Compared to wave soldering a much higher temperture is required.
There is much less solder mass touching the solder joint to transfer heat.
There is less dross as well.
Smaller variations arise from the variability of PCA and components.
Selective doing point to point soldering will be higher than a dip into a
multiwave selective solder.
The actual temp of the solder can be cooler than the pot settings when
measured at the top of the solder nozzle. There is less delta with a 12mm
nozzle compared to a 4mm nozzle. The design of the nozzle and how the solder
flows over the edge varies..
Frequently the optimum flux will be different than that used by a wave.
The preheaters are much less robust compared to the 6 foot with convection
available on many wave solder machines. Most selective preheaters are not
convection, which makes VOC free fluxes more challenging.
Most of the preheat is lost on point to point soldering.
Just ran a panel that took 5:55 minutes to solder. Not much preheat left
for the 2 and 3rd PCA in the array.
The 285 to 290C mentioned above would be a place to start.
Profile your own product and process for actual numbers.
On Wed, Jan 28, 2009 at 10:51 AM, Stadem, Richard D. <
[log in to unmask]> wrote:
> 290C. Per Pillarhouse recommendations, supported by qualification
> results. Preheat temp is critical.
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Braddock, Iain (UK)
> Sent: Wednesday, January 28, 2009 10:46 AM
> To: [log in to unmask]
> Subject: Re: [TN] SELECTIVE SOLDERING TEMPERATURES
>
> 285C!
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Lee Whiteman
> Sent: 28 January 2009 16:32
> To: [log in to unmask]
> Subject: [TN] SELECTIVE SOLDERING TEMPERATURES
>
> *** 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.
>
> What temperatures do folks operate their selective solder units with
> SnPb solder?
>
> In my prior life, I ran my wave soldering machine with SnPb at ~ 500F /
> 260C with good results. Guys in the shop are running considerably higher
> (~ 584F / 306C) citing board density concerns. My response would be to
> judiciously increase the thermal profile / preheat temperatures but not
> the solder pot temperature. The higher solder pot temperature results in
> much more dross and tin oxides.
>
> Just curious...
>
> Lee Whiteman, PMP
> Senior Member Engineering Staff
> L-3 Communications East
> Telephone: (856) 338-3508
> FAX: (856) 338-2906
> E-Mail: [log in to unmask]
>
> ---------------------------------------------------
> 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
> -----------------------------------------------------
>
> ---------------------------------------------------
> 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=4.3.16for 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
-----------------------------------------------------
|
