Session 4 - Post Processing
1.
UNDERSTANDING THE 6 CAD ELEMENTS
The 6 CAD ELEMENTS are: PADS ~ VIAS ~ TRACES ~ LINES ~ COPPER ~ TEXT
PADS
APPLICATION:
PADS are used to solder Component Leads on a Printed Circuit Board or used as Mounting Holes. PAD
clearance violations are checked using the DRC Mode clearance rules established in SETUP/DESIGN
RULES/DEFAULT & NET/CLEARANCES menu.
CREATION:
PADS can only be used in a Library Decal, so to create them you must use the TOOLS/DECAL
EDITOR. Once inside the Decal Editor, Select the [DRAFTING] Icon, then Select the PAD Icon.
PADSTACKS can contain all or any of the 30 layers, but the defaults are: Mounted Side, Inner Layer,
Opposite side & Layer_25 (Ground Plane Clearances and Thermo-relief outside diameters).
LIMITATIONS:
The PADS must be numeric characters, numbered sequentially, so that PAD numbers cannot be skipped.
To turn a PAD off, insert a PAD SIZE value of Zero and Shape must be Round. Alphabetical pin
number reassignments must be done in the creation of the PART TYPE. PAD size limit is .250” wide
for an Oval or Rectangle PAD with an unlimited length or .500” round or square.
QUERY MODE:
To Query a PAD: Right Mouse Button/Select Traces/Pins ~ Left Mouse Button click on the PAD, Right
Mouse Button/Query Modify.
APERTURE DECRIPTION:
Round & Square PADS are represented as a Flash Round or Flash Square, Rectangle PADS are drawn
with a square and Oval PADS are drawn with a round.
VIAS
APPLICATION:
VIAS are used to connect traces between layers. VIA clearance violations are checked using the DRC
Mode clearance rules established in SETUP/DESIGN RULES/DEFAULT & NET/CLEARANCES
CREATION:
VIA creation is done in the SETUP/PADSTACK pull down menu. Once inside the dialog box, select
the VIA button. The Padstack is: Start, Inner, End & Layer 25 (Ground Plane Clearances & Thermo-reliefs).
LIMITATIONS:
VIAS must be inserted while routing a trace, and cannot exist without a trace. You cannot put or use a
VIA to connect 2 Copper Pours on two different layers.
QUERY MODE:
To Query a VIA: Right Mouse Button/Select Traces/Pins ~ Left Mouse Button click on the VIA, Right
Mouse Button/Query Modify.
APERTURE DESCRIPTION: Most VIAS are round, and are represented by a Flash Round. Maximum
size .500”.
Rev. 2217 ©2002 ACUCAD ~ 1011 Glacier Pkwy, Algonquin, IL 60102-5004 Voice (847) 854-6052 FAX (847) 854-6053
4.1.1
Session 4 - Post Processing
TRACES
APPLICATION:
Traces are used to connect component decal PADS together per a schematic generated netlist. Traces are
checked by the DRC Mode by the clearance rules established in SETUP/DESIGN RULES.
CREATION:
Traces can be added to a design ON THE FLY using the ECO TOOL BOX, or by way of a PADS
Format Netlist. The Netlist is an ASCII text file. Use FILE/IMPORT ASCII to bring the Netlist into the
design file.
LIMITATIONS:
Traces require a Net Name. Traces can only reside on routing layers defined in the SETUP/LAYER
DEFINITION. Trace width cannot exceed .250”. To add more than one trace between a pin pair you
must use Route Loop.
QUERY MODE:
To Query a Trace: Right Mouse Button/Select Traces/Pins ~ Left Mouse Button click on the VIA, Right
Mouse Button/Query Modify.
APERTURE DESCRIPTION:
All Traces are drawn with a round aperture. The size of the draw aperture is determined by the Trace
Width.
2D-LINES
APPLICATION:
Drafting features like Board Outlines, Dimensioning, Title Blocks & Charts. 2D-Lines are not checked
by PADS software DRC checker. They can be used to short 2 PADS together without resulting in a
DRC checking error. The origin for a 2D-Line is the starting point of where the 2D-Line is inserted.
