Micro-transfer-printing at X-FAB: Demonstration of a New Technology For 3D Wafer Level Packaging

- Micro-Transfer-Printing (µTP) was introduced as a new and promising technology for 3D- and heterogeneous integration.
- The main advantage of µTP is the parallel placement of up to thousands of small chiplets with a very high printing accuracy.

- Within a European funded project called MICROPRINCE a pilot-line for µTP was installed at XFAB and first demonstrators were built.
- Process developments for this 3D-integration technology including tether formation, printing and post-processing were executed.
- Further, application examples for printing of optical filters, GaN LEDs & HEMTS, InP photodiodes and printable Si-based ASICs were shown.
- For these applications print yields of up to 99% with low placement deviations as low as 0.78µm (3σ) were demonstrated.