CIS Component Identification & Handling 3

Question 1

What does MSL 3 indicate for a moisture-sensitive component?

Accepted Answer

The component must be stored at 30°C/60% RH and used within 168 hours of opening

Answer

MSL 3 per J-STD-020 allows a floor life of 168 hours at ≤30°C/60% RH after removal from dry packaging before soldering must occur.

Question 2

Which marking system is used on SMD resistors to identify their value in a three-digit code, such as '472'?

Accepted Answer

Standard three-digit EIA code where the third digit is the multiplier

Answer

In the standard three-digit SMD marking, the first two digits are significant figures and the third is the power-of-10 multiplier, so '472' = 47 × 10² = 4,700 ohms.

Question 3

What is the significance of a white dot or painted stripe on an electrolytic capacitor?

Accepted Answer

It indicates the negative terminal

Answer

On electrolytic capacitors, the stripe or marking (often white or colored) indicates the negative terminal, which must be oriented correctly to prevent component failure.

Question 4

How should tape-and-reel packaged components be stored when not in use to preserve component quality?

Accepted Answer

Resealed in moisture barrier bags with desiccant if MSDs, stored in controlled conditions

Answer

Unused tape-and-reel MSDs should be resealed in moisture barrier bags with fresh desiccant and humidity indicator cards, stored per J-STD-033 requirements.

Question 5

What does the 'JEDEC' polarity marking on a SOT-23 transistor package typically consist of?

Accepted Answer

A molded dot or alphanumeric code on the package surface

Answer

SOT-23 packages use a molded dot, embossed mark, or alphanumeric date/type code on the package surface to identify pin orientation per JEDEC TO-236 standards.

(CIS) Certified IPC Specialist Practice Test

(CIS) Certified IPC Specialist Practice Test

CIS Component Identification & Handling 3