ZnO thin film-based new electroless metal deposition

Electroless metal deposition plays an important role in the fabrication of printed circuit boards mainly due to its ability to produce uniform metal f ilms on insulating substrates (e.g., ceramics, glass, polymers). However, t he adhesion of the electrolessly deposited metal films, particularly coinag e metals (Cu, Ag, Au) on ceramic substrates is usually poor, even on roughe ned substrates. Nevertherless, using our newly developed electroless metal deposition process, which is characterized by the use of a ZnO thin film as an intermediate layer between the substrate and the metal deposit, metal f ilms with high adhesive strength can be achieved even on smooth glass subst rates. In addition, this new process possesses the advantages of 1) simple processing procedures and 2) the ability to fabricate fine metal patterns i n a fully additive fashion based on the photosensitivity of the ZnO films. New functions based on this process have been discovered in our recent rese arch. In the present paper, the processing steps involved in this new metho d, the formation mechanism of catalytic Pd particles, the adhesion mechanis m, as well as its possible applications in pattern fabrication, are briefly reviewed, based on our recent work.