In-mould measurement with optical coherence tomography for compensating positioning error in injection overmoulding of optoelectronic devices

In this work we present an optical coherence tomography (OCT) setup for in-mould measurements, which is combined with a mechatronic actuator, that adjusts the position of an opto-electronic part (LED), which will be overmoulded with a lens-shaped structure to form a fiber optic transceiver (FOT). In particular, the lens increases the coupling efficiency of the LED, and precise positioning with respect to the mould (lens) will increase the overall product quality. This work is part of the EU-funded project FLOIM (Flexible Optical Injection Moulding of optoelectronic devices). The OCT measurement is applied before the overmoulding process, to find out the displacement of the LED. The calculated LED displacement is passed to the control unit of the mechatronic device, which in turn corrects the displacement by moving the sample. It is shown that the overall concept is feasible, and it is also pointed out where additional research is required.