Hello All, I have three design questions open for discussion or debate. Please feel free to respond to any or all. 1.) Circuit Routing Programs: I have seen several designs where traces are routed at the minimum spacing, between two pads, when they could be routed differently to optimize spacing. These are typically designs with multiple traces running between pads. It appears the design algorithm will not automatically jog a single or multiple lines to maximize the spacing. Do effective, reliable, high quality programs exist that could maximize these types of designs? Does the design community support these programs, assuming they exist? You can guarantee I would notify the customer and let them review any changes prior to making implementing any changes. 2.) Plated Hole/Trace Spacing: In an effort to increase density I have seen a few designs where non functional pads have been removed from internal layers to rout the traces closer to the holes. The problem is that the traces have been 0.20 mm (0.0080) from the hole barrel. Referring to Table 5-10, in IPC-D-275 the minimum standard fabrication allowance is 0.25 mm (0.010). Therefore, using this value I would predict the minimum finished spacing I could assure the customer would be 0.08mm, (0.0030). I subtracted half of the minimum standard fabrication allowance from the minimum distance found between the trace and the hole barrel. Do you concur with this result? 3.) Drill/Gerber Data Misregistration: It is more common to find customers who provide drill data and gerber data which misregisters, approximately 1 out of every 5 jobs. We typically see this when Gerber data is provided in 2.4 format and the drill data is provided in 2.3 format. The amount of misregistration has been 0.03 mm (0.0010). We have also been told this misregistaration can be a result of the design software used. The main concern is this misregistration can effectively reduce your hole location allowance by 33%, considering 0.25 mm (.010) DTP. We correct the errors but wonder if this trend will be improving. Thanks is Advance for your thoughts, Mark Santos [log in to unmask]