I agree with Bev, what would be the point? The crystal structure of ISn changes overnight as the IMS grows very quickly. TEM results would not assure whether the finish will readily wet, or not.

Were you thinking of using it as an acceptance measurement from the fabricator? Most companies simply assign a "use life" of 2 to 6 weeks from date of plating. 

Sometimes 6 weeks is too long, depending on the plating and storage factors.



-----Original Message-----

From: TechNet [mailto:[log in to unmask]] On Behalf Of Bev Christian

Sent: Wednesday, September 27, 2017 2:50 PM

To: [log in to unmask]

Subject: Re: [TN] TEM Analysis



Steve,

First time I have ever heard someone asking for a TEM for a surface finish!

I know that at least in certain instances TEM can be used for determining crystal structure, but my return question is “what would be the point?”.

XRF, x-section, EDX and solderability testing should be sufficient.



IF you do want TEM done, approach the University of Toronto or CANMET in Hamilton.



Regards,

Bev



Sent from Mail for Windows 10



From: Steven Kelly

Sent: Wednesday, September 27, 2017 8:39 AM

To: [log in to unmask]

Subject: [TN] TEM Analysis



Hi all,

One of my customers has asked me to do a TEM analysis on immersion tin pads on a flex we make.



 1.  what will this tell me that XRF, x-section and EDX does not  2.  If it does tell me something – suggestions of a source to get the work done.



Thanks. Steve Kelly