JPH0734498B2 - 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 high-frequency laminate 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, a laminate using an epoxy resin or an imide resin is known as a laminate having a large interlayer adhesive force and a metal foil adhesive force, and poly-4-fluoroethylene resin is an excellent one for high frequency performance. The one used is 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 laminated board 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 is excellent in high frequency performance,
It has the drawback of being extremely expensive.

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 laminated plate, while utilizing the characteristics of the resin substrate for a polyphenylene oxide-based laminated plate, the interlayer adhesion and metal An object of the present invention is to provide a laminated plate which 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.
Keeping at 40 ℃ or higher
170 ~ 190 after primary lamination molding with metal foil at temperature of 140 ℃
Provided is a method for manufacturing a high-frequency laminate, which comprises performing secondary lamination molding at a temperature of ° C.

The polyphenylene oxide used for the resin of 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. Is. This polyphenylene oxide has, for example, the following general formula (1): (R represents hydrogen or a hydrocarbon having 1 to 3 carbon atoms, and each R may be the same or different.) As an example thereof, 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 this invention, in order to improve its heat resistance, chemical resistance, processability, and dimensional stability without impairing the high-frequency performance of the resin of the laminate, the resin composition containing the polyphenylene oxide as described above A crosslinkable polymer and / or monomer having excellent performance is contained.

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 laminated plate 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 present invention, the polyphenylene oxide, the crosslinkable polymer and / or the above polyphenylene oxide is used in order to reduce the shrinkage during curing of the resin composition to reduce the internal stress and improve the interlayer adhesive force and the metal foil adhesive force of the laminate. Other than monomers,
Further, a crosslinkable prepolymer is 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 laminated plate 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. Then, this blending ratio is considered as a general range also in blending other kinds 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. In order to impart appropriate flexibility to the cured resin and improve the interlaminar adhesive strength and metal foil adhesive strength of the laminated board, the resin composition is kept at a temperature (varnish temperature) of 40
It is used at a temperature of not less than ℃, preferably not less than 55 ℃. That is,
A sheet substrate is formed from the resin composition heated to 40 ° C. or higher, 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.

For example, when forming a sheet substrate from a resin composition, a casting method can be used. 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. By using the casting method, it is possible to obtain a cured product at a relatively low temperature without using the costly calendering 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 a polyethylene terephthalate (hereinafter abbreviated as "PET") film, a polyethylene film, a polypropylene film, a polyester film, a polyimide film, or the like which is insoluble in the solvent is preferable, and Those subjected to 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.

The sheet, prepreg, and core material formed from the resin composition are then laminated and integrated with other base material, film, prepreg, metal foil, etc. to produce a laminated plate.

In this invention, in order to promote sufficient wetting of the resin composition on the surface of the metal foil and subsequent curing, and to promote the unification of the resin of the laminated board, first, the resin component is in a molten state without curing. Primary molding is performed at a temperature of 70 to 140 ° C. Next, secondary molding is performed at 170 to 190 ° C. for complete curing. The time of this primary molding and secondary molding depends on the constituent components of the resin composition, the thickness of the laminate, etc., but in general,
The primary molding can be for 10-40 minutes and the secondary molding for 60-120 minutes. In the case of thermally crosslinking the resin composition, since the progress of the crosslinking reaction also depends on the reaction temperature of the initiator used, the heating conditions for the primary molding and the secondary molding are:
It is determined according to the type of the initiator within the above range.

As the metal foil for forming a circuit used when forming a laminated board, those used for a normal wiring board 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 may be combined so as to have a predetermined design thickness. According to the above, a metal foil is also combined and laminated. When performing heat pressing, primary molding is performed at 70 to 140 ° C as described above, and secondary molding is further performed at 170 to 190 ° C, sheets to each other, sheets to prepregs or core materials, prepregs to each other, sheets to metal. The foil, prepreg and metal foil are adhered to each other to form a laminated plate. By this heat fusion, strong adhesion can be obtained, but if the crosslinking reaction by the radical initiator is caused by heating at this time, even stronger adhesion can be obtained. In addition,
Such adhesion may be performed by using an adhesive together.

Here, there is a combination when a sheet, a prepreg, and a core material are used together, but there is no particular limitation, but a vertically symmetrical combination is effective in preventing warpage after molding and secondary processing (etching, etc.). preferable. 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.

