Oak Ridge Micro-Energy, a developer and manufacturer of thin-film, rechargeable lithium-ion batteries, has announced that its batteries meet new requirements for lead-free circuit assembly.

It was on July 1 that the European Union adopted new regulations (RoHS) requiring the use of lead-free solders in the manufacture of electronic products. Similar legislation is pending in China. Because lead-free solders melt at higher temperatures than traditional solders, reflow assembly will require temperatures of up to 260 degrees C (500 degrees F).

Oak Ridge Micro-Energy's thin-film, lithium-ion batteries were designed to exceed the new stringent requirements of solder reflow assembly. They can withstand temperatures above 285 degrees C (545 degrees F) in a discharged state. Conventional lithium-ion batteries cannot survive temperatures much above 130 degrees C.

In recent tests, ORME's batteries subjected to three successive reflow processes at temperatures of 265 degrees C (509 degrees F), exhibited less than a 10% average change in performance. Stricter controls in the packaging steps are expected to eliminate any significant changes in performance.

Oak Ridge Micro-Energy Inc. develops and produces custom-designed, thin-film lithium and lithium-ion batteries that are well suited for applications where a small power source is needed. These batteries can be fabricated on a variety of substrates as well as onto chips, chip carriers or multichip module packages. By using the available space on a ceramic package or a silicon die, the battery can provide the required power while occupying otherwise wasted space and adding negligible mass.