Rules¶

A pcb-rules statement represents a set of design rules that the user can define for the system to enforce. These constraints are often driven by the limitations of a specific PCB manufacturer's fabrication process.

Signature¶

pcb-rules rules-name (arg1:Type1, ...):
  name = <String>           ; optional
  description = <String>    ; optional

  min-copper-width = <Double>
  min-copper-copper-space = <Double>
  min-copper-hole-space = <Double>
  min-copper-edge-space = <Double>
  min-annular-ring = <Double>
  min-drill-diameter = <Double>
  min-silkscreen-width = <Double>
  min-pitch-leaded = <Double>
  min-pitch-bga = <Double>
  max-board-width = <Double>
  max-board-height = <Double>
  min-silk-solder-mask-space = <Double>
  min-silkscreen-text-height = <Double>
  solder-mask-registration = <Double>
  min-th-pad-expand-outer = <Double>
  min-soldermask-opening = <Double>
  min-soldermask-bridge = <Double>
  min-hole-to-hole = <Double>
  min-pth-pin-solder-clearance = <Double>

The expression rules-name uniquely identifies this ruleset definition in the current context.

The argument list (arg1:Type1, ...) is optional and provides a means of constructing parameterized rules definitions.

Optional Parameters
name - Alternative name for this ruleset. rules-name expression is used by default.
description - Statement to describe this ruleset and capture any noteworthy details.

**Note that these parameters are not design rules themselves

All design rules are required to have a value. As such, any ruleset must specify a value for every rule. If no ruleset is explicitly set for the design, JITX applies a default ruleset. The supported design rules and their default values are as follows :

Rule Statement	Default Rules Value	Description
`min-copper-width`	0.127mm	Minimum size of a copper feature on a `geom`.
`min-copper-copper-space`	0.127mm	Minimum distance between copper features on the same layer.
`min-copper-hole-space`	0.2032mm	Minimum distance from a hole or cutout feature to a copper feature on any layer.
`min-copper-edge-space`	0.5mm	Minimum distance from the edge of the board to a copper feature on any layer.
`min-annular-ring`	0.1524mm	Minimum size of the annular ring around a hole or via.
`min-drill-diameter`	0.254mm	Minimum diameter of a hole, either in a pad or via.
`min-silkscreen-width`	0.127mm	Minimum size of a silkscreen feature.
`min-pitch-leaded`	0.35mm	Minimum distance between pad centers of a leaded component.
`min-pitch-bga`	0.35mm	Minimum distance between pad centers of a BGA component.
`max-board-width`	457.2mm	Maximum size of a board in the `x` direction.
`max-board-height`	609.6mm	Maximum size of a board in the `y` direction.
`min-silk-solder-mask-space`	0.15mm	Minimum distance between silkscreen and solder mask features.
`min-silkscreen-text-height`	0.1mm	Minimum height of text on silkscreen layers.
`min-pth-pin-solder-clearance`	0.762mm	Minimum distance between a through hole pad and solder mask.
`solder-mask-registration`	0.15mm	Minimum distance from the edge of a copper pad and solder mask feature.
`min-soldermask-opening`	0.152mm	Minimum size of a solder mask shape.
`min-soldermask-bridge`	0.102mm	Minimum distance between solder mask features.
`min-hole-to-hole`	0.254mm	Minimum distance between two holes in pads or vias.
`min-pth-pin-solder-clearance`	3.0mm	Minimum distance from the outer edge of a PTH pad's annular ring to any copper feature.

Usage¶

The design rules for a design are set by passing a pcb-rules definition to the set-rules function. The design rules for a design are set by passing a pcb-rules definition to the set-rules function.

public pcb-rules my-rules :
  name = "ruleset 35"
  description = "This is a toy example for pcb-rules."

  min-copper-width = 0.13
  min-copper-copper-space = 0.2
  min-copper-hole-space = 0.2032
  min-copper-edge-space = 0.381
  min-annular-ring = 0.1524
  min-drill-diameter = 0.254
  min-silkscreen-width = 0.2
  min-pitch-leaded = 0.35
  min-pitch-bga = 0.35
  max-board-width = 457.2
  max-board-height = 609.6
  solder-mask-registration = 0.15
  min-silk-solder-mask-space = 0.15
  min-silkscreen-text-height = 0.762
  min-th-pad-expand-outer = 0.15
  min-soldermask-opening = 0.152
  min-soldermask-bridge = 0.102
  min-hole-to-hole = 0.254
  min-pth-pin-solder-clearance = 3.0

...

set-rules(my-rules)

Introspection¶

print-current-rules() will print out the list of rules currently being applied and their current values.