At 14:21 18/08/98 -0400, you wrote: >To TechNet Forum Members, > We are a contract manufacturer who assembles boards in a high mix low to medium volume environment. >Questions: >What PWB manufacturing process could be causing this? >There is no evidence of measling which is usually evident after gross Z-axis expansion, is there something we can do during the assembly process to help minimize Z-axis expansion? > How would you proceed with this situation? Mark , From our own experience , as PCB manufacturer , this is not your foult . The problem exists allready in the boards . First of all , locate the open via and perform crossection . It will give all answers . There are a lot of reasons for such opens . The most important point to your consideration : opens in small vias found after assembly are indicating , that reliability of finish boards is not good . You might be in situation , that there are a lot of opens in copper and only solder inside the hole create electrical connection . Send the boards to inspections . Good lack Edward Szpruch Eltek Ltd - Israel Tel 972 3 9395050 Fax 972 3 9309581 E-mail : [log in to unmask] ################################################################ 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 ################################################################ ################################################################ 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 ################################################################