Jack,
With some of our product just providing a generic DFM rule as you have
quoted is not enough/acceptable, on some boards with the 'real estate'
available it's necessary to provide a further option, i.e. allowing a
reduction of the clearance on one or two sides but increasing it on the
other two such that you can solder 'off centre'.
Hope this helps,
Iain.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Jack Olson
Sent: 19 November 2009 14:59
To: [log in to unmask]
Subject: Re: [TN] Selective Soldering Nozzle Clearance
*** WARNING ***
This mail has originated outside your organization, either from an
external partner or the Global Internet.
Keep this in mind if you answer this message.
Fortunately for us, Ioan was kind enough to forward a copy of the ERSA
DFM guidelines to us, which I never could find on the ERSA website (or I
would provide a link to it) but the name of it is VF_Layout_eng_V203.ppt
Anyway it was VERY helpful, they did a good job on it.
If anyone is interested, they put a restriction on the height of
components near the board edge, a bottom-side height restriction, and a
clearance around every soldering point depending on the nozzle diameter.
We have decided to design for a 6mm nozzle by default, and for that one
there should be no components in a 3mm radius of the CENTER of the
nozzle (that's for single-point soldering, for rows they want 3mm from
the edge of the nozzle, not the center ) and an EXTRA 3mm clearance to
the conveyor rail if the soldering point is close to the board edge.
thanks for the help, everyone (and a SPECIAL thank you to Ioan!)(smile)
Jack On Tue, Nov 17, 2009 at 9:42 AM, Dave Schaefer
<[log in to unmask]>wrote:
> Jack,
>
> Clearance is dictated by the Nozzle Size of the select solder machine.
> We use Nozzle Size +3mm diameter as a clearance rule. For most
> products we end up with a 11mm (0.433") keepout diameter ... we did at
> times violate but only with smt components that could be glued and not
> damaged by being subjected to secondary select solder.
>
> hth,
> Dave
>
>
---------------------------------------------------
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 email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person.
MBDA UK Limited, a company registered in England and Wales, registration number 3144919 whose registered office is at Six Hills Way, Stevenage, Hertfordshire, SG1 2DA, England.
********************************************************************
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please visit http://www.messagelabs.com/email
______________________________________________________________________
---------------------------------------------------
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
-----------------------------------------------------
|
