JPH01190734A - Thermoplastic resin prepreg and its laminate - Google Patents

Abstract

PURPOSE:To obtain the title prepreg which can give a laminate excellent in electrical properties, peeling strength of copper foil and interlaminar adhesiveness and suitable as a printed wiring board, by impregnating a substrate with an epoxy resin and a fluorocarbon resin-containing thermosetting resin composition so as to form a plurality of, for example, alternate layers. CONSTITUTION:An epoxy resin is optionally mixed with a curing agent such as an amine and dissolved in an organic solvent such as acetone to obtain an epoxy resin varnish (A). A thermosetting resin composition such as a polyaminobismaleimide resin or an epoxy resin containing 0.1-10wt.% fluorocarbon resin such as polytetrafluoroethylene or tetrafluoroethylene/ hexafluoropropylene copolymer is dissolved in an organic solvent such as MEK to obtain a varnish (B) of said composition. A substrate prepared from a glass fiber, an organic synthetic fiber such as a polyamide or a polyester or a (non) woven fabric thereof or the like is impregnated with components A and B so as to form a plurality of layers in a sequence of component A component B, component B component A or component A component B component A, or the like and dried.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a thermosetting resin prepreg, which is a material for a laminate used as a printed wiring board, and a thermosetting resin formed by laminating a plurality of sheets of the prepreg. This relates to laminates.

[Prior art] Conventionally, as a substrate for wiring boards used in the electrical and electronic fields, a laminate of prepregs made by impregnating a base material with epoxy resin, polyimide resin, bismaleimide/triazine resin, etc. The board is in practical use. Such a laminate can be formed at a low temperature of 250° C. or lower, for example, and has good formability. However, it has a drawback that it has a high dielectric constant and is not suitable for high frequency applications. On the other hand, although polytetrafluoroethylene resin copper-clad laminates have been put into practical use as laminates with a low dielectric constant, the molding temperature is high at 300°C or higher, and the moldability is poor, and the thickness of the substrate When the thermal expansion coefficient is [X to -'/'c or more], it has an inherent drawback of poor thermal dimensional stability. Therefore, as a multilayer printed wiring board with high packaging density, there is a problem in that the connection reliability of the conductors is poor.

Under these circumstances, various improved metal foil-clad laminates have been proposed to eliminate the above-mentioned drawbacks. For example, a substrate made of a mixed system of tetrafluoroethylene resin powder and thermosetting resin such as epoxy resin has been proposed. Although it is well known, fluorine-based resins generally have poor affinity with thermosetting resins, and therefore have poor dispersibility, so prepregs are obtained by impregnating a base material with a mixed system with thermosetting resins. Even if this is laminated and molded as a laminate, there is a problem in that peeling, ie, delamination, is likely to occur at the interface between the thermosetting resin and the fluororesin. Furthermore, the adhesion to the metal foil is not sufficient.

[Problems to be Solved by the Invention] The present invention was made in view of the above-mentioned problems that the prior art had, and its purpose is to improve the thermal dimension by improving moldability and low expansion coefficient. A laminate for printed wiring boards that has excellent stability and is designed for reliability without causing delamination as a laminate for printed wiring boards while utilizing the excellent electrical properties of fluororesin. An object of the present invention is to provide a thermosetting resin prepreg and a thermosetting resin laminate thereof suitable for this purpose.

[Means for Solving the Problems] That is, the present invention is characterized in that a base material is impregnated with an epoxy resin and a thermosetting resin composition containing a fluororesin in multiple layers, and [A] an epoxy resin composition is impregnated with the base material. Resin → fluororesin-containing thermosetting resin composition.

[B] Fluororesin-containing thermosetting resin composition → epoxy resin.

or [C] a thermosetting resin prepreg formed by impregnating an epoxy resin → a fluororesin-containing thermosetting resin composition → an epoxy resin in this order to form an impregnated layer, and a plurality of sheets of at least one of the prepregs are laminated. The present invention provides a thermosetting resin laminate comprising:

In the fluororesin-containing thermosetting resin composition of the present invention, examples of the fluororesin contained include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), and tetrafluoroethylene-hexafluoropropylene. Polymer (FEP), polyvinylidene fluorolite (PVdF), polyvinyl fluoride (PVF), tetrafluoride ethylene-
Ethylene (polymer), chlorotrifluoroethylene-ethylene copolymer, tetrafluoroethylene-perfluorovinylether copolymer (PFA), etc. can be mentioned. Polytetrafluoroethylene (PTFEI) and tetrafluoroethylene-hexafluoropropylene copolymer (FEPI) are preferable.
It is not limited to specific species, and several species can be used in combination.

In the fluororesin-containing thermosetting resin composition, examples of the thermosetting resin include polyamino bismaleimide resin (addition type imide resin), bismaleimide triazine resin, synthetic resin, and unsaturated polyester. Resin, phenolic resin, urethane resin, acrylic resin, etc. are used.
I get Xed. Moreover, these can also be used in combination of two or more types. From the viewpoint of good heat resistance and electrical properties, preferred are polyamino bismaleimide resin, bismaleimide triazine resin, epoxy resin, and the like.

