IPC states (IPC-6012A.1 3.8.1.e) that mask is allowable in PTH where no
lead is intended.  Smaller vias (.010" and less) will typically have
residual mask from development, due to the lack of solution flow into
the hole to remove the material.  Mask in vias above .010" would
indicate some development issues in process.  No mask however is allowed
in the land areas that are intended to be clear. 

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: Chellis, Tammy [mailto:[log in to unmask]] 
Sent: Tuesday, December 21, 2004 1:19 PM
To: [log in to unmask]
Subject: [TN] FW: [TN] Plated through holes

Why is it acceptable in Vias?


-----Original Message-----
From: Jeffrey Bush [mailto:[log in to unmask]]
Sent: Monday, December 20, 2004 7:29 PM
To: TechNet E-Mail Forum; Chellis, Tammy
Subject: RE: [TN] Plated through holes


Vias yes - leaded holes no.

-----Original Message-----
From: Chellis, Tammy [mailto:[log in to unmask]]
Sent: Mon 12/20/2004 5:39 PM
To: [log in to unmask]
Cc:
Subject: [TN] Plated through holes



Is it acceptable for the LPI masking to be left in a plated through hole
preventing proper solder wetting?

---------------------------------------------------
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
<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] 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
-----------------------------------------------------