 
| Subject: | |
| From: | |
| Reply To: | |
| Date: | Thu, 23 Mar 2006 07:57:02 +0200 |
| Content-Type: | text/plain |
| Parts/Attachments: |
|
|
As far as I know Chromate layer is present on top of the copper foil. 99.9%
of probability that this is removed during surface preparation procedures
prior to plating and/or before photoresist application.
Edward
> -----Original Message-----
> From: David D. Hillman [SMTP:[log in to unmask]]
> Sent: ד מרץ 22 2006 2:03
> To: [log in to unmask]
> Subject: Re: [TN] chromates on copper surface (Cr6)?
>
> Hi Eddie! Just to add to Rudy's comments - any chromate conversion coating
> that is Cr+6 based does convert to Cr+3 when damaged (e.g. the self
> healing
> aspect) but there is always some of the Cr+6 species around. Any chromate
> conversion coating that is Cr+6 based is not RoHS compliant. Your supplier
> is incorrect unless he/she is supplying a Cr+3 or zero chromate conversion
> coating as Rudy described. Qualifying a substitute conversion coating that
> is "as good as or better than" a Cr+6 conversion coating is not an easy
> task depending on your use environment conditions. Good Luck.
>
> Dave
>
>
>
> Eddie Rocha
> <[log in to unmask]
> M> To
> Sent by: TechNet [log in to unmask]
> <[log in to unmask]> cc
>
> Subject
> 03/21/2006 05:56 Re: [TN] chromates on copper
> PM surface (Cr6)?
>
>
> Please respond to
> TechNet E-Mail
> Forum
> <[log in to unmask]>
> ; Please respond
> to
> Eddie Rocha
> <[log in to unmask]
> M>
>
>
>
>
>
>
> Was this a tough question? I didn't receive but one
> response. Thanks Rudy.
>
>
>
>
> Eddie:
>
> Not clear I can "explain" something which is likely
> incorrect.
> If your vendors start with Cr +6, the likelihood of there
> being zero Cr+6 on the foil is near zero... certainly some
> of the Cr +6 reacts with Copper metal Cu0 to form Cr+3 and
> Cu+2, but all of it? Hah... dream on.
>
> However, before you go off and begin screaming, I suspect
> strongly that some producers of foil may well be switching
> from Cr+6 to zero Cr coating... I cannot fathom why
> organics could not do as good a job...
>
> And if there are foil producers who need some technology to
> assist this change, contact me... :-)
>
> Rudy Sedlak
> RD Chemical Company
>
> Eddie Rocha <[log in to unmask]> wrote: I understand that
> copper foils are protected with chromates
> (Cr6) prior to producing laminate. Since this is an RoHS
> banned substance I need to understand why all my laminate
> suppliers have certified their material to be RoHS
> compliant.
>
> One supplier responded by stating that Cr6 is reduced to a
> state of Cr3 or Cr0 which is not a restricted substance.
>
> Can somebody explain how it goes from a state of Cr6 to one
> of the reduced states and why sometimes Cr3 versus Cr0?
>
>
> Thank you,
> Eddie Rocha
>
> ---------------------------------------------------
> Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for
> additional information, or contact Keach Sasamori at
> [log in to unmask] or 847-615-7100 ext.2815
> -----------------------------------------------------
>
>
>
> ---------------------------------
> Brings words and photos together (easily) with
>
> ---------------------------------------------------
> Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for
> additional information, or contact Keach Sasamori at
> [log in to unmask] or 847-615-7100 ext.2815
> -----------------------------------------------------
> PhotoMail - it's free and works with Yahoo! Mail.
>
> ---------------------------------------------------
> Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16
> for additional information, or contact Keach Sasamori at [log in to unmask] or
> 847-615-7100 ext.2815
> -----------------------------------------------------
>
> ---------------------------------------------------
> Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16
> for additional information, or contact Keach Sasamori at [log in to unmask] or
> 847-615-7100 ext.2815
> -----------------------------------------------------
---------------------------------------------------
Technet Mail List provided as a 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/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------
|
|
|
