Ed,
Thanks for the response.
The only solder in the holes is from the paste. The board is Cu with OSP.
We use this particular press fit connector directly on the copper. The
boards were washed so no flux is left behind but they were not washed until
after reflow. I'm guessing that the solder is difficult to remove because
it was forced so deeply in the barrels when it was wiped. It also went
through a 2nd reflow process so it had an extra heat cycle to really melt.
We tried the hot air method but began to blister the solder mask and
oxidize the copper heavily before we could heat up enough to clear all of
the solder out. And, when you have 100 holes to clear, it's pretty risky.
Thanks,
Cheryl Tulkoff
Phone:(512) 683-8586
Fax: (512) 683-8847
National Instruments
11500 N. Mopac Expressway
Building A
Austin, TX 78759-3504
Ed Popielarski
<[log in to unmask] To: [log in to unmask]
OM.COM> cc:
Sent by: TechNet Subject: Re: [TN] Removing solder from PTH barrels
<[log in to unmask]>
08/10/2004 10:47
PM
Please respond to
TechNet E-Mail
Forum; Please
respond to Ed
Popielarski
Cheryl,
Are you trying to remove fused solder or solder paste from the barrels?
If fused, I caution an attempt to remove "all" of the solder, as the
remaining Cu base metal might not be compatible with the press pins.
Removal
of excess solder would easily be accomplished with a hot air method. Total
removal of the solder would most likely require drilling to remove the
intermetalic layer (Sn,Pb,Cu alloy) which can be accomplished with a "bomb
site" drill. Time consuming and somewhat risky, but it can be done.
If it's solder paste in the hole, most likely it could be washed out, and
should, since the flux remaining in the interface can cause serious
problems
down the road. Wiping the surface can compact the spheres into the hole and
make washing impractical, so an adequate cleaning process must be utilized.
Austin American Technologies makes an outstanding system for cleaning
misprint boards and stencils called the "X-Cleaner". Please feel free to
contact me offline to discuss this further if you like.
Regards,
Ed Popielarski
QTA Machine
27291 Jardines
Mission Viejo, Ca. 92692
Phone:949-581-6601
Fax: 949-218-7829 <------NEW!
WWW.QTA.NET
Be true to your work, your word, and your friends.
Henry David Thoreau
---------------------------------------------------
Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16
for additional information, or contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
-----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------
|
