IMHO, equipment is more important than the water quality. With the right
cleaning/drying machines, used correctly, you can oftimes get away with
500 µS-cm water. With poor equipment, reasonably pure water becomes a
must. Of course, this also depends on the application.
I had one client successfully using mains water derived from a borehole
in the Jura mountains (as the name implies, calcareous Jurassic rock).
That water was so hard, with a conductivity of ~650 µS-cm, that you
almost stubbed your fingers when washing your hands (OK, I exaggerate,
but the lime visibly precipitated when heating it). His application was
not critical (office equipment).
Brian
On 22/04/2011 15:56, Karen Tellefsen wrote:
> It's been my experience that the SIR and ROSE results I get for test
> coupons washed in 2 Mohm cm water are considerable better than the result
> obtained after washing with city water, This would also depend on the
> particular city water, some are better than others.
>
> Karen Tellefsen - Electrical Testing
> [log in to unmask]
> 908-791-3069
>
>
>
>
>
>
> Re: [TN] Aqueous Wash, DI water and IPC Specifications.
>
>
> Robert Kondner
> to:
> TechNet
> 04/21/2011
> 06:46 PM
>
>
>
>
> Sent by:
> TechNet<[log in to unmask]>
> Please respond to rkondner
>
>
>
>
>
>
>
>
>
> 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
> -----------------------------------------------------
>
>
>
> ______________________________________________________________________
> 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
-----------------------------------------------------
|
