GT Advanced Technologies Inc fka GTAT

[Netsurfer]

The article that was in the earlier post listed virtually all of GTAT's ASF customers during the go-go days back in 2011 2012. It must be one of those. Maybe a little Googling might shed some light on who it might be.

This might be a repeat of an earlier post but making screens has several choke points. Boule yield is the obvious first one.
The second one is in the cutting and polishing of the boule to get the final screen. The challenge comes with cutting the holes.
The process of cutting the holes creates stress in the screen which give rise to areas that could let a crack propagate or leads to areas that show color bands due to the stress. These are typically visible under UV light but might be visible under fluorescent light as well. This would be a cause for reject.

The final screens...with holes...need to be annealed to fix these issues and there in is the problem / challenge. They can be annealed in small batches but to make thousands at a time with acceptable yields was difficult. Any tooling used to support the parts led to contact points that resulted in rejects.
Some of the early Court Docs referred to Apple keeping the IP associated with annealing as they apparently making some progress.

I would guess that the "customer" is one of the ones listed in the article.

Below are links to what seem to be the largest

http://www.ghtot.com/index.php?shownews-2091
http://www.teraxtal.com/english/product_page/product_page2.html
http://www.compoundsemiconductor.net/article/89241-oci-aspires-to-become-a-top-provider-of-sapphire.html

Again this may be old news or not significant to some people's DD.