JoAnn, When a standard is released and supersedes another standard, it is effective immediately. Some procurement contracts will allow automatic migration to the latest standard, while others require an approval. Very often an old standard becomes inactive for new designs. The 2000 series of standards have only recently been released by IPC. Therefore a number of companies are reviewing the impact of its content before retiring the IPC-D-275. On another note, the Pwb Design Certification process currently uses the IPC-D-275. The program is not affected since it utilizes the principles of design, rather than specific numbers in the tables of IPC-D-275. At some point, we will update our tables to those in the newer design standards. If would be happy to discuss the table on page 5 offline. Regards, Gary Ferrari Executive Director IPC Designers Council (860) 350-9300 Fax (860) 350-9309 [log in to unmask] >>> JoAnn Amerson <[log in to unmask]> 04/13/98 07:52AM >>> > The IPC Designers Council Certification Preparation Study Guide covers the DFM issues > surrounding sound printed board design practices. The basis of the guide is > IPC-D-275, Design Standard for Rigid Printed Boards and Rigid Printed Board > Assemblies. In addition, it references a number of other industry and IPC Standards. Gary, This reminds me of a question I've been curious about. I recently received my copies of IPC-2221 and 2222. They state that they supercede IPC-D-275. Is that effective immediately or down the road a bit? I'm confused because I still read a lot of posts referring to the latter and none to the former. Also, if any of you who understand Table 3-1 on page 5 of IPC-2221, would you please contact me? I have several questions about how to read that table and would appreciate some "simple" answers. I'm far from being a "guru" or an engineer (I can't even spell 'train'). Thanks everyone! JoAnn L. Amerson Design Librarian Red Lion Controls, Inc. E-mail: [log in to unmask] Voice: (717) 767-6961 ext 6308 ################################################################ DesignerCouncil 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 DesignerCouncil <your full name> To unsubscribe: SIGNOFF DesignerCouncil ################################################################ 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 ################################################################ ################################################################ DesignerCouncil 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 DesignerCouncil <your full name> To unsubscribe: SIGNOFF DesignerCouncil ################################################################ 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 ################################################################