Flame resistant glass-epoxy printed wiring boards with no halogen or phosphorus compounds

A highly flame-resistant glass-epoxy laminate-type printed wiring board (PWB) that does not contain such flame-retarding additives as halogen compounds and phosphorus compounds has been developed to overcome environmental problems caused by these flame-retarding additives. The PWB contains a self-extinguishing epoxy resin compound (phenol aralkyl type) and a limited amount of harmless metal hydroxide (aluminum hydroxide). It has high flame-resistance with no inclusion of halogen or phosphorus compounds and shows other good characteristics, including resistance to solder heating and chemical agents in processing, electronic properties, and moldability, which make it a practical FR-4 board. These good characteristics were obtained by utilizing the epoxy resin compound's superior properties, including its pyrolysis resistant, hydrophobicity and non-polar properties, and by minimizing the amount of metal hydroxide. The board is very safe when burned, disposed of, and reused as a filler after pulverizing.