Eltek Ltd. - Process Engineering wrote: > > At 23:52 15/12/97 -0500, you wrote: > >As a board manufacturer, I would be reluctant to agree to a 0.7% (.007in/in) > >flatness requirement without first reviewing the design of the circuitry in > >question. It is absolutely imperative that the board design is optimized for > >board flatness before any control can be achieved. I often state that the > >top five causes for non-flatness in todays products are, in order of > >significance: > > > >1) board design > >2) board design > >3) board design > >4) board design > >5) all other factors > > > >Dave Rooke > >Viasystems Canada > > David ! > I just can add my signature to Your statement . How many times we are > discussing this problem with DESIGNERS !!! > Most of them do not care about our remarks such us : > non - symetrical construction regarding dielectric spaces > unballaced construction regarding signals , ground , VSS > unballanced copper > Most of the anwers are : YYY supplied such boards to me without asking all > question , so take the job as it is or I will go to someone else ! > Edward > ARE THERE ANY SPECS OR GUIDELINES TO FOLLOW IN REGARDS TO THE BEST SPACING, ETC TO ACHIEVE FLAT BOARDS? THANKS -- ****************************** Mission Peak Services Engineering Department Visit us at: http://www.missionpeak.com ****************************** ############################################################## TechNet Mail List 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://www.ipc.org/html/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################