Ken,

Our manufacturing engineers conducted an extensive DOE study of extent,
thickness and adequacy of  Humiseal 1B31 conformal coating -- they even went
to the extent of doing various ratios of added thinner to enhance flow under
large components and leads and verifying results by cutting off the parts &
measuring coating thicknesses underneath.  If you'd like to send me your
address or fax number, I'll see if I can get a copy of the results for your
use.  By the way, for our production line, which is batch coating of boards
once or twice a week, we didn't even consider dip or flow as a cost
effective approach -- we were forced to make spray application work!

Sheila Smith, Tracor AES


At 11:55 AM 9/24/97 -0400, you wrote:
>Hello TechNet,
>
>I am looking for peer perspective on conformal coating coverage of CCA's
>and components.
>
>We currently are spraying Humiseal 1B31 manually from four directions.
>We have recently been requested to guarantee coverage under all
>components.
>Historically there has been debate on the degree of coverage under
>certain components - examples include
> large pin grid arrays, large potted transformers, and I suspect even
>BGA components.
>Even the insides of DIP leads (mounted on heatsinks) have been
>questioned in the past.
>
>Has anyone investigated coverage on these types of parts and / or does
>anyone have
>experiences with dip coating 1B31, either as an initial coat before
>spray coating or as a
>full coating?
>
>Hearing of your experiences would be much appreciated.
>
>Best regards,
>
>
>Ken Devitt  973-284-3880
>Manufacturing Engineering
>ITT Avionics
>Clifton, NJ
>
>##############################################################
>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.
>For the technical support contact Dmitriy Sklyar at [log in to unmask] or
847-509-9700 ext.311
>##############################################################
>

##############################################################
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.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
##############################################################