The Bulk Metal® Foil resistor is based on a special thermo-metalic stress concept wherein a proprietary bulk metal cold rolled foil is cemented to a ceramic substrate. It is then photoetched into a resistive pattern. Then it is laser adjusted to any desired value and tolerance. Because the metals used are not drawn, wound or mistreated in any way during manufacturing process, the Bulk Metal Foil resistor maintains all its design, physical and electrical characteristics while winding of wire or sputtering does not. Z Foil resistors achieve maximum stability and near-zero TCR. These performance characteristics are built-in for every unit, and do not rely on screening or other artificial means for uniform performance.