Circuit Repair Using Palladium Seeding and Selective Electroless Plating
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Vigliotti, DR: AUTHOR [+2]
The present disclosure describes a new technique for the repair of an open circuit using palladium seeding and selective electroless plating.
Circuit Repair Using Palladium Seeding and Selective
disclosure describes a new technique for the repair
of an open circuit using palladium seeding and selective electroless
The region of
a break or open in the circuit is first seeded
with palladium acetate. A laser is used to drive off the organic
ligands of the palladium acetate, leaving behind a "bridge" of
essentially pure palladium metal. The palladium bridge establishes
an electrically continuous circuit of a high resistance over the
open. Such palladium seeding techniques have been described
previously in the literature.
is then immersed in an electroless copper-plating
solution heated to a temperature of about 40ºC. Certain
formulations of electroless copper-plating solutions when heated to
such a temperature give rise to selective copper plating. In the
present technique, the high-resistance palladium bridge increases in
thickness due to deposition of copper, whereas copper essentially
does not plate out on the copper lines of the circuit. The selective
plating on the seeded region occurs without the use of a mask. Thus,
it becomes possible to repair a number of palladium-seeded opens on a
single substrate in a batch-process manner by submerging the
substrate in electroless copper-plating solution to build up copper
on the opens to obtain low-resistance repairs.
In one specific example, a copper line had...