CREATION:
2D-Lines can only be created using the DRAFTING Tool Box, Pencil ICON. The width of a new line
can be changed by using the modeless command W. The layer that the line can be inserted on can be
changed by using the modeless command L. The Layer and Width can be changed by: Right mouse
button/Select Shapes, select the 2D-Line, Right mouse button/Query/Modify.
LIMITATIONS:
2D-Line width cannot exceed .250”. 2D-Lines should not be used on any routing layers inside the board
outline because they cannot be checked by the DRC checker.
QUERY MODE:
To Query a 2D-Line: Right Mouse Button/Select Shape ~ Left Mouse Button/Double Click the 2DLine.
APERTURE DESCRIPTION:
All 2D-Lines are drawn with a round aperture. The value (size) of the draw aperture is determined by the
line width.
4.1.2
Rev. 2217 ©2002 ACUCAD ~ 1011 Glacier Pkwy, Algonquin, IL 60102-5004 Voice (847) 854-6052 FAX (847) 854-6053
Session 4 - Post Processing
COPPER & COPPER POUR
APPLICATION:
To cover large areas of a printed circuit board with copper. Typically used for Voltage and Ground nets.
Another use is to remove solder mask from large areas. Can also be used in the creation of irregular
shaped PADS in the DECAL EDITOR. Copper can be placed on all Layers however only Copper
located inside the board outline on a routing layer will be checked by the DRC.
CREATION:
Copper can only be created using the DRAFTING TOOL BOX. The width of a new Copper fill or line
can be changed by using the modeless command W. The layer that the Copper is on can be changed by
using the modeless command L. Copper can be assigned to a net using the QUERY/MODIFY mode.
LIMITATIONS:
Copper line width cannot exceed .250”. The suggested minimum line width should be .005”, to prevent
large Gerber Data files. Copper cannot be created using a square draw, so the corners will always be
rounded.
QUERY MODE:
To Query Copper: Right Mouse Button/Select Shape ~ Left Mouse Button/Double Click the edge of the
Copper polygon (Not in the middle of the Polygon).
APERTURE DESCRIPTION:
All copper is drawn with a round aperture. The size of the draw aperture is determined by the line width
that was used to insert the polygon.
TEXT
APPLICATION:
Reference Designators, Documentation, Drafting and Dimensioning. Text on routing layers will be
checked by the DRC and Text on Layer 25 will come out as a negative or anti-copper. The best Text
Height and Width for Reference Designators on Silkscreen is .080” X .008” using a .0125 snap grid.
CREATION:
Text can only be created using the DRAFTING Tool Box. Default Text Height and Width can be set in
the SETUP/PREFERENCES/DRAFTING dialog box. Text Tip: Text Width ratio should be 10% of
Text Height, IE: .100”H X .010”W, .080”H X .008”W, .060”H X .006”W, etc.
LIMITATIONS:
Text Height cannot exceed 1.0”, and Text width cannot exceed .05”. Minimum text Height .05”, Width
.006” for best silk screen results.
QUERY MODE:
To Query Text: Right Mouse Button/Select Documentation ~ Left Mouse Button/Double Click the text.
APERTURE DESCRIPTION:
All text is drawn with a round aperture. The size of the draw aperture is determined by the text width.
Rev. 2217 ©2002 ACUCAD ~ 1011 Glacier Pkwy, Algonquin, IL 60102-5004 Voice (847) 854-6052 FAX (847) 854-6053
4.1.3
Session 4 - Post Processing
2.
