A preferable one is /Mn=2.0 to 6.0 (Mn is a number average molecular weight).

In the manufacturing method of the present invention, its heat resistance, chemical resistance, workability, without impairing the high frequency performance of the resin of the resin substrate,
In order to improve the dimensional stability, the resin composition containing the polyphenylene oxide as described above contains a crosslinkable polymer and / or a monomer excellent in high frequency performance.

Examples of the crosslinkable polymer include 1,2-polybutadiene, 1,4-polybutadiene, styrene-butadiene copolymer, polystyrene, modified 1,2-polybutadiene (malein-modified, acrylic-modified, epoxy-modified), and rubbers. Each can be used alone or in combination of two or more. The state of these polymers may be elastomer or rubber. Particularly preferable examples include styrene-butadiene copolymer and / or polystyrene.

However, when the resin substrate of the present invention is manufactured using a sheet by a casting method described later, it is preferable to use polystyrene having a relatively high molecular weight from the viewpoint of improving the film forming property of the sheet.

Examples of the crosslinkable monomer include acrylates such as ester acrylates, epoxy acrylates and urethane acrylates, and polyfunctional compounds such as triallyl cyanurate, triallyl isocyanurate, ethylene glycol dimethacrylate, divinylbenzene and diallyl phthalate. Examples thereof include monomers, monofunctional monomers such as vinyltoluene and ethylvinylbenzene, and polyfunctional epoxies, which can be used alone or in combination of two or more kinds.

Of these, triallyl cyanurate and / or triallyl isocyanurate are preferable because they have good compatibility with polyphenylene oxide and improve film formability, crosslinkability, heat resistance and dielectric properties. This triallyl cyanurate and triallyl isocyanurate have an isomer relationship in terms of chemical structure, and have almost the same film-forming property, compatibility, solubility, reactivity, etc., so both are used in the same manner. can do.

The above-mentioned crosslinkable polymer and crosslinkable monomer,
Only one of them may be used, or both may be used together, but the combined use is more effective in improving the characteristics.

In the method of the present invention, the shrinkage during curing of the resin composition is reduced to reduce the internal stress, and to improve the interlayer adhesion and the metal foil adhesion of the laminate, the polyphenylene oxide, the crosslinkable polymer and In addition to the monomer and / or the monomer, a crosslinkable prepolymer is further contained in the resin composition.

As the crosslinkable prepolymer, the prepolymer of the above-mentioned crosslinkable monomer can be used, and in particular, triallyl cyanurate prepolymer and triallyl isocyanurate prepolymer can be preferably used.

When curing such a resin composition, an initiator can be used.

The type of initiator is appropriately selected depending on whether the resin composition is an ultraviolet curable type or a thermosetting type. In that case, a single type of initiator may be used, or a plurality of types of initiators may be used. Further, an ultraviolet curing type initiator and a thermosetting type initiator may be used in combination.

Needless to say, the resin composition used for the resin substrate of the present invention may contain various additives as long as its properties are not impaired. For example, brominated polyphenylene oxide, brominated bisphenol type polycarbonate or the like can be contained as a flame retardant. Further, in order to control the dielectric constant and improve the shaping property, an inorganic powder such as a ceramic dielectric powder can be contained, and further, in order to prevent the embrittlement of the resin when the inorganic powder is contained, a glass is used. A fibrous reinforcing material such as fiber or aramid fiber may be contained.

The blending ratio of such a resin composition can be determined according to the type of the crosslinkable polymer, the crosslinkable monomer, the crosslinkable prepolymer used together with the polyphenylene oxide, the molding method applied to the resin composition, and the like. For example, 10 to 70 parts by weight of polyphenylene oxide, 30 parts by weight or less of styrene-butadiene copolymer and / or polystyrene, 10 to 60 parts by weight of triallyl isocyanurate and / or triallyl cyanurate, preallyl isocyanurate prepolymer and / or triary. A composition containing 5 to 40 parts by weight of the lucyanurate prepolymer can be exemplified as a preferable example. And this compounding ratio is considered as a general range also in the compounding of other types of crosslinkable polymers, crosslinkable monomers and crosslinkable prepolymers.

