Al Slagle, PCB shops amaze me sometimes, one minute they want to remove non-functional lands, the next minute they want to add thieving (robber bars) to low density areas to assist plating thicknesses and the Z-axis thickness (especially for thick copper boards). What up with these guys! Is it really necessary to remove these lands if no holes are drilled at that location. Correction! Holes are drilled at this location. A non-functional pad is an inner layer pad (with a hole) that has no traces associated with it at that layer. That is why these non-anchored pads may float during lamination. The hole is most definitely there. Thieving is an entirely different issue. This typically is requested on outer layers where plating is involved. If the copper to be plated is imbalanced, overplating or burnt plating sometimes occurs on isolated features in order to get enough plating to the dense areas of the outer layers. That's "What (sic) up with these guys!" Hey, maybe we can start removing non functional conductors that are difficult to remove with most CAD systems. But with all fairness, I worked for a respected PCB shop and now work for a very respected assembly shop and in many ways I understand the perils each side. Guess what, I'm still a strong advocate for PCB vendors. Thomas John Gulley PCB Project Coordinator email: [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: pull-pads Author: [log in to unmask] at halsic_ccsmtp Date: 10/19/95 8:20 AM Al Slagle wrote: __________________________________________________________________ >AS DESIGNERS, WE OFTEN REMOVE SPECIFIC INTERNAL PADS BECAUSE OF DESIGN >CONSIDERATIONS; HIGH VOLTAGE, DENSITY PROBLEMS, RIGID-FLEX PCB'S, >WHATEVER. >BUT, WHEN FAB SHOPS WANT TO DO SO WE BAULK. >WE HAVE TO PULL PADS TO CREATE A VALID PCB DESIGN. >THEY WISH TO PULL PADS TO INCREASE THEIR YIELDS. >SO THE NEXT LOGICAL QUESTION IS; IF YOU ARE GOING INCREASE YOUR YIELDS AND >INCREASE YOUR PROFITS WHEN PRODUCING OUR BOARDS. ARE YOU ALSO GOING TO >PASS ALONG SOME OF THE SAVINGS BACK TO YOUR CUSTOMERS?? >TELL US HOW MUCH WE MIGHT BE LOWERING OUR COSTS, AND THEN LET'S DECIDE. >AL SLAGLE >CAD DESIGNER >HONEYWELL DASD ____________________________________________________________________ If the pads are pulled is the design invalid??? maybe sometimes but not always. If your design causes a decrease in yields will you pay more for the product, if an alternative design does not have a detrimental efect? Why would you baulk if the change does not impact performance? brian