Mixed Mode PCB Layers to Accelerate Design

27 February, 2019


Mixed Mode for PCB layer modeling is now available in Release 13 of 6SigmaET. In the previous releases of 6SigmaET, there were two options for modeling the copper on a board when modeling a PCB as either 3 layer Average or as explicit layers: Detailed or Simplified.  

The introduction of Mixed Mode was driven primarily by user feedback. Users occasionally found that Simplified did not provide a sufficient representation of the conduction path away from key components. In this instance, the only option was to switch to Detailed and take a significant hit in terms of grid count and solve times.

In Detailed, Traces & PCB Conductors exist in the model as explicit blocks of copper which are gridded finely. This mode provides the most detail to the model at the expense of requiring a lot of grid cells, which subsequently places a lot of demand on hardware. 

When using Simplified, the layer is converted to an image and an image processing algorithm determines the percentage of copper in each grid cell across the board. Material properties are then adjusted on a (grid) cell by cell basis. 

The advantage of this method is that additional grid cells aren’t created for the copper, which reduces computational expense when solving. It often provides a sufficient level of detail for most users.

So how does Mixed Mode combine the benefits of both? You start with a detailed layer, most likely imported from ECAD. Then, switch the ‘Modeling Level’ of the Layer Object to ‘Mixed’. You can then choose the PCB Conductor or Trace Segment object which you wish to model as Detailed and uncheck ‘Simplified’ in the ‘Construction’ section of the property sheet. When you hit ‘Solve’, you will be asked if you wish to convert the mixed model layer to image. Clicking ‘Yes’ generates the image needed to model the simplified parts of the mixed layer. You need to select this option the first time you solve, as well as after making any changes to the layer (e.g. selecting different traces to model in detail).

Mixed Mode allows you to model PCB Conductors & Traces in detail in specific areas of the board – such as in the vicinity of critical components – and model the rest of the board using the Simplified image processing method. This mode provides maximum detail where required, while also saving grid in less important areas. 


Blog written by: Matt Evans, Product Engineer