Further, the blending ratio of the initiator to be added in addition to such blending is preferably 0.1 to 5 parts by weight (more preferably 0.1 to 3 parts by weight). If the proportion of the initiator is less than the above range, curing of the polyphenylene oxide resin composition may be insufficient, and if it exceeds the above range, physical properties after curing may be adversely affected.

The resin composition as described above is usually dissolved in a solvent to obtain a dispersion mixed state (varnish). As the solvent, halogenated hydrocarbons such as trichloroethylene, trichloroethane, chloroform, methylene chloride and chlorobenzene, aromatic hydrocarbons such as benzene, toluene and xylene, acetone, carbon tetrachloride and the like can be used, and particularly, such as benzene and toluene. Aromatic hydrocarbons are preferred. These may be used alone or in admixture of two or more.

Such a resin composition can be shaped into various desired shapes including a sheet by molding or impregnating a base material. In the present invention, the molecular chain of the polymer component is allowed to have a sufficient spread. , The temperature of the resin composition (varnish temperature) in order to impart appropriate flexibility to the cured resin and improve the interlayer adhesive strength of the resin substrate and the metal foil adhesive strength.
Is used at 40 ° C. or higher, preferably 55 ° C. or higher.

There is no particular limitation on the method of forming the resin substrate as long as the resin composition is heated to 40 ° C. or higher before use. That is, a sheet substrate is formed from the resin composition, or a base material is impregnated with the resin composition to form a prepreg, and if necessary, a core material or the like is manufactured from the sheet substrate or the prepreg, and then they are added to another substrate. The materials, films, prepregs, metal foils, etc. are laminated in a multilayer manner by a conventional method.

In this case, the sheet substrate from the resin composition, for example,
It can be formed by a casting method. The casting method is a method in which a resin composition mixed with a solvent is cast or applied to form a thin layer, and then the solvent is removed to cure the resin composition. According to the casting method, a cured product can be obtained at a relatively low temperature without using the costly calendar method. This casting method will be described more specifically. For example, a resin composition in a state of being mixed with a solvent is applied onto a mirror-treated iron plate or a carrier film for casting, for example, 5 to 70%.
A sheet is obtained by casting or coating to a thickness of 0 (preferably 5 to 500) μm and sufficiently drying to remove the solvent.

The casting carrier film is not particularly limited, but polyethylene terephthalate film, polyethylene film, polypropylene film, polyester film, polyimide film and the like which are insoluble in the above solvent are preferable, and those subjected to a release treatment are preferable.

Drying is performed by air drying or hot air drying. In this case, it is preferable that the upper limit of the temperature range is lower than the boiling point of the solvent or lower than the heat resistant temperature of the casting carrier film (when drying is performed on the casting carrier film). The lower limit is determined by the drying time and processability. For example, when using trichlorethylene as a solvent and PET film as a carrier film for casting, room temperature to 80 ° C
It is preferable that the range is up to. If the temperature is raised within this range, the drying time can be shortened.

When the base material is impregnated with the resin composition to produce a prepreg, the following method can be generally adopted.

That is, the resin composition is dispersed in a solvent, and the base material is dipped in the solvent dispersion to impregnate the base material with the resin composition and adhere it thereto. Then, the solvent is removed by drying or the like or semi-cured to obtain the B stage. The impregnated amount of the resin composition in this case is not particularly limited, but is preferably 30 to 80% by weight. The substrate is not particularly limited, for example, glass cloth,
Resin-impregnated cloth-like materials such as aramid cloth, polyester cloth and nylon cloth, mat-like materials made of these materials and / or fibrous materials such as non-woven fabric, and paper such as kraft paper and linter paper can be used.
Since such a prepreg does not need to melt the resin, it can be easily manufactured at a relatively low temperature.

