Air Card Question

I received 20 Cisco AIR-P121AG-A-K9 WiFi cards that have an antenna wired directly into each card. When I broke one of the antennae open, it had one of these cards in it. Flimsy card but gold traces throughout. I tested using 10, 14, 18, and 22k acids. 10 and 14 didn't do anything after letting it sit on the gold trace for more than 30 seconds. 18k acid test fizzed and ate a portion of the trace away as shown in the pic. So am I to assume that these cards have 14k foils? (Still a noob when it comes to acid testing :) )


http://i1064.photobucket.com/albums/...ps5377bdd3.jpg