High accuracy flip-chip assembly of MOEMS [optical switch example]

Flip-chip assembly is now being employed as a simple and cost-effective method for assembly and packaging of MEMS devices. However for MOEMS micromirror devices used in n×n optical switches, the requirements for placement accuracy and levelling are much more critical, because of the need to align optical paths. The device bonder presented in this paper is capable of the required post bonding accuracy. MOEMS devices can be successfully assembled using a flip-chip method, with sufficient parallelism to ensure optical path alignment. The x, y and z placement is accurate to within 1 μm. This 1 μm accuracy is sufficient to ensure that optical paths align to waveguides which are subsequently used to align to a 9 μm singlemode fiber core. This method of MOEMS transfer or placement reduces the complexity of the assembly process. Use of existing flip-chip placement and bonding techniques speeds the development cycle of MOEMS devices. This method is enabled by a high-accuracy device bonder for 1 μm accuracy placement and in-situ bonding.