Typical metals for these lids include Kovar, Alloy 42, nickel, and stainless steel. PEI also provides in-house plating capabilities, including electrolytic nickel, electroless nickel, and nickel followed by gold. Electroless nickel plating, with a maximum phosphorus level of 10 offers the maximum eutectic melting temperature.
PEI also has the ability to etch lids in any thickness up to 50 mils (1.27 mm) with a 0.005 in. (0.127 mm) flange. Graphics can be etched into the part, and lids with slots and holes for glass windows can also be manufactured.