Copper Balancing

Copper Balancing is a read-write DFM action designed to balance copper distribution for plating uniformity over signal layers, enhancing the etching process in different parts of the layer. To achieve this goal, small thieving features are added to blank areas of a layer. Special care is taken to maintain correct spacing between thieving features (round, squares, diamonds or special symbols) and actual signal layer features. Also maintained are the correct properties of the PCB, electrical or other.

Copper Balancing operates on any layer, but is mainly designed for signal layers. Relevant solder mask, silk screen and rout layers are referenced to the processed layer (if they exist).

Note: All thieving features are tagged with the .pattern_fill special attribute.

 

Copper Balancing Principles

The Copper Balancing Action performs the following:

*     It creates a grid of rectangular boxes where each box will contain the symbol selected for the fill pattern.

*     The size of the boxes, and therefore distances between symbols (pitch) are:

-         w= Pitch (or Symbol Pitch X, if Shape=Other)

-         h=Pitch (or Symbol Pitch Y, if Shape=Other)

*     The lower left corner of the grid, 0,0, is located at the layer datum point.

The placement of the shapes in the copper surfaces will be constrained by spacing requirements of circuitry and the existence of copper. A shape will not be created if placed partially on the profile or too close to a trace.

If the layer datum point is moved down, for example, or the shape size changed, one or more rows of shapes may disappear. In some cases you may find that where there is place for two rows of shapes in a certain section, they do not appear.

Special Reports

Displays the total thieving features added to each layer.

Result Attributes

 

Attribute

Description

...copper_balance_added

Number of thieving features added to each layer