TECHNET Archives

March 2003

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:
Bev Christian <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Thu, 13 Mar 2003 08:25:53 -0500
Content-Type:
text/plain
Parts/Attachments:
text/plain (155 lines)
If the fluxing materials come from different suppliers you will never get them to officially put in print that they are compatible with each other. I know if I were them, I never would.  Think of all the combinations they would have to test!  

Now if you are lucky, on a good day you might get some of the bigger companies to say their own wave flux and own solder paste are compatible.

I know for a fact that some fluxes/solder pastes produced five years ago were not compatible with certain solder masks.  But things have got better in terms of both the flux and solder mask chemistries, so this is much more rare.

Some companies also have internal tests where they mix their wave solder flux, paste flux, cored wire flux and chip adhesive and test that dog's breakfast using SIR and electromigration.  Again they are obviously only testing the most likely combinations, not every combination possible from their AVL (approved vendor list).

But I know of no standard that specifically deals with this issue.

regards,
Bev Christian
Research in Motion

-----Original Message-----
From: Cagle, James [mailto:[log in to unmask]]
Sent: March 12, 2003 1:52 PM
To: [log in to unmask]
Subject: Re: [TN] Mixing fluxes - documentation vacuum


In J-STD-001,it says the fluxes must be compatible. Have your CM show you
data from both Paste/Flux manufacture that their products are OK to be used
with each other. >
>                                  James Cagle
> Tyco Printed Circuit Group-Hayward Division
>
>               email: [log in to unmask]
>


-----Original Message-----
From: Dave Hillman [mailto:[log in to unmask]]
Sent: Tuesday, March 11, 2003 7:45 AM
To: [log in to unmask]
Subject: Re: [TN] Mixing fluxes - documentation vacuum


Hi John! Take a look in the IPC-HDBK-001, section 7.2.1 flux application,
last paragraph. There is a cautionary statement (similar to the JSTD-001
statement Guy referenced) about the mixing of fluxes and the potential
hazard of added liquid flux as a soldering aid.

Dave Hillman
Rockwell Collins
[log in to unmask]




                      "Vivari, John"
                      <[log in to unmask]        To:       [log in to unmask]
                      COM>                     cc:
                      Sent by: TechNet         Subject:  [TN] Mixing fluxes
- documentation vacuum
                      <[log in to unmask]>


                      03/11/2003 08:10
                      AM
                      Please respond to
                      "TechNet E-Mail
                      Forum."; Please
                      respond to
                      "Vivari, John"






Dear TechNetters,

A customer of ours came to us with a request for a reference to an IPC
document or other industry standard that explicitly states the hazards of
mixing flux types on an assembly.  He asked for this because his contract
manufacturer built a set of boards using a No-clean solder paste and
reworked some BGAs with a water soluble solder paste.  The contract
manufacture states that he cannot find a standard "anywhere" that says the
flux types should not be mixed or that there will be any long term
reliability issues.  I know this seems naive but that is their position.

We have searched our library of specifications, books, and industry
periodicals and have come up empty except for vague statements about having
to clean between soldering operations for certain classes of product
without
explaining why and a reference in Ning-Cheng Lee's new book cautioning
against combining incompatible fluxes between reflow and wave soldering.
We
are well versed in the hazards of mixing our own fluxes (never mind others)
but have never been asked to provide "industry standard documentation"
before (as opposed to a letter of explanation).

Can anyone point to a reference that we have missed?

Hopefully yours,

John Vivari
Technical Service Engineer
EFD Inc.
[log in to unmask]
www.efdsolder.com
Ph: 401-333-3800
Fx: 401-333-4954

---------------------------------------------------
Technet Mail List provided as a free 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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
 -----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a free 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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a free 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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a free 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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------

ATOM RSS1 RSS2