CIS Quality Control & Inspection Procedures 3

Question 1

An inspector observes a solder bridge between two adjacent SMD pads on a Class 2 assembly. Which of the following best describes the disposition?

Accepted Answer

Defect — requires rework or rejection

Answer

Solder bridges between conductors that should not be electrically connected are unconditional defects under IPC-A-610 for all product classes.

Question 2

What is the purpose of a control chart in a PCB assembly quality system?

Accepted Answer

To track process variation over time and detect out-of-control conditions

Answer

Control charts (SPC tools) monitor process metrics over time, enabling detection of trends or special-cause variation before defects are produced.

Question 3

Per IPC-A-610, which condition is allowed for a Class 1 product but not for Class 3 regarding chip component solder joints?

Accepted Answer

End-cap solder coverage extending only onto the bottom face

Answer

For Class 1, solder restricted to only the bottom (land) face of a chip component termination may be acceptable, whereas Class 3 requires solder on the end cap for maximum mechanical strength.

Question 4

When performing solderability testing per J-STD-003, what does the wetting balance test measure?

Accepted Answer

The force exerted on a component lead as it is immersed in molten solder

Answer

The wetting balance (Meniscograph) test measures the time-force curve as a lead is immersed in solder, quantifying the speed and degree of solder wetting.

Question 5

A CIS inspector observes a through-hole lead that extends 0.5 mm beyond the secondary side of the board on a Class 3 assembly. Per IPC-A-610, this is:

Accepted Answer

A defect — lead protrusion is below the minimum

Answer

IPC-A-610 Class 3 requires a minimum lead protrusion of 0.5 mm (some versions specify slightly higher), so 0.5 mm is at the borderline — verify against the current revision, but insufficient protrusion is a defect.

(CIS) Certified IPC Specialist Practice Test

(CIS) Certified IPC Specialist Practice Test

CIS Quality Control & Inspection Procedures 3