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 performed by stacking a predetermined number of sheets and / or prepregs in advance and heating and pressing, and then superposing a metal foil on one or both surfaces of the sheet and then heating and pressing again. Good.

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

Further, in this manufacturing method, the resin composition contains a crosslinkable prepolymer so that the shrinkage upon curing is small,
Since the internal stress is reduced, the interlaminar adhesive strength and the metal foil adhesive strength of the laminate are improved. Further, the resin composition is heated to 40 ° C. or higher to allow the molecular chain of the polymer component to have a sufficient spread and then cured, thereby improving the interlayer adhesive strength and the metal foil adhesive strength of the laminate. .

In addition, the heating and pressing at the time of forming the laminated plate is
Since primary molding is performed at 140 ° C, the resin component is in a molten state without being cured, and it is possible to sufficiently wet the resin composition on the surface of the metal foil before curing, and also to promote integration of the resin. it can. Then, after such primary molding is performed, secondary molding is performed at 170 to 190 ° C. to completely cure the resin, so that the interlayer adhesive strength and the metal foil adhesive strength of the laminated plate are further improved.

Next, examples will be shown to further explain the method for manufacturing a high frequency laminate 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, and
As shown in (1), primary molding was performed at a temperature of 115 ° C. and a pressure of 30 kg / cm ² for 30 minutes, and then secondary molding was performed at a temperature of 180 ° C. and a pressure of 30 kg / cm ² for 100 minutes to obtain a laminated plate.

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 comparison with Comparative Examples described later shown in Table 1, this laminated plate was excellent in high frequency characteristics, and was also extremely excellent in copper foil adhesive force and interlayer adhesive force.

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 laminate, and (b) shows a metal foil.

Comparative Examples 1 and 2 Using the resin compositions shown in Table 1, laminated plates were prepared in the same manner as in the above examples without primary molding. In Comparative Example 2, the holding temperature when impregnating the glass cloth with the resin composition was set to 20 ° C.

Similarly, the physical properties of the laminated plate were evaluated. The results are also shown in Table 1. The characteristics were far inferior to the examples.

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.

Molding was performed under the same primary molding and secondary molding conditions and the characteristics thereof were evaluated, and excellent results as shown in Table 3 were obtained.

Comparative Examples 3 to 4 Corresponding to Examples 6 to 10, without performing primary molding, pressure was applied.
It was molded under the conditions of 20 kg / cm ² , 180 ° C. and 110 minutes. As shown in Table 2, without using the crosslinkable prepolymer, the laminate (Comparative Example 3) and the resin composition were kept at a temperature of 25 ° C. to impregnate the laminate base material, and then without primary molding. The performance of the molded laminated plate (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.

(Effect of the Invention) By the method of the present invention, a high-frequency laminate having excellent high-frequency performance can be obtained.

This high-frequency laminated plate is heated and pressed in two stages of primary molding at 70 to 140 ° C and secondary molding at 170 to 190 ° C.
The adhesive strength between the metal foil and the interlayer is remarkably excellent.

In addition, this high frequency laminated plate is a
Since an expensive component such as 4-fluoroethylene resin is not 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) Reference JP 62-149728 (JP, A) JP 57-203548 (JP, A) JP 60-166331 (JP, A)

Claims (6)

[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 to impregnate into a molding or substrate, and then at a temperature of 70 to 140 ° C. A method for producing a laminate for high frequency, which comprises performing primary lamination molding with a metal foil and then secondary lamination molding at a temperature of 170 to 190 ° C. 2. 60 to 120 after primary lamination molding for 10 to 40 minutes
The method for producing a high-frequency laminate according to claim 1, wherein the secondary laminate molding is performed for one minute. 3. The method for producing a high frequency laminate according to claim 1, wherein the crosslinkable polymer is a styrene-butadiene copolymer and / or polystyrene. 4. The method for producing a high frequency laminate according to claim 1, wherein the crosslinkable monomer is triallyl isocyanurate and / or triallyl cyanurate. 5. The method for producing a laminate for high frequencies according to claim 1, wherein the crosslinkable prepolymer is a triallyl isocyanurate prepolymer and / or a triallyl cyanurate prepolymer. 6. 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 manufacturing a high frequency plate according to claim 1, further comprising a part by weight.