Thank you everybody for their feedback.
Amol
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Hogg, Blair K.
Sent: Monday, February 05, 2007 9:28 AM
To: [log in to unmask]
Subject: Re: [TN] Conformal Coating Masking Requirements
Amol,
We use an Asymtek coating machine which avoids the need for masking. For
keep out areas the machine is programmed to skip these, and we make sure
that as a minimum all soldered areas are coated so that the solder
masked area around a keep out may or may not be coated. If a .100
diameter test point is needed to be left uncoated, we may leave a .250
square area around the keep out uncoated as long as it doesn't leave any
soldered areas exposed. As an OEM, we can make realistic decisions
in-house on how to perform our coating process. CMs can't be as
flexible, as they need to make sure that the result is acceptable to the
customer.
We test before coating, so we don't have to mask or skip test points
during the process.
Blair
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Kane, Amol (349)
Sent: Monday, February 05, 2007 9:07 AM
To: [log in to unmask]
Subject: [TN] Conformal Coating Masking Requirements
Dear all,
Since we are on the topic of conformal coating, I wanted to get a feel
for how conformal coating masking requirements are being requested by
the customer and being handled by the manufacturers. The customer
drawing usually states the type of CC to be used and the keep-out areas
for the coating (usually location Ids on the board). When one is masking
on the keep-out areas, what tolerances are being used around the
keep-out areas?.......IPC 610 D only states that there should be no CC
on keep-out areas, and therefore by logical deduction, also assumes that
all areas except the keep-out areas are to be covered by coating.
Obviously, there are practical limitations to this requirement. For
example, a test via is a keep-out area, but the trace running from the
via is not. Is everybody out there JUST masking the via, and then doing
manual touch up on the extra keep-out area if any, afterwards? If one
goes too close, the coating flows on the keep-out area, and if one
leaves some space, you are violating IPC specs! .,..........I am
thinking along the lines of asking customers to specify a tolerance for
the keep-out areas as some of them are very particular about this issue.
Requesting your thoughts, current best practices etc
Regards,
Amol
*******************************************************************
This email and any files transmitted with it are confidential and
intended solely for the use of the individual or entity to whom they
are addressed. If you have received this email in error please notify
the system manager.
This footnote also confirms that this email message has been swept
for the presence of computer viruses.
www.Hubbell.com - Hubbell Incorporated
---------------------------------------------------
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
-----------------------------------------------------
CONFIDENTIALITY NOTICE:
This e-mail, and any attachments, is for the sole use of the intended
recipient(s) and may contain information that is confidential and
protected from disclosure under the law. Any unauthorized review, use,
disclosure, or distribution is prohibited. If you are not the intended
recipient, please contact the sender by reply e-mail, and delete/destroy
all copies of the original message and attachments.
Thank you.
---------------------------------------------------
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
-----------------------------------------------------
|
