Message
Getting the paste isn't too hard. But, reflow (25-40
degrees above liquidous) temperature for those alloys is hazardous for FR-4, and
many components. Ceramic chip caps and thick film resistors might be okay
but this is clearly over the top for most plastic IC packages. We have done some
experimenting with direct attach and forming-gas to ceramic using these alloys.
One day we ran an FR-4 board though the oven without thinking. What came out of
the oven would best be described as ash with body.
Hi
Steve,
Hope you don't mind, I put a subject in the subject box for
your post...
As far as through-put issues with your dispenser, why not
print your epoxy. You would do the whole board in well less than 30-seconds,
and have much better accuracy and consistency than you could ever expect from
a dispenser.
As far as high temperature pastes go, you would need one
of the high-lead alloys in order to be above the typical solder pot
temperature of 500° F (260° C). Getting these alloys in paste form is going to
be challenge as well, you can bet that it's going to be a custom order with a
minimum buy too.
A few of those alloys are:
°
F ° C
Sn10Pb90 514 -
576
268 - 302
Sn10Pb88Ag02 514 -
570
268 - 299
Sn05Pb92.5 Ag2.5
536
280
My two-cents...
-Steve Gregory-
---------------------------------------------------------------------------------
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
---------------------------------------------------------------------------------