Highly flame-resistant glass-epoxy laminates without flame-retarding additives such as halogen and phosphorous compounds have been developed to overcome environmental problems caused by these additives. The laminates consist mainly of a self-extinguishing epoxy-resin compound (phenol aralkyl), an incombustible-gas generator (amino-triazine-novolac hardener: ATN hardener), and inorganic materials such as a charring promoter (zinc molybdate on talc: ZMT) and a limited amount of harmless metal hydroxide (aluminum trihydroxide: ATH). They are highly flame-resistant and have other beneficial characteristics, including soldering-heat resistance, humidity resistance, electronic properties, and processing advantages. These qualities make them applicable enough to replace the FR-4 type printed wiring boards (PWBs) that are widely used today. Simultaneously using the ATN hardener and ZMT in the laminates, including the epoxy-resin compound and ATH, greatly improved their flame retardance. We then reduced the amount of ATH to obtain even better flame retardance in the laminates. This reduction of the ATH, consequently, improved other practical characteristics such as soldering-heat resistance, humidity resistance, and electronic properties. (c) 2006 Wiley Periodicals, Inc.