Recycling of thermosetting plastic waste from electronic component production processes

This paper describes the recycling of the mold waste from printed wiring boards (PWBs) and the molding resin used for IC packages, which are the main types of thermosetting plastic waste produced in the electronic component production processes. A practical process for pulverizing the PWB waste and separating the resulting powder into a copper rich powder and a powder consisting of glassfiber and resin (glassfiber-resin powder) was developed. Using this process, up to 94% of the copper was recovered from a pulverized PWB of 100-300 /spl mu/m average particle size. The recovered glassfiber-resin powder was found to be more useful than either talc, calcium carbonate or silica at improving the mechanical strength and the thermal expansion properties of polymer products, such as paints and adhesives. The molding resin powder showed good surface reactivity, comparable to that of a silica powder surface. In recycling the molding resin powder to the original molding resin, recycling of the waste powder of the low stress type molding resin to standard mold resin was especially effective in improving the humidity penetration and the thermal impact resistance of the original standard resin. Moreover, the molding resin powder could be used as a general filler for resin type construction materials, and as a decorating agent for improving the surface hardness of construction materials.