You may have hit the nail on the head. We've found traces of dried gummy "oil"
on the surface of the pwb. The temp. was in excess of 350 F used to bond.
Thanks, will look into the rubber.
Ernie
Chuck Brummer <[log in to unmask]> on 31/10/2000 17:17:18
Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond to
Chuck Brummer <[log in to unmask]>
To: [log in to unmask]
cc: (bcc: Ernie Crump/WLO/Raytheon/CA)
Subject: Re: [TN] Silicone
Ernie,
Just as you stated, it was probably a silicone rubber sheet, usually red in
color. We use
these often in lamination for leveling the load. Some of the rubber is good to
about 345F.but
will ooze oil above that temperature. We try to use a different rubber, black
in color for
higher temperatures, up to 390F. This oil is very difficult to remove from
parts or panels.
Best bet is to clean with IPA then give it a plasma cleaning with a mostly
oxygen cycle.
Good Luck
Chuck Brummer
Acuson
Ernie Crump wrote:
> We have had a vendor use a silicone rubber mat on his platen while bonding a
> heatsink to a polymide pwb, and we suspect that the silicone has become part
of
> the pwb surface on the one side, as the UR coating process has produced
> fisheyes, and peelable coating, just on the one side.
> We use Bioact-7R, alcohol and then di water to clean in a proper monitored pwb
> washer, but the removal of silicone is very difficult.
> What cleaners are recommended for removing it, without destroying components,
or
> leaching under the bonded heatsink?
> Thank you. Ernie Crump Raytheon Systems Canada.
> Phone 519-885-0110, fax. 519-885-1178
>
>
---------------------------------------------------------------------------------
> Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
> To unsubscribe, send a message to [log in to unmask] with following text in
> the BODY (NOT the subject field): SIGNOFF Technet
> Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail 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 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail 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 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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
---------------------------------------------------------------------------------
|
