TECHNET Archives

March 2010

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:
Robert Kondner <[log in to unmask]>
Reply To:
Date:
Thu, 4 Mar 2010 13:01:52 -0500
Content-Type:
text/plain
Parts/Attachments:
text/plain (75 lines)
Kenny,

  I would clean before I coat. I am no chemist but I would bet $$$ that
whatever it is on the board can interfere with the coating cure/dry process.


I know that no coating will stop moisture penetration and having voids or
other material where water can be trapped is really bad. The amount of water
within the coating is very small and the coating still remains a good
insulator. But if the water meets any ionic source under the coat you have
conduction at the PCB surface.

 If it was me I would rather go through another wash rather than coat over
the flux and not understand the process. 

 I do a little silicon spray coat on some boards. I rework with WS flux then
clean. 

Bob Kondner

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Ken Bloomquist
Sent: Thursday, March 04, 2010 12:20 PM
To: [log in to unmask]
Subject: [TN] Conformal Coat Over No-Clean Flux

We have a twelve leaded, through-hole component that has to be hand soldered
on the circuit board. The assembly gets conformal coated with urethane. We
would like to hand solder these twelve leads using no-clean and then
conformal coat the board. The component would be added as a final step after
the assembly has first been cleaned.

Since this is not a "total no-clean" process do you see any issues applying
conformal coat over these twelve no-clean solder joints?

Best regards,

KennyB


______________________________________________________________________
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.asp?Pageid=4.3.16
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 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.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------

ATOM RSS1 RSS2