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 -----------------------------------------------------