JPS5869044A - Copper lined laminated board - 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 improvements in copper-clad laminates.

In general, the manufacturing method for copper-clad laminates consists of using an uncrosslinked, uncured raw molded sheet mainly made of prepregs such as paper and phenol resin, glass and epoxy resin, paper and polyester, which can serve as the substrate, and generally an electrolytic foil. A method is used in which a primer or an adhesive is further applied to a 65 to 70 .mu.m thick surface of steel, and the materials are heated and pressed using a multi-stage press or a continuous pressure bonding method to integrate the materials.

However, the adhesive strength is on the order of 1 Kg/m, and the rate of decrease is large as can be seen in the peel strength at elevated temperature (Tl8-O-6480-6485).

In addition, conventional copper foil laminates use electrolytic copper foil as the copper foil and use the anchor effect as an adhesion method, but the formation of copper oxide (flower) in the bonding surface roughening process The powder becomes a bottleneck in the manufacturing process, and it also leads to unstable adhesion. Moreover, the problem lies not in the manufacturing process itself, but in the adhesive bonding method, and there is no margin for margin in product performance.

Another problem in addition to these is the problem of balancing the curing speed of the substrate and the curing speed of the adhesive itself in order to achieve complete adhesion. It is a known problem from experience that if these speeds cannot be balanced, adhesion cannot be achieved and is insufficient.

And, inevitably, an adhesive similar to that of the board can be considered,
When the adherend is copper, deterioration due to copper, and further, for example, as specified in JIS-0-6481 to 6485,
In order to satisfy various performance requirements, it is of course possible to use additives such as flame retardants in addition to the pace polymer and curing agent, and in general, the adhesion is generally lowered by the addition of additives.

However, flame retardants and lubricants that can leach from the surface must be avoided.

The present invention was made in view of the above-mentioned situation, and an object of the present invention is to provide a copper-clad laminate that can improve the adhesive strength, heat resistance, solvent resistance, and stress cracking resistance of the adhesive layer. be.

The copper-clad laminate of the present invention is made by laminating thin copper plates on a substrate made of paper, phenol resin, glass, epoxy resin, etc. with an adhesive layer of resin interposed therebetween, and the adhesive layer is cross-linked by electron beam irradiation. It is what it is.

Examples of the copper-clad laminate of the present invention will be described below.

When copper foil is bonded to paper, phenol resin, glass, epoxy resin, paper, polyester, or other substrate using silane-modified polyolefin or silane-modified polyolefin copolymer, J-Ko S-C! In the standards such as -6480 to 6485, the problem is that the adhesive layer is a thermoplastic resin, so there are problems with heat resistance, chemical resistance, oil resistance, and solvent resistance. In order to solve this problem, a crosslinked structure may be considered. The viscosity, average molecular weight, and branching of many polymers increase upon irradiation. These changes are based on the binding of two molecules to each other.

That is, crosslinking is a reaction in which side chain bonds are cleaved by radiation and new bonds are formed between adjacent molecules through the resulting radicals.

Generally, in vinyl polymers whose main chain is C--C bonded, there is a certain relationship between the radiation effect and the chemical structure. If the polymer has the structure (-OH2-cHR-)n, it will be crosslinked, and COH20(CH3)
Generally speaking, if it has the structure R)n, it will collapse. Here, R is )(, OH3°C!6H5, etc.) This relationship does not necessarily hold true if the substituent is a non-vinyl polymer.

Polymers gelled by radiation become macromolecules with a three-dimensional structure and are therefore insoluble in solvents, but this depends on the degree of crosslinking.

For example, when polyethylene is irradiated, crosslinking occurs between molecules, so those that are sufficiently irradiated will have improved heat resistance, solvent resistance, stress cracking resistance, etc. Most of the irradiation is performed using electron beams generated by high-capacity electron accelerators. 10 Mr for sufficient crosslinking to provide heat resistance
AD or more requires a significantly larger absorbed dose. When radiation with a high dose rate, such as an electron beam, is used, crosslinking can be efficiently achieved even when irradiated in air. Crosslinking of polyolefins such as polyethylene can also be carried out by chemical methods. but,
One chemical method generally uses high temperatures and is difficult to apply to thin, already bonded plates or thin films, so radiation treatment may be considered more advantageous than other methods.

Sample, width 5011II11 x length 100mm x thickness 1.
A rolled copper foil with a 100 μm thick silane-modified polyolefin adhesive layer attached to a 6 mm glass and epoxy resin substrate (
45 μm) from the substrate side of the composite which has already been adhesively laminated.
1. Irradiation was carried out at an irradiation voltage of '55 MV and an irradiation dose as shown in the figure. The dose at this time is calculated as follows.

Dose calculation 1.35MVX2mA=2.7XjO”W==2.7X
10" joule 2.7X10" joule = 2.7X10
"Erg jrad = 100 erg/vr Total dose 2.7X1 [1 company rug x 1/1oo x (15 seconds x 1/2
+5 seconds) = 5.575X10"Mrad/fr Since the utilization efficiency is empirically known to be 0.05 to 0.15, if it is set to 0.01, it will be about 34 Mrad.

The results of the adhesive strength test for the above samples are shown in Table 1.

1. Surface Load As shown in Table 1, there is a significant difference in peeling at 23°C and 110°C. For each sample with two numbers, the smaller number is the value at the beginning of peeling, and the larger number is at the time the peeling is completed. In addition, the value of 1 indicates that peeling is started and completed at the same time.

In this way, in the copper-clad laminate of this example, by crosslinking the adhesive layer by electron beam irradiation, the adhesive strength is improved compared to untreated laminates at various temperatures, and it is significantly improved at relatively high temperatures, and also has solvent resistance. It can also improve stress resistance and stress cracking properties.

As described above, the copper-clad laminate of the present invention has the effect of improving the adhesive strength, heat resistance, solvent resistance, and stress cracking resistance of the adhesive layer.

[Brief explanation of drawings]

The figure is an explanatory diagram of the amount of electron beam irradiation on the adhesive layer of the copper-clad laminate according to the embodiment of the present invention.

Claims (1)

[Claims] 1. A substrate made of paper, phenol resin, glass, epoxy resin, etc., in which a thin copper plate is laminated with an adhesive layer of a resin material interposed therebetween, characterized in that the adhesive layer is crosslinked by electron beam irradiation. Copper clad laminate.