Issue link: https://resources.pcb.cadence.com/i/1533021
3. The values from the footprint properties will be populated both down and across the resulting table. Filling in each blank requires you to add up the two numbers that correspond to that location. Since the DFA_Bound shape is symmetric with the Place_Bound shape, you can use the same number for all values in the cell. If you type the value once, it will automatically repeat it in the format that allows customization on all sides. I've tried to adapt the values to account for an irregular Place_ Bound shape. I found it more expedient to just do a uniform reduction of the Place_Bound to make the DFA_Bound shape that uses the same value all around. Figure 5. The blue column with the hatch pattern is currently hard to read, however what it's indicating is that the package spacing rule is applied to the DFA class and not the symbol. In any case, the numbers represent the total of what's on the outside, kind of like a multiplication table except it's using the addition function. The last step is to save the table with a meaningful name related to the density of the board. From here on out, you do not use different footprints to create different spacing rules. Component spacing is controlled by the size of the DFA_Bound shape plus the values in the field. Of course, you will want to test drive the design rules to make sure you have the correct unit of measure and that all of the footprints have the DFA shapes and attributes. You could also go about this using each footprint rather than classes of footprints but that will lead to a rather large table requiring more clerical work to fill out the spacing rules. One possible way that improves things in the long run goes like this. When a Test Point Can Be Close to Anything Except Another Test Point A test point wants a nominal gap from a short component and a little more for a taller component. Beyond that, it wants a larger gap between itself and any other test points. So, you could have a line for the test points where the values are small until it gets to the cell where test point meets test point. Set that one to the value that pleases the bean counters that have to purchase the ICT fixture. The rest of the values are driven by the assembly people with the potential for wishful thinking from the EE side. Remember, it's your job to design the board for DFx. When I see DFM, I read "Design For Money". That may mean that you have to challenge the Assembly team rather than saying "No" to everyone else. One example of how the DFA process was more suitable was when I started the Chromecast device. Google had a library with the functional categories. The air gaps were set up by the people who design the internet backbone. Those data center boards required more space between parts than we could manage. 7 www.cadence.com Smart Placement Using Design for Assembly Tools