Keywords
Citation
(2002), "Ecological alternative to electroless Cu for HDI mass production", Circuit World, Vol. 28 No. 3. https://doi.org/10.1108/cw.2002.21728cad.004
Publisher
:Emerald Group Publishing Limited
Copyright © 2002, MCB UP Limited
Ecological alternative to electroless Cu for HDI mass production
Ecological alternative to electroless Cu for HDI mass production
Keywords: Ecology, Copper
Called Seleo CP this direct plating process from Atotech is based on a conductive polymer.
The plated layer shows unsurpassed conductivity for highest throwing power demands for high aspect ratio HDI production. The acidic adhesion promoter creates a fine, uniform manganese dioxide layer for increased efficiency of the subsequent chemical reactions. This prevents the excessive formation of manganese dioxide, which may cause a reduction of conductivity in reducing post polymerisation steps (in reducing environment, such as H2O2, oxygen can evolve and destroy or at least reduce the polymer's conductivity). Furthermore perfect wall adhesion of the Cu plated is obtained. In the polymerisation step the Seleo CP Polyconduct acid and the new monomer ensure excellent conductivity. The resistivity of the polymer formed was measured on a bare surface.
This new process offers true selectivity, i.e. no material is being deposited on copper during the entire sequence. Therefore no etch cleaner step is required after the metallization sequence. This minimizes the risk of ring voids in through holes or folding at the interface between resin and capture pad of blind microvias. With conductive polymer processes the highest requirements for thermal cycle tests are fulfilled revealing the connection between selectivity and reliability.