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Width规则

Width Summary Defines the width of tracks placed on the copper (signal) layers.

Other Topics

Creating Design Rules

Design Rules

Width规则

Constraints

Min Width specifies the minimum permissible width to be used for tracks when routing the board. Specifying a value here

will apply to all signal layers.

(Default = 10 mil).

Max Width specifies the maximum permissible width to be used for tracks when routing the board. Specifying a value here

will apply to all signal layers.

(Default = 10 mil).

Preferred Width specifies the preferred width to be used for tracks when routing the board. Specifying a value here will apply to all

signal layers.

(Default = 10 mil).

Check Tracks/Arcs

Min/Max Width

Individually

checks individual widths of tracks and arcs fall within the minimum and maximum range.

(Default = enabled).Check Min/Max

Width for

Physically

Connected

Copper

checks the width of routed copper formed by a combination of tracks, arcs, fills, pads & vias fall within the minimum and maximum range. (Default = disabled)Characteristic

Impedance

Driven Width If the design needs to be routed to strict impedance requirements, ensure that this option is enabled. When the rule is configured in this mode, the routing width required on each routing layer is calculated based on the specified impedance, using the appropriate equation (microstrip or stripline) and the physical parameters of the

layer stack.

Once the rule is defined, as you route a net that falls under the scope of the rule, the track width will automatically

be set to the width required to meet the specified impedance for that layer.

(Default = disabled).

Layers in layerstack only

allows you to display and edit the width constraints for just the defined signal layers in the layer stack. When

enabled, only the layers in the stack will be displayed in the Layer Attributes Table. When disabled, all signal

layers will be displayed.

(Default = enabled).

Width规则

Width规则

Rule Classification

Unary

How Duplicate Rule Contentions are Resolved

All rules are resolved by the priority setting. The system goes through the rules from highest to lowest priority and picks the first one whose scope expression(s) match the object(s) being checked.

Rule Application

Preferred Width

The setting is obeyed by the Autorouter.

The and settings are obeyed by the Online DRC and Batch DRC. They also determine the range of permissible values that Min Width Max Width

TAB

can be used during interactive routing (press key while routing to change the trace width within the defined range). If a value is entered outside of this range a dialog will appear alerting you to this fact. You will be prompted to either continue, in which case the value will automatically be clipped, or cancel and change the value yourself.

Layer Stack Manager

The impedance equations used for calculating the impedance and trace width are accessed from the dialog, by pressing Impedance Calculation

the button. The subsequent dialog that appears

Impedance Formula Editor

- the dialog

- contains impedance calculators for both microstrip and stripline impedance calculations.

Width规则

Default equations are in place to calculate the impedance and the required trace width in order to satisfy that impedance when routing. Clicking Helper Query Helper

the button associated with an equation will open the dialog, from where you can edit the equation if required.

When defining values for the minimum, maximum and preferred routing widths, the Layer Attributes Table will highlight any invalid entries by using red text. This could happen, for example, when you specify a minimum constraint value that is greater than the maximum constraint value.

Width规则

The incorrect rule definition is further highlighted by the rule name becoming red in both the folder-tree pane and the respective summary lists.