Signal Layers Checks

The Signal Layer action is a read-only action intended to find potential manufacturability defects in signal and mixed layers, and generate statistics. The action can operate on any layer, but is mainly intended for signal layers. It uses the layer itself and any NC (drill or rout) layer that pierces it. Categories, reports and attributes are generated.

The following tests can be applied to signal layers, as listed in the Action Screen and below:

1.      Spacing - reports spacing violations between pads, circuits and nets, and between text to text. Also reports shorts and spacing between different CAD nets and close distances between non-touching features on same CAD or Layer nets.

2.      Drill - reports distance violations between NPTHs/PTHs/Vias to pads, circuits, annular rings, and copper. Also reports missing pads.

3.      Rout - reports distance violations between edge of rout features to pads, circuits, etc.

4.      Size - reports sizes of pads, shaved lines, text, line neckdowns, arcs and shaved arcs.

5.      Sliver - reports on slivers between lines and pads or between pads and pads.

6.      Stubs - reports unconnected line endpoints.

7.      Center - not implemented at present.

8.      SMD - lists SMD pads, reports on pitch of SMD pads, and identifies SMD packages.

9.      Bottleneck - reports thin copper surfaces.

Attributes

A summary of Feature and Component attributes used during the Signal Layer Checks is shown below.

Feature Attributes

Attribute Name

Description

.nomenclature

This attribute defines a feature as a nomenclature legend feature. The attribute affects the fabrication analysis by directing spacing checks between such features into a new category (Text to text).

.pad_usage

The .pad_usage attribute can be attached to a feature and can one of five values:

*    toeprint

*    via

*    g_fiducial

*    l_fiducial

*    tooling_hole

.smd

This attribute should be attached to outer layer pads which are lands for SMD components. It is set by the 'Set SMD Attribute' Cleanup Action.

.drill

This attribute is attached to hole features in drill layers. It defines the type of the drill and is used extensively during fabrication analysis.

.pattern_fill

This attribute is attached to features which are added during a pattern fill operation, either manually or through the Copper Balance DFM action.

*         If a line / arc has this attribute attached, then it will not be reported in the line histogram display.

Component Attributes

Attribute Name

Description

.toep_spacing_req

This attribute is specifically attached to components for reporting in the Toeprint to Toeprint category. It defines the maximum spacing within which to report pad to pad spacing measurements

Range: 1-500

Units: inch/mm

 

Special Reports

In addition to a textual listing of all the categories and histograms (for all layers), the following special reports are created:

Parallel Line Spacing

This report lists the total length, in which spacing runs parallel between lines, for every spacing width in the design (in user definable width increments). This report is very useful in planning and forecasting yields.

Parallel Spacing Summary

#

Spacing (ml)

Total Length ()

1

6.0 - 6.2

16.732

2

8.4 - 8.6

55.740

3

10.0 - 10.2

10.622

4

13.4 - 13.6

12.194

Line Length Summary

This report lists the total length of all lines of the same width for every line width in the design (in user definable width increments).

Line Length Summary

#

Line width (ml)

Total Length ()

1

8.0 - 8.2

27.367

2

8.8 - 9.0

7.067

3

9.8 - 10.0

0.068

4

10.0 - 10.2

6.456

5

11.8 - 12.0

0.058

6

12.0 - 12.2

8.174

Result Attributes

 

Attribute

Description

...typ_par_space

Typical parallel spacing value over all parallel spacing measurements

...min_p2p

Minimum spacing between any two pads that belong to different nets

...typ_p2p

Typical pad to pad spacing

...min_p2c

Minimum spacing between any different net pad and conductor

...typ_p2c

Typical spacing between any different net pad and conductor

...min_c2c

Minimum spacing between any different net conductors

...typ_c2c

Typical spacing between any different net conductors

...min_self_spacing

Minimal spacing between two non-touching same net features (minimum sliver width)

...typ_self_spacing

Typical spacing between two non-touching same net features

...min_text2text

Minimum spacing between any two text features

...typ_text2text

Typical spacing between any two text features

...dra_npth2p

The DRA of the NPTH to Pad category

...min_npth2p

Minimum distance from an NPTH to a pad that does not touch it

...typ_npth2p

Typical distance from an NPTH to a pad that does not touch it

...dra_npth2c

The DRA for the NPTH to Pad category

...min_npth2c

Minimum distance from an NPTH to a non pad that does not touch it

...typ_npth2c

Typical distance from an NPTH to a non pad that does not touch it

...dra_pth2c

The DRA for the PTH to Copper category

...min_pth2c

Minimal measurement in the PTH to Copper category

...typ_pth2c

Typical measurement in the PTH to Copper category

...dra_via2c

The DRA for the Via to Copper category

...min_via2c

Minimal measurement in the Via to Copper category

...typ_via2c

Typical measurement in the Via to Copper category

...dra_ar

DRA for annular ring

...min_ar

Minimal annular ring measurement

...typ_ar

Typical annular ring measurement

...dra_pth_ar

The DRA for PTH annular ring

...min_pth_ar

Minimal PTH annular ring measurement value

...typ_pth_ar

Typical PTH annular ring measurement value

...dra_via_ar

DRA for via annular ring

...min_via_ar

Minimal via annular ring measurement value

...typ_via_ar

Typical via annular ring measurement value

...min_reg

Minimal PTH Registration measurement value

...typ_reg

Typical PTH Registration measurement value

...dra_npth_ar

DRA for NPTH annular ring

...min_npth_ar

Minimal NPTH annular ring measurement value

...typ_npth_ar

Typical NPTH annular ring measurement value

...min_npth_reg

Minimal NPTH Registration measurement value

...typ_npth_reg

Typical NPTH Registration measurement value

...min_r2c

Minimal Rout to Copper distance

...typ_r2c

Typical Rout to Copper distance

...min_pad

Minimal pad diameter

...typ_pad

Typical pad diameter

...min_line

Minimal line width

...typ_line

Typical line width

...min_shaved_line

Minimal (original) width of a shaved line

...typ_shaved_line

Typical (original) width of a shaved line

...min_sliver

Minimal sliver width

...typ_sliver

Typical sliver width

...num_stub

Number of stubs alarms

...typ_stub

Typical stub width

...min_smd_pad

Minimal SMD pad size

...typ_smd_pad

Typical SMD pad size

...min_smd_pitch

Minimal SMD pitch (distance between adjacent pad centers)

...typ_smd_pitch

Typical SMD pitch

...min_smd_package

Small dimension of the smallest SMD package

...typ_smd_package

Typical small dimension of the SMD packages

...min_conductor_width

Minimum value of all conductor width measurements

...typ_conductor_width

Typical value of conductor width measurements

...min_arc

Minimal width of arcs

...typ_arc

Typical width of arcs

...min_shaved_arc

Minimal (original) width of shaved arcs

...typ_shaved_arc

Typical (original) width of shaved arcs

...num_miss_via

Number of Missing Pad for PTH alarms

...num_miss_pth

Number of Missing Pad for Via alarms

...dra

Overall DRA of a board is the minimum of all DRAs for categories for which a DRA is defined: dra_npth2p, dra_npth2c, dra_pth2c, dra_via2c, dra_ar, dra_pth_ar, dra_via_ar

...num_npthtc

Number if all the cases of NPTH touches Copper alarms.