LED Transfer via Parylene Deposition

In addition to the transfer of silicon dies, the transferability of electronic components is also of practical relevance (see column (c) in Figure 1 as well as Figure 2). Hence, bulky packaged LEDs of 2.0 mm × 2.0 mm × 1.4 mm width, length and depth, which are usually designed for surface mounting (SMD), were used to investigate the transferability. The LEDs are obtained from CML innovative Technologies (CMD28-21 Series SMT LEDs) and have a red color, a maximum forward voltage of 2.8 V and a current of 20 mA.
For the sample preparation, two contact pads and two electrical connectors were printed on the PVA using the aerosol jet and the GenesInk S-CS31506 again, as described in Section 2.1. Afterwards, the LED was glued onto the printed electrodes using conductive glue LOCTITE ABLESTIK ICP 4015, which is a silver and silicone-based glue. The glue was cured in accordance with the datasheet at 80 °C for 30 min in air. After this, the Parylene deposition and lift-off were performed. In order to prove the successful transfer of the LED, it was tested as to whether it was still glowing after the transfer when applying a forward voltage using a Statron power supply, type 3225.