TECHNET Archives

October 2008

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:
Phil Nutting <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Phil Nutting <[log in to unmask]>
Date:
Wed, 29 Oct 2008 11:29:28 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (62 lines)
Pete,

This is a great starting point for issues I'm seeing in our process too.

Thanks,

Phil Nutting

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Pete Houwen
Sent: Wednesday, October 29, 2008 9:07 AM
To: [log in to unmask]
Subject: Re: [TN] How to improve solder filling and wetting contact angles for thermal vias at wave soldering process.

We did some testing of design parameters when we switched to lead-free, and
found that the lead-hole ratio is more critical.  We also found that top side
pad size is irrelevant for hole fill, but large bottom side pads can adversly
affect hole fill.  Using this chart, we are able to achieve 75% with regularity
(and we do not have the best process controls in our plant):

Lead Range      Pad Size        Hole Size
.000-.017       0.05    0.026
.018-.022       0.06    0.035
.023-.027       0.07    0.04
.028-.032       0.07    0.046
.033-.042       0.08    0.052
.043-.052       0.09    0.062
.053-.063       0.1     0.073
.064-.076       0.11    0.086
.077-.086       0.12    0.096
.087-.106       0.14    0.116
.107-.115       0.15    0.125
(dimensions in inches)

standard plane connects are thermal relief, using (4) .008" spokes.

This testing was done only to establish design parameters, there are plenty of
process parameters that will affect hole fill.  But if your design parameters
aren't good, all the process tweaks in the world won't fix trhe problem.

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

Note: All the information contained in this e-mail and its attachments is proprietary to Kaiser Systems, Inc. and it may not be reproduced without the prior written permission of sender.  If you have received this email in error, please immediately return it to sender and delete the copy you received.

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