And speaking of expelling noxious fumes... Consider the level of fumes expelled by a human body, if you rode a bicycle from SF to LA via Hyway 1? In my younger day, I used to consider this a wonder vacation... I believe the expression that applies here is "No Brain = No Pain". Rudy Sedlak --- On Tue, 8/26/08, Bev Christian <[log in to unmask]> wrote: > From: Bev Christian <[log in to unmask]> > Subject: Re: [TN] NTC > To: [log in to unmask] > Date: Tuesday, August 26, 2008, 1:52 PM > Paul, > Actually people expel hydrogen sulfide, not sulfur dioxide. > I read it in > a book about the subject written by a medical doctor. I > regaled Doug > Pauls and Dave Hillman with hilarious trivia from the book > as we drove > down highway one from SF to LA. > > At room temperature I would expect no reaction between > methane and > silver. I am not so sure about possible reactions at > elevated > temperatures. I am not a catalyst chemist. > Bev > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Paul > Reid > Sent: Tuesday, August 26, 2008 3:02 PM > To: [log in to unmask] > Subject: [TN] > > Remembering the Guys from Myth Busters, key note speakers > at IPC > LA...are those flatulent people who express sulfur dioxide > in their > gaseous eruptions (from eating deviled eggs) belonging to > the order of > the red flame or the order of the blue flame? > > I believe, that day in LA, that Bev enlightened us as to > the major > component of the gases expressed by flatulent new born > babies (H2). How > he would know such a thing was never explained however. > > Paul Reid > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Douglas > O. Pauls > Sent: Tuesday, August 26, 2008 2:23 PM > To: [log in to unmask] > Subject: [TN] > > Well, I guess that depends on what the previous meal was. > I don't know > if methane has the same harmful effect on immersion silver > as sulfur. I > suppose I could go knock back a dozen or so deviled eggs > and let you > know...... > > And Dewey, that was a horrid pun, even for you. Well done. > > Doug Pauls > > > > > Inge <[log in to unmask]> > Sent by: TechNet <[log in to unmask]> > 08/26/2008 10:12 PM > Please respond to > TechNet E-Mail Forum <[log in to unmask]>; Please > respond to Inge > <[log in to unmask]> > > > To > [log in to unmask] > cc > > Subject > [TN] > > > > > > > So a TV living with a gaseous family is at risk? > Inge > > > ----- Original Message ----- > From: "Woolley, Mark D. (Mark)" > <[log in to unmask]> > To: <[log in to unmask]> > Sent: Tuesday, August 26, 2008 7:37 AM > Subject: [TN] > > > Any environment that contains sulfur, like hydrogen sulfide > or sulfur > dioxide should preclude the use of IAg. The sulfur will > react with the > silver and "grow" sulfides which can be > electrically conductive > resulting is shorts between vias. This can occur even when > the > concentrations are within OSHA limits for human exposure. > Silver sulfides can be semiconductors or conductors > depending on the > chemical composition. They are black in color instead of > silver, any > exposed silver will be affected. > > Mark Woolley > Failure Analyst > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of James > Verrette > Sent: Tuesday, August 26, 2008 8:25 AM > To: [log in to unmask] > Subject: [TN] > > What characteristics of the end use environment would cause > IAg to not > be an appropriate finish and why? > > Jim Verrette > Senior Electrical Engineer > > ------------------------------ > > Date: Mon, 25 Aug 2008 08:24:35 -0500 > > From: "Stadem, Richard D." > <[log in to unmask]> > > Subject: Re: ENIG White paper > > Dave, > > You write as if you are not at all familiar with IAg, which > is totally > > understandable. However, IAg has been around in full > production mode for > > many years now, and is rapidly becoming the most-used > finish in the > > market. Do not confuse it with immersion tin finish, which > has little or > > no shelf life. > > IAg-finished circuit boards have a recommended shelf or > storage life of > > about 1 year. However, if packaged properly in a > hermetically sealed bag > > with silver saver paper liners, and stored away from > sulfates, it is > > possible to use boards up to 5 years old or even longer > with no issues > > whatsoever. All you need to do is call out the packaging on > the > > fabrication drawing per IPC 4553. > > I have soldered IAg boards that sat around exposed to the > elements for > > more than 4 years in previous lives, and they soldered up > just fine, no > > change in the DPMO. > > Some of the bare boards we use here at GD are 34" by > 40", 48 layers, > > 1/2" thick, cost is about $48,000 each. Their finish > is IAg. =20 > > I have had a lot of experience with IAg over the past 10 > years or so, > > having seen at least 150,000 IAg boards assembled and > soldered with > > every type of component you can think of, and I have never > experienced > > any issues with them. I have experienced many, many issues > with ENIG, > > however, and that is the finish that would keep me up at > night waiting > > for the bomb to go off. There are many reliability issues > associated > > with ENIG such as black pad, brittle nickel, etc., etc, but > just think > > about the fact that you are soldering to nickel, which has > a dissolution > > rate about 50 times slower than copper. > > Should you ever have a solderability issue with IAg, you > can have the > > fabricator rework the finish. If you have an issue with > ENIG, the only > > thing you can do is rework your scrap account. > > However, you need to take the end-use environment into > consideration > > when you select a circuit board finish. ENIG > (unfortunately) may be your > > best choice. I would fully qualify just one assembly at a > time, and I > > would fully qualify it. For Space use, I would not suggest > IAg. > > -----Original Message----- > > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using > LISTSERV 15.0 > To unsubscribe, send a message to [log in to unmask] with > following text > in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt or (re-start) delivery of Technet send > e-mail to > [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send > e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: > http://listserv.ipc.org/archives > Please visit IPC web site > http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for > additional > information, or contact Keach Sasamori at [log in to unmask] or > 847-615-7100 > ext.2815 > ----------------------------------------------------- > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using > LISTSERV 15.0 > To unsubscribe, send a message to [log in to unmask] with > following text > in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt or (re-start) delivery of Technet send > e-mail to > [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send > e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: > http://listserv.ipc.org/archives > Please visit IPC web site > http://www.ipc.org/contentpage.asp?Pageid=4.3.16 > > for additional information, or contact Keach Sasamori at > [log in to unmask] > or > > 847-615-7100 ext.2815 > ----------------------------------------------------- > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using > LISTSERV 15.0 > To unsubscribe, send a message to [log in to unmask] with > following text > in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt or (re-start) delivery of Technet send > e-mail to > [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send > e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: > http://listserv.ipc.org/archives > Please visit IPC web site > http://www.ipc.org/contentpage.asp?Pageid=4.3.16 > for additional information, or contact Keach Sasamori at > [log in to unmask] > or > 847-615-7100 ext.2815 > ----------------------------------------------------- > > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using > LISTSERV 15.0 > To unsubscribe, send a message to [log in to unmask] with > following text > in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt or (re-start) delivery of Technet send > e-mail to > [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send > e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: > http://listserv.ipc.org/archives > Please visit IPC web site > http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for > additional > information, or contact Keach Sasamori at [log in to unmask] or > 847-615-7100 > ext.2815 > ----------------------------------------------------- > > --------------------------------------------------- > Technet Mail List provided as a service by IPC using > LISTSERV 15.0 > To unsubscribe, send a message to [log in to unmask] with > following text > in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt or (re-start) delivery of Technet send > e-mail to > [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send > e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: > http://listserv.ipc.org/archives > Please visit IPC web site > http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for > additional > information, or contact Keach Sasamori at [log in to unmask] or > 847-615-7100 > ext.2815 > ----------------------------------------------------- > > --------------------------------------------------------------------- > 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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