CIS CIS PCB Design & Fabrication Standards 2

Question 1

What IPC class designation applies to high-reliability electronic products such as life-support equipment?

Accepted Answer

Class 3

Answer

Class 1

Answer

Class 2

Answer

Class 4

Question 2

What is the purpose of a 'via-in-pad' design in PCBs?

Accepted Answer

To place a via directly within a surface mount pad to save space

Answer

To reduce board layer count

Answer

To improve mechanical strength of through-hole components

Answer

To increase annular ring size

Question 3

The glass transition temperature (Tg) of a PCB laminate is important because:

Accepted Answer

It indicates the temperature at which the laminate transitions from rigid to soft

Answer

It defines the maximum copper plating thickness

Answer

It determines the minimum drill bit diameter required

Answer

It sets the maximum current-carrying capacity of traces

Question 4

What is the function of a 'thermal relief' in PCB design?

Accepted Answer

It connects a through-hole pad to a copper plane with spoke connections to ease soldering

Answer

It dissipates heat from high-power components

Answer

It reduces stress on solder joints near copper pours

Answer

It prevents warpage during reflow soldering

Question 5

According to IPC-6012 Class 3, what is the minimum acceptable annular ring for supported holes in internal layers?

Accepted Answer

0.050 mm

Answer

0.025 mm

Answer

0.075 mm

Answer

0.100 mm

Question 6

What does 'DFM' stand for in PCB fabrication?

Accepted Answer

Design for Manufacturing

Answer

Dielectric Film Measurement

Answer

Drill Feed and Motion

Answer

Defect-Free Manufacturing