Hi, From what I have read and heard it is ionic content on the board after the rinse/dry cycle that matters. That means you need an idea of final rinse dissolved solids content (assume they are all ionic) and how much water remains on the board after the rinse cycle. If you have an air knife or blowing system that removes most of the rinse water then it does not matter what you rinse with. From the amount of water I could measure on a PCB after rinse and blow off even the worse tap water is fine for rinse as the final board is very clean. Ok, now all the DI Rinse Only folks can start throwing rocks. Bob K. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Forrester, Michael (H USA) Sent: Thursday, April 21, 2011 6:17 PM To: [log in to unmask] Subject: Re: [TN] Aqueous Wash, DI water and IPC Specifications. Dave, For water washable fluxes, where cleaning is required, is DI water REQUIRED per IPC? IPC-AC-62A section 13.3 Final Rinse: implies DI water, section 10.6 I'm not sure what it implies. It states DI is preferred and then goes on to say it (refering to DI water) doesn't have to be ultra pure (18.2 MegOhm-cm) and that 1 to 5 MegOhm-cm is satisfactory. 1-5 MegOhm-cm DI water a min. REQUIREMENT? I have one side saying IPC spec REQUIRES DI water and the other side saying IPC spec only recommends/prefers DI water. It is basically a compliance issue. If DI water is not used in the aqueous wash is that a violation of IPC specifications? Best Regards, Michael Forrester Sr. Product Engineer CSMTPE Siemens Healthcare Diagnostics 101 Silvermine Rd. Brookfield, CT 06804 PH: (203) 740-6452 -----Original Message----- From: David Bealer [mailto:[log in to unmask]] Sent: Thursday, April 21, 2011 5:56 PM To: TechNet E-Mail Forum; Forrester, Michael (H USA) Subject: RE: [TN] Aqueous Wash, DI water and IPC Specifications. As I read IPC-610E; cleaning is not a requirement, as Flux residues from no-clean processes are acceptable for classes 1,2,& 3. We require our assemblies to meet IPC class 2, however we separately require those same assemblies to meet specific cleanliness requirements because of the end use environment. To meet those cleanliness requirements we use a water washable flux, and an inline recycling water wash system where the final rinse water is a minimum of 2Mohm. BR, David Bealer | SMT Department Manager Phone: (217) 442-0611 ext. 6022 | Fax: (217) 477-7134 Watchfire Signs by Time-O-Matic Inc. [log in to unmask] www.watchfiresigns.com -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Forrester, Michael (H USA) Sent: Thursday, April 21, 2011 4:06 PM To: [log in to unmask] Subject: Re: [TN] Aqueous Wash, DI water and IPC Specifications. What I'm trying to find out is do IPC specifications REQUIRE DI water? Best Regards, Michael Forrester Sr. Product Engineer CSMTPE Siemens Healthcare Diagnostics 101 Silvermine Rd. Brookfield, CT 06804 PH: (203) 740-6452 -----Original Message----- From: Woolley, Mark D. (Mark) [mailto:[log in to unmask]] Sent: Thursday, April 21, 2011 4:57 PM To: TechNet E-Mail Forum; Forrester, Michael (H USA) Subject: RE: [TN] Aqueous Wash, DI water and IPC Specifications. Unless DI water is continuously cleanses and filtered, DI water will decrease in resistivity due to disolved CO2. I believe that clean water without dissolved ions should be used for celaning, but it does not have to meet the DI water standard of 20Mohm resistivity as would be required for a wafer process. mark mark Mark Woolley |PTRL Laboratory | Avaya | 1300 West 120th Ave | Westminster, CO 80234 USA | Voice (Lab): (303) 538-2166 | email: [log in to unmask] | -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Forrester, Michael (H USA) Sent: Thursday, April 21, 2011 1:36 PM To: [log in to unmask] Subject: [TN] Aqueous Wash, DI water and IPC Specifications. I have a question about aqueous wash. There is a difference of opinion on what IPC REQUIRES as far as wash water. The main issue is does IPC specifications REQUIRE or PREFER/RECOMMEND DI water for aqueous wash? IPC-AC-62A I don't think is clear. The spec in section 10.6 states: "Rinse Water Parameter: Good quality deionized water is the preferred rinse medium. However, this is not meant to suggest that ultapure, 18.2 megohm-cm water is necessary. Water in the 1 to 5 megohm-cm region will be satisfactory for most operations" The same spec in section 13.3 states: "Final Rinse: This cleaning step is where the board is subject to purified DI water rinse." The PCBA print basically calls out build to IPC-610 class 2 and does not call out any specific cleaning specifications. So, with all that said, Is it an IPC REQUIREMENT to use DI water for aqueous wash? Thank you. Best Regards, Michael Forrester Sr. Product Engineer CSMTPE Siemens Healthcare Diagnostics 101 Silvermine Rd. Brookfield, CT 06804 PH: (203) 740-6452 ------------------------------------------------------------------------ ------- This message and any included attachments are from Siemens Healthcare Diagnostics and are intended only for the addressee(s). The information contained herein may include trade secrets or privileged or otherwise confidential information. Unauthorized review, forwarding, printing, copying, distributing, or using such information is strictly prohibited and may be unlawful. If you received this message in error, or have reason to believe you are not authorized to receive it, please promptly delete this message and notify the sender by e-mail with a copy to [log in to unmask] ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ------------------------------------------------------------------------ ------- This message and any included attachments are from Siemens Healthcare Diagnostics and are intended only for the addressee(s). The information contained herein may include trade secrets or privileged or otherwise confidential information. Unauthorized review, forwarding, printing, copying, distributing, or using such information is strictly prohibited and may be unlawful. If you received this message in error, or have reason to believe you are not authorized to receive it, please promptly delete this message and notify the sender by e-mail with a copy to [log in to unmask] ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ---------------------------------------------------------------------------- --- This message and any included attachments are from Siemens Healthcare Diagnostics and are intended only for the addressee(s). The information contained herein may include trade secrets or privileged or otherwise confidential information. Unauthorized review, forwarding, printing, copying, distributing, or using such information is strictly prohibited and may be unlawful. If you received this message in error, or have reason to believe you are not authorized to receive it, please promptly delete this message and notify the sender by e-mail with a copy to [log in to unmask] ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------