Power / Ground Checks

Power / Ground Checks

Power / Ground Checks

Power/Ground Checks analyzes power/ground layers for design errors and creates a report to list all the findings
Power / Ground Check use different analysis method for positive and negative layers
For thermal pad analysis, thermal pads are required to be in negative layer and drawn with thermal symbols
Power / Ground Checks only provide analysis check, does not change layout content

Open Power / Ground Checks

In the Graphic Editor screen, click "Analysis" ，then click "Power / Ground Checks" 。( Command：chklist_single )

Parameters

Parameters values can be changed in the respective fields and saved in ERF
All values and settings shown in this guide is by default
Parameters interface are shown below ：

Parameters：

Layer

Select layer to run analysis

Drill to copper

Set maximum search range for drill to copper spacing

Minimal Sliver

Set value to detect sliver, feature with lower value will be regarded as sliver

Rout to copper

Set maximum search range for rout to copper spacing

NFP spacing

Set maximum search range for NFP spacing and NFP to copper spacing

Plane spacing

Set maximum search range for copper surface spacing

Test list

The following items will be analyzed for errors:
- Drill: Check for spacings between PTH / NPTH / Via to copper surface, annular Ring size
- Sliver: Detect slivers
- Rout: Check spacing between layer features to rout
- Thermal: Check Thermal pads for design errors
- NFP spacing: Check spacing between NFP to NFP, NFP to copper spacing
- Plane spacing: Check spacing between copper surfaces

Apply to

All: Analysis all features
Selected: Analysis selected features

Use Compensated Rout

Choose methods to analysis rout
- Yes:Use compensated rout for analysis
- No:Use original rout for analysis
- Skeleton:use rout skeleton for analysis

Set Range

Command：chklist_ erf_range

Set range value for each analysis check items
There are three types of analysis result: Critical, Warning or Safe
Default setting is avaialble for all parameters
Value can be changed in respective fields, and saved in ERF
See below picture for the Range interface：

Range ：

NPTH to Copper

Analyze NPTH to copper surface spacing, distance lower than Drill to copper value will be regarded as error
- Calculation method differs base on polarity：
  - Positive layer：spacing for NPTH and copper surface
  - Negative layer：spacing for NPTH and Annular Ring

NPTH to Plane

Analyze spacing between NPTH to Plane

yellow pad is NPTH hole，outter red part is Plane, blue is the spacing
- Limitations：for positive layer only

PTH annular ring

Analyze spacing between PTH hole to Thermal pad

Green is PTH，red is Thermal pad ，blue is the spacing
- limitatons：for negative layers only

PTH to Copper

Analyze spacing for PTH holes to copper surface
- works for layers with both polarity

PTH to Plane

Analyze spacing between PTH to Plane

yellow is PTH hole ，outter red part is Plane，blue is the spacing
- Limitations：for positive layer only

VIA annular ring

Analyze spacing between via holes to Thermal pads

Green is Via hole ，red is Thermal pad ，blue is the spacing
- limitatons：for negative layers only

VIA to Copper

Analyze spacing for via holes to copper surface
- works for layers with both polarity

VIA to Plane

Analyse spacing between Via hole to Plane

Yellow is Via hole，outter red part is Plane，blue is the spacing
- Limitations：for positive layer only

PTH partial touch copper

Turn on Report partial touch copper ，Detect if PTH hole touches copper surface
- works for layers with both polarity

VIA partial touch copper

Turn on Report partial touch copper , Detect if via hole touches copper surface
- works for layers with both polarity

PTH contains Clearance

Detect if PTH hole is larger than hole on copper surface based on [Drill to copper] value(#Power5)
- limitatons：for negative layers only

VIA contains Clearance

Detect if via hole is larger than hole on copper surface based on [Drill to copper] value(#Power5)
- limitatons：for negative layers only

NPTH contains Copper

Detect if NPTH hole is larger than hole on copper surface based on [Drill to copper] value(#Power5)
- limitatons：for negative layers only

PTH Registration

Detect center point distance between PTH hole and Pad，based on Reg allowance and Max reg value

NPTH Registration

Detect center point distance between NPTH hole and Pad, based on Reg allowance and Max reg value

VIA Registration

Detect center point distance between via hole and Pad, based on Reg allowance and Max reg value

Missing Cu for VIA

Detect if via hole is cover by copper without clearance

Spot NFP

Detect if pad size is smaller than drill holes
- Limitations：for positive layer only

Rout to Copper

Detect spacing for rout feature to copper suface
- Positive layer：spacing between rout to copper suface
- Negative layer：rout clearance

Missing Rout Clearance

Detect if rout feature contacts copper surface
- Limitations：for negative layer only

Slivers

Detect slivers
- Positive layer：detect slivers
- Negative layer：detect minimum spacings between features

Local Spacing

Detect silver on negative layers (Not functional)
- Limitations：for negative layer only

Spoke width

Detect Thermal pad spoke width size
- Limitations：for negative layer only

Thermal connect reduction

Detect possible error from Thermal Connect reduction

Complex Thermal Geometry

Detect if thermal pad spoke is overlaps with other features

Thermal air gap

Analyze air gap for thermal pads
Limitations：for negative layer only

Small Spoke Width

Analyze thermal pad spoke width
Limitations：for negative layer only

NFP spacing

Detect PTH and via holes covered in copper surface
Limitations：for negative layer only

NFP spacing (pos)

To be continued.

