TECHNET Archives

September 2009

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Inge <[log in to unmask]>
Date:
Tue, 22 Sep 2009 23:12:01 +0200
Content-Type:
text/plain
Parts/Attachments:
text/plain (83 lines)
Some may be.  Did not think of that. Will check.
/Inge


----- Original Message ----- 
From: "Thayer, Wayne - IIW" <[log in to unmask]>
To: "'TechNet E-Mail Forum'" <[log in to unmask]>; "'Inge'" 
<[log in to unmask]>
Sent: Tuesday, September 22, 2009 10:57 PM
Subject: RE: [TN] Knock, knock, knock on the heaven's door


Hi Inge!

The DIPS aren't socketed, are they?

Wayne

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Inge
Sent: Tuesday, September 22, 2009 3:34 PM
To: [log in to unmask]
Subject: [TN] Knock, knock, knock on the heaven's door

Well, not exactly that, but knock, knock, knock on a earthly board. One 
customer needs fix a intermittent problem asap. 19 inch racks with hundreds 
of PTH double sided boards, old technology, no BGAs, no QFMs etc, but lots, 
lots of DIPs. The edge contact fingers have a very thick and good gold over 
nickel, and the backplane connectors have really stiff double tongues. The 
contact pressure/sq is extremly high and I think the contact spots are 
really gastight once the board is plugged in. Now, they have electrical 
issues, and they've found, that the signals are interrupted or coming back 
when they knock on the boards. Someone is going to take a flight the other 
day to fix the problem. The electricians believe, stubborn as mules, that 
the only think needed, is to take out the boards and clean the edge contact 
fingers with a solvent and that will fix it. Myself, with quite many year's 
experience from connectors, I don't think that is the problem, because when 
such robust contact springs wipe along the contact fingers, they slide 
pretty deep into the gold and makes good connection. Each spring has double 
contact ridges, so the risk that some dirt should cause interrupts is 
minimal. There is more that talks against their theory, namely, that the 
problem is still there after plugging, deplugging more than once. I'm sure 
there is a solder joint issue, or maybe a bond wire problem in the packages.
Logically, this later is more likely because you have thousands of 
solder/bond joints vs, just some one hundred edge connector ditto. A ratio 
like 10,000/100 per board. Without knowing all details, what is your general 
experience between the index finger and the big toe?

/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
-----------------------------------------------------

This e-mail and any files transmitted with it may be proprietary and are 
intended solely for the use of the individual or entity to whom they are 
addressed. If you have received this e-mail in error please notify the 
sender.
Please note that any views or opinions presented in this e-mail are solely 
those of the author and do not necessarily represent those of ITT 
Corporation. The recipient should check this e-mail and any attachments for 
the presence of viruses. ITT accepts no liability for any damage caused by 
any virus transmitted by this e-mail. 

---------------------------------------------------
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
-----------------------------------------------------

ATOM RSS1 RSS2