MEMS devices and methods of assembling micro electromechanical systems (MEMS)

A Micro ElectroMechanical Systems device according to an embodiment of the present invention is formed by dicing a MEMS wafer and attaching individual MEMS dies to a substrate. The MEMS die includes a MEMS component attached to a glass layer, which is attached to a patterned metallic layer, which in turn is attached to a number of bumps. Specifically, the MEMS component on the glass layer is aligned to one or more bumps using windows that are selectively created or formed in the metallic layer. One or more reference features are located on or in the glass layer and are optically detectable. The reference features may be seen from the front surface of the glass layer and used to align the MEMS components and may be seen through the windows and used to align the bumps. As an end result, the MEMS component may be precisely aligned with the bumps via optical detection of the reference features in the glass layer.