Flexible automated assembly of micro-optical elements (optical SMD)

An automated assembly technique for small optical components has been developed. It concerns components such as, e.g., laser diodes and LEDs, fibers, lenses, beamsplitters, polarizers, mirrors, crystals, prisms, diffractive elements or photodiodes. It is based on the flexible 2-dimensional arrangement of an universal tripod holder (10 x 10 x 4 mm) on a planar mounting plate. Its particular mechanical structure allows to align the optical elements on-line and to attach them to the mounting plate in a one step procedure. The different elements are aligned with an accuracy of +/-1 mu m and attached one after the other. Very good position stability (+/-0,7 mu m, +/-0,2 mad) during the attachment procedure has been achieved by laser point welding. They are optically interconnected by free-space propagation of a light beam with a diameter of up to 8 millimeters. Mass production has been shown with a collimator as test vehicle. The collimator is composed of two elements (laser diode and collimating lens) and is mounted entirely automatically by two co-working robots. Easy prototyping has been shown with the realization of the optical position sensing system featuring a high precision linear magnetic bearing. Flexibility, simple handling, high packaging density and low cost make this new assembly technique suitable to both mass production and protoyping of small opto electronical devices.