CIS CIS Rework, Repair & Modification

Question 1

Which IPC standard is the primary reference for rework, repair, and modification of electronic assemblies?

Accepted Answer

IPC-7711/7721

Answer

IPC-A-610

Answer

IPC-2221

Answer

IPC-6012

Question 2

What is the key difference between 'rework' and 'repair' in IPC terminology?

Accepted Answer

Rework restores the assembly to original design; repair allows deviation from original design to restore function

Answer

Rework is performed by operators; repair requires engineer approval

Answer

Rework applies only to through-hole components; repair applies to SMT only

Answer

Rework involves replacing components; repair involves re-soldering existing joints only

Question 3

What is the maximum number of times a through-hole plated barrel may be thermally stressed during rework per IPC-7711?

Accepted Answer

Four times

Answer

One time only

Answer

Two times (original solder plus one rework)

Answer

There is no IPC limit on thermal cycles

Question 4

When removing a BGA component for rework, which technique is most commonly used?

Accepted Answer

Localized infrared or hot-air rework station that heats the entire BGA body uniformly

Answer

Hot air pencil direct on each solder ball individually

Answer

Immersion in solder pot to melt all balls simultaneously

Answer

Wicking with desoldering braid across the component body

Question 5

Which tool is used for the controlled removal of desoldering braid (wick) excess from a PCB pad without lifting the land?

Accepted Answer

Low-temperature soldering iron with a chisel tip held at a shallow angle to slide braid off

Answer

Vacuum desoldering tool

Answer

Side-cutting pliers trimmed close to the pad

Answer

Hot air pencil to loosen the braid before lifting

Question 6

What is 'skipping' in the context of wave soldering rework evaluation?

Accepted Answer

A through-hole lead that did not receive solder during wave soldering, leaving an open joint

Answer

A component that moved from its pad during rework

Answer

A flux skip causing areas of unwetted pads

Answer

A wave soldering defect where alternating joints are bridged