Lead frame cleaning is necessary prior to the die attach process. Lead frames are usually cut from thin copper sheets, stamped and refined via galvanic processes. Plasma is often used to clean thin and homogenous contamination layers.

However, cleaning with plasma alone is not sufficient to remove heavier contamination caused by stamping and cutting oils from the lead frames.

A wet cleaning process is highly recommended prior to the die attach process as well as other subsequent production steps, i.e. wire bonding and molding.