Cecilia Alkhagen said:


>What is the stat of the art regarding silicon adhesives and any silicon
>products in the electronics industry?
>Our company has a strong restriction against any silicon. Has the
>adhesives etc improved so that no monomers etc can evaporate?

You refer (assumedly) to silicone (silicon elastomers). If Ericsson is
proposing silicon free electronics, this could be radical. ;-)

Many of these so-called RTV (room temperature vulcanizing) silicones will
evolve acetic acid, which is added to the green adhesive to inhibit
polymerization. Thus, most of the silicone RTV adhesives can cause problems
to sensitive metal surfaces due to the corrosive effects of the acid.

I know that both Dow-Corning and GE are producing silicone adhesives which
do not contain acetic acid, and are marketed as being safe for use on
circuit boards.

The silicone "oils" (lubricants, release agents etc.) are also problematic
in that they can spread passive films which will inhibit wetting by paints,
fluxes, etc. which could affect soldering or other finishing.

As to the evolution of monomers, I'm unfamiliar with the mechanism or the
effect. The Swedes are quite possibly ahead of Texans in these matters,
however.


regards,





Jerry Cupples
Interphase Corporation
Dallas, TX USA
http://www.iphase.com

##############################################################
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
##############################################################