I think it's not so much that it's pressurized, actually atmospheric pressure in a submarine is on the low side (I served on one from 1988-92) but that it's enclosed with a recirculated atmosphere. In a submarine, oxygen is replenished, CO2 is scrubbed out and CO and hydrocarbons are oxidized, but certain contaminants are harder to remove.
Mercury vaporizes enough to be a concern under standard conditions, and normally things vaporize more as the pressure is lowered.
But you're right that it's not too surprising to receive a request for mercury-free certification.
Best Regards,
Timothy Reeves
Technical Service Engineer - Matsushita Electronic Materials, Inc.
4114 Heather Street, Forest Grove, Oregon, 97116
Main (503) 357-8695 Direct (503) 992-5109 Cell (503) 781-1495 Fax (503) 357-8868
-----Original Message-----
From: Quality [mailto:[log in to unmask]]
Sent: Thursday, March 20, 2003 1:40 PM
Subject: Re: Mercury Free Cert
Mark,
This is a fairly common request - especially for product that is
going into a pressurized vessel. (Submarines, airplanes etc.)
Seems mercury has a nasty habit of vaporizing under pressure.
Anyway, we went through the effort a few years ago to assure no
mercury is used in any materials we use - there were none. What
you have to watch for is the use of things that contain mercury like
thermometers.
pete
[log in to unmask]
On 18 Mar 03, at 7:46, Mark Hargreaves wrote:
> Hi All,
> Seems to be my month for receiving unusual certification requests from our
> bare board customers.
>
> Yesterday, a customer asked us to certify that our boards (or is it our
> processes?) are "mercury free".
>
> Before I start sifting through MSDS's, is anyone aware of any PCB materials
> (FR4), chemistries or processes that typically contain mercury?
>
> Are there any good info sources out there regarding mercury & PC fab?
>
> Many thanks for your responses to all of my past questions.
>
> Mark Hargreaves
>
> ---------------------------------------------------
> 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
> -----------------------------------------------------
Peter Menuez
QA Manager
Proto Circuit, Inc.
330-572-3400
---------------------------------------------------
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
-----------------------------------------------------
|
