Hi Bill,
How'd you arrive at an hour for preheat time?
(Why question it, Hans, it works, run with it.)
Since we only have bottom side preheat our assemblies get baked in an oven
too - pallet and all.
Hans
~~~~~~~~~~~~~~~~~~~
Hans M. Hinners
Materials Engineer (Process & Manufacturing)
Warner Robins Air Logistics Center
Avionics Production Division
Manufacturing Branch
380 Second Street, Suite 104
Building: 640, Mail Stop: LYPME
Robins AFB, GA 31098-1638
Voice: (478) 926 - 1970 Fax: (478) 926 - 7164
mailto:[log in to unmask]
http://www.robins.af.mil
-----Original Message-----
From: Kasprzak, Bill (esd) USX [mailto:[log in to unmask]]
Sent: Wednesday, August 16, 2000 11:57 AM
To: [log in to unmask]
Subject: Re: [TN] Wave soldering ancient designs...
Steve:
I kept my nose outta your problem with respect to not getting solder joint
topside fillets on selected connections because I wanted to see if your
problem could be solved by folks who use RMA fluxes. Seeing that you're
still in deep doodo, I'll offer the following:
I have several different "backpanel" that are .095 thick PWB's with heavy
heatsink holes in certain areas on the board. I am able to wavesolder these
boards quite easily by using a flux that is water-based instead of alcohol
based.
What I do is pre-heat my loaded assembly in an oven at about 190 - 200 deg.
F for about an hour. From the oven the "hot" assembly is transported
directly to my conveyor on my wave machine. I manually spray the bottom of
the board with my water based flux (Kester HF-1189A) and send the board on
its merry way through my regular soldering process on my ancient Treiber
Wavesolder machine. Results are usually pretty good. Seems that the water
based flux takes longer to dry out as opposed to the alcohol based flux and
is still quite active at the wave.
The only other process I can suggest is a vapor phase process which is not
too common anymore.
You can contact me off line via e-mail or give me a call. I can fill you in
on details.
Yes, this board is for a High-Rel Mil program.
Just my two-cents worth.
Bill Kasprzak
Moog Inc.
716-652-2000 ext 2507
> -----Original Message-----
> From: Stephen R. Gregory [SMTP:[log in to unmask]]
> Sent: Tuesday, August 15, 2000 9:58 PM
> To: [log in to unmask]
> Subject: [TN] Wave soldering ancient designs...
>
> Hey all...
>
> The last couple of weeks have been interesting to say the least as far as
> my
> wave soldering goes...(Hey Joyce! Any openings at your new
> place?...gofer',
> janitor, anything?... ;^)...).
>
> You may have read about my problems with the way pins connect to inner
> planes
> and all that, but now the last few days I've been trying to wave
> assemblies
> that have metal heat-sinks bonded to the top of the PCB with the PTH
> components installed on top of the heat-sink and then into the PCB...
>
> Again, I've tried everything that my feeble mind (at this point) can
> possibly
> do to wave these bloody things...
>
> I'm thinking that designs such as these cannot be wave soldered with any
> good
> results. Am I wrong in thinking that? Do these designs have to be hand
> built?
> Am I just spinning my wheels trying to wave solder them?
>
> Gawd, I'm getting beat-up by so many people because I can't figure out how
> to
> wave these pieces of...of...of..."work"...
>
> -Steve Gregory-
>
> ##############################################################
> 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 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 1.8c
##############################################################
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 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 1.8c
##############################################################
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 Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
##############################################################
|
