What is Orbital Welding?

Quite simply, orbital welding is the welding of a circular or orbital object (like a tube) to a substrate or to another, similar tube, executed by a GTAW weld head. Pioneered for airplane manufacturing in the 1960′s for affixing the noses to the bodies of airplanes, orbital welding has since been employed in fields from water boiler to pharmaceuticals manufacturing.

In the semiconductor manufacturing world, the refers to a type of process welding in which specially-designed gas delivery equipment, arc machines, and weld heads (connected to a power source) are used to perform extremely precise, sometimes microscopic welds to fix round ‘tubes’ or other semi-conductive components onto silicon substrate for chips, and also for larger applications, wherein tubes must be joined and no contaminant can be present on the smooth inner walls. The weld head focuses the arc around the intersection of the substrate and the object to be welded to it, essentially orbiting the perimeter. In applications that require greater precision or very small welds, mass flow controllers are employed and the arc is aimed through the manipulation of a field of conductive gas through an inert environment: as the tunnel of conductive gas moves, so does the arc produced by the tungsten electrode, allowing for near-molecular precision of the arc.

Orbital welding is employed because it has a number of advantages over torch welding – advantages that make entire technologies like mass-produced processors and solar panels possible. First, specially-designed weld-heads create a welding environment of near-perfectly pure inert “shield gas” (usually argon). An environment with such low PPM of atmospheric gas improves arc accuracy and ensures that the weld itself is free from contaminants that change the conductive properties of the widget. Second, small, sharp tungsten electrodes are able to focus current through a channel of conductive gas to create an arc that is smaller and more precise than  the arc produced by any torch of any size. Third, because the arc is directed automatically to follow a programmed outline (some weld heads are even ‘smart’ and ‘see’ where the weld should go) welds are more consistently placed and executed with more consistent quality. And of course, because orbital welds are performed mechanically, they save producers the cost of employees to weld – irrelevant for semiconductor producers, since human welders cannot perform the orbital welds produced by the new technology.

While GTAW is not a new technology, the weld heads used in today’s clean-room environment are exemplary of technological advancements in machinery making the production – never mind mass-production – of new technologies possible.