To explain in a layman's term; A long time ago, semiconductor mfg's produces IC's (Intergated Circuits) in DIP (dual in-line package) package styles. As advancements of packaging technology and other infrastructures, they started producing IC's in SMT package forms (surface mount technology) which are: - SOIC: small outline IC - PLCC: plastic leaded chip carrier - LCC: leadless chip carrier - QFP: quad flat package - SOT23: small outline transistor and so on. Without getting into details of SMT process, you can consider a BGA (Ball Grid Array) package as a second level of SMT packaging development. A BGA is a retangular or square flat body shape with numerous and tiny solder balls attached under the body in a grid. These tiny solder balls make interconnections to PCB (printed circuit board). The package is tended to be more expensive than QFP's or PLCC's at this time, but expect to be cheaper as the popularity of package increases. Blind/Buried via's Via's holes are connected thru from top to bottom sides of board by drilling all the way thru. A blind via is made half-way (less or more) from one side of board, therefore you don't see the same via hole from the other side. A buried via as the name states, is buried inside PCB, so you don't see the via hole from either side. re. mpark >>> BKDoughty1 <[log in to unmask]> April 8, 1998 12:58 pm >>> I need some very basic info on things that everyone here seems to know about. I'm feeling a little insecure (OK fine, I feel stupid asking but I don't know and want too) What are Ball Grid Arrays, do they replace IC's? Is it more expensive that other compatable parts.....will it drive up price if I use them. Are they only used for certain app.'s I know it's alot of questions, also what actually is a blind or buried via. Is a buried via for internal layers only? ################################################################ 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 ################################################################ ################################################################ 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 ################################################################