As a metal foil for forming a circuit used when forming a resin substrate, those used for ordinary wiring boards can be widely used. For example, a metal foil such as a copper foil or an aluminum foil can be used. In this case, a metal foil having a smooth adhesive surface and good conductivity is preferable for improving the dielectric property.

Such a metal foil can be formed by vapor deposition or the like, but may also be formed as a desired conductor (circuit, electrode, etc.) by a subtractive method, an additive method (full-additive method, semi-additive method) or the like. Good.

As a method for forming a laminated sheet using a core material, a sheet, and a prepreg manufactured from a resin composition, for example, a predetermined number of sheets and / or prepregs that have been appropriately dried are combined to have a predetermined design thickness, and necessary. According to the above, the metal foil is also combined and laminated, and the resin is melted by heating and pressing, and the sheets are bonded together, the sheet and the prepreg or the core material, the prepregs together, the sheet and the metal foil, and the prepreg and the metal foil are bonded to each other. To make a laminated plate. By this fusion, strong adhesion can be obtained, but if heating at this time is caused to cause a crosslinking reaction by a radical initiator, even stronger adhesion can be obtained. Note that such adhesion may be performed by using an adhesive together.

Here, the combination of the sheet, the prepreg, and the core material used in combination is not particularly limited, but a vertically symmetrical combination is preferable from the viewpoint of preventing warpage after molding and secondary processing (etching or the like). Further, it is preferable to combine them so that the sheet comes to the adhesive interface with the metal foil, because the adhesive force can be improved.

The temperature at the time of heat pressing depends on the combination of the metal foil and the sheet or the prepreg, but for example, the adhesion between the metal foil and the sheet can utilize the heat fusion property of the sheet, so the laminating pressing temperature is the glass of the sheet. Above the transition point, about 160
It is preferably in the range of about 300 ° C. Further, when the resin composition is thermally crosslinked, the crosslinking reaction depends on the reaction temperature of the initiator used, and therefore the heating temperature and the heating time are determined according to the type of the initiator. For example, temperature 150
~ 300 ℃, time is about 10-60 minutes.

Clamping is performed for joining sheets, for sheets and prepregs, for prepregs, for joining metal foils and sheets, for joining metal foils and prepregs, and for adjusting the thickness of the laminated plate. For example, the pressure can be about 20 to 70 kg / cm ² .

The heating and pressing as described above may be carried out by heating and molding a predetermined number of sheets and / or prepregs in advance, superposing a metal foil on one or both surfaces thereof, and then heating and pressing again.

(Operation) By the manufacturing method of the present invention, a resin substrate having excellent high frequency performance can be obtained.

Further, since this resin composition contains a crosslinkable prepolymer, shrinkage upon curing is small and internal stress is reduced, so that the obtained laminate has improved interlayer adhesion and metal foil adhesion strength. Becomes

Furthermore, by heating this resin composition to 40 ° C. or higher and using it to form a laminated plate, the molecular chain of the polymer component in the resin composition can be sufficiently spread and cured, The interlayer adhesive strength of the plate and the metal foil adhesive strength are further improved.

Next, examples will be shown to further explain the high frequency resin substrate of the present invention.

Examples 1 to 5 With the formulations shown in Table 1, polyphenylene oxide, styrene butadiene copolymer (Sorprene T406: Asahi Kasei Corporation), triallyl isocyanurate monomer (m-TA
IC: Nippon Kasei Co., Ltd. or triallyl cyanurate monomer (m-TAC), triallyl isocyanurate prepolymer (p-TAIC) or triallyl cyanurate prepolymer (p-TAC), initiator (perbutyl P: Nippon Oil & Fats Co., Ltd. and toluene were mixed and sufficiently stirred until a uniform solution was obtained to obtain a resin composition.

Next, the resin composition was impregnated with glass cloth while keeping the temperature at 55 ° C. or higher and dried to prepare a resin cloth.

