CIS Component Identification & Handling 2 — Questions and Answers
Question 1: What does a yellow triangle with a hand symbol on component packaging indicate?
- High voltage hazard
- Electrostatic sensitive device (ESD) (Correct answer)
- Moisture sensitive level warning
- Flammable material
Correct answer: Electrostatic sensitive device (ESD)
The yellow triangle with a hand symbol is the ESD sensitivity symbol per ESDA/JEDEC standards, indicating the device is susceptible to electrostatic discharge damage.
Question 2: Which component feature is used to identify pin 1 on a dual in-line package (DIP) IC?
- A square pad on the PCB
- A notch or dot on the package body (Correct answer)
- The longest lead on the component
- A colored stripe on one side
Correct answer: A notch or dot on the package body
DIP ICs use a notch (indent) at one end or a dot near pin 1 on the package body to identify pin 1 orientation.
Question 3: What is the primary purpose of moisture barrier bags (MBB) used for electronic components?
- To prevent ESD damage during shipping
- To protect moisture-sensitive components from humidity exposure (Correct answer)
- To prevent physical damage to component leads
- To identify RoHS-compliant components
Correct answer: To protect moisture-sensitive components from humidity exposure
Moisture barrier bags protect moisture-sensitive devices (MSDs) from absorbing ambient humidity, which can cause internal delamination or 'popcorning' during soldering.
Question 4: A component is marked '4R7' on its body. What does this marking represent?
- 4.7 ohms (Correct answer)
- 47 ohms
- 4.7 kilohms
- 470 ohms
Correct answer: 4.7 ohms
The 'R' in component markings indicates a decimal point, so '4R7' means 4.7 ohms — a standard EIA marking convention.
Question 5: When handling BGAs (Ball Grid Array packages), what is the primary concern regarding the solder balls?
- The balls may oxidize in normal air
- Physical contact can deform or contaminate the solder balls (Correct answer)
- The balls are not visible and cannot be inspected
- The balls must be kept at room temperature
Correct answer: Physical contact can deform or contaminate the solder balls
BGA solder balls are delicate; physical contact, pressure, or contamination from oils/skin can deform balls or leave residues that affect solder joint quality.
Question 6: What information does the lot code on an electronic component typically provide?
- The component's electrical rating
- Date of manufacture and production batch traceability (Correct answer)
- The component's lead finish type
- The pin 1 orientation
Correct answer: Date of manufacture and production batch traceability
Lot codes provide manufacturing traceability, typically encoding the date code and production batch, which is critical for quality control and failure analysis.
Question 7: According to IPC standards, what is the correct way to handle a component that has been dropped on the floor during assembly?
- Clean it and return it to the feeder immediately
- Inspect it under magnification and scrap if damaged (Correct answer)
- Use it if no visible damage is found
- Return it to the original tape packaging
Correct answer: Inspect it under magnification and scrap if damaged
Dropped components must be inspected under magnification per IPC handling procedures; any damage or contamination requires scrapping the component to prevent assembly defects.
CIS Component Identification & Handling 2
What does a yellow triangle with a hand symbol on component packaging indicate?