Micro FSW

Friction Stir Welding of Foils and Very Thin Sheets

Dr. Nee Joo Teh and John Dadson of TWI explain in this two-minute long video published in February 2013, how micro friction stir welding can be used to join less than 1 mm thick aluminium foils or sheets for the manu­fact­ure of electronic housings at very high rotation speeds and low forces.

Encapsulation of electronics using Micro FSW 

2:00 min, © TWI Ltd, 6. Februar 2013



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.


More Information

For companies, who want to know more about Micro FSW, we are happy to provide further information on the process and the possible applications on request. Please contact the AluStir team by phone (+49 6024 636 0123) oder E-Mail (stephan.kallee@alustir.com)