The proportion of the fluororesin contained in the fluororesin-containing thermosetting resin composition in the present invention is O1 to 10, preferably 0.2 to 5, based on the weight ratio of the thermosetting resin. If the proportion of the fluororesin is less than 0.1, the laminate obtained by laminating the prepregs will not have good electrical properties, while if it exceeds 10, the mechanical strength will be low.

When impregnating a base material with a fluororesin-containing thermosetting resin composition, an organic solvent such as acetone, MEK, DMF, NMP is used to suitably impregnate the base material.
It is prepared as a press by dissolving it alone or in a mixture.

Further, the epoxy resin used in the present invention is also prepared as a varnish, and amines as a hardening agent are blended therein, and the epoxy resin is made into a varnish using an organic solvent such as acetone.

Examples of the base material include inorganic fibers such as glass, asbestos, and silica fibers, organic synthetic fibers such as polynisdel, polyamide, polyvinyl alcohol, and acrylic, woven fabrics, nonwoven fabrics, or mats made of natural fibers such as cotton, and paper. Due to combinations, etc.
Any material that is generally used as a base material for laminates can be used without particular limitation. Particularly preferred are glass fiber woven fabric, nonwoven fabric, or paper.

The thermosetting resin prepreg in the present invention is impregnated into a multilayer by sequentially impregnating the base material with a varnish of the epoxy resin prepared as described above and the thermosetting resin composition containing a fluorine resin, and drying the varnish. A layer is formed, but the method for forming this multilayer is essentially [A], [B],
Or the following method is adopted for [C].

That is, in [A], the base material is impregnated in the order of epoxy resin → fluororesin-containing thermosetting resin composition, but the base material is first impregnated with epoxy resin varnish and dried, and then It is obtained by impregnating and coating the surface with a varnish of a thermosetting resin composition containing a fluororesin and drying.

In [B], the base material is impregnated in the order of fluororesin-containing thermosetting resin composition → epoxy resin. Obtained by impregnating and drying, then applying a press of epoxy resin to the impregnating and surface coating and drying.

[C] is obtained by impregnating the base material in the order of epoxy resin → fluorocarbon resin-containing thermosetting resin composite acid → epoxy resin, but the prepreg obtained in [A] above is further impregnated with epoxy resin. Obtained by impregnating and coating the surface with varnish and drying.

The method of impregnating the varnish as described above is carried out by a known method. Moreover, drying is for volatilizing the solvent of the varnish.

The amount of epoxy resin impregnated into the base material in the thus obtained prepreg is 2 to 50% by weight, preferably 5 to 30% by weight, based on the total amount of the obtained prepreg, and within this range, the laminate formed by laminate molding The most suitable properties can be imparted to the board. The amount of impregnation can be adjusted by adjusting the concentration of the resin or composition in the varnish. The amount of fluororesin-containing thermosetting resin composition impregnated is determined according to the amount of epoxy resin impregnated with respect to the total weight of the prepreg.

A plurality of sheets of the thermosetting resin prepreg of the present invention are laminated to form a thermosetting resin laminate. Furthermore, metal foil is laminated on one or both of the outer end surfaces and heat pressed.
A metal foil-clad laminate is produced by other methods. In laminating the prepreg as a laminate, the prepreg used is a plurality of each of the above [A], [B] and [C],
Or [A] and [B],, [A] and [C],
[B] and [C], [A], [B], and [C1 are each alternately or arbitrarily combined. Lamination can be carried out using commonly used equipment such as a heated lamination press. The conditions for lamination are, for example, when pressurized, the pressure is 30 to 70 kg/
cm2. The heating temperature is 150-200℃, and the time is 30℃.
Minutes to 2 hours is sufficient.

Materials for the metal foil include commonly used copper foil, aluminum foil, iron-based alloy foil, and the like.

The thermosetting resin laminate of the present invention thus obtained has excellent adhesiveness not only between prepregs but also with metal foils. Therefore, it can be suitably used as a printed wiring board with excellent electrical properties, mechanical strength, heat resistance, chemical resistance, etc. for electrical and electronic component applications.

[Function] In the thermosetting resin prepreg and its laminate of the present invention, the mechanism of action by which excellent properties, especially the effect of improving adhesion, are obtained is not necessarily clear, but the surface-inactive fluorine-based resin This is presumably due to the fact that the activity is supplemented by the epoxy resin.

[Examples] The present invention will be explained in more detail with reference to Examples, but it goes without saying that the present invention is not limited to these Examples.

Preparation Example 1 Preparation of epoxy resin varnish Epoxy resin made into a 30% solution by dissolving 25 parts (parts by weight, same below) of bisphenol A type epoxy resin with epoxy equivalent of 471, 1 part of dicyandiamide and 05 parts of benzyldimethylamine in acetone. A varnish was prepared.

