CIT Acceptability of Electronic Assemblies 1 — Questions and Answers
Question 1: According to IPC-A-610, what is considered an acceptable solder joint on a through-hole component?
- Flat solder with no fill
- Barrel completely filled with good wetting (Correct answer)
- Partial barrel fill only on component side
- No solder fillet visible
Correct answer: Barrel completely filled with good wetting
An acceptable solder joint on a through-hole component should show good wetting and full barrel fill on the solder side.
Question 2: What is a critical factor for determining solder joint acceptability on surface mount components?
- Color of the component
- Location of the PCB logo
- Fillet shape and proper wetting (Correct answer)
- Amount of flux residue
Correct answer: Fillet shape and proper wetting
For surface mount solder joints, wetting, alignment, and fillet formation are key indicators of acceptability.
Question 3: Which of the following is considered a defect under IPC-A-610 standards?
- Slightly off-center silkscreen
- Exposed unintentional copper (Correct answer)
- Excess flux residue
- Long solder leads
Correct answer: Exposed unintentional copper
Exposed copper that is not part of a pad or trace is typically classified as a defect as it may lead to corrosion or short circuits.
Question 4: What condition must be met for acceptable component mounting per IPC standards?
- Component must be at an angle
- Component leads must be hidden
- Component must be mechanically secure and properly aligned (Correct answer)
- Solder must cover component body
Correct answer: Component must be mechanically secure and properly aligned
Components must be securely attached and correctly oriented to ensure proper functionality and mechanical stability.
Question 5: What level of cleanliness is required on finished electronic assemblies per IPC-A-610?
- Light dusting is acceptable
- Only flux residue must be cleaned
- Assemblies must be free from all visible contamination (Correct answer)
- Contaminants are acceptable under coating
Correct answer: Assemblies must be free from all visible contamination
Finished assemblies must be free from visible contamination such as dirt, dust, oils, and flux residues.
Question 6: Which IPC class allows for the highest reliability requirements in electronics manufacturing?
- Class 1 – General Electronic Products
- Class 2 – Dedicated Service Electronic Products
- Class 3 – High Performance Electronic Products (Correct answer)
- Class 4 – Disposable Devices
Correct answer: Class 3 – High Performance Electronic Products
Class 3 IPC standard is intended for high-performance electronics where continued performance is critical, such as aerospace and military applications.
CIT Acceptability of Electronic Assemblies 1
According to IPC-A-610, what is considered an acceptable solder joint on a through-hole component?