A second prize winner from Herriot Watt
The 2011 winner of AILU's Young UK Engineer's Prize is Norbert Lorenz, a graduate of the University of Applied Science in Emden (Germany) who is studying within the Applied Optics and Photonics Group at Heriot-Watt University towards a PhD on the theme of “Laser-based Packaging of Microdevices”.
Norbert has been developing a laserbased process for hermetic packaging of new laser-based MEMS and other micro-devices in a joint project between GE Aviation Systems of Newmarket and Heriot-Watt University. Packaging is important to protect these highly sensitive, fragile devices from harsh external environments whilst at the same time maintaining some connection with the external environment.
Conventional (i.e. non-laser) hermetic packaging processes heat the entire unit, and so limit the materials that can be encloses (e.g. polymers or magnetic materials are unsuitable with high levels of heating) and also generate problems in multi-step bonding processes where several bonding cycles are carried out in sequence; parts joined in an earlier heating step can disassemble in a later one. Norbert’s work has therefore been to develop a laser-based process where the laser is a highly controlled, localised heat source.
Norbert designed and constructed suitable equipment to allow the laser-based process to be used in an inert gas or vacuum (since some devices require a vacuum inside). Management of the heat flow by appropriate design of heat sinking was crucial in development of the process. Excellent results were achieved, with parts passing leak testing, temperature cycling, constant acceleration, and shear force testing. GE Aviation Systems – Newmarket are looking to exploit the technology in the sealing of temperature sensitive devices, such as Microsystems, where it is necessary sometimes for the devices to operate in vacuum. The laser sealing process could provide significant advantages over generalised heating techniques.Norbert is the second winner from Heriot-Watt University, a reflection of the excellent collaborative projects that the university has established with industry.