TECHNET Archives

March 2003

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:
Mel Parrish <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Thu, 20 Mar 2003 15:17:57 -0600
Content-Type:
text/plain
Parts/Attachments:
text/plain (158 lines)
Hi Bev,
There was a previous requirement in IPC specs J-STD-001B and IPC-A-610B
which stated a component standoff height (dimension G) of 0.2 mm.  Although
this was stated as a requirement for cleaning, that actually was a side
benefit to the original primary purpose of improved survivability of the
solder connections for non compliant lead components. It was based upon a
study that supported the improved performance with that dimension rather
than those closer to the surface of the board.
Happy reading!

Mel Parrish
Director, Training Materials Resources
Soldering Technology International
102 Tribble Drive
Madison, AL 35758
256 705 5530
256 705 5538 Fax
[log in to unmask]
www.solderingtech.com

-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Bev Christian
Sent: Thursday, March 20, 2003 1:31 PM
To: [log in to unmask]
Subject: Re: [TN] SMT Component Standoffs


Ha! I just got a copy and have read up to page 33, right before Appendix A.
Now I know I will be reading tonight. :}
Bev
--------------------------
Sent from my BlackBerry Wireless Handheld (www.BlackBerry.net)


-----Original Message-----
From: Guy Ramsey <[log in to unmask]>
To: 'TechNet E-Mail Forum.' <[log in to unmask]>; Bev Christian
<[log in to unmask]>
Sent: Thu Mar 20 14:28:19 2003
Subject: RE: [TN] SMT Component Standoffs

Yes, now you are getting picky ;~) Do you have a copy of IPC-D-279?
Section 3.5 Solder Joint Reliability, specifically 3.5.1.3 Solder Joint
Height seems to be the variable you are asking about. It is part of the
prediction equations A-3 and A-4 in the Design Guidelines. I have not
seen these translated into DFR rules. I think the other variables you
mentioned would exert too much of an influence to make any hard and fast
rules. Flexible rules . . . Sounds like Philadelphia traffic laws.
Werner?

> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Bev Christian
> Sent: Thursday, March 20, 2003 1:31 PM
> To: [log in to unmask]
> Subject: Re: [TN] SMT Component Standoffs
>
>
> Thanks, Guy, BUT this has to do with cleaning rather than
> mechanical reliability.
> Bev
> --------------------------
> Sent from my BlackBerry Wireless Handheld (www.BlackBerry.net)
>
>
> -----Original Message-----
> From: Guy Ramsey <[log in to unmask]>
> To: 'TechNet E-Mail Forum.' <[log in to unmask]>; Bev Christian
> <[log in to unmask]>
> Sent: Thu Mar 20 13:17:55 2003
> Subject: RE: [TN] SMT Component Standoffs
>
>
> There is help in IPC-SM-782A section 3.6.1.7 Component Stand
> Off Height for Cleaning and the associated table 3-7. The
> stand off recommendation varies with the component size. For
> example small component < 3mm x 3mm stand off > 0.05 mm. A
> large component 50mm x 50 mm stand off > 0.5 mm.
>
> > -----Original Message-----
> > From: TechNet [mailto:[log in to unmask]] On Behalf Of Bev Christian
> > Sent: Thursday, March 20, 2003 12:56 PM
> > To: [log in to unmask]
> > Subject: [TN] SMT Component Standoffs
> >
> >
> > TechNetters,
> > When I was at a former employer there was a minimum stand off
> > in the company specs.  I have forgotten what that was.  Now I
> > know that it can/should be different based on the solder, use
> > environment, pad sizes and lead/termination materials, but I
> > was wondering if anyone would be willing to share what they
> > have on the subject. I am particularly interested in land
> > grid array devices, if I may be so bold as to be picky.  :)
> > Thanks in advance.
> > Bev Christian
> > Research in Motion
> >
> > ---------------------------------------------------
> > Technet Mail List provided as a free service by IPC using
> > LISTSERV 1.8e 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/html/forum.htm for
> > additional information, or contact Keach Sasamori at
> > [log in to unmask] or 847-509-9700 ext.5315
> > -----------------------------------------------------
> >
>
> ---------------------------------------------------
> Technet Mail List provided as a free service by IPC using
> LISTSERV 1.8e
> 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/html/forum.htm for additional
> information, or contact Keach Sasamori at [log in to unmask] or
> 847-509-9700 ext.5315
> -----------------------------------------------------
>
>

---------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8e
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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------

ATOM RSS1 RSS2