CIS PCB Design & Fabrication Standards Flashcards
6 cards from real CIS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CIS PCB Design & Fabrication Standards flashcards as text
What is the primary purpose of solder mask on a PCB?
Answer: To protect copper traces from oxidation and prevent solder bridging
Solder mask protects exposed copper traces from oxidation, corrosion, and inadvertent solder bridging during assembly.
Which test verifies the registration accuracy of drilled holes to their corresponding pads on a PCB?
Answer: X-ray inspection
X-ray inspection is used to verify drill-to-pad registration and check internal layer alignment without destructive sectioning.
What does 'impedance stack-up' refer to in multi-layer PCB design?
Answer: The arrangement of signal, plane, and dielectric layers to achieve target trace impedances
Impedance stack-up defines how signal, power, and ground layers are arranged with specific dielectric thicknesses to achieve controlled impedance traces.
IPC-4101 specifies requirements for which PCB material?
Answer: Base materials (laminates and prepregs) for rigid PCBs
IPC-4101 covers specification for base materials (laminates and prepregs) used in the fabrication of rigid and multilayer printed boards.
What is 'copper weight' as specified on PCB fabrication drawings?
Answer: The thickness of copper foil expressed in ounces per square foot
Copper weight is the thickness of copper foil expressed in ounces per square foot (oz/ft²), where 1 oz/ft² equals approximately 35 µm thickness.
What is the purpose of 'fiducial marks' on a PCB?
Answer: To serve as optical reference points for automated assembly equipment
Fiducial marks are optical reference targets etched in copper that automated pick-and-place machines use to align component placement accurately.