Quality Control & Inspection Procedures Flashcards
7 cards from real CIS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Quality Control & Inspection Procedures flashcards as text
During a first-article inspection, a CIS inspector finds solder joints on a fine-pitch QFP that appear dull but have adequate fillet geometry. What is the most likely cause?
Answer: Grainy appearance from lead-free alloy solidification
Lead-free solder alloys (e.g., SAC305) naturally produce a duller, grainier surface finish compared to tin-lead solders due to their solidification characteristics.
Which IPC-A-610 acceptance condition describes a solder connection that does not meet minimum requirements but is not cause for rejection under certain conditions?
Answer: Process indicator
A 'process indicator' in IPC-A-610 flags a condition that could indicate process control problems but does not by itself constitute a defect.
When inspecting through-hole components, what is the minimum acceptable solder fill percentage in the barrel for a Class 3 assembly?
Answer: 100%
IPC-A-610 Class 3 (high-reliability) requires 100% vertical fill in the through-hole barrel to ensure maximum joint integrity.
An inspector using automated optical inspection (AOI) flags a component as misaligned, but manual re-inspection finds it acceptable. What is the best corrective action?
Answer: Recalibrate the AOI thresholds using golden-board references
AOI false-call rates should be managed by recalibrating the system against approved golden-board samples to reduce pseudo-defects without compromising defect detection.
Per IPC-7711/7721, what is the maximum number of times a surface-mount pad may be reworked before it must be scrapped for a Class 2 product?
Answer: The standard does not set a limit; engineering disposition is required
IPC-7711/7721 does not specify a universal rework cycle limit; instead, engineering disposition is required based on pad condition, substrate type, and product class.
What does a 'lifted pad' defect indicate during PCB inspection?
Answer: The copper pad has delaminated from the substrate surface
A lifted pad occurs when the copper foil pad separates from the laminate substrate, typically caused by excessive heat, mechanical stress, or repeated rework.
Which sampling plan standard is most commonly referenced in IPC documentation for incoming inspection of electronic components?
Answer: MIL-STD-105 / ANSI/ASQ Z1.4
ANSI/ASQ Z1.4 (formerly MIL-STD-105) provides attribute sampling procedures widely referenced for incoming component inspection in IPC environments.