>-----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 ################################################################