What's Good About Cline Change Width in APD? It's in SPB16.2!

In IC package design, it is becoming increasingly necessary to change a cline’s width in a given region, whether for signal integrity reasons or to allow all necessary traces to pass through a particularly dense region. This can be done to a limited extent through the use of constraint areas, glossing, and the change command.

However, depending on the nature of the desired width change, this can be difficult to achieve. Constraint areas can be time consuming to construct, and if a cline serpentines around itself for delay reasons, the region can be difficult to accurately specify. The change command can only be used to modify an entire segment, and cannot add new vertices.

This command will overcome the above limitations and allow the user to more efficiently update key sections of their design, such as the fanout area beneath a flip-chip.

Upon launching the tool, you should select either the two-pick or window mode. In two-pick mode, you pick the first point on the cline, then the second point. The length of the clines between these two points (following the cline path) will be changed. In window mode, you make two picks to mark the two corners of the box. Two separate picks are still used, so that you are able to “oops” the first pick if it is not in the desired location, same as with the single trace mode.

Next, set the desired new line width.

Finally, make your selections in the main drawing canvas.

The picture below shows two copies of a cline, with the lower one resulting from a cline change width operation to lessen the line width between the two user picks.

Menu and Command-Line Access

Menu Pick: Edit > Cline Change Width… (near edit vertex)

Command Line: cline change width

 Graphical User Interface

The interface for this tool exists within the mini status options panel. It is shown in its default configuration in the figure below. The fields are defined as follows:

·        Two-pick single trace mode: Select this option (the default) to pick two locations on a single cline and change the width along the cline between those two points.

·        Window pick multi trace mode: Select to draw a selection window in the main canvas and change all the clines inside that region to the new width.

·        New width: The new width for the modified pieces of the cline(s). This defaults to the minimum line width on the top conductor layer in the design.

Once again, I'm always interested in your perspective on the new SPB16.2 features!

Jerry GenPart