The mechanism of direct copper plating on nonconducting resin substrates wa
s investigated by high resolution transmission electron microscopy and scan
ning electron microscopy observation and surface analysis techniques. The s
ubstrates were catalyzed by Pd/Sn mixed catalyst and accelerated in an alka
line solution containing copper ions and a reductant before the direct plat
ing. After the acceleration, copper crystalline particles measuring approxi
mately 300 nm were found to be dispersed at the population density of 1.4 X
10(11) m(-2) in addition to adsorbed palladium colloids. The colloids form
ed clusters measuring 20 to 50 nm which consist of individual particles mea
suring approximately 2 nm. The addition of copper ions in the acceleration
solution exerted a remarkable promotion effect on the speed of lateral prop
agation of direct plating. This effect can be explained by a modified stepw
ise propagation mechanism in which dispersed copper particles formed in the
Cu(II) containing accelerating solution play a critical role in determinin
g the propagation speed. The copper particles also play an important role i
n determining the uniformity of the propagation of copper plating. (C) 1999
The Electrochemical Society. S0013-4651(98)01-058-1. All rights reserved.