How to Overlay Shapes on Top of Sets of Reference Objects with the Latest Cadence IC Packaging Tools

Many of you are familiar with the bond finger soldermask opening creation tool—used for years, it allows you to create a single, smooth hole in your soldermask shapes that exposes all the bond fingers in a single row of fingers. Rather than having indents and sharp edges that can peel away, creating a simple opening allows for improved manufacturing and a cleaner overall design. But, did you know that you can now do this for any objects in your design—pins, vias, bond fingers, even cline segments? And that you can do so not just on the soldermask layer, but on any conductor, manufacturing, or geometry layer? Interested to learn more about this capability? Keep reading, and we’ll let you in on the secret. Create Bounding Shape The first step here is to enable the command. As a late addition to the 16.6 software release, this tool is still officially under beta. Don’t let that deter you, however. It is just a matter of the timing of its development. It will very quickly move to a standard feature. Until then, set the “icp_bounding_shape_beta” in your User Preferences (under the IC Packaging/Early Adopter category). Be sure to restart your tool to see the new entry in the Shapes menu. What exactly is a bounding shape, you ask? In mathematics, they would be called a convex hull. But, to most of us, the best explanation is that it is the shape you would get snapping a rubber band around the objects you selected. There are no cut-ins, no holes, and no acute angles to worry about (unless you had one in the actual outline of the items selected, of course). Below, you’ll find a graphical example: There are a number of options you have when creating these shapes with the new command. An image of the options panel is shown below, and we’ll walk you through the most interesting of these items: To start with, you can still automatically have the tool delete existing shapes. This matches the functionality in the bond finger soldermask tool, saving you a step of deleting the old shape before entering the command. You also have the option of whether to assign the net to the shape or not (assuming the target is a conductor layer)—if so, then the objects picked must be on that net. We don’t want you creating accidental shorts! And, you can specify whether a dynamic or static shape is used. Normally, you will likely want a static shape with this command, otherwise elements nearby could end up causing acute angles and cuts in the shape that you are trying to avoid. But there are always exceptions to every rule! An offset from the edge of the selected objects can also be set. This can be 0 (the default), positive (outside the reference items), or negative (inside the items). Plus, you can set the maximum distance between groups, allowing you the ability to window all the power pins on a layer at once and have the tool group them together into sets based on their proximity. Finally, you need to tell the tool what layer to pick up the pad shapes and segments from. You can sync this to the shape creation layer for those scenarios where you are creating a lot of shapes to join elements together, but if you disable that, pick the reference layer and place the shape wherever you like! Do You Create Reference Shapes in a Different Way? We have covered the creating bounding shape tool today, which deals with convex hulls around elements. Do you have a different way to create shapes that isn’t accommodated by such a tool? Or other useful parameters and options that should be in the bounding shape command when it moves from beta to production? If so, give our customer support team a call with your idea. We love hearing your suggestions and putting them into the tool to save you time, energy, and money in meeting your design timelines!