Isn't it remarkable: JEDEC 142 OBTAINING AND INSPECTING MATERIAL/COMPONENTS FOR HYBRIDS/MCM Not a word about checking for pure Tin ! With the apparent risk of whiskers, a line or two about that would not be wrong...or did I miss something? Maybe I don't have a fresh copy? Steve, as a specialist on these, what's your comment. Inge > On 20 March 2012 19:50, Stadem, Richard D. >> <[log in to unmask]>wrote: >> >> > Tin whiskers can grow in leaded circuits, ie, CCAs soldered with Sn63. >> >> > The issue is that the parts need to be tinned of their lead-free >> > original finish, and the ENTIRE LEAD then must be tinned with Sn63. If >> >> > you leave a portion of a SAC305-finished lead untinned, the line of >> > demarcation between the Sn63 solder and the SAC305 C -----Original >> > Message----- >> > From: TechNet [mailto:[log in to unmask]] On Behalf Of Joyce Koo >> > Sent: Tuesday, March 20, 2012 12:57 PM >> > To: [log in to unmask] >> > Subject: Re: [TN] Out of the world tin whiskers >> > >> > I thought space is exempt for leadfree. Why? >> > -------------------------- >> > Sent using BlackBerry >> > >> > >> > ----- Original Message ----- >> > From: Inge Hernefjord [mailto:[log in to unmask]] >> > Sent: Tuesday, March 20, 2012 01:47 PM >> > To: [log in to unmask] <[log in to unmask]> >> > Subject: Re: [TN] Out of the world tin whiskers >> > >> > DO THEY NEVER LEARN! >> > >> > Inge >> > >> > On 20 March 2012 18:08, Gervascio, Thomas L >> > <[log in to unmask] >> > >wrote: >> > >> > > Tin whiskers at Saturn >> > > >> > > PASADENA, Calif. -- The Cassini plasma spectrometer instrument >> > > (CAPS) aboard NASA's Cassini spacecraft at Saturn has resumed >> operations. >> > Mission >> > > managers received confirmation on Friday, March 16, that it was >> > > turned >> > on. >> > > They plan to monitor the instrument for any unusual behavior. >> > > Last June, short circuits in the instrument led to unexpected >> > > voltage shifts on the spacecraft. As a precaution, mission managers >> > > turned off >> > the >> > > CAPS instrument while engineers investigated the issue. The >> > > investigation led to the conclusion that tin plating on electronics >> > > components had >> > grown >> > > "whiskers." The whiskers were very small, less than the diameter of >> > > a >> > human >> > > hair, but they were big enough to contact another conducting surface >> >> > > and carry electrical current. Researchers are still trying to >> > > understand why whiskers grow on tin and other metals, but they know >> > > now that whiskers >> > can >> > > grow in space and on Earth. It is believed that these or additional >> > > tin whiskers that may grow on Cassini cannot carry enough current to >> >> > > cause problems, but will burn out on their own like a lightweight >> fuse. >> > > >> > > >> > > >> > > ____________________________________________________________________ >> > > __ This email has been scanned by the Symantec Email Security.cloud >> > > service. >> > > For more information please contact helpdesk at x2960 or >> > [log in to unmask] >> > > ____________________________________________________________________ >> > > __ >> > > >> > >> > >> > ______________________________________________________________________ >> > This email has been scanned by the Symantec Email Security.cloud >> service. >> > For more information please contact helpdesk at x2960 or >> > [log in to unmask] >> > ______________________________________________________________________ >> > >> > --------------------------------------------------------------------- >> > This transmission (including any attachments) may contain confidential >> >> > information, privileged material (including material protected by the >> > solicitor-client or other applicable privileges), or constitute >> > non-public information. 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