SURFACE ACTIVATION OF PA-COPPER HYBRID

This work demonstrated the effect of different surface activation methods for PA66 fabrics onto the percolation behaviour for surface plating by the electroless copper deposition process. This study demonstrated how the percolation of a PA66 fabric can be affected in an electroless copper deposition process by altering the surface properties of the fabric. It was possible to shift the percolation threshold to lower copper contents and thus to increase the efficiency of the process. The copper content required to form conductive structures was reduced between 59 to 89%. In addition, the process time was reduced between 37 to 57% resulting in a faster percolation of the fabric. Differences between the surface modification techniques were observed: The copper contents during the electroless copper deposition process of the CEW treated fabrics were smaller than those of the reference, APPA treated and grafted fabric for the same deposition times. Reasons for this observation might be the exposed reduced surface area, decreased wettability and porous shell “barrier” of the CEW modified substrate. On the other hand, these samples exhibited lower electrical resistance values at lower copper contents due to the decreased and fused surface. The APPA modified fabric showed the highest copper contents during the deposition process within this series and also a lower percolation threshold than the reference due to an improved metallisation ability and the formation of a more uniform metal layer. This is a result of changed topography, increased amount of oxygen- and nitrogen containing groups and improved wettability, which allowed the initial silver particle seeds to the activated surface more uniformly. The grafting process also lowered the percolation threshold and improved the metallisation ability of the fabric compared to the reference due to the new oxygen containing groups on the surface and the improved wettability. For future work, a combination of CEW and plasma treatment could provide promising results to combine the advantages of both techniques for enhancing the metallisation ability in the fabric.

Publication:

Gleissner C, Biermaier C, Bechtold T, Pham T (2024) Altering the percolation threshold of PA66‐copper hybrid in an electroless copper deposition process by surface activation of the polymer. Polym Compos 45:14066–14076. https://doi.org/10.1002/pc.28754