Dave try a flanged nut , so that the top layer of lamination is over the flange, Alternately try cleaned , treated Pems so that the Epoxy flows and adheres to the pems. That will give you a pull strength equal to the shear strength of the adhesive system in the prepreg. Also you could try a high strength epoxy after lamination to bond the insert to the hole wall. A though in closing , If the Pem or some insert has large threads or other protrusions on the outside then during the flow of the prepreg it should encapsulate and bond the insert in place. The trick is to keep the resin out of the treads. A high melting point wax plug is one way to do that , along with a liberal coating of PVA mold release Hope this gives you something else to think about Russ ---------- From: Dave Curry To: [log in to unmask] Subject: [TN] Technologies for blind HW Date: Friday, July 24, 1998 5:14PM We have a very unique application that require the use of 4-40 screw to mount a surface mount contactor to the topside of a PCB board but the HW can not interfere with Surface mount pads on the opposite side of the board. The board will use blind/buried via technology. We don't belive that a PEM inserted in to a blind machined hole will stay in place. Has anyone seen a technology for inserting hardware before the layer are laminated? Any other ideas? ################################################################ 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 ################################################################