JPS587345A - Manufacture of metallic foil lined laminate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a metal foil clad laminate.

There are the following methods for producing a metal foil-clad laminate, particularly a copper-clad laminate using copper foil as the metal foil. That is, a resin with unsaturated bonds such as unsaturated polyester resin, diallyl phthalate prepolymer, vinyl ester resin, etc. is diluted with vinyl monomer, a polymerization initiator is further added to create an unsaturated resin face, and this is impregnated into the base material. A resin-impregnated base material that will become the substrate of the copper-clad laminate is prepared. Next, there is a method in which a plurality of resin-impregnated substrates are stacked, and then copper foil is stacked and passed through a roll to laminate, and then heated under no pressure to produce a copper-clad laminate. This method does not involve placing the steel foil and resin-impregnated base material on top of one another in a press and applying heat and pressure (pressure molding method), but instead heats them under no pressure (non-pressure molding method). Continuous production is possible because the steel clad laminate is manufactured using the following method. However, a steel clad laminate obtained by directly stacking steel foil on a resin-impregnated base material does not have sufficient beer strength for use as a printed circuit board because of poor adhesion between the copper foil and the substrate. Furthermore, even if the commercially available adhesive-coated copper foil used up to now was used, satisfactory results could not be obtained. That is, the above-mentioned adhesive-coated steel foil is for pressure molding, and even if it is used for pressureless molding, peeling occurs between the adhesive layer and the substrate.

Therefore, as a result of intensive research into solving these problems, the inventors dissolved vinyl ester resin in a crosslinking monomer to form a vinyl ester resin varnish, and applied it to copper foil as an adhesive. B by pre-curing
-stage state, and the content of crosslinking monomer in this n-stage vinyl ester IN resin varnish adhesive is 1
If a copper foil with an adhesive layer is prepared by setting the copper foil to 5% by weight or less, and a metal foil-clad laminate is manufactured using this, the metal foil-clad laminate has sufficient beer strength for use as a printed circuit board. This invention was discovered by discovering that the body can be improved.

That is, this invention laminates an adhesive-coated metal foil onto an unsaturated resin-impregnated base material with the adhesive side facing the unsaturated resin-impregnated base material, and heat-cures it under no pressure to form a metal foil. A method for producing a laminate, in which a vinyl ester resin varnish adhesive containing a crosslinking monomer as a solvent component is applied to the surface of the metal foil as an adhesive-coated metal foil and precured to form a B-stage shape. The gist thereof is to use an adhesive-attached metal foil in which the content of the crosslinking monomer component in the B-stage vinyl ester resin varnish adhesive is set to 15% by weight or less. be.

The vinyl ester resin varnish used as an adhesive in this invention includes a vinyl ester resin VR produced by reacting an epoxy resin with an unsaturated carboxylic acid, a vinyl monomer (styrene, acrylic acid, etc.), and a diallyl phthalate prepolymer.

It is dissolved in a crosslinking monomer such as trimethylolpropane triacrylate, and a polymerization initiator is added if necessary. This invention provides a B-stage state by applying such a vinyl ester resin varnish to a metal foil such as steel foil and pre-curing it, and controlling the content of crosslinking monomer components in this B-stage varnish. Adjust the weight to 15 weight 1 (hereinafter abbreviated as "chi") (it may be adjusted at the same time as B-stage, or it may be adjusted afterwards) to make an adhesive-coated metal foil, and then By using it, the intended purpose is achieved.

Epoxy resin adhesives have excellent adhesion to copper foil and the like, but their curing speed is significantly different from that of unsaturated resin varnishes in resin-impregnated base materials. Therefore, timing of adhesion between the adhesive layer and the resin-impregnated base material is difficult, and peeling phenomenon is likely to occur during this time.