LAYER CONFIGURATIONS
Layer 1
Layer 2
2
2A
(Top)
(TOP)
(Bottom) (GND)
2B
(GND)
(Bottom)
Layer 1
Layer 2
Layer 3
Layer 4
4
(Top)
(GND)
(PWR)
(Bottom)
4A
(Top)
(PWR)
(GND)
(Bottom)
4B
(Top)
(GND)
(Signal)
(Bottom)
4C
(Top)
(Signal)
(GND)
(Bottom)
4D
(Top)
(Signal)
(Signal)
(Bottom)
Layer 1
Layer 2
Layer 3
Layer 4
Layer 5
Layer 6
6
(Top)
(Signal)
(GND)
(PWR)
(Signal)
(Bottom)
6A
(Top)
(Signal)
(PWR)
(GND)
(Signal)
(Bottom)
6B
(Top)
(GND)
(Signal)
(Signal)
(PWR)
(Bottom)
6C
(Top)
(PWR)
(Signal)
(Signal)
(GND)
(Bottom)
6D
(Top)
(Signal)
(Signal)
(Signal)
(Signal)
(Bottom)
Layer 1
Layer 2
Layer 3
Layer 4
Layer 5
Layer 6
Layer 7
Layer 8
8
(Top)
(Signal)
(GND)
(Signal)
(Signal)
(PWR)
(Signal)
(Bottom)
8A
(Top)
(Signal)
(PWR)
(Signal)
(Signal)
(GND)
(Signal)
(Bottom)
8B
(Top)
(Signal)
(Signal)
(GND)
(PWR)
(Signal)
(Signal)
(Bottom)
8C
(Top)
(Signal)
(Signal)
(PWR)
(GND)
(Signal)
(Signal)
(Bottom)
8D
(Top)
(GND)
(Signal)
(Signal)
(Signal)
(Signal)
(PWR)
(Bottom)
8E
(Top)
(PWR)
(Signal)
(Signal)
(Signal)
(Signal)
(GND)
(Bottom)
8F
(Top)
(Signal)
(Signal)
(Signal)
(Signal)
(Signal)
(Signal)
(Bottom)
Layer 1
Layer 2
Layer 3
Layer 4
Layer 5
Layer 6
Layer 7
Layer 8
Layer 9
Layer 10
10
(Top)
(Signal)
(Signal)
(GND)
(Signal)
(Signal)
(PWR)
(Signal)
(Signal)
(Bottom)
10A
(Top)
(Signal)
(Signal)
(PWR)
(Signal)
(Signal)
(GND)
(Signal)
(Signal)
(Bottom)
10B
(Top)
(Signal)
(Signal)
(Signal)
(GND)
(PWR)
(Signal)
(Signal)
(Signal)
(Bottom)
10C
(Top)
(Signal)
(Signal)
(Signal)
(PWR)
(GND)
(Signal)
(Signal)
(Signal)
(Bottom)
10D
(Top)
(Signal)
(GND)
(Signal)
(Signal)
(Signal)
(Signal)
(PWR)
(Signal)
(Bottom)
10E
(Top)
(Signal)
(PWR)
(Signal)
(Signal)
(Signal)
(Signal)
(GND)
(Signal)
(Bottom)
10F
(Top)
(GND)
(Signal)
(Signal)
(Signal)
(Signal)
(Signal)
(Signal)
(PWR)
(Bottom)
10G
(Top)
(PWR)
(Signal)
(Signal)
(Signal)
(Signal)
(Signal)
(Signal)
(GND)
(Bottom)
10H
(Top)
(Signal)
(Signal)
(Signal)
(Signal)
(Signal)
(Signal)
(Signal)
(Signal)
(Bottom)
10J
(Top)
(GND 1)
(Signal)
(Signal)
(PWR 1)
(GND 2)
(Signal)
(Signal)
(PWR 2)
(Bottom)
10K
Layer 1 (Top)
Layer 2 (GND 1)
Layer 3 (Signal)
Layer 4 (PWR 3)
Layer 5 (Signal)
Layer 6 (Signal)
Layer 7 (PWR 5)
Layer 8 (Signal)
Layer 9 (GND 2)
Layer 10 (Bottom)
Rev. 2217 ©2002 ACUCAD ~ 1011 Glacier Pkwy, Algonquin, IL 60102-5004 Voice (847) 854-6052 FAX (847) 854-6053
4.2.1