Issue link: https://resources.pcb.cadence.com/i/1180282
High Density Interconnect Working with HDI October 2019 19 Product Version 17.4-2019 © 1999-2019 All Rights Reserved. This combination automates the sequence of layer transitions using stacked, staggered, and inset vias by localizing the steps of layer transition near the point of occurrence to maintain focus on the working board area, limiting travel to side panels or to the toolbar during routing. Metrics can be established to measure increased productivity and efficiency, relative to the number of mouse clicks to complete a connection. For more information, see Use Models for Adding Vias, in Chapter 8 of the Routing the Design user guide in your documentation set. Working Layer Model A list of layers currently in use for routing, working layers offer more flexibility than the availability of a single alternate layer. Working layers are only valid within the Route Connect (add connect command) and are expected to be a subset of visible layers. The active layer is typically expected to be one of the working layers, but it is not required to be. The Working Layers mode addresses the challenges of working on HDI designs. In this mode, the Working Layers dialog box displays all the etch layers in the current design and controls the layers that appear in the Via Popup interface. Instead of being confined to routing from an active layer to a single alternate layer, a double-click in this mode launches the pop-up interface with all working layers available for selection. A single pick on any layer resumes routing on that respective layer. When routing to HDI rules, you can automatically add stacked vias or semi-automatically add staggered vias across multiple layers. Additionally, you do not need to continually navigate from your design to the Options pane in order to select individual vias for each layer. For more information, see Adding Vias Using the Working Layers Mode in Chapter 8 of the Routing the Design user guide in your documentation set. Add Via Popup Interface The Via popup interface combines the selection of a layer and a via into one graphical display. This facilitates the transition of signals across HDI layers, accounting for stacking and staggering rules, as well as standard thru-hole technology. For more information, see Adding Preferred and Alternative Vias in Chapter 8 of the Routing the Design user guide in your documentation set. Ordered Via List An ordered via list lets you select the target layer to which to route while Allegro populates the preferred vias in the layer series. In Working Layers mode, you must have predefined vias in