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| From: | |
| Reply To: | (Leadfree Electronics Assembly Forum) |
| Date: | Thu, 22 Jul 2004 07:56:42 -0700 |
| Content-Type: | text/plain |
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I would like a copy of the paper
Thank you
Alan Cash NCE NCT PE
Northrop Grumman
Electronic Systems
Defensive Systems Division
M/S H6185
600 Hicks Rd.
Rolling Meadows, Illinois 60008-1098
E-Mail address: [log in to unmask]
Tel: 847-259-9600 X-6764 Fax: 847-870-5746
-----Original Message-----
From: Leadfree [mailto:[log in to unmask]]
Sent: Thursday, July 22, 2004 9:44 AM
To: [log in to unmask]
Subject: Re: [LF] LeadFree and Land Patterns (Wave solder)
Dear Bill,
Within Philips we have seen the necessity to change the solder pads for
wave soldering in some cases ad have made design rules.
Some general rules that we apply are stated below:
-Enlarged solder spacing QFP end solder thief pads
- Enlarged solder spacing multi row connectors
- Place multi pin components parallel to the solder transport direction
- Additional solder thief application
- No track/solder land connection, which reduces solder spacing
We reported about this at the IPC/JEDEC Pb-free conference in San Jose in
March this year together with our experiences of introducing Pb-free. If
you would like I can send a copy of this paper to you.
We have also worked with C-cut pads for similar problems and this seems to
work.
With kind regards,
Pascal
------------------------------------------------------------------
Dr. ir. P. Oberndorff
Philips CFT, SAQp 233
Process Technology/ Electronic Packaging & Thin Film
P.O. Box 218
5600 MD Eindhoven
Tel: +31 (0)40 27 32223
fax: +31 (0)40 27 36815
e-mail: [log in to unmask]
To: [log in to unmask]
cc: (bcc: Pascal Oberndorff/EHV/CFT/PHILIPS)
Subject: Re: [LF] LeadFree and Land Patterns (Wave solder)
"William E. Hunt" Classification:
<[log in to unmask]
M>
Sent by:
Leadfree
<[log in to unmask]>
2004-07-21 10:21 PM
Please respond to
"(Leadfree Electronics
Assembly Forum)"; Please
respond to
william.e.hunt
Has anyone seen changes for LF wave solder pad geometries? Our contract
mfg has requested pad changes for a component that is hand soldered after
the board passes through wave solder. The pad was collecting too much
solder and filling the hole. Then the hole would need to be cleaned out
and the part hand soldered to the board. The change was to a C-cut pad.
The idea of a C-cut pad is to prevent solder from filling the hole during
wave soldering so the component can be easily inserted and hand soldered
post wave. Instead of having just one opening in the pad the CM proposed
openings on both sides (leading and trailing edges) of the pad. This is a
high volume, simple type III assembly using a XPC laminate. We are still
investigating the need for this change and continue to test but I'm
interested in other experiences with LF wave soldering.
What are your experiences with LF wave solder?
Bill Hunt
Eastman Kodak
Office: 585-726-4892
Fax: 585-726-3278
Pratap Singh <[log in to unmask]>
Sent by: Leadfree <[log in to unmask]>
07/21/2004 03:13 PM
Please respond to "(Leadfree Electronics Assembly Forum)"; Please respond
to Pratap Singh
To: [log in to unmask]
cc:
Subject: Re: [LF] LeadFree and Land Patterns
Roger,
No need to fret. Land pattern should not be affected by converting to LF
solder. Depending upon the solder used, reflow profile settings will
change since LF solders flow at higher temperature.. Visual inspection
and void inspection should also remain same.
_____________________
pratap singh
Tel./Fax: (512) 255-6820
email: [log in to unmask]
www.rampinc.com
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847-509-9700 ext.5315
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To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Leadfree
To temporarily stop delivery of Leadree for vacation breaks send: SET Leadfree NOMAIL
Search previous postings 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
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-------------------------------------------------------------------------------Leadfee Mail List provided as a service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Leadfree
To temporarily stop delivery of Leadree for vacation breaks send: SET Leadfree NOMAIL
Search previous postings 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
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