Jordi, Any comment about the adhesion of gold to bare aluminum? I've read somewhere it's pretty awful. Thomas -----Original Message----- From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On Behalf Of Jordi Teva Sent: Tuesday, January 27, 2009 12:20 PM To: General MEMS discussion Subject: Re: [mems-talk] Aluminum Bond pad reference the Al bond pads provided by the semiconductor industry are not pure Al, they are alloys with others metals, mostly Cu, just to avoid the problem you have.. I do agree with Morten¨'s proposal with the Gold layer.., I think you will have a layer of alumina as soon as you place your chips in the ambient air... Jordi