Micro-MID Manufacturing By Two-Shot Injection Moulding

With the advent of MID (Moulded Interconnect Device) technologies more and more products are taking the advantage of MIDs both in macro and micro applications. By combining the mechanical and electrical functions on a single device, MIDs can miniaturize the final product to some extent. But when a specific MID process chain is used for micro products, many technical challenges are encountered which would not be problems for macro scale products. This paper investigates on a specific MID process chain (two shot moulding) and discusses the technical difficulties associated with the production process when the production shifts from macro to micro scale products. The investigation shows that some of the materials which are suitable for macro MIDs are not suitable for micro MIDs. Polymer-polymer bond strength, interface between two polymers and interface metallization of polymers are critical for micro applications. The discussion presented in the paper increases the over all knowhow of MIDs and presents a guideline for important considerations when the MID production for micro applications is in question.