Maskless Ball-Limiting Metallurgy
Original Publication Date: 1983-Jul-01
Included in the Prior Art Database: 2005-Feb-07
Ball-limiting metallurgy (BLM) is formed without masked subetching of the BLM by use of a blanket deposit of BLM and a masked deposit of PbSn followed by reactive ion etching of the BLM using the PbSn as a mask. A simpler and cleaner (no photoresist residue in vias) process is achieved along with self-alignment of the BLM to the PbSn.