Layout

1
Layout

• Power Supply
• Nate Moehring

2
Perspective
OrCAD Capture
OrCAD Layout
Gerber Files
LPKF CircuitCAM
LPKF BoardMaker Pro
3
Complete Schematic

• Only libraries from the Capture\PSPICE folder can
  be simulated.
• To find the fuses, switches, and potentiometers,
  add the discrete library from the Capture folder.
• Document electrolytic capacitor orientation.
• Regulator package TO-220, Regulator library in
  Capture folder.

4
Complete Schematic
5
Export to Layout

• Click on project browser
• With Schematic selected in the browser, select
  Tools gtgt Create Netlist from the Menu bar.

6
Export to Layout

• In Layout tab, check Run ECO to Layout

7
Export to Layout

• Start Layout
• File gtgt New, select Default.tch (new project
  with default attributes)
• Then open the netlist file ltprojectnamegt.mnl
  created by the Capture export we just did.
• Save as Layout project ltprojectnamegt.max

8
Selecting footprints
Axial/.300LX.100W/.031 lead diameter
9
Selecting footprints
Professional version has more detail
10
Selecting footprints

• Pots will be mounted on the box, not on the
  board, so footprint selection is not important.
  I prefer VRES gtgt VRES13.
• We are using regulators with the standard form
  factor of TO-220, mounted vertically.
• Professional version has TO-220 library.
  Vertical mount is TO-220AB
• If using student version, any 3 leg footprint
  with proper dimensions will work, such as using a
  VRES footprint.

11
Selecting footprints

• Switch, fuse, and LED are mounted on the box, so
  footprint is not important.
• Other regulators are same form factors, but
  different pin outs! Double check their traces.
• Modify selections for large capacitors.
• Create footprint for transformer.

12
Position components on board

• Double check space needed by components
  (especially heatsinks).
• Double check all pin outs.
• Add vias for input, transformer, and output power
  connections.

13
Mounting Holes?

• Plan where you would like to position the PCB and
  transformer in the project box to determine if it
  is possible to drill a whole through the PCB at
  design time (in Layout) so it will easily and
  securely attach to the box.
• Do this using a large via or custom footprint.
  (screws will need to be provided by the student)

14
Tool Tutorial

• Every operation has a different tool in Layout.
• Each tool has different modes.
• To remove a track, select the tool component from
  the toolbar or menu.
• You must then place the tool into the Select,
  Add, or Delete mode from the menu or by right
  clicking.

15
Tool Tutorial

• You must use the Component tool to move, add, or
  delete components.
• Use the Measure tool to find the dimensions of
  your board or a component.
• Must use the lttooltypegt tool to move, add, or
  delete lttooltypegt.

16
Creating a new footprint

• Open the library manager

• Create New Footprint
• Use Pin tool to add, delete, and move pin
  connections.

• Use text tool to add, delete, and move text
  labels.

17
Connection Points

• Using component tool, select a via to use as an
  empty whole to connect items off of the board
  (ie, transformer, fuse, etc)
• Once placed, must use via tool to move and
  delete. (Can also use via tool to create, but
  then it tries to associate the via to a net.)

18
Capacitor Footprint

• 2200uF, 50V, electrolytic, radial (cylindrical)
  16mmx31mm (from datasheet) (lead spacing/lead
  diameter?)
• 1inch 1000mils
• 1mil/.001inch 1inch/2.54cm 1cm/10mm
  39.37mils/mm
• Xmm .0254mm Y mils
• Ymils Xmm/.0254mm

19
Capacitor Footprint

• Cylinder/Diameter/Lead Spacing/Lead Diameter

20
Disable Unused Layers

• Were constructing a single layer board, but
  CircuitCAM must have top and bottom layers in
  project.
• Disable layers for Gerber export in Options gtgt
  Post Process Settings gtgt Uncheck Enable for Post
  Processing for all layers except .top and .bot,
  device as Extended Gerber.
• Disable all routing layers except Bottom for
  trace routing in Tool gtgt Layer gtgt Select from
  Spreadsheet gtgt Select Unused Routing (Drill
  layer must be enabled)

21
Global Spacing (for Routing)
22
Increasing Pad width

• Tool gtgt Padstack gtgt Select From Spreadsheet
• Change Bottom and Drill Width for each
  components unique pin style. Make sure to not
  make pads and holes so big that they overlap!
• Diameter of AWG18 wire is 40mils. Recommend
  32mils of copper around whole. Typical padstack
  size 72mils

23
Potential Padstack sizes
These sizes are not guaranteed. It is up to the
student to determine the best size holes and pads
for their project. It is better to err on the
size of too large rather than too small.
24
Changing trace width(as shared by Nicholas Ange)

• Tool gtgt Net gtgt Select From Spreadsheet
• Double click on the Width column header
• Set all values to desired width

25
AutoRoute Board/DRC

• Make sure overall board size is lt 8in2
• Options gtgt Global Spacing
• Because were going to use thick traces (for
  higher current), and because this is a simple
  board and space is not a concern, were going to
  space everything by 32 mils.
• Auto gtgt Autoroute board/DRC

26
Changing trace width(post-autoroute method)

• Tool gtgt Track gtgt Select Tool
• Place cursor over desired trace, but do not
  click! Push w on the keyboard.
• Select Net, and set width to
• 32 mils.
• Trace width calculator
• http//www.geocities.com/CapeCanaveral/Lab/9643/Tr
  aceWidth.htm

27
Improving Traces

• As a general rule
• Use the Track tool to make changes to an entire
  net.
• Use the Track Segment tool to modify just a
  single stretch of a trace.
• To draw a new trace, you must first use the
  Connection Tool to connect from here to there,
  then click on the connection line using the track
  or track segment tool to draw the trace. Track
  tool will do a little more work for you when
  drawing new traces.
• Avoid
• 90o angles in your traces.
• Unnecessarily complex (unintelligent) traces
• Keep digital and analog traces separated.

28
Adding a Border

• Tool gtgt Obstacle gtgt New
• Draw a shape outlining your board (typically a
  box). Select the obstacle gtgt right click gtgt
  Properties
• Change the obstacle type to Free Track on
  Bottom layer.
• CircuitCAM will use this to determine where to
  cut out the board from the rest of the copper.
  (contour routing)

29
Adding Text

• Write your name on the board using the text tool.
  

30
Final Product
31
Gerber Preferences
32
Final Gerber Export(as recommended by LPKF)

• Copy ORCAD2CCAM.PPS to your project directory.
• Options gtgt Post Process Settings
• Right Click gtgt Load Post Processing Setup
• Load ORCAD2CCAM.PPS
• Right Click gtgt Run Batch to generate necessary
  gerber files.

33
Final Gerber Export(as recommended by Sara
Barnard)

• Double check Gerber Settings.
• Setup top and bottom layers for export in Post
  Processor Settings, with device as Extended
  Gerber.
• Auto gtgt Run Post Processor
• Email to me ltprojectnamegt.top, ltprojectnamegt.bot,
  and thruhole.tap in ltyournamegt.zip by 1159pm
  Thursday.