CAD CAD Specialist Electrical and Electronics Design 2

Question 1

What is the purpose of a 'Design Rule Check' (DRC) in PCB CAD software?

Accepted Answer

Checks that physical layout constraints such as clearances and trace widths are satisfied

Answer

A DRC automatically verifies that the PCB layout meets specified manufacturing and electrical constraints — such as minimum clearances, trace widths, and annular ring sizes — before fabrication.

Question 2

In PCB design, what is a 'via'?

Accepted Answer

A plated hole that electrically connects copper traces on different PCB layers

Answer

A via is a plated-through (or blind/buried) hole whose barrel wall is copper-plated, creating an electrical connection between traces on different PCB layers.

Question 3

Why is 'controlled impedance' important in high-speed PCB design?

Accepted Answer

It matches trace impedance to source and load impedance to preserve signal integrity

Answer

Controlled impedance ensures that trace characteristic impedance matches the source and load, preventing signal reflections, ringing, and degradation at high frequencies.

Question 4

What does a 'copper pour' (flood fill) accomplish on a PCB layer?

Accepted Answer

Fills unused board areas with copper connected to a net — typically ground

Answer

A copper pour fills unused PCB real estate with copper tied to a specified net (usually ground) to lower impedance, improve EMI shielding, and assist heat dissipation.

Question 5

In Gerber-based PCB fabrication output, what information does the NC drill file contain?

Accepted Answer

X,Y coordinates and diameters of all holes to be drilled

Answer

The NC drill file (Excellon format) contains the x,y coordinates and tool-size codes for every hole — vias and component through-holes — that the CNC drill must produce.

(CAD) Certified Computer-Aided Design Specialist Practice Test

(CAD) Certified Computer-Aided Design Specialist Practice Test

CAD CAD Specialist Electrical and Electronics Design 2