The Sliver & Acute Angles action is a read-write DFM action that runs on a layer and checks for sliver or acute angle instances that can be potential manufacturing defects. The action may fix the defects, if the right conditions exist. It returns information in the form of histograms, an ASCII detailed report, and result attributes. The action deals with slivers and with acute angles separately.
The fixing of acid traps and acute angles of most forms is performed intelligently, with only one to two lines. The action also fixes clearance spacing issues on negative power & ground layers. This is done by drawing a line between the centers of two clearances with a diameter two-thirds the size of the minimum of the two offending clearances (this default value can be changed by an ERF variable). It will then repair any remaining resist slivers.
This DFM action can be run on any layer. It is governed by the ERF file smooth.erf .
Screen
Parameters
Max. Sliver = 3.0 mils, maximum sliver width to be filled.
Angle (Deg) = 30.0 mils, maximum angle to be considered acute.
Max Pg Space = 2.0 mils, maximum space between clearances on a P&G layer that will be fixed.
Overlap = 1.0 mils, the overlap to use when filling slivers or acute angles.
Fix Clearances - Yes - will repair slivers between clearances on P&G layers.
Fix Acute - Yes - repairs or fixes acute angles.
Mode -
Analyze - runs Sliver & Acute Angles analysis only
without repair.
Repair - runs analysis and performs repairs.
DFM Mode |
Fix Acute |
|
Yes |
No |
|
Analyze |
Report on acute angles (default) |
Does not report on acute angles |
Repair |
Fix and report acute angles (default) |
Does not fix or report acute angles |
Work-On -
Copper - works on copper on both positive and negative layers (that is, on negative layers the system still considers copper as copper).
Features - on positive layers same as Copper, on negative layers works between features, as protrusions.
None.
None.
Notes
All features that are added will acquire the sliver_fill attribute.
The differences between slivers and filled slivers are:
Ø The ERF names are slivers and filled_slivers .
Ø Activation in the case of slivers is Mode=Analyze, in the case of filled_slivers it is Mode=Repair.
Ø In the case of filled_slivers , the feature (same size and shape as measurement) is added to the layer as a repair.
The function of both slivers and filled slivers are otherwise identical, and should reflect the same information.