However, vinyl ester resin varnish has a curing speed that is comparable to that of unsaturated resin varnish in a resin-impregnated base material.
Does not cause the above problems. However, even if this is used unconditionally, the intended purpose cannot be achieved. That is, a vinyl ester resin dissolved in 50 to 25% of a crosslinking monomer (mostly styrene) is commercially available as a vinyl ester resin liquid, but even if this solution is used as it is, the intended purpose cannot be achieved. The reason why large amounts of crosslinking monomers are used in commercially available products is to lower the viscosity of highly viscous liquid or solid vinyl ester resins and improve workability (and reduce costs). Commercially available products containing such a large amount of crosslinking monomer cannot achieve good adhesion because the large amount of crosslinking monomer inhibits adhesion to metals. Furthermore, simply reducing the content of the crosslinking monomer does not provide a good adhesion state. In other words, when the amount of crosslinking monomer is reduced, the viscosity of the vinyl ester resin varnish increases and its flowability against copper foil etc. decreases. A mixing phenomenon occurs between the varnish and the unsaturated resin varnish in the resin-impregnated base material, making it impossible to obtain a good adhesive state. Note that if a solvent is used to lower the viscosity of the vinyl ester resin, the solvent cannot be completely removed after it is applied to a copper foil or the like and before it is laminated onto a resin-impregnated base material. Blisters occur between copper foil, etc. Therefore, if this is done, K also has a problem.

In order to achieve good adhesion without causing the above problems, K applies vinyl ester resin varnish to metal foil such as steel foil, and then heat-treats the applied varnish to B-stage. At the same time, the content of the crosslinking monomer in the varnish in this state was adjusted to 5% or less to produce an adhesive-coated metal foil, and this was used to form a metal foil-clad laminate. The goal is to manufacture the product. That is, by applying a vinyl ester resin varnish to a metal foil such as copper foil and subjecting it to heat treatment (B-staging), the amount of crosslinking monomer can be reduced while maintaining the flowability of the vinyl ester resin varnish to the metal foil. It also prevents the occurrence of mixing phenomenon with the unsaturated resin varnish in the resin-impregnated base material when the metal foil is laminated on the resin-impregnated base material and heated and cured. . the result,
It becomes possible to obtain a metal foil-clad laminate having sufficient beer strength to be used as a printed circuit board.

As for the resin-impregnated base material that becomes the substrate of the metal foil-clad laminate, as before, unsaturated polyester resin, diallyl phthalate prepolymer, An unsaturated resin such as vinyl ester resin is diluted with styrene, diallyl phthalate, acrylic monomer, etc. as necessary, and is impregnated with an unsaturated polyester resin varnish containing a polymerization initiator. . Further, examples of the metal foil include copper foil, aluminum foil, stainless steel foil, etc., but copper foil is usually used. Furthermore, a commonly used method is used to manufacture the metal foil-clad laminate in the present invention. For example, ``a predetermined number of resin-impregnated base materials are stacked, a metal foil having a B-stage vinyl ester resin varnish adhesive layer is layered on top of that, passed through a roll, and the metal foil is cured by heating under no pressure. Continuous production of metal foil clad laminates is carried out. Continuous production of such metal foil clad laminates is usually carried out by continuously transporting a plurality of base materials, impregnating them with unsaturated resin varnish, and then impregnating them with resin-impregnated base materials. Overlapping materials and laminating metal foil.

Continuous heat curing equipment and metal foil lamination)K
This is done using manufacturing equipment that combines a device that continuously applies vinyl ester resin varnish to the metal foil in advance and a heating device that pre-cures the applied vinyl ester resin varnish so that these devices work together. be exposed.

In order to produce a metal foil-clad laminate as described above, the present invention provides a metal foil-clad laminate having sufficient beer strength to be used as a printed circuit board while achieving resource and energy saving. It can be manufactured continuously.

Next, examples will be explained together with comparative examples.

First, the following five types of vinyl ester resin varnishes 3 to d were prepared.

(For vinyl ester resin varnish) Vinyl ester resin (manufactured by Showa Kobunshi Co., Ltd., Lipoxy R-8
40DA): 100 parts by weight (hereinafter abbreviated as "parts") (manufactured by NOF Corporation, Bark Mill H-81 = 1.
5-part crosslinking monomer (styrene) [0% (relative to resin, same below) (vinyl ester resin varnish b) Vinyl ester resin (Lipoxy R-840DA)
: 100 parts hardening agent (manufactured by Kayaku Turley Co., Ltd., hardening agent 8
28E): 1.0 //Styrene
:80j (Vinyl ester resin varnish C) Vinyl ester resin (manufactured by Showa Kobunshi Co., Ltd., Lipoxy H-6
00): 100 parts〃 (Percmill H-80), 1.
5//Styrene 280q
Ib (vinyl ester resin varnish d) Same composition as vinyl ester resin varnish 1, but removed from styrene under vacuum Styrene: 15%
The following two types of unsaturated polyester resin varnishes were prepared.

