High precision passive alignment flip chip assembly using self-alignment and micromechanical stops

The implementation of passive alignment in optoelectronics packaging is still a challenge. Flip chip assembly of single mode laser diodes requires a post bond alignment accuracy of less than 1 μm. A low cost approach to achieve such high precision alignment is using the self-alignment mechanism in combination with micromechanical stops. In order to prove that this approach is feasible test vehicles were designed and fabricated. This work presents the concept of passive alignment pursued, the experimental setup and results thereof. The design of the test vehicles is described including the bump design as well as bumping and flip chip assembly.