PCB Technology & Digital Applications 3 — Questions and Answers
Question 1: Which simulation type in SPICE-integrated PCB tools predicts how a signal degrades as it travels along a PCB trace?
- Signal Integrity (SI) simulation (Correct answer)
- Thermal simulation
- Electromagnetic interference simulation
- Power integrity simulation
Correct answer: Signal Integrity (SI) simulation
SI simulation models transmission line effects, reflections, and crosstalk on high-speed PCB traces.
Question 2: What does 'back-annotation' mean in the PCB design workflow?
- Updating the schematic with changes made in the PCB layout, such as reference designator swaps (Correct answer)
- Writing fabrication notes onto the silkscreen layer
- Exporting the layout back to the manufacturer's portal
- Re-importing a modified Gerber into the EDA tool
Correct answer: Updating the schematic with changes made in the PCB layout, such as reference designator swaps
Back-annotation propagates ECOs like pin swaps or reference changes from the PCB layout back to the schematic.
Question 3: In OrCAD PCB Designer, what is a 'Constraint Manager' used for?
- Defining and enforcing electrical and physical design rules such as trace width and spacing (Correct answer)
- Managing component inventory and pricing
- Scheduling the PCB review meetings
- Importing BOM data from procurement systems
Correct answer: Defining and enforcing electrical and physical design rules such as trace width and spacing
The Constraint Manager in OrCAD centralizes rules for impedance, spacing, length matching, and other design parameters.
Question 4: Which file format is commonly used to exchange PCB designs between different EDA tools in a neutral, standardized way?
- IPC-2581 (Correct answer)
- CSV
- DXF
Correct answer: IPC-2581
IPC-2581 is an open XML-based standard for transferring complete PCB design and fabrication data between EDA platforms.
Question 5: What is the purpose of a 3D STEP export from a PCB EDA tool?
- To allow mechanical engineers to perform enclosure fit checks and clearance analysis (Correct answer)
- To generate drill files for the fabrication house
- To create a BOM for procurement
- To produce Gerber outputs for photoplotting
Correct answer: To allow mechanical engineers to perform enclosure fit checks and clearance analysis
A STEP file is imported into MCAD software so the mechanical team can verify the PCB fits inside the housing.
Question 6: Which EDA software concept automatically assigns physical copper areas to specific nets based on connectivity?
- Net-aware copper pour / plane assignment (Correct answer)
- Footprint wizard
- Schematic block diagram
- Gerber viewer
Correct answer: Net-aware copper pour / plane assignment
Net-aware copper pours automatically connect filled copper regions to the assigned net, updating dynamically when the design changes.
Question 7: In PCB layout software, what does 'highlight net' functionality do?
- Visually emphasizes all copper features belonging to a selected net across all layers (Correct answer)
- Exports the net list to an Excel spreadsheet
- Locks all traces on the highlighted net to prevent accidental edits
- Runs DRC only on the selected net
Correct answer: Visually emphasizes all copper features belonging to a selected net across all layers
Highlighting a net dims all other features and brightens that net's pads, traces, and vias for easy visual tracing.
PCB Technology & Digital Applications 3
Which simulation type in SPICE-integrated PCB tools predicts how a signal degrades as it travels along a PCB trace?