bet you used TIB0203 100k logics those days, and less than 500 MHz Inge ----- Original Message ----- From: "Stadem, Richard D." <[log in to unmask]> To: <[log in to unmask]> Sent: Thursday, September 10, 2009 9:46 PM Subject: Re: [TN] Need clever comments Funny you guys should mention that. When I started out as a digital troubleshooting tech at Honeywell in 1978, I worked in Underseas Systems on the Mod 2, Mk-46 Neartip, and Mk-50 Advanced Lightweight Torpedo guidance and control systems. I did that for 10 years. Brings back a lot of memories, so to speak. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Jerry Dengler Sent: Thursday, September 10, 2009 2:23 PM To: [log in to unmask] Subject: Re: [TN] Need clever comments Actually he is probably from the Mk-46 era . Jerry -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Inge Sent: Thursday, September 10, 2009 3:21 PM To: [log in to unmask] Subject: Re: [TN] Need clever comments pfffff.....handguns is nothing for Steve. He is probably more comfortable with MK-50 onboard a P-3. /Inge ----- Original Message ----- From: "Dwight Mattix" <[log in to unmask]> To: <[log in to unmask]> Sent: Thursday, September 10, 2009 8:52 PM Subject: Re: [TN] Need clever comments > At 10:45 AM 9/10/2009, Stadem, Richard D. wrote: >>Or hanging around the Laundromat with his .44 automatic. > > .44 automatic? I didn't take Steve for a Desert Eagle sort of guy. > > >>-----Original Message----- >>From: TechNet [mailto:[log in to unmask]] On Behalf Of Inge >>Sent: Thursday, September 10, 2009 11:25 AM >>To: [log in to unmask] >>Subject: Re: [TN] Need clever comments >> >>I will post a handful SEM images to Steve, so you get an idea what it's >>all >>about. >>It may take a while, because he is probably on the market place to buy >>curtains and wallpaper >>for his new appartment. Or jogging. Or having a drink on the balcony. >>/Inge >> >> >>----- Original Message ----- >>From: "Inge" <[log in to unmask]> >>To: <[log in to unmask]> >>Sent: Thursday, September 10, 2009 5:10 PM >>Subject: Re: [TN] Need clever comments >> >> >> > Jack &Paul, FYI. >> > >> > Today I had a close look at the cross sections. What I found was this: >> > >> > 1. The Tin plating was done AFTER solder mask (Jack was right) >> > 2. The solder mask was very uneven, thickness between 5um and 25 um. >> > 3. Despite the corrupted surface, the solder mask is homogenous, no >> > vertical cracks found. >> > 4. The copper that I found earlier on top of the conductor, i.e. on >>the >> > solder mask, that copper had no connection with the conductor copper. >> > Which means that these contaminations had NOT migrated through the >>solder >> > mask. >> > 5. I can still not figure out from where the copper contaminations >>come. >> > >> > So, all that remains is the question about the copper contaminations >>tha >> > embedded in the very surface of the solder mask. I have to adjust my >> > report and resend it to our customer and the board maker. >> > >> > Thanks to your critisism, I can now redo the analys, starting from a >>more >> > correct standpoint. >> > >> > Your are great! >> > >> > /Inge >> > >> > >> > >> > >> > ----- Original Message ----- >> > From: "Inge" <[log in to unmask]> >> > To: <[log in to unmask]> >> > Sent: Wednesday, September 09, 2009 8:09 PM >> > Subject: Re: [TN] Need clever comments >> > >> > >> >> Jack, >> >> >> >> SMOBC is the common industrial standard, as you pointed out, however, >> >> >> there ARE some fabricators that apply the solder mask after >>Tin/Lead-ing >> >> the copper traces. The later method has an obvioius disadvantage, see >> >> >> below quoted from an article written by US Environmental Agency: >> >> >> >> " This method predominates for several reasons. Copper is a surface >>that >> >> lends itself to rigorous cleaning, which is essential for solder mask >> >> >> adhesion. Tin-lead under solder mask will liquefy during soldering >>and >> >> may cause the mask to blister and peel. The hot air solder leveling >> >> process generally produces less waste water and introduces less lead >>into >> >> the waste water stream than tin-lead plating and reflow. Despite >>these >> >> advantages, well-known disadvantages also exist. The shelf-life of >>hot >> >> air solder leveled circuits is short and solder thicknesses on pads >>and >> >> hole barrels is notoriously difficult to control. For these reasons, >>a >> >> small minority of specifications continue to call for tin-lead plate >>and >> >> reflow or other alternati air solder leveling, nomenclature >>screening, >> >> and finally, gold edge plating if necessary. " >> >> >> >> I think that is what happened to our boards....." cause the mask to >> >> blister and peel"... >> >> >> >> Another paper describes Tin under solder mask this way: >> >> >> >> " Facility F initially was concerned with the soldermask breakdown >>where >> >> the Tin leaches underneath the soldermask....etc" >> >> >> >> Quoted from EPA (United States Environmental Protection Agency. >> >> >> >> When I started the investigation (had just some hours to spend before >> >> >> reporting the result!), I was fully convinced that these boards were >> >> SMOBC, but our customer said they used tinning before soldermask. I >>have >> >> asked for a confirmation from the board fabricator, but got no >>answer. >> >> >> >> Thanks for your comment, good critics. >> >> >> >> Inge >> >> >> >> >> >> ----- Original Message ----- >> >> From: "Jack Olson" <[log in to unmask]> >> >> To: <[log in to unmask]> >> >> Sent: Wednesday, September 09, 2009 4:44 PM >> >> Subject: [TN] Need clever comments >> >> >> >> >> >>>I know I'm late to the game, but I can't resist asking this question: >> >>> >> >>>>From my experience, the tin is applied AFTER soldermask, so >> >>> you have mask over bare copper, and tin over exposed copper. >> >>> >> >>> The tin in PHOTO2.JPG in the exposed area looks beautiful, >> >>> so isn't the question (ignoring the whiskers for the moment) >> >>> "How can bare copper erupt through the mask?" >> >>> >> >>> Unless I missed one of your previous posts, it seems to me that >> >>> any speculation about copper poking through the tin finish is >> >>> irrelevant. I'm only addressing Question 2 below, but you mentioned >> >>> introducing a nickel barrier, and that will not be plated under the >>mask >> >>> either, will it? only on exposed circuitry... >> >>> >> >>> just wondering, >> >>> Jack >> >>> >> >>> >> >>> -=-=-=- >> >>> >> >>> *Subject:* Need clever comments *From:* Hernefjord Ingemar < >> >>> [log in to unmask]> *Reply-To:* TechNet E-Mail Forum < >> >>> [log in to unmask]>, Hernefjord Ingemar >><[log in to unmask]> >> >>> * >> >>> Date:* Mon, 7 Sep 2009 13:21:54 +0200 *Content-Type:* text/plain >> >>> >> >>> >> >>> Hi all, need some professional backup regarding MIL quality boards. >> >>> >> >>> Objects: FR-4 Class III double-sided multi-layer boards, populated >> >>> with SOICS, BGAs,and a lot of passive components. >> >>> >> >>> Observation 1 : the non soldered board have lots of Tin whiskers on >> >>> inside of the PTH barrel. My thought is this: if whiskers can grow >> >>> long before the board is assembled, then ain't it likely that even >>CAF >> >>> can be generated? See photo 1. >> >>> >> >>> Observation 2: Copper has somehow penetrated the solder mask. This >> >>> can be found everywhere along the conductor traces. You need a very >> >>> good light microscope and a SEM to see it. See photo 2. >> >>> >> >>> Board data: Copper with 0.8 micrometer Immersion Tin. No nickel >> >>> barrier. Solder mask thickness not specified. >> >>> >> >>> Application: Typical MIL-883 environment >> >>> >> >>> Q1: What is your opinion about that thin Tin directly on copper? I >> >>> dislike the concept. Copper is very mobile at high temperatures, and >> >>> combined with humidity, there can be leakage currents and corrosion >> >>> issues. Even if the boards are CCd, there is a risk with copper . >> >>> >> >>> Q2: I gave the advice to introduce a nickel barrier, but our >>customer >> >>> claimed, that they can't because of pressfit connectors and pressfit >> >>> test pins on the board. Furthermore, they had heard that one cannot >> >>> have nickel platings when pressfitting, because the nickel will >>crack >> >>> and oxidize and cause electrical disfunction. Is this your opinion >> >>> too? Are there any relevant testing behind such statements? >> >>> >> >>> Thanks in advance >> >>> >> >>> Inge >> >>> >> >>> --------------------------------------------------- >> >>> 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 >>----------------------------------------------------- > > --------------------------------------------------- > 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 -----------------------------------------------------