In response to your questions both Grades 1 and 3 copper foils are readily available and the price difference between them is small. Their cost effectivness depends on the end use requirements. The answers to some questions will help you and your supplier determine the best alternative. Why was Grade 7 originally specified? Was it because of resistance to inner layer cracking? Then Grade 3 is the better alternative. Was it because a high frequency circuit is being used? If so then a low profile foil should be used. Is Grade 7's very low profile an important charcteristic? The a drum side treated foil in the appropriate Grade 1 or 3 is the better choice. Other considerations may also be factors. Sid Clouser Gould Foil Eastlake, OH Reply to message from [log in to unmask] of Thu, 25 Jan > >We are the design agent and user of printed circuit boards. Just recently >one of our board suppliers requested a material change >from: Rolled & Annealed Copper {IPC-MF-150, GR 7} on both sides of >0.031" FR-4 Laminate. > >to: Electrodeposited Copper {IPC-MF-150, GR 1} on both sides of 0.031" >FR-4 Laminate. > > OR > > Electrodeposited HTE Copper {IPC-MF-150, GR 3} on both sides of 0.031" >FR-4 Laminate. > >My question is which of the above material configurations is the most >available and the most cost efficient. > >Thank You One And All > > >