Hello all, We are now placing 56 bump uBGA's on several boards. Occationally some of the parts are blown off in the reflow oven, usually in the first 2 zones. I have also noticed that the parts after placement move quite easily, (appears that so little paste is deposited that what's left is not very sticky). Presently I'm using a standard .012 aperture in a .004 stepdown. I am considering trying a .014 square aperture with .006 radii on the corners on a .006 stainless stencil laser cut of course. Has anyone run into this problem or know of any solutions? Any help is welcomed. Russ Vertefeuille ################################################################ 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 ################################################################