TECHNET Archives

February 2011

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Paul Edwards <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Paul Edwards <[log in to unmask]>
Date:
Tue, 1 Feb 2011 10:01:04 -0800
Content-Type:
text/plain
Parts/Attachments:
text/plain (91 lines)
1) "City water" is chlorinated and fluorinated in most cities in the US so if you do not used DI water... You also get Fe-complexes, Chloride/Fluoride-complexes as the halogens react with organic material in the water...

2) How do you know you have "Chlorine contamination and gold
Dendrites" inside the post molding of the IC?

3)   Pressure - Again that depends... What type of nozzle and how far away are they...Those make all the difference...

Paul

Paul Edwards
Process/Quality Engineering
Surface Art Engineering


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Forrester, Michael (H USA)
Sent: Tuesday, February 01, 2011 9:08 AM
To: [log in to unmask]
Subject: [TN] PCBA Water Wash

I have three questions I hope someone can help me with:
 
    1) We have a vendor that uses "city water" directly into their SMT
PCA washer.  I believe DI water is industry standard.
    Does anyone know if it is documented anywhere?  Spec?
 
    2) We had an issue where there was Chlorine contamination and gold
dendrites found inside some standard gull-wing 6 pin SMT ICs.
        This issue seems to be batch related.  The chip manufacturer
claims that chlorine is never used in their process.  Should the SMT 
        process expect to handle the possibility that the wash solution
may get into a part? The PCA vendor uses unfiltered "city water", 
        with no cleaner, in the wash process and does a ROSE test on one
board of each lot.  Since the ROSE test passes, the PCA vendor 
        is blaming the part manufacturer for having "leaky" parts, since
the thinking is the wash is getting into the part and trapped.  
    3) One issue I have is the water pressure in the wash is 80-100 psi.
I think this is too strong, and should be half of that?  You want to 
        flood the board with water, not hit the board and bounce off?
 
    Thank you in advance.
 
Best Regards,
 
Michael Forrester
Sr. Product Engineer
 

______________________________________________________________________
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 15.0
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
Please visit IPC web site http://www.ipc.org/ContentPage.aspx?Pageid=E-mail-Forums for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------


==============================================================================

This email and any attachments thereto may contain private, confidential, and
privileged material for the sole use of the intended recipient. Any review, copying,
or distribution of this email (or any attachments thereto) by others is strictly prohibited.
If you are not the intended recipient, please contact [log in to unmask]
immediately and permanently delete the original and any copies of this email and
any attachments thereto. 

==============================================================================


______________________________________________________________________
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 15.0
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
Please visit IPC web site http://www.ipc.org/ContentPage.aspx?Pageid=E-mail-Forums for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------

ATOM RSS1 RSS2