Electroless Plating Pretreatment Agent and Copper-Clad Laminate for Flexible Substrate

Abstract

Provided are an electroless plating pretreatment liquid used in a copper-clad laminate for a flexible substrate whose initial adhesive force between the substrate material and copper plating layer in an ordinary state as well as the adhesive force in a peel test after aging (in the atmosphere at 150° C. for 168 hours) are at least 0.4 kgf / cm, and a copper-clad laminate for a flexible substrate produced using same. The electroless plating pretreatment agent used in a substrate material of a copper-clad laminate for a flexible substrate comprising a thermoset resin and a silane coupling agent having a metal capturing capability. The copper-clad laminate for a flexible substrate wherein a substrate material is treated with the electroless plating pretreatment agent, a copper plating layer is then formed by electroless plating, and a copper plating layer is formed thereon by electroplating.

Description

TECHNICAL FIELD [0001] The present invention relates to an electroless plating pretreatment agent used in materials of a copper-clad laminate used as a base material or the like of flexible substrates for printed wiring and to a copper-clad laminate for a flexible substrate produced using same. BACKGROUND ART [0002] Polyimide substrates are often used as a material of insulating substrates for electronic components. With the recent trend toward smaller, thinner electronics, two-layer copper polyimide substrates in which a metal layer is directly formed on a polyimide film have attracted attention for their greater flexibility. Although the initial adhesive force of these substrates between polyimide films and metal layers in the ordinary state is on a practical level, the characteristics such as adhesive force in an environment requiring heat resistance, or in that of high temperature and high humidity are considered unstable. [0003] A method for producing a metal layer in a flexibl...

AI Technical Summary

Benefits of technology

The present invention provides an electroless plating pretreatment liquid for a copper-clad laminate for a flexible substrate that improves adhesion between the substrate material and copper plating layer. The electroless plating pretreatment agent comprises a thermoset resin and a silane coupling agent having a metal capturing capability. The use of this agent results in an initial adhesive force between the substrate material and copper plating layer of at least 0.4 kgf / cm, and an adhesive force in a peel test after aging (in the atmosphere at 150°C for 168 hours) of at least 0.2 kgf / cm. The electroless plating pretreatment agent can be applied to the substrate material using a spray or roll coating method. The resulting copper-clad laminate for a flexible substrate has improved adhesion and reliability.

Problems solved by technology

Although the initial adhesive force of these substrates between polyimide films and metal layers in the ordinary state is on a practical level, the characteristics such as adhesive force in an environment requiring heat resistance, or in that of high temperature and high humidity are considered unstable.

However, that method costs high, and the adhesive force is not adequate in an environment requiring heat resistance, or an environment of high temperature and high humidity.

Methods to improve the adhesion of the polyimide film and metal layer include plasma, UV, and other dry processes as well as alkaline and other wet processes, but in addition to safety and operability issues of the liquid used, these methods can lead to unevenness in the metal layer surface if excessively applied, damaging fine wire formation.

The main object of this method is to form a resin composite layer as an adhesion imparting layer, but the processes are complex and results in a resin composite layer having a thickness of 1 to 20 μm.

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