JPH11309808A - Metal foil with adhesive, prepreg with metal foil, and laminated plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a laminated plate which does not cause air pollution, can save resources, and is good and stable in quality at low costs. SOLUTION: In a laminated plate, at least on one side of sheet-shaped copper foil, copper foil with a resin containing a powdered thermosetting resin composition in which a powdered thermosetting resin and a powdered curing agent are used as indispensable components, or a prepreg with copper foil obtained by laminating a sheet-shaped fiber backing is laminated on the copper foil with a resin is used. Preferably, as the powdered thermosetting resin composition, a substance in which mechanical energy is given to each powdered component, and the surfaces of powder particles are fused is used. In a multilayer laminated plate, the prepregs with copper foil are laid to overlap each other and heated/pressed. In the production method, the laminated plates and the multilayer laminated plates are produced continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated board and a multilayer laminated board which are particularly suitable for printed circuit boards used for electric equipment, electronic equipment, communication equipment and the like.

[0002]

2. Description of the Related Art As for printed circuit boards, demands for downsizing and high functionality are becoming stronger, but price competition is fierce. In particular, multilayer laminated boards, glass cloth base epoxy resin laminated boards, and glass nonwoven fabrics used for printed circuit boards are particularly important. The composite laminate having a structure in which is used as an intermediate layer base material and a glass woven fabric is used as a surface layer base material, and which is impregnated with an epoxy resin and molded by heating and pressurizing, has a major problem of cost reduction. In recent years, measures against global warming and reduction of environmental pollution have been required. Conventionally, a large amount of solvent has been used in a process of manufacturing a prepreg or a laminated board used for these in view of resin impregnation of the base material and uniformity of the resin. On the other hand, this large amount of solvent evaporates in the coating and drying step and is released to the atmosphere as it is without being present in the product, or it is treated by a combustion treatment device and released to the atmosphere as carbon dioxide gas or the like. Therefore, there is a problem that causes air pollution and global warming. On the other hand, it has been difficult to reduce the amount of solvent and thereby reduce the cost due to manufacturing problems such as resin impregnation of the base material.

As a technique for eliminating the solvent, studies have been made to heat-mix a low-melting resin or a liquid resin to uniformly mix and apply the coating. However, the heating temperature during continuous production cannot be sufficiently uniform. Due to the decrease, solidification in the equipment and gelation of the thermosetting resin at the time of heating and difficulty in cleaning of the equipment due to this cause difficulty in continuous production. On the other hand, when the powdery resin is applied as it is, there is a problem that uniform mixing and application cannot be performed, and partial curing occurs and impregnation of the substrate cannot be performed.

[0004]

SUMMARY OF THE INVENTION The present invention has been studied to obtain a laminate or a multilayer laminate using a solventless resin, which has been conventionally difficult to produce. And that the powder composition undergoes a mechanochemical reaction to achieve uniform mixing and the impregnation of the substrate to the same level as the resin using conventional solvents. To complete the present invention.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a resin-attached metal foil characterized in that a powdery resin or a resin composition is present on the surface of the metal foil. The composition is a powder in which each component is a powder, and these are subjected to mechanical energy to cause surface fusion between powder particles by a mechanochemical reaction, or a heat-curable resin and a curing agent are kneaded or melt-mixed. Then, a prepreg with a metal foil, which is finely pulverized, and a sheet-like fiber substrate is superimposed on the resin side of the metal foil with a resin, and heated, and the prepreg with a metal foil described above. Use one or two sheets, or combine them with a prepreg in which a metal fiber and / or resin is impregnated in a sheet-like fiber base material, and press and heat so that the metal foil is the outermost layer. Laminate according to claim relates.

Furthermore, a powdery resin or a resin composition is present on the surface of the metal foil to obtain a resin-coated metal foil, and a sheet-like fiber base material is superposed on the resin side of the resin-coated metal foil, and heated. To obtain a prepreg with a metal foil, and then combine one or two of the prepreg with a metal foil, or the prepreg with the metal foil, a prepreg in which a metal fiber and / or a resin is impregnated into a sheet-like fiber base material, The method for producing a laminate according to claim 6, wherein the foil is the outermost layer, and a method for producing a laminate, wherein the laminate is heated and pressed, and the steps are performed continuously.
It is about.

