Micro FSW

The development of friction stir welding had already gone through several loops since its invention in 1991, for example 150 mm thick aluminium plates have already been welded at TWI Yorkshire - in a single layer.

This video is about something completely different. These aluminium sheets are only 300 µ (i.e. 0.3 mm) thick. Friction stir welding in this thickness range can be used to manufacture electronic housings.

Micro friction stir welding is a process that deals with joining thin sheets and foils that are less than 1 mm thick. In February 2013, Nee Joo Teh was working with 300 µ thin sheets and planned to weld 100 µ thin foils by the end of the year. One of the main applications is the hermetic encapsulation of photonics assemblies or electronic circuits.

This is a purely mechanical process without shielding gas or filler materials. It is very reliable and because no welding fumes are generated, it can be used in cleanrooms at low cost.

By 2013, friction stir spot welding of thin sheets in lap joints had been developed, as well as longitudinal seams in lap joints and butt welding of very thin foils. In tensile tests, a tensile strength of up to 90 % of the base material was achieved. Initially, work was carried out with aluminium alloys, but the welding of copper also looked promising, and even the welding of plastics was to be investigated.