Jason -
Check in with the folks at Enthone-OMI for tech support. Their contact
information is as follows: PX=(203)934-8661; FAX=(203)799-1513; WEB=
http://www.enthone-omi.com They are the formulator of CU-106A, and provide
some very good information on its "care and feeding".
These type materials tend to be quite sensitive to application conditions
and process controls by the board fabrication, but they can also be affected
by storage and handling within your own facility. Ron has provided some
good guidance in his comments.
Regards - Kelly
-----Original Message-----
From: Hollandsworth, Ron <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Thursday, December 16, 1999 7:50 AM
Subject: Re: [TN] OSP and wave soldering
>Jason:
>We have tried some OSP boards using what is suppose to be the "good stuff"
>OSP Cu106A. What we found was each heat cycle, i.e., reflow bottom, reflow
>top???, and/or glue operation for bottom side requiring a bake cycle, etc.,
>etc. . . . Every heat cycle the OSP is exposed to reduces your odds of
>getting the quality you or the customer would like at post wavesolder.
>
>As far as help or a solution, I am not sure what to say except maybe some
>things to consider. First, check the date code of the OSP boards. OSP
>boards normally have a shelf life. Second, reduce the amount of heat
cycles
>the OSP is exposed to as much as possible. Third, go out of the box and
>eliminate the OSP and if possible do a paste-in-hole rather than
wavesolder.
>So as not to mislead you into thinking paste-in-hole is a panacea,
>paste-in-hole presents another volume of opportunities for hole fill and
>potential wetting issues. Paste-In-Hole can be done, but will require some
>experimentation on your part with paste application/stencils/lead to hole
>ratios/etc . . . Fourth, the comment on HASL process. Your comment on
>"They won't do HASL either.", is/are "They" the customer or your PWB
>supplier? Do you have other options? Finally, what are your requirements
>for hole fill and does your inspection and customer know and understand
>these requirements?
>
>Hopefully this can help a little. There are a lot of TechNetters out there
>that are a lot more apt at giving you some great direction and ideas. If
>they haven't left for Christmas break.
>
>Ron Hollandsworth
>
>-----Original Message-----
>From: Jason Smith [mailto:[log in to unmask]]
>Sent: Thursday, December 16, 1999 7:50 AM
>To: [log in to unmask]
>Subject: Re: [TN] OSP and wave soldering
>
>
>I am having problems with wave soldering OSP boards. After the boards have
>seen
>a heat cycle (reflow), they are impossible to get hole fill on topside
>without
>first cleaning the boards to remove either oxidation or hardened OSP. I
>don't
>know which one I have because I haven't had them analyzed yet. The flux
>used to
>wave solder the boards is a very weak customer dictated rosin no clean
flux.
>The OSP is Cu106A. I am not familiar with OSPs. They won't do HASL
either.
>Any insight? Suggestions? Assistance?
>
>As it stands now, the process is to flux with high solids water
soluble/heat
>to
>clean the board-->wash off flux-->immediately wave solder with rosin
>containing
>no clean. This is not a production process........
>
>Jason Smith
>Process Materials Engineer
>Lexmark Electronics
>
>##############################################################
>TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
>##############################################################
>To subscribe/unsubscribe, send a message to [log in to unmask] with following
>text in
>the body:
>To subscribe: SUBSCRIBE TECHNET <your full name>
>To unsubscribe: SIGNOFF TECHNET
>##############################################################
>Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
additional
>information.
>If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
>847-509-9700 ext.5365
>##############################################################
>
>##############################################################
>TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
>##############################################################
>To subscribe/unsubscribe, send a message to [log in to unmask] with following
text in
>the body:
>To subscribe: SUBSCRIBE TECHNET <your full name>
>To unsubscribe: SIGNOFF TECHNET
>##############################################################
>Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
additional
>information.
>If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
>847-509-9700 ext.5365
>##############################################################
##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe: SUBSCRIBE TECHNET <your full name>
To unsubscribe: SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################
|