Mike,
The issue centers around organic compounds containing bromine and/or
chlorine.  Fluorine is not an issue because the carbon-fluorine bonds are
much stronger and fluorine does not get involved in the same biochemical
cycles that the larger, less polarizing chlorine and bromine atoms do.

regards,
Bev Christian
Nortel Networks

> -----Original Message-----
> From: Mcmaster, Michael [SMTP:[log in to unmask]]
> Sent: Thursday, July 08, 1999 12:39 PM
> To:   [log in to unmask]
> Subject:      Re: [TN] FR4 Replacement
>
> Is the issue bromine or halogens?  PTFE also contains a halogen.
> Mike McMaster
> RF Product Engineer
> Merix Corporation
> 503-992-4263
>
> > ----------
> > From:         Manfred Huschka[SMTP:[log in to unmask]]
> > Reply To:     TechNet E-Mail Forum.;Manfred Huschka
> > Sent:         Thursday, July 08, 1999 10:13 AM
> > To:   [log in to unmask]
> > Subject:      Re: [TN] FR4 Replacement
> >
> > The issue is revolving around the brominated flame retardant
> > Tetrabromobisphenol A, which the
> > resin manufacturers have to add to epoxy resin to achieve V-0
> > flammabiliy rating.
> > Alternatives are based on phosphorous compounds.
> >
> > Most polyimides do not contain bromine, but as you indicate,
> > polyimides are several times as
> > expensive as FR4. For high-speed digital work you could use low cost
> > PTFE/woven glass base
> > materials, like RF-35 from Taconic, which are in the BT-Epoxy price
> > range. PTFE base
> > materials do not contain any flame retardant and are V-0 approved (due
> > to the fluorine in the
> > molecular structure).
> >
> > Manfred Huschka
> > Taconic
> >
> > ------------------------
> >   From: "Hollandsworth, Ron" <[log in to unmask]>
> >   Subject: [TN] FR4 Replacement
> >   Date: Thu, 8 Jul 1999 10:30:45 -0500
> >   To: [log in to unmask]
> >
> >
> > Hello TechNet
> >
> > I have observed tons of conversation on Lead Free issues and
> > speculation
> > which is great, however, I have a question concerning the replacement
> > of
> > board material.  Specifically FR4.  I have heard that there is concern
> > surrounding the flame retardant used in FR4 and therefore FR4 may have
> > to be
> > replaced by some other board material.  Polyimide may be an option,
> > but what
> > will that do to cost.  Is polyimide more expensive?  Are there other
> > options?
> >
> > Ron Hollandsworth
> > Ops Task Leader AME Group
> > ITT
> >
> >
> > ---------------End of Original Message-----------------
> >
> > --------------------------------------------------------
> > Manfred Huschka
> > Taconic Advanced Dielectric Division
> > Mullingar Business Park
> > Mullingar, Co. Westmeath
> > Republic of Ireland
> >
> > NEW MOBILE PHONE NO.: +353/87/2858528
> >
> > Office until July 31/1999: PF 1275, D-51676 Wipperfuerth, Germany
> >                            Tel.: +49 2267 888004
> >                            Fax:  +49 2267 888005
> >
> >        after August 1/1999: Mullingar, Ireland
> >                             Tel. +353 44 34080 (direct)
> >                             Fax. +353 44 44369
> >
> > E-mail: Manfred Huschka <[log in to unmask]>
> > Web: http://www.taconic-add.com
> > Date: 07/08/99
> > Time: 18:13:01
> >
> > Taconic is exhibiting at European Microwave Week in Munich (Germany)
> > October 5 - 7, 1999. We look forward to meet you on our stand no. 16A.
> > http://www.eumw.com
> >
> > This message was sent by Z-Mail Pro - from NetManage
> > NetManage - delivers Standards Based IntraNet Solutions
> > --------------------------------------------------------
> >