Russell
Yes, I chuckle when I hear the term halogen free, when you consider the
epoxide group in epoxy resins comes from epichlorohydrin! OK, I know
that most of the ionic chloride that is formed is removed in electrical
resins, but certainly not all, nor the remaining co-valent C-Cl bonds
that may result from the non-stoichiometry in the prepolymerisation
reaction.
Reminds me of the argument when the Germans introduced fluxes to DIN
8511 F-SW32 (halogen-free, rosin, carboxylic acid activated). Great fuss
and carry-on because they didn't clean as easily as halogen-activated
fluxes in ... wait for it ... trichlorotrifluoroethane (CFC-113)
azeotropes :-)
The problem with our industry is that we are prone to rule by buzzwords.
The current ones are lead-free and halogen-free, as if lead and halogens
were terrible problems, rather than elements that help us produce
reliable electronics at a reasonable price. We NEVER look at the
holistic picture, any more than the technocrats and politicians who
govern our lives by the introduction of stupid regulations which often
make us jump from the frying pan into the fire. What we need is guidance
from polyvalent people, rather than narrow-minded, blinker-wearing
cranks or vested interests: polyvalent people who can see the broad picture.
Brian
Smith, Russell (US LA) wrote:
> Your right on the money , I wonder why everyone considers something Halogen free , when It can have 900ppm of Cl and Br. to the best of my knowledge, they don't even look for F, or I . We have had a halogen free green for a couple of years now, but no major need in the States. Real big in Japan though. Another big monkey wrench in the mess of halogen is how to test it , and do you count free, bonded , or total in the material? I have seen some literature that some folks actually only count free halides. Any way What in this industry is changed without a major discussion.
>
> On the other hand yes they did pack me up and ship me to Ca. I still have to work for a living, haven't hit the lotto yet. I guess Ill go by a ticket this week!
>
> Nice hearing from you again
> Russ
> -----Original Message-----
> From: Dennis Fritz [mailto:[log in to unmask]]
> Sent: Tuesday, April 08, 2003 7:58 AM
> To: [log in to unmask]
> Subject: Re: [TN] New Topic: Why are most solder mask requirements,for
> GREENm...
>
>
> In a message dated 4/7/03 4:56:26 PM Central Daylight Time,
> [log in to unmask] writes:
>
> << So My point was it's not rocket science to get most of the halogen out
> when you make the mask blue. do you agree? >>
>
> Yes, should be halogen minimized, of course with purified epoxy and no
> brominated bisphenol A. Not much halogen in fumed silica filler, and
> catalysts for polymerization are not halogen containing.
>
> Did you move to California for Vantico, or are you still in Atlanta?
>
> Denny Fritz
> MacDermid.
>
> ---------------------------------------------------
> 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
> -----------------------------------------------------
>
>
>
---------------------------------------------------
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
-----------------------------------------------------
|
