Study of MID Technologies for Automotive Lighting and Light Signaling Devices

The production of Molded Interconnect Devices (MIDs) may be achieved through different processes. In this work Centro Ricerche Plast-optica (CRP) has chosen to evaluate, implement and assess Laser Direct Structuring (LDS) and In Mold Labeling (IML) technologies for the production of MIDs. Both alternative methods have been analyzed starting with a 2D component, mainly used for implementation and optimization of the process, and finally a more complex 3D component, that has been designed and produced. The first phase of the activity regards the production of several conductor patterns on planar substrates dedicated to evaluate properties as conductors resistance, adhesion, SMD components solderability, wire bondability of bare LED dice etc. In the case of IML, a flexible circuit has been over-molded during the production of the component by injection molding process: planar parts have been tested also in terms of adhesion of flexible circuit to the injected polymer. The second phase of the activity concerns the production of 3D circuits. Both technologies have been implemented in order to select to materials, process conditions and parameters, design rules and to verify the reliability in the automotive severe conditions. Exploitation of technologies have been performed on an automotive rear lamp. A prototype has been produced in LDS technology and allowed to define the conditions that make economically affordable this solution. Differently, the IML technology allowed to produce a completely new device by embedding a planar electronic circuits into the plastic material.