Method for preparing plastic particles coated with metal

Abstract

The present invention relates to a method for preparing plastic particles coated with metal, which comprises the following steps. First, mix a plurality of plastic particles with a tin / palladium solution to form a first mixed liquid. Alternatively, first mix the plurality of plastic particles with a stannous chloride / hydrochloric acid solution. Then mix the plurality of plastic particles adsorbing the plurality of stannous ions with a palladium chloride / hydrochloric acid solution and form the first mixed liquid. Next, microwave the first mixed liquid so that the tin / palladium colloidal particles coat the plastic particles and thus forming first metal particles. Afterwards, mix the first metal particles with an electroless nickel solution and form a second mixed liquid. Metal nickel then coats the first metal particles and forming a plurality of second metal particles. Use microwave to activate the plurality of tin / palladium colloidal particles adsorbed on the surfaces of the plastic particles, and hence increasing adsorption of the plated metal layer on the surfaces of the plastic particle. Thereby, roughness and peeling-off of the plated metal layer can be reduced.

Description

FIELD OF THE INVENTION[0001]The present invention relates generally to a method for preparing plastic particles coated with metal, and particularly to a method for preparing plastic particles coated with metal having enhanced adhesion by special pre-processing of particles using microwave activation.BACKGROUND OF THE INVENTION[0002]Owing to technological progresses and requirements for efficient, small-sized, and low-priced electronic products, flip-chip technology has become the main architecture of interconnection in packaging. The interconnection methods in flip-chip technology include metal interconnection, conductive paste interconnection, micro-bump bonding interconnection, anisotropic conductive film (ACF) interconnection, and conductive resin interconnection. Currently, metal interconnection and ACF interconnection are mainly adopted. In the trend of high reliability and fine spacing, the ACF used by flip-chip technology includes conductive particles of polymer plastic powde...

AI Technical Summary

Benefits of technology

The present invention provides a method for preparing plastic particles coated with metal using microwave activation of tin / palladium colloidal particles adsorbed on the surface of the plastic particles. This method reduces roughness and peeling-off of the plated metal layer, resulting in a higher quality plated layer. The method involves mixing plastic particles with a tin / palladium solution, then adding a palladium solution to form a mixed liquid. Microwave activation of the colloidal particles is then performed to increase adsorption of the plated metal layer on the plastic particles. This method also involves mixing the plastic particles with an electroless nickel solution to form second metal particles, which coat the first metal particles and further enhance the quality of the plated layer.

Problems solved by technology

However, chromate produces chromium mists, which are carcinogenic and toxic, endangering the health of operators.

Nevertheless, this type of chemicals has strong corrosiveness, and hence endangering the health of operators.

However, because the physical adsorption of the Sn / Pd colloid on the surfaces of the plastic particles is inferior, the Sn / Pd colloid tends to aggregate, which retards the adsorption quantity of the Sn / Pd colloid on the surfaces of the plastic particles, and hence making the amount of the activation centers for surface catalysis insufficient.

The insufficiency is disadvantageous for adsorption of the plated metal layer on the surfaces of the plastic particles.

Thereby, the plated metal layer tends to appear rough and peel off, and its quality cannot be controlled with precision.

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