In the present invention, the resin used is generally a thermosetting resin, such as an epoxy resin,
Polyimide resin, polyester resin, phenol resin,
Melamine resins and their modified resins are preferably used, but other resins such as thermoplastic resins and natural resins are also used, and are not limited thereto. As the thermosetting resin, an epoxy resin is desirable, but in addition, a polyimide resin, a polyester resin, a phenol resin, or the like can be used. When the thermosetting resin is an epoxy resin, the curing agent in the form of powder is preferably an aromatic amine-based resin or a novolak resin-based resin, but may be an acid anhydride-based resin. Further, it is preferable to use a powdery curing accelerator. As such a curing accelerator, an imidazole type, a tertiary amine type, a phosphine type or the like can be used. These components are not limited to those described above.

In the case where the powdery thermosetting resin composition is a powdery material obtained by applying a mechanical energy to a mixture of the powdery thermosetting resin and the curing agent to cause a mechanochemical reaction, Is preferably in the form of a powder, but when the blending amount is small (for example, 20% by weight or less based on the resin), the mixture may be in a liquid state, and can be used as long as the mixture with the resin can be powdered after applying mechanical energy. is there. Also,
Preferably, a curing accelerator is used. The curing accelerator is preferably in the form of a powder, but a liquid accelerator can also be used as described above.

The particle size of these powders is usually 100
0 μm or less, preferably 0.1 to 500 μm, more preferably 0.1 to 200 μm. This is because if the particle size exceeds 1000 μm, the surface area with respect to the particle weight becomes small, the number of contact points of each component such as a thermosetting resin, a curing agent and a curing accelerator decreases, and uniform dispersion becomes difficult. It may react at a different ratio than the target ratio,
There is a possibility that a uniform reaction is not performed. For the mechanochemical reaction, when the curing agent and / or the curing accelerator is in a powder form, the particle size of the thermosetting resin is preferably 5 to 15 times the particle size of the curing agent and / or the curing accelerator. This is because the curing agent and / or the curing accelerator are easily fused to the thermosetting resin in this range. Further, an additive such as an inorganic filler can be blended if necessary.

[0010] The modification by mechanochemical reaction is "a modification of a solid by a solid, which utilizes the surface activity of particles by grinding, grinding, friction, and contact, and surface appliances. The activity itself is a crystal form. In some cases, the dissolution or thermal decomposition rate is modified by increasing the transition energy or strain energy, or mechanical strength or magnetic properties are obtained. In other cases, surface activity is used for reaction or adhesion with other substances. Uses mechanical impact energy to perform not only physical modification but also chemical modification such as adhesion by electric charge or magnetism by friction, contact, embedding of modifier in nuclear material, formation of film by melting, etc. ("Overview of Practical Surface Modification Technologies" edited by the Material Technology Research Association, Industrial Technology Service Center, published March 25, 1993, p786)
Things. The present invention utilizes chemical modification by a mechanochemical reaction, but also includes a case where a solid and a liquid are chemically modified by mechanical energy.

[0011] Powder processing methods for applying mechanical energy for the mechanochemical reaction include Raikai machines, Henschel mixers, planetary mixers, ball mills,
There is mixing or kneading by a jet mill, an ong mill, a multi-stage mill-type kneading extruder or the like. Among these, Ongmill (Mechanofusion method manufactured by Hosokawa Micron Corporation),
Mixing or kneading with a multi-stage mill-type kneading extruder (manufactured by KCK Corporation: mechanochemical dispersion method, etc.) or a jet mill (manufactured by Nara Machinery Works, Ltd .: hybridizer method, etc.) is preferred. In order to perform it efficiently, a multi-stage mill-type kneading extruder (K
CK: Mechanochemical dispersion method).

In order to carry out the mechanochemical reaction, the softening point of the thermosetting resin is preferably 50 ° C. or higher, more preferably 70 ° C. or higher, and further preferably 80 ° C. or higher. This is because heat of about 20 to 50 ° C. is generated due to friction, pulverization, and fusion between the powders or between the powder and the processing apparatus during the above-mentioned processing, so that this influence is minimized. On the other hand, if the softening point is too high, an effective mechanochemical reaction is unlikely to be performed, and it is difficult to impregnate the base material with the resin composition in a later step. Each component such as a powdery thermosetting resin and a curing agent is preferably mixed as uniformly as possible with a Henschel mixer or the like after pulverizing to the above particle size in advance before powder treatment for mechanochemical reaction. .

