>-----Original Message-----
>From:  Kittel, H. James @ SLC
>Sent:  Tuesday, March 23, 1999 3:35 PM
>To:    'Send Tech Net'
>Subject:       LPI Tented Vias for BGA's
>
>Gentleman,
>We just received some PWB's with what I expected would be "tented VIA's"
>inside the BGA footprint.  The VIA's were tented with LPI solder mask. They
>were tented closed on the top side but open on the back.  On the back side,
>the mask had dropped into the 12 mil diameter VIA hole instead of bridging
>across and sealing the VIA, something I didn't expect.
>
>The vendor tells me that is the only way to tent with LPI and other users in
>the industry are assembling cards with these partially closed VIA's without
>concern or problems.
>
>Are you guys building cards with partially closed VIA's?  What about
>contamination getting trapped in the VIA?  Is this a valid concern?
>
>Appreciate any comments.
>
>Jim Kittel
>
>
>
>

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################