Loop antenna?  wire bond stitch up when  it needed if it is what you  
are talking about. (if it is gold plated).. just a guess.
https://www.researchgate.net/figure/Square-loop-antenna-left-flat-and- 
wide-loop-top-right-and-the-feeding-area-tapering_fig1_324381724
jk
On Aug 10, 2021, at 10:23 AM, Nutting, Phil wrote:

> Esteemed colleagues,
>
> I have been asked about a square spiral pattern of etch on several  
> of our circuit boards.  The ends are not connected to anything.  I  
> assume it is for verifying copper etch width or etched space width.
>
> Can someone shed some light on these patterns?
>
>
> Phil Nutting | Senior Development Engineer | Lab: +1-978-224-4334 |  
> Mobile: +1-978-828-. 8664
> 35 Congress Street | Salem, MA 01970 | U.S.A. |  
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>
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