Hi----- from Jurassica---- An over-simplified response to ------ G10 / FR4 (the Flame Retardant G-10) (old NEMA designations ----- equivelant to the original Mil Spec designations of GE and GF respectively ---- Considering G10 as the basic epoxy glass laminate, the FR4 was considered the G10 with Flame Retardant characteristics. The Mil spec permitted certification of the higher level in a hierarchy of products to pertain to the products on the lower levels and did permit certification of the GF to pertain to GE callouts on contract drawings. The differences in performance or processing was invariably a function of how the laminator achieved the flame-retardant properties ---- what modifications were made to the epoxy resin formula. Essentially, however, the properties for which one selected epoxy glass laminates---- certain mechanicals and moisture resistance amongst others ---- were not compromised by the flame-retardant characteristic. This is a broad stroke reply ----- the supplier in the case noted was correct in what he did. Best to all--- Bernie Kessler *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************