TECHNET Archives

December 2005

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:
"Schaefer, Chris" <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Schaefer, Chris
Date:
Wed, 14 Dec 2005 08:24:15 -0600
Content-Type:
text/plain
Parts/Attachments:
text/plain (80 lines)
I agree with that statement - Localized cleaning causes problems. We use a Humiseal 1A33 (UR) type coating on particular assemblies and when needed, we strip using the stripper stated by the matrix at the Humiseal website (I can't recall the material name - sorry). We deal with Class 3 and 2 assemblies with quite complex geometries and have had zero problem removing the bulk of the coating. I agree with the statement that once stripped that (if possible) send the CCA through an inline clean (preferably with saponifier) to ensure that all of the coating is removed. We do this without incident and once cleaning is complete we bake the boards, then re-coat. Be sure to check the material compatibility sheet with the stripper used and make sure that the components will not be damaged as a result - typically with most chemistries it takes anywhere from 1-XX minutes before it will cause any damage, but there are exceptions to this.

Hope this helps. Oh, you might want to try using ultrasonic cleaning if you have the right materials and the right equipment (20-40Khz I believe if the right range in order not to damage sensitive components), you should be able to clean underneath almost anything.

CAS

Chris Schaefer
Suntron Corporation
Process Engineer
540 N. Rogers Road
Olathe, Kansas 66062
913.393.5878
[log in to unmask]

NOTICE:
 
This message is intended for the use of the individual entity to which it is addressed and may contain information that is privileged, confidential and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, or the employee or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by calling 913.393.5878 or returning the original message to us.


-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of - Bogert
Sent: Wednesday, December 14, 2005 4:06 AM
To: [log in to unmask]
Subject: Re: [TN] Help with removing UR Conformal Coating


Don't use chemicals unless you can strip the complete PWA and clean it with an in-line cleaner.  The chemicals can become trapped under components and cause electrical shorts since some of these are conductive.  If the area is small, use heat only.  Better yet, switch to type AR coatting.
  ----- Original Message ----- 
  From: Joseph H. Smith<mailto:[log in to unmask]> 
  To: [log in to unmask]<mailto:[log in to unmask]> 
  Sent: Tuesday, December 13, 2005 9:47 AM
  Subject: [TN] Help with removing UR Conformal Coating


  Has anyone had experience or success with removing conformal coating for PWA that has been coated with UR coating especially using a chemical means.  I am particularly interested with how you handled coating around or under BGA's.

  Any help would be grateful.


  Thanks.

  Andrew Kettlewell
  Process Engineer
  Sypris Electronics
  Tampa, FL
  ___________________________________________________
  Try the New Netscape Mail Today!
  Virtually Spam-Free | More Storage | Import Your Contact List
  http://mail.netscape.com<http://mail.netscape.com/>

  ---------------------------------------------------
  Technet Mail List provided as a service by IPC using LISTSERV 1.8e
  To unsubscribe, send a message to [log in to unmask]<mailto:[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]<mailto:[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]<mailto:[log in to unmask]>: SET Technet Digest
  Search the archives of previous posts at: http://listserv.ipc.org/archives<http://listserv.ipc.org/archives>
  Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16<http://www.ipc.org/contentpage.asp?Pageid=4.3.16> for additional information, or contact Keach Sasamori at [log in to unmask]<mailto:[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
-----------------------------------------------------

ATOM RSS1 RSS2