Development of heat-resistant, solderable, triple-insulated winding wire

To meet the trend in power supply units toward downsizing and higher efficiency, we have developed heat-resistant (class B), solderable, triple-insulated winding wire with using technologies of polymer alloy and thin insulation. Modified polyethersulfone resin was applied to a 1/sup st/ and 2/sup nd/ layer for achieving both heat-resistance and solderability. And poly (phenylene sulfide) was selected as a 3/sup rd/ layer for improving chemical-resistance of the winding wire. It was confirmed that the newly developed wire has class B heat resistance according to safety standards relating to switching power supplies, and features excellent electrical endurance and a high voltage for the inception of partial discharge.