An in situ XRD study of electroless copper deposition on a nylon film substrate using Rochelle salt as a complexing agent and formalin as reducing agent have been carried out using a purpose-designed cell to clarify the effect of additives and aeration on the initial stage of the deposition. The additives used were 2, 2'-dipyridyl (dpy), 4, 4'-dpy, polyethylene glycol (PEG) 300, PEG 600 and PEG 1000, which are usual additives for obtaining uniform distribution of crystal size in the Cu deposits. There has been little discussion of average crystal size, inclusion of Cu2O and other additive effects, or of bath aeration effect. The present study characterized the average crystal size of the Cu deposits as a function of additive concentration and plating time. It is suggested that 2, 2'-dpy promotes the codeposition of Cu2O with Cu. The addition of 4, 4'-dpy appeared to limit the diameter of the deposited Cu crystals, while the average particle size increased with plating time depending on the additives used. Acration of the plating bath greatly retarded the undesired codeposition of Cu2O in the presence of 2, 2'-dpy. XRD measurement showed no clear additive effect for PEG.