Example 1 Polyamino bismaleimide resin (“Kelimide 601”)
: Nippon Polyimide Co., Ltd.)) and 70 parts of finely powdered polytetrafluoroethylene ("Fluon L17" : Asahi Glass Co., Ltd.) (thermosetting resin: fluorine thread resin = 3 = 7 weight ratio) were thoroughly mixed. A solution varnish of a fluororesin-containing thermosetting resin composition with a resin concentration of 40% was prepared using NMP/MEK.

Next, a 210 g/m2 glass cloth was impregnated with the epoxy resin varnish prepared in Preparation Example 1 and dried, and this was impregnated with the varnish of the fluororesin-containing thermosetting resin composition prepared above and dried. ]2 A prepreg was prepared by doing the following.

10 sheets of prepreg obtained in this way were laminated, and one sheet of copper foil with a thickness of 0.035 mm was placed on each of the top and bottom surfaces, and the pressure was 50 kg/cm'', the temperature was 180°C, and the temperature was 180°C for 1 hour. Pressure molding was carried out, followed by post-treatment at 250° C. for 124 hours to obtain a double-sided copper-clad laminate.The properties of this laminate were measured and the results are shown in Table 1.

Example 2 50 parts of bismaleide triazine resin (“Br3170”: manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 20% MEK organosol of polytetrafluoroethylene (“AG・1, ub”)
, a polytetrafluoroethylene sol manufactured by Asahi Glass Co., Ltd., in which the solvent was substituted with MliK) and 250 parts of (
A solution varnish of a thermosetting resin composition containing a fluororesin having a resin concentration of 33% was prepared (thermosetting resin: fluorine thread resin = 5:5 weight ratio).

Next, a 210 g/m2 glass cloth was impregnated with the epoxy resin varnish prepared in Preparation Example 1 and dried, and this was impregnated with the varnish of the fluororesin-containing thermosetting resin composition prepared above and dried. . Furthermore, the epoxy resin varnish prepared in Preparation Example 1 was impregnated into this "2" and dried to prepare a prepreg.

Ten prepregs obtained in this way were laminated, and one layer of copper foil with a thickness of 0.035 mm was placed on the lower surface of each layer.
A double-sided copper-clad laminate was obtained by arranging the sheets and press-molding them at a pressure of 50 kg/cm 2 and a temperature of 175° C. for 1 hour. Table 1 shows the properties of this laminate.

Example 3 Finely powdered polytetrafluoroethylene (
Add 26 parts of "Fluon 1169" (manufactured by Asahi Glass Co., Ltd.) (thermosetting resin, fluororesin - 1:1 weight ratio) and mix thoroughly with a spike cooler to form a fluororesin-containing thermosetting resin composition. A solution varnish was prepared.

A 210 g/m2 glass cloth was impregnated with this varnish and dried, and then impregnated with the epoxy resin varnish of Preparation Example 1 and dried to prepare a prepreg.

Ten prepregs obtained in this way were laminated, and one sheet of copper foil with a thickness of 0.035 mm was placed on each of the ten sides, and the pressure was 50 kg/cm2 and the temperature was 175°C.
A double-sided copper-clad laminate was obtained by pressure forming under certain conditions. The properties of this laminate are shown in Table 1.

Example 4 Five sheets of each of the prepregs produced in Example 2 and Example 3 were alternately laminated, and further a layer of 0 thickness was applied to the bottom surface of the prepregs.
．． One piece of copper foil of 0.035 mm was placed and the pressure was 50 kg
A double-sided laminate was obtained by pressure molding under the following conditions: cm2, temperature 180°C, ] time. Table 1 shows the properties of this laminate.

Comparison Examples 1 to 2 Prepregs were prepared in the same manner as in Examples 1 and 3, except that the epoxy resin varnish prepared in Preparation Example 1 was not impregnated in Examples 1 and 3, and these prepregs were used. A laminate was obtained. Table 1 shows the properties of these laminates.

Table 1 [Effects of the invention] When applied as a printed wiring board, the laminate formed by laminating multiple thermosetting resin prepregs of the present invention has excellent electrical properties, copper foil peel strength, and interlayer adhesion. The effect of being excellent in terms of sex is that agents (patent attorneys) are half good.

Claims (2)

[Claims] 1. A base material is impregnated with an epoxy resin and a thermosetting resin composition containing a fluororesin in multiple layers, and with respect to the base material, [A] Epoxy resin → thermosetting resin composition containing a fluororesin, [ B] Fluorine resin-containing thermosetting resin composition → epoxy resin, or [C] Epoxy resin → fluorine resin-containing thermosetting resin composition → epoxy resin impregnated in this order to form an impregnated layer. Polymer resin prepreg. 2. The epoxy resin and the fluororesin-containing thermosetting resin composition are impregnated in multiple layers, and the base material is [A] epoxy resin → fluororesin-containing thermosetting resin composition, [B] fluorine-based resin. A thermosetting resin prepreg formed by impregnating a resin-containing thermosetting resin composition → epoxy resin, or [C] epoxy resin → fluororesin-containing thermosetting resin composition → epoxy resin to form an impregnated layer. A thermosetting resin laminate formed by laminating a plurality of sheets of at least one type.