(Unsaturated polyester resin varnish A) Unsaturated polyester resin (manufactured by Nippon Shokubai Co., Ltd., Eboratsuku N
-18B): 100 parts BPO = l tt (Unsaturated polyester resin varnish B) Unsaturated polyester resin (manufactured by Dainippon Ink Co., Ltd., FG-
104'): 50 copiestt (tt
, FG-208): 5 G'/BI'O: 1
/1 Next, a copper-clad laminate was obtained using the above raw materials in the following manner.

[Examples 1 to 6] Kraft paper treated with melamine in a conventional manner (melamine l
Five sheets (containing O) were impregnated with unsaturated polyester resin varnishes A and B shown in the table below, and these were stacked to form a stacked body. On the other hand, on one side of the 85 μ thick steel foil,
After applying the vinyl ester resin varnish I-C shown in the table below to the thickness shown in the same table, the adhesive is bonded by placing it in a dryer at the temperature shown in the table for a predetermined period of time and heat-treating it to B-stage. We made copper foil coated with the agent. Next, this adhesive-coated copper foil was laminated on the stacked body with the adhesive surface thereof facing the surface of the stacked body. At this time, a 50 μm thick polyester film was laminated on the back side of the stacked body. Then, this was heated and cured in a dryer at 120° C. for 10 minutes and then in a dryer at 150° C. for 80 minutes to obtain a single-sided steel-clad laminate having a fin thickness of 1.6±0.05.

[Comparative Examples 1 and 2] After applying vinyl ester resin varnish to copper foil, it was laminated in an A-stage state without pre-curing. Other than that, single-sided steel clad laminates were obtained in the same manner as in Example 1.6.

[Comparative Example 8] A single-sided steel clad laminate was obtained in the same manner as in Example 1 except that the preliminary curing conditions were 90° C./2 minutes. Although the vinyl ester resin varnish was semi-cured under the above pre-ill curing conditions, the styrene content was as high as 20 Jt.

[Conventional Example 1] Copper foil can be used as is without applying vinyl ester resin varnish. A single-sided steel clad laminate was obtained in the same manner as in Example 1 except for the above.

[Conventional Example 2] After applying vinyl ester resin varnish d to copper foil, the varnish was laminated in an A-stage state without pre-curing. Other than that, a single-sided steel clad laminate was obtained in the same manner as in Example 1.

The results of the performance test of the single-sided steel clad laminate obtained as described above are also shown in the table below. As is clear from the table, the single-sided steel clad laminates obtained in the Examples have significantly superior beer strength and solder heat resistance compared to those of the Comparative Examples and Conventional Examples.

(Margins below) Note: In Examples 1 to 6 and Comparative Example 8, it was confirmed as follows that the adhesive was B-staged by preliminary curing. That is, the precured adhesive-coated copper foil was immersed in a methyl ethyl ketone solution for 5 minutes, air-dried, and the presence or absence of an adhesive layer on the surface of the copper foil was determined using an optical microscope.

Note 2: The styrene content after pre-curing was determined using a gas mass analyzer.

Patent applicant Matsushita Electric Works Co., Ltd. Agent: Patent Attorney Takehiko Matsumoto

Claims (1)

[Scope of Claims] (1) An adhesive-coated metal foil is laminated on an unsaturated resin-impregnated base material with the adhesive side facing the unsaturated resin-impregnated base material, and heat-cured under no pressure. A method for manufacturing a metal foil-clad laminate, wherein a vinyl ester resin face adhesive containing a crosslinking monomer as a solvent component is applied to the metal foil surface as an adhesive-attached metal foil, pre-cured, and B-staged. The content of the crosslinking monomer component in this B-stage vinyl ester resin face adhesive is 15% by weight.
A method for manufacturing a metal foil clad laminate, characterized by using adhesive-backed metal foil set below. (2) The unsaturated resin is an unsaturated polyester resin. The method for producing a metal foil clad laminate according to claim 1, wherein the resin is at least one resin selected from the group consisting of diallyl phthalate resin and vinyl ester resin. (8) Claim 1 or 2, wherein the crosslinking monomer is at least one crosslinking monomer selected from the group consisting of vinyl monomer, diallyl phthalate prepolymer, and trimethylolpropane triacrylate. A method for manufacturing metal foil laminates.