The particle size of the powdery thermosetting resin composition subjected to the mechanochemical reaction is usually 1000 μm or less, preferably 0.1 to 500 μm, and more preferably 0.1 to 200 μm. Such a particle size is to improve the fluidity of the powder composition at the time of spraying or application, and to improve the flow and surface smoothness at the time of heating and melting, to improve the resin impregnation property of the base material, It is suitable for stabilizing the distribution of the resin composition.

In the case where the powdery thermosetting resin composition is a finely pulverized powder obtained by heat-kneading or melt-mixing a thermosetting resin and a curing agent, the thermosetting resin and the curing agent, if necessary, Along with additives such as inorganic fillers to be added, heat kneading or melt mixing by a heating roll or the like,
Next, it is finely pulverized by a pulverizer. As the thermosetting resin and the curing agent, solid materials are usually used, but components other than the thermosetting resin and the inorganic filler (for example, the curing agent and the curing accelerator) may be liquid. .

Apparatuses for heating kneading or melt mixing include a heating roll, a single-screw or twin-screw extruder, a heating kneader such as a co-kneader, a stirring vessel equipped with a heating device such as a Henschel mixer, a reactor, and the like. Practically, a heating roll, a single screw or twin screw extruder, and a Henschel mixer are preferable. The pulverizer may be any pulverizer that can finely pulverize the resin composition that has been heated and kneaded or melt-mixed, and examples thereof include a hammer mill, an atomizer, and a jet mill.

The particle size of the finely pulverized thermosetting resin composition is usually 1000 μm or less, preferably 0.1 μm or less.
1 to 500 μm, and more preferably 0.1 to 200 μm.
μm. Such a particle size is to improve the fluidity of the powder composition at the time of spraying or application, and to improve the flow and surface smoothness at the time of heating and melting, to improve the resin impregnation property of the base material, It is suitable for stabilizing the distribution of the resin composition.

As described above, an inorganic filler is added to the thermosetting resin composition used in the present invention in advance before a mechanochemical reaction occurs, or before heat kneading or melt mixing, as described above. can do. When an inorganic filler is added, characteristics such as tracking resistance, heat resistance, and a decrease in coefficient of thermal expansion can be imparted. Such inorganic fillers include aluminum hydroxide, magnesium hydroxide,
Examples include calcium carbonate, talc, wollastonite, alumina, silica, unfired clay, fired clay, and barium sulfate. These particle sizes are the same as above. In addition,
An additive such as a coupling agent may be blended.

In the present invention, the metal foil includes a copper foil, an aluminum foil, a stainless steel foil, a steel foil, a titanium foil, a gold foil, a silver foil, and the like. Generally, a copper foil is used from the viewpoint of conductivity, cost, and the like. The method for causing the resin powder to be present on the surface of the metal foil is not particularly limited, such as a method of sprinkling from the upper side of the metal foil, an electrostatic coating method, a fluid immersion method, a spraying method with a spray, and a coating method using various coaters. When the resin powder is present on the surface of the metal foil, the metal foil may be horizontal, vertical or oblique depending on the method of attachment. If the metal foil is heated to about 60 to 170 ° C. in advance, the resin powder adheres well when it is present on the metal foil, and when the subsequent sheet-like fiber base material is overlaid and heated, A good prepreg with a metal foil that penetrates well into the base material and has good impregnation properties can be obtained. The amount of the resin powder to be present in the metal foil varies depending on the fiber material, properties, and weight (per unit area) of the sheet-like fiber base material to be superposed, but is usually 40 to 60% of the weight of the sheet-like fiber base material. It is about.

