CIS CIS PCB Design & Fabrication Standards 3

Question 1

What is the primary purpose of solder mask on a PCB?

Accepted Answer

To protect copper traces from oxidation and prevent solder bridging

Answer

Solder mask protects exposed copper traces from oxidation, corrosion, and inadvertent solder bridging during assembly.

Question 2

Which test verifies the registration accuracy of drilled holes to their corresponding pads on a PCB?

Accepted Answer

X-ray inspection

Answer

X-ray inspection is used to verify drill-to-pad registration and check internal layer alignment without destructive sectioning.

Question 3

What does 'impedance stack-up' refer to in multi-layer PCB design?

Accepted Answer

The arrangement of signal, plane, and dielectric layers to achieve target trace impedances

Answer

Impedance stack-up defines how signal, power, and ground layers are arranged with specific dielectric thicknesses to achieve controlled impedance traces.

Question 4

IPC-4101 specifies requirements for which PCB material?

Accepted Answer

Base materials (laminates and prepregs) for rigid PCBs

Answer

IPC-4101 covers specification for base materials (laminates and prepregs) used in the fabrication of rigid and multilayer printed boards.

Question 5

What is 'copper weight' as specified on PCB fabrication drawings?

Accepted Answer

The thickness of copper foil expressed in ounces per square foot

Answer

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.

(CIS) Certified IPC Specialist Practice Test

(CIS) Certified IPC Specialist Practice Test

CIS CIS PCB Design & Fabrication Standards 3