Plane spacing

Analyze spacing between planes

Plane width

To be continued.

Segmentation lines

To be continued.

Net too large

Detect if features in the net exceeds value in max net size，if so sliver or plane in this net will not be analyzed

Ignored Net

Detect net not analyzed in sliver checks because it was ignored

NPTH annular ring

Set NPTH annular ring to "yes" to include NPTH annular ring in analysis

Isolated Drill

Analyze isolated drill holes

Mechanical VIA annular ring

Analyze annular ring for mechanical via holes

Laser VIA annular ring

Analyze annular ring for laser via holes

Photo VIA annular ring

Analyze annular ring for Photo via holes

Set Advance Variables

Parameters values can be changed in the respective fields and saved in ERF
All values and settings shown in the examples is by default
Parameters interface are shown below ：

Advance Variables：

Drill

Reg allowance

Set center point distance tolerance for pad and drill, pad and drill is considered aligned if center point distance is within this value

Max reg

Set maximum center point distance tolerance for pad and drill
Pad and drill with center point distance higher than this value is considered not aligned, will not be analyzed

Report isolated drill

Report isolated drill = Yes, isolated drills will be analyzed
Report isolated drill = No, isoloated drill will not be analyzed

Report partial touch copper

Settings for PTH or Via drill holes that are partially overlaps with copper surface
- report_ptc = No，PTH or Via drill holes that are partially overlaps with copper surface will be included in PTH to Copper or Via to Copper
- v report ptc = Yes，PTH or Via drill that are partially overlaps with copper surface will be included in PTH partial touch copper or Via partial touch copper category

Report npth annular ring

Set NPTH holes that goes through copper surface to be categorized as npth_ar or npth2c

Take npth range

Set search range for NPTH drills to copper spacings，Use pp d2c parameter (take npth_range = 0) or npth2c range (take npth range = 1)

Classify via annular ring

Set this variable to "yes"，analysis result for via hole annular ring will be separated in three categories: mechanical, laser，and photo via annular ring.

Sliver

Min sliver length

Set minimum sliver length, Sliver length lower than input value will be categorized to "local spacing"

Dist to sliver ratio

Define sliver with edge to edge distance
If dist2sliver_ratio value is lower than input value, this feature will not be considered as sliver

Thermal

Min spoke width

Set Thermal spoke width, thermal pas with spoke width lower than input value will be categorized as: small_spoke
Set min spoke width = 0 (default value) to ignore this
Limitations：for negative layer only

Plane Spacing

Max net size

Set maximum allowed features in a net, nets with features

Min line length

Set minimum line length for line features to be analyzed.

length to width ratio

Set minimum length to width ratio for line features to be analyzed.

Plane Width

To be continued.

NFP spacing

NFP clear extend

In the power/ground negative layer, a drill hole without clearance can be a thermal pad or drill hole with non functional pad，to analyze NFP to Plane spacing，set distance value for NFP spacing between pad center point and maximum range
- example：Hole radius + Drill to Copper + NFP Spacing + nfp clr spacing, so spacing for NFP with extended annular rings could still be analyzed

Ignore Attributes

Set attributes to be ignored in analysis

Ignore Text

Yes = Ignore features with .nomenclature attribute in a net
These Nets will be categorized as Ignored Net
Ignore Text only works with sliver checks

Run Power / Ground Checks

Run Power / Ground Checks (Command：chklist_run)
Three buttons in the lower interface, each button runs the module at different area range
- Global ：Analyze all features in the layer ( Command：chklist_cupd )
- Screen ：Analyze all features in the screen display area( Command：chklist_cupd )
- Profile ：Analyze all features in profile frame( Command：chklist_cupd )

View Analysis Report

Click the " ＋ " button on the lower right to view analysis report ( Command：chklist_ res_show )

Result Viewer Form will be opened after click on the " ＋ " button

Result Viewer Form

In Result Viewer Form, Severity report will be displayed based on selected layers

Result Viewer Form Introduction

：Display analysis result by selected layers

Click None to unselect all layers in the list
Click All to select all layers in the list

：

Select Replace Layer to view all results in the layer list
Select Keep Layer to view single layer results

：Number of detected error types

：Back to the first error entry

：View previous error entry

：View next error entry

：Jump to the last error entry

：Error entry index number

：Choose method to view error entry in the layout：

Auto Zoom: zoom in error area when selecting the error entry
Pan Only: move screen to center on the error area
Popview: open popview on the error area
None: highlight error area only

：Remove reference mark

：Add reference mark

：Remove error entry marked with reference mark

：Open Result Report

：Open Result Histogram

：Error entry severity levels, red color is the most critical errors

：Display all error area in the layout

View Detected Error in the Layout

In Result Viewer Form, click " <-- " or " --> " to view each error entry in the layout (See example below)

Click "Show All" will highlight all the error spots in the layout(See example below)

View Result Histogram for Analysis

Select an error entry, click the bar icon on lower right to open Result Histogram

Command：chklist hist close

Command：chklist hist show

Example of Result Histogram ：