From the resin-coated metal foil thus obtained, a prepreg with a metal foil is obtained by laminating a sheet-like fiber substrate on the resin side and heating. As a sheet-like fiber substrate, glass woven fabric, glass non-woven fabric,
In addition to glass fiber base materials such as glass paper, woven fabrics and nonwoven fabrics made of paper, synthetic fibers, and the like, woven fabrics, nonwoven fabrics, mats, and the like made of metal fibers, carbon fibers, mineral fibers, and the like. May be used alone or as a mixture. Of these, glass woven fabrics are the most common. The heating temperature may be a temperature at which the resin powder melts and impregnates the base material, and is usually 80 to 180 ° C. The heating time is
The resin powder melts, but hardening does not proceed substantially, and it takes about 1 to 30 minutes depending on the heating temperature. Up to the step of producing the prepreg with a metal foil, it can be usually continuously performed.

Next, the prepreg with a metal foil is formed into a metal foil-clad laminate by applying heat and pressure in the following configuration. In each case, the metal foil is configured to be the outermost. (1) Only one prepreg with metal foil (2) One prepreg with metal foil and metal foil (3) Two prepregs with metal foil (4) One prepreg with metal foil and one or more prepregs (5 ) Two prepregs with metal foil and one or more prepregs (6) One prepreg with metal foil and one or more prepregs with prepreg, where the conventional resin varnish is a sheet-like fiber base material A prepreg impregnated and dried may be used, but a prepreg impregnated into a sheet-like fiber substrate with the resin powder used in the present invention is preferable. The above-mentioned structure including the prepreg with a metal foil is heated and pressurized by an ordinary method. In the case of a simple structure, for example, in the case of the above (1), (2) or (3), a resin is attached. The process from the production of the metal foil to the formation of the laminate can be continuously performed.

As described above, while maintaining and improving the performance of the laminated board, it is possible to save resources and reduce air pollution by using no solvent, and to achieve cost reduction. The idea of the present invention is to apply the use of powdery components (resin, curing agent, etc.) and the mechanochemical reaction of each powdery component, and impregnate the resin on the metal foil into the sheet-like fiber substrate from one direction. Thus, good impregnation without voids could be performed. Such a technique makes it possible to uniformly bond and disperse the resin powder and to uniformly impregnate the sheet fiber substrate.

[0022]

Next, examples of the present invention will be specifically described together with comparative examples.

Example 1 (Hosokawa micron, sprayed) 100 parts by weight of a powdery epoxy resin having an average particle diameter of 150 μm (brominated epoxy resin Ep5048, manufactured by Yuka Shell Epoxy Co., Ltd., epoxy equivalent: 675), average particle diameter 15 μm
5 parts by weight of a powdery curing agent (dicyandiamide) and a powdery curing accelerator (2-ethyl-
4-methylimidazole) was pre-mixed at a ratio of 1 part by weight, and then mixed with a mechanofusion machine (AM-15F manufactured by Hosokawa Micron) at a rotation speed of 2,000 rpm.
After that, a powder composition having an average particle size of 150 μm was obtained. This powder composition was coated on one side of a copper foil having a thickness of 18 μm by 6 μm.
The mixture was evenly distributed with a 0-mesh sieve so that the resin weight became 100 g / m ² . 100g / m
After overlapping the glass woven fabrics of No. ^{2 with each} other, drying was performed from the copper foil side for 3 minutes with a dryer at 170 ° C. to obtain a prepreg with a copper foil.
On the prepreg side of this prepreg with copper foil,
8μm copper foil is superimposed, temperature 165 ℃, pressure 60k
g / cm ² for 90 minutes under heat and pressure.
mm copper-clad laminate was prepared.

Example 2 (Henschel mixer, spraying) A powdery epoxy resin having an average particle size of 150 μm (Ep
5048) 100 parts by weight, 5 parts by weight of a powdery curing agent (dicyandiamide) having an average particle diameter of 15 μm, and 1 part by weight of a powdery curing accelerator (2-ethyl-4-methylimidazole) having an average particle diameter of 15 μm The mixture was mixed at the same ratio, and then treated with a Henschel mixer at a rotation speed of 500 rpm for 5 minutes to obtain a powder composition having an average particle size of 150 μm. Hereinafter, using this powder composition, a copper-clad laminate having a thickness of 0.22 mm was produced in the same manner as in Example 1.

