My company is designing a MCM using chip on board technology. It uses a BT substrate and a PLCC package with castellations. The substrate is 1 inch square and gold plated. We have had problems in the past with vendors successfully manufacturing the substrate with castellations. I have a few questions: 1) Is this type of package widely used today? 2) Is there a better technology? 3) Recommendations on a vendor that is proven to be able to handle such a substrate. 4) Are there any reliability issues with this type of package? 5) Has anyone had experience attaching a MCM with castellations to an OPC type board (Entek PLUS)? Any comments would be greatly appreciated! Thank you. Best Regards, Mike Forrester LeCroy Corp. [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 web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################