ECET360
Lab Week 4 : ECAD
Object: the objectives of this lab are:
- Re/acquaint yourselves with PCB Artist. Remember the Help files are your friend!!
- layout a PCB which can be used on automated equipment.
- Create a new component footprint
Procedure:
Working in pairs:
1.
Use the PCB Layout tool in PCB Artist. If you have not used the tool for PCB layout, there is a Design
Tutorial under the Help menu.
2.
Start a file for a 4X4 board with 2-layers (no inner planes) including parts as noted below. To begin your
board layout, start PCB Artist, and select PCB design. Now examine the right column “interaction bar”
(toggle it with F9). The top 3 pull-down windows are:
3.

The library pulldown, which shows all the component/package libraries available in Artist.
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The component pulldown, which lists the components available in the library you have selected.

The package pulldown, which shows the packages that the selected component are available in.
In the non-company libraries (i.e. don’t bother with TI or AD or Altera, etc.) determine which libraries
contain SMT footprints. You don’t need to find all the SMT footprints in a library, just whether it includes
SMT footprints. List those libraries for your report.
Using the Library Manager (the little book in the toolbar), create a new Component using the Wizard for
that function. Follow Advanced Circuit’s “Part Creation Tutorial” in their Tips & Tools at www.4pcb.com .
Note that:
o
A Component consists of two parts, a schematic representation and a PCB footprint
representation.
o
A Component can be defined with only one or the other representation, but the definition must
include that information.
Create the new PCB component/footprint-only for a 20-lead QFN package, with a center DAP. For a
dimensional model, use the Peregrine Semiconductor QFN-20, such as that used by their PE4308:

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Be sure to set the dimensional basis correctly (mm or inch?)
Make the PCB pads the same width as the component terminations.
Make the PCB pads extend beyond the component body by 0.5mm
Make the DAP PCB pad the same size as the ICs DAP
Now layout a 4"X4” printed circuit board using the following footprints in the quantities listed:
4.
2-QFP 44 (25-mil pitch)
2-SO 16
1 QFN, your design (#4 above)
1206-package chip capacitors, as noted below
1-6 pin header (pins at 0.100” pitch)
4.7μf tantalum caps at each SO between pin 9 & com

Use 8mil/0.25mm traces on the board. This should be very close to the width of the pads on your QFN.

Remember you must create connections with the Connection Tool and thereby create a netlist before
you route copper traces. Create the connects as follows:
o Connect all IC pin #16’s together, terminating at pin 1 of a 6-pin header with 0.100” pitch. The
header is to be in the middle of one side, 1/2” from the edge of the board and parallel to the
edge.
o Connect all pin#8’s together, terminating at pin 6 of the same 6-pin header. This is GROUND.
o Connect pin#12 of each IC to individual 1206 chip Cs – connect the other end to a common
node/net.
o Connect that common of the chip C’s (and thereby establish ground) at pin 3 of the header.
o Be certain to connect the DAP solder pad on the bottom of the QFN per Peregrine’s
requirements on the PE4308 data sheet.
o Layout should be neat, with space between parts for inspection of solder joints.
The board is to have one tooling/mounting hole, suitable for use as an index on automated machines.
3/16”
3/16”
Tooling hole is 1/8” diameter, and must be 3/16” from the corner of the board. Metric equal OK.
While a “tooling hole” and a “mounting hole” have different functions on the board, you can create a
tooling hole in the same way as a mounting hole is created. To do this, search Help in PCB Artist for
“Add Pad”, and in the Add Pad function you will find a section on “To add a mounting hole”.

Board to have three 1/8” or 0.5 mm diameter fiducials near different corners. These are necessary to
use a board on an automated system. The fiducials must be in the top copper layer, unconnected to any
net.
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Be certain that any mounting holes or a fiducials are on the board but not in the schematic/netlist,
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Board must have lettering which will read correctly in the copper on an etched board. The lettering will
be “ECET360” and the initials of the two people who worked on the board, e.g “ECET360 DNJC”.
Routing/Printouts:
 Move the components around so that the routing will be the most straightforward.
 Create the rats nest with the connection tool, then print the rats/board. You may need to do a
Screen Print, then take that into a Word doc.
 Route the board using AutoRoute. And print the resulting routed PCB. Label the printout ‘auto
route’.
 Unroute the board
 Now route the board manually. You should find that you can do a cleaner job of routing (fewer
vias, etc) than the autoroute function. Print the resulting routed PCB. Label the printout
‘manual route’.
When you make printouts, you will be able to verify your QFN design with the actual part, which is
available in the lab. At this point a magnifier is your friend to verify that the part fits accurately on the
pads you have designed.
The printouts due with your report must be suitable for fabrication. This means you must separately
printout each layer: top copper, bottom copper, top silkscreen, and if used, bottom silkscreen.
Report: (due the beginning of the following week's lab)
For this lab, the deliverables are:
- Any problems you encountered during the Layout work, and their solutions
- Library list from procedure #2.
- Printouts per “Routing/Printouts” above: rats only, autorouted, manually routed. For manually
routed, include top copper, bottom copper, top silkscreen and bottom silkscreen layers
separately.
- the netlist for your design
Note: any layouts turned in that are found to be identical to another teams’ will be assumed to be the
result of copying. All student teams involved will receive “0” as a grade.
Report is DUE at the beginning of your 360 lab the 5th week of classes, or
before at the ECET office if you have it completed.
As the work for this week’s lab can be done in a number of labs, or at home,
etc., you are not required to attend the 360 lab the 4th week of classes.
Your lab instructor will be available in MGL1222 or his office during lab times if
you want to work in MGL1222, or have questions.