Example 3 (KCK, knife coater) A powdery epoxy resin having an average particle size of 150 μm (Ep
5048) 100 parts by weight, 5 parts by weight of a powdery curing agent (dicyandiamide) having an average particle diameter of 15 μm, and 1 part by weight of a powdery curing accelerator (2-ethyl-4-methylimidazole) having an average particle diameter of 15 μm Mixing, and then multi-stage mill-type kneading extruder (Mechanochemical dispersion system KCK-80X2-V manufactured by KCK Co., Ltd.)
Using (6)), the powder was treated at 200 rpm for 1 minute to obtain a powder composition having an average particle diameter of 150 μm. This powder composition was uniformly applied on one surface of a copper foil having a thickness of 18 μm using a knife coater so that the resin weight became 100 g / m ² . A 100 g / m ² glass woven fabric was overlaid on the resin-coated copper foil, and dried with a dryer at 170 ° C. for 3 minutes from the copper foil side to obtain a prepreg with the copper foil. After two sheets of this prepreg with copper foil were laminated with the copper foil on the outside,
It was heated and pressed at 65 ° C. under a pressure of 60 kg / cm ² for 90 minutes to produce a copper-clad laminate having a thickness of 0.42 mm.

Example 4 (KCK, Aerosil, knife coater) Powder composition 100 having an average particle size of 150 μm obtained in Example 3
1 part by weight of fine powdered silica (Aerosil # 200 manufactured by Nippon Aerosil) having an average primary particle diameter of 0.05 μm was added to the parts by weight, and the mixture was mixed with a Henschel mixer at 500 rpm for 5 minutes. Hereinafter, using this powder composition, a copper-clad laminate having a thickness of 0.42 mm was produced in the same manner as in Example 3.

Example 5 (Novolak, Roll, Knife Coater) A powdery epoxy resin having an average particle size of 150 μm (Ep
5048, epoxy equivalent 675) 100 parts by weight, powdered phenol novolak resin having an average particle diameter of 30 μm (PR-51470 manufactured by Sumitomo Durez, hydroxyl equivalent 105) 1
6 parts by weight and 1 part by weight of powdery triphenylphosphine having an average particle diameter of 10 μm are preliminarily mixed, and then, using two rolls having a diameter of 12 inches, a high-speed rotation speed of 20 rpm
m, high-speed roll temperature 60 ° C, low-speed roll temperature 30
After treatment at 30 ° C. and a rotation ratio of 1.5: 1 for 30 times, the mixture was taken out in a sheet form, cooled with cold air, and then pulverized with a fine pulverizer to obtain a powder composition having an average particle diameter of 200 μm. Hereinafter, using this powder composition, a thickness of 0.42 mm was obtained in the same manner as in Example 3.
Was produced.

Example 6 (Novolak, roll, Aerosil, knife coater) Powder composition 100 having an average particle size of 150 μm obtained in Example 5
1 part by weight of fine powdered silica (Aerosil # 200 manufactured by Nippon Aerosil) having an average primary particle diameter of 0.05 μm was added to the parts by weight, and the mixture was mixed with a Henschel mixer at 500 rpm for 5 minutes. Hereinafter, using this powder composition, a copper-clad laminate having a thickness of 0.42 mm was produced in the same manner as in Example 3.

Comparative Example 1 A powdery epoxy resin having an average particle size of 150 μm (brominated epoxy Ep50 manufactured by Yuka Shell Co., Ltd.)
48) 100 parts by weight, 5 parts by weight of a powdery curing agent (dicyandiamide) having an average particle diameter of 15 μm, and an average particle diameter of 15 μm
A mixture of 1 part by weight of a powdery curing accelerator (2-ethyl-4-methylimidazole) was mixed by hand for 5 minutes, and then heated at 100 ° C. to dissolve the powder. And a thickness of 1 so that the resin solid content is 100 g / m ^2.
A prepreg with a copper foil was obtained by applying the composition to an 8 μm copper foil, further laminating a 100 g / m ² glass woven fabric, and drying with a dryer at 170 ° C. for 2 minutes. A copper foil having a thickness of 18 μm is further laminated on the copper foil of the prepreg with the copper foil and the prepreg side, and heated and pressed at a temperature of 165 ° C. and a pressure of 60 kg / cm ² for 90 minutes to form a copper clad having a thickness of 0.22 mm. A laminate was prepared.

