TECHNET Archives

March 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:
"Dehoyos, Ramon" <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Dehoyos, Ramon
Date:
Wed, 30 Mar 2005 14:17:23 -0500
Content-Type:
text/plain
Parts/Attachments:
text/plain (206 lines)
        Hi Steve:
                        I have used on green LPI, a heat gun and a somewhat sharp wide solder iron tip. Move the heat around the area and scrap the masking with the tip. It comes off very fast.
        Regards,
        Ramon

-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Stephen Gregory
Sent: Wednesday, March 30, 2005 1:59 PM
To: [log in to unmask]
Subject: Re: [TN] Selective LPI soldermask removal...


I  messed up the URL in my email, some may have figured that
out. But it's: http://www.stevezeva.homestead.com


Kind regards,

-Steve Gregory-
Senior Process Engineer
LaBarge Incorporated
Tulsa, Oklahoma
(918) 459-2285
(918) 459-2350 FAX


|---------+----------------------------->
|         |           Jeffrey Bush      |
|         |           <Jeffrey.Bush@VTCI|
|         |           RCUITS.COM>       |
|         |           Sent by: TechNet  |
|         |           <[log in to unmask]> |
|         |                             |
|         |                             |
|         |           03/30/2005 12:39  |
|         |           PM                |
|         |           Please respond to |
|         |           TechNet E-Mail    |
|         |           Forum; Please     |
|         |           respond to Jeffrey|
|         |           Bush              |
|         |                             |
|---------+----------------------------->
  >--------------------------------------------------------------------------------------------------------------|
  |                                                                                                              |
  |       To:       [log in to unmask]                                                                              |
  |       cc:                                                                                                    |
  |       Subject:  Re: [TN] Selective LPI soldermask removal...                                                 |
  >--------------------------------------------------------------------------------------------------------------|




We could do this for you with laser.

Jeffrey Bush
Director, Quality Assurance and Technical Support

VERMONT CIRCUITS INCORPORATED
  76 Technology Drive - POB 1890
    Brattleboro, Vermont 05302
      Voice: 802.257.4571.21 Fax: 802.257.0011
           http://www.vtcircuits.com


-----Original Message-----
From: Stephen Gregory [mailto:[log in to unmask]]
Sent: Wednesday, March 30, 2005 12:25 PM
To: [log in to unmask]
Subject: [TN] Selective LPI soldermask removal...

Happy "Hump-day"!

I might have asked the list about this over a year ago, I can't
remember.
But I have this
assembly that goes into a Radar system. There's a device on the assembly
that has to
be sitting over the metal of the top layer plane, with no solder mask on
the board beneath
the footprint of the device for it to work properly. Unfortunately, the
solder mask file in the
gerbers didn't reflect this. So at the time (over a year ago), I
reworked
the boards that we
had to correct the problem...and let me tell you, it's a REAL PIA!

Go to: http://www.stevzeva.homestead.com and look at "Mask Removal", and
"After Tinning"
to see what I'm trying to do.

I did this over a year ago, and we got an order for these assemblies
again...but the gerber never
got corrected, and I get to do this again. WHOOPEE!

I have to remove the solder mask beneath where the device is going to be
installed, and then
I solder coat the area to cover the exposed copper. I'm removing the
solder
mask very, very
carefully with a Dremel and a very fine abrasive tip, and I'm using an
exacto knife with various
blades. This is all being done tediously under a microscope to prevent
the
copper from being
removed from the plane. We have a micro-blaster here to remove conformal
coating, but it can't
get down to the bare copper. That's why I'm using the Dremel and exacto
knife. This time when
the board house did their micro-etch or pumice scrub just prior to
applying
the solder mask, they
really did a good job! That mask is on there, and meant to stay put! I'm
really having a hell of a
time doing this on these latest fabs.

Is there any other way to remove this coating in the area that I need
to?
I'm thinking maybe a
laser. Does anybody know where I would go to get this done, and about
what
it would cost?
There's only 5-boards that I need this done to, but it takes me a couple
of
hours with each board
to complete the job.

Kind regards,

-Steve Gregory-
Senior Process Engineer
LaBarge Incorporated
Tulsa, Oklahoma
(918) 459-2285
(918) 459-2350 FAX
__________________________________________________________________
This message may contain information that is privileged and confidential
to
LaBarge, Inc.  It is for use only by the individual or entity named
above.
If you are not the intended recipient, you may not copy, use or deliver
this message to anyone.  In such event, you should destroy the message
and
kindly notify the sender by reply e-mail.

---------------------------------------------------
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
-----------------------------------------------------




__________________________________________________________________
This message may contain information that is privileged and confidential to
LaBarge, Inc.  It is for use only by the individual or entity named above.
If you are not the intended recipient, you may not copy, use or deliver
this message to anyone.  In such event, you should destroy the message and
kindly notify the sender by reply e-mail.

---------------------------------------------------
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