We have produced a resin-based tungsten sheet made of composite materials of resin and tungsten as an alternative material of lead, but this product has problems of heat-resistance and moisture-resistance. So we struggled to improve these problems. Firstly we improved the heat-resistance of resin-based tungsten sheet keeping its strength and flexible property by introducing the bridge constructing process to resin material. In this review, we show various evaluation results of the sheet on heat-resistance. Secondary we did the improvement of moisture-resistance by incorporating coupling treatment process to tungsten powder. And we inspected the fact that this process was effective by evaluating the result of Environmental Testing of experimental product sheets.