Comparative Example 2 A powdery epoxy resin having an average particle size of 150 μm (brominated epoxy Ep50 manufactured by Yuka Shell Co., Ltd.)
48) 100 parts by weight, 5 parts by weight of a powdery curing agent (dicyandiamide) having an average particle diameter of 15 μm, and an average particle diameter of 15 μm
Was mixed with 1 part by weight of a powdery curing accelerator (2-ethyl-4-methylimidazole) in 100 parts by weight of methylcellosolve. Copper The varnish was coated on a copper foil having a thickness of 18μm such that the 100 g / m ² of resin solids, was further dried for 2 minutes at 170 ° C. dryer by superimposing glass fabric of 100 g / m ² A prepreg with a foil was obtained. A copper foil having a thickness of 18 μm is further laminated on the prepreg side of the prepreg with the copper foil.
It was heated and pressed at a pressure of 60 kg / cm ² for 90 minutes to produce a copper-clad laminate having a thickness of 0.22 mm.

In the above Examples and Comparative Examples, for the prepreg, the impregnating property of the glass cloth with the resin was measured, and for the copper-clad laminate, the moldability, tensile strength, copper foil peeling strength, and solder heat resistance were measured. Properties and insulation resistance were measured. Table 1 shows the results.

[0032]

[Table 1]

[0033]

[Table 2]

(Measurement method) Impregnating property: The presence or absence of voids between glass fibers was confirmed with a prepreg under a stereoscopic microscope. 2. Formability: The copper foil of the copper-clad laminate is etched, and the presence or absence of precipitation of a curing agent or the like is visually observed to evaluate the dispersibility. 3. Tensile strength: Etching copper foil of copper clad laminate,
After cutting to 10 × 100 mm, the tensile strength was measured with Tensilon. 4. 4. Copper foil peel strength: JIS C 6481 Solder heat resistance: A laminate of 50 x 50 mm square was converted to 260
The sample was floated in a solder bath at a temperature of 3 ° C. for 3 minutes, and the presence or absence of blister was measured. 6. Insulation resistance: Measured according to JIS C6481.

Regarding the manufacturing cost, the method of the embodiment does not use a solvent, and thus the obtained laminate is the same as that of the comparative example 2.
The cost could be reduced by about 30 to 40% as compared with the one obtained in the above. In Comparative Example 1, the curing characteristics of the resin significantly changed with time in the step of melting the resin at 100 ° C., and the resin adhered to the equipment hardened, making cleaning difficult.

[0036]

According to the method of the present invention, since no organic solvent is used, there is no air pollution and resources can be saved. In particular, good impregnation without voids can be performed by impregnating the resin on the metal foil into the sheet-like fiber base material from one direction, so that a good laminated board with stable quality can be obtained. It is excellent in terms of cost reduction, and is suitable as an industrial method for manufacturing a laminate.

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI B29K 105: 08

Claims (7)

[Claims] 1. A metal foil with a resin, wherein a powdery resin or a resin composition is present on the surface of the metal foil. 2. The resin-coated metal foil according to claim 1, wherein the powdery resin composition is obtained by applying mechanical energy to each component to cause the surface of the powder particles to be fused by a mechanochemical reaction. 3. The metal foil with resin according to claim 1, wherein the powdery resin composition is obtained by kneading or melt-mixing a thermosetting resin and a curing agent and then pulverizing the mixture. 4. A prepreg with a metal foil, wherein a sheet-like fiber base material is superposed on the resin side of the metal foil with a resin according to claim 1, and heated. 5. The prepreg according to claim 4, wherein one or two prepregs are used, or a prepreg obtained by impregnating a metal fiber and / or a resin into a sheet fiber base material is combined with the prepreg. Characterized in that the laminate is heated and pressed. 6. A powdered resin or a resin composition is present on the surface of a metal foil to obtain a metal foil with a resin, and a sheet-like fiber base material is superimposed on the resin side of the metal foil with a resin and heated. To obtain a prepreg with a metal foil, and then combine one or two of the prepregs with a metal foil, or the prepreg with a metal foil, with a prepreg obtained by impregnating a metal fiber and / or a resin into a sheet fiber base material, And heating and pressurizing the laminate so as to be the outermost layer. 7. The method according to claim 6, wherein each of the steps is performed continuously.