Just a follow up concerning a decision made here a few hours ago. We have decided to go with micro vias in our 30 mil pitch, 20 mil diameter BGA pads instead of plating over the top and to avoid the sequential lamination process, and associated costs and time factor. As some of us did this over a year ago, there was enough evidence to get the right folks to make this decision based on how well it worked when we came up with a paste and profile preventing some outgassing problems. Thieving no issue on our designs first because our outer dielectric thickness is less than 5 mils, as yours must be, and the via diameter is about 3 mils, as yours must be. Also, solder paste really not needed to effect solder joints as the balls do that. The solder paste becomes the fill and provides the compliance needed to "catch/capture" all the balls evenly for good solder joint formation. Hope this makes sense, Earl Moon --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------