Hi All: Maybe I'm missing something in this whole Cr6 laminate thread but I see it as a non-issue. Most of these chromate coatings are extremely thin 200-300 angstroms i.e. a millionth of an inch. Hot alkaline chemistry, strong acidic chemistries or mechanical surface prep strip the chromate conversion coating from the surface of the copper foil. So whether you are processing innnerlayers in a cleaning or oxide process or outerlayers in a cleaning or metallization process the presence of alkaline cleaners, surface treatments and/or acidic micro etches will remove the thin deposit of chromate coating from the foil. Thus making it RoHS compliant. Regards Michael Barmuta Staff Engineer Fluke Corp. Everett WA 425-446-6076 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Jeffrey Bush Sent: Wednesday, March 22, 2006 9:06 AM To: [log in to unmask] Subject: Re: [TN] chromates on copper surface (Cr6)? High presence of Cr3/Cr6 will cause issues with oxide treatment when using reduction/replacement chemistries. The chem clean process prior to resist lamination is designed to reduce the Cr3 to levels not affecting etch, strip and bonding treatment. Detecting levels related to this would seem to be evident in other areas in the process. Jeffrey Bush Director, Quality Assurance and Technical Support VERMONT CIRCUITS INCORPORATED 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302 Voice - 802.257.4571 ext 21 Fax - 802.257.0011 <http://www.vtcircuits.com/> -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Eddie Rocha Sent: Wednesday, March 22, 2006 10:45 AM To: [log in to unmask] Subject: Re: [TN] chromates on copper surface (Cr6)? A few responses are saying this same thing, that it won't be present after fabrication. I'll have to test it for myself because I have a customer that detected Cr. But the customer doesn't know which state of Cr. Do we just assume it is Cr3 and not Cr6? Thank you, Eddie Rocha If the Cu on the laminate is Cr+6 passivated on receipt, it won't be by the time you've prepared it for lamination as surely the pretreatment will remove the passivation layer? Regards Ian Fox Goodrich ECS -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman Sent: 22 March 2006 00:03 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 ----------------------------------------------------- --------------------------------------------------- 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 ----------------------------------------------------- This message (including any attachments) contains confidential and/or proprietary information intended only for the addressee. Any unauthorized disclosure, copying, distribution or reliance on the contents of this information is strictly prohibited and may constitute a violation of law. If you are not the intended recipient, please notify the sender immediately by responding to this e-mail, and delete the message from your system. If you have any questions about this e-mail please notify the sender immediately. Ce message (ainsi que les eventuelles pieces jointes) est exclusivement adresse au destinataire et contient des informations confidentielles. La copie, la communication ou la distribution du contenu de ce message sans l'accord prealable de l'expediteur sont strictement interdits et peuvent constituer un delit. Si vous n'etes pas destinataire de ce message, merci de le detruire et d'avertir l'expediteur. Si vous avez des questions se rapportant a ce courrier electronique, merci de bien vouloir notifier l'expediteur immediatement. --------------------------------------------------- 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 -----------------------------------------------------