Laminate this resin cloth, place copper foil on both sides, 180
A laminate was obtained by pressure molding at 50 ° C. and 50 kg / cm ² for 100 minutes.

Each of the obtained laminated plates was evaluated for dielectric constant, dielectric loss tangent, solder heat resistance, copper foil adhesive force, and interlayer adhesive force.
The results are shown in Table 1.

As is clear from the comparison with Comparative Examples described below shown in Table 1, a laminate having excellent high frequency characteristics, and also excellent copper foil adhesive strength and interlayer adhesive strength was obtained.

The dielectric constant and the dielectric loss tangent were measured at 1 MHz as shown in FIGS. 1 and 2. In the figure, (a) shows a resin substrate and (b) shows a metal foil.

Comparative Examples 1 and 2 As shown in Table 1, a laminated sheet was prepared in the same manner as in the above-mentioned Examples using a resin composition containing no triallyl isocyanurate prepolymer (Comparative Example 1).

Further, a laminated board was produced in the same manner as in the above-mentioned Example using a resin composition having the same composition as in Example 2 except that the heat retention temperature of the resin composition was set to 25 ° C. (Comparative Example 2).

The physical properties of the laminated plates obtained in Comparative Examples 1 and 2 were evaluated in the same manner. The results are also shown in Table 1. The performance was far inferior to the example.

Examples 6 to 10 In the same manner as in Example 1, resin compositions having the formulations shown in Table 2 were produced to obtain laminated plates.

The characteristics were evaluated and excellent results as shown in Table 3 were obtained.

Comparative Examples 3-4 Corresponding to Examples 6-10, as shown in Table 2, in the case where the crosslinkable prepolymer was not used (Comparative Example 3), and the heat retention temperature of the resin composition was set to 25 ° C. The performance of the laminated plate impregnated with the material (Comparative Example 4) was also evaluated. As shown in Table 3, the adhesive strength was inferior in each case as compared with Examples 6-10.

(Effects of the Invention) According to the present invention, a laminate having excellent high frequency performance can be obtained.

This high-frequency laminate also has extremely excellent interlayer adhesion and metal foil adhesion.

In addition, this high frequency laminated plate is a
Since no expensive component such as 4-fluorinated ethylene resin in the related art is required, it can be manufactured at extremely low cost.

[Brief description of drawings]

FIG. 1 and FIG. 2 are a perspective view and a circuit diagram showing a method for measuring the dielectric constant and the dielectric loss tangent, respectively.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication H05K 3/00 R (72) Inventor Shuji Maeda 1048 Kadoma, Kadoma-shi, Osaka Matsushita Electric Works Co., Ltd. (72) Inventor Takayoshi Ozeki 1048, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd. (56) References JP 62-149728 (JP, A) JP 60-72933 (JP, A)

Claims (5)

[Claims] 1. A resin composition containing polyphenylene oxide, a crosslinkable polymer and / or a monomer, and a crosslinkable prepolymer is kept at 40 ° C. or higher while being molded or impregnated into a base material and laminated and integrated with a metal foil. A method for manufacturing a high-frequency laminated plate, comprising: 2. The method for producing a high frequency laminate according to claim 1, wherein the crosslinkable polymer is a styrene-butadiene copolymer and / or polystyrene. 3. The method for producing a high frequency laminate according to claim 1, wherein the crosslinkable monomer is triallyl isocyanurate and / or triallyl cyanurate. 4. The method for producing a high frequency laminate according to claim 1, wherein the crosslinkable prepolymer is a triallyl isocyanurate prepolymer and / or a triallyl cyanurate prepolymer. 5. A resin composition comprising polyphenylene oxide
10-70 parts by weight, styrene butadiene copolymer and /
Or polystyrene 30 parts by weight or less, triallyl isocyanurate and / or triallyl cyanurate 10 to 60
Parts by weight, triallyl isocyanurate prepolymer and / or triallyl cyanurate prepolymer 5-40
The method for producing a high-frequency laminate according to claim 1, wherein the method comprises a part by weight.