The Adhesion Promotion and Metallisation Process: The Critical Step in MID Manufacturing

Like the conventional PCB, the Moulded Interconnect Device (MID), be it 2‐ or 3‐dimensional, will have, as its interconnection medium, conductive patterning or structuring upon the surface of the device. This interconnection pattern will, in the majority of MID products, take the form of a metal (usually copper) deposited upon the surface of the plastic. How this metal is deposited and remains attached to the surface is the critical step in the production of a MID. That is the bond, or adhesion, between plastic and the applied metal circuitry. Without a strong and reliable bond between circuitry and plastic it will not be possible to manufacture a MID with the characteristics of a conventional interconnection medium, the PCB, the technology it is probably replacing within the finished product. This paper describes the development of a chemical adhesion process, and how the selection of a suitable resin and its moulding parameters can influence the adhesion performance of the metallisation process.