Yield and quality control

In sampling inspection, which judges an entire lot as accepted or rejected by inspecting a sample, which metric expresses the quality level considered acceptable?

  1. AMTBF
  2. BSNR
  3. CAQL (acceptable quality level)
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Answer: C. AQL (acceptable quality level)

Sampling inspection uses the AQL (acceptable quality level) to set, according to lot size, how many items to sample and how many defects are allowed for acceptance. Lot quality can be assured with a given probability without inspecting every item.

  • A. MTBF is mean time between failures, a reliability metric.
  • B. SNR is the signal-to-noise ratio.
  • C. Correct. It is the quality level accepted in sampling inspection.
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More Yield and quality control questions

  1. When analyzing yield data, which example correctly illustrates that "a correlation between two quantities does not mean one causes the other"?
  2. Which correctly describes efforts to raise yield by analyzing the large amounts of equipment data, metrology data and test results accumulated in a fab with machine learning and similar methods?
  3. Which yield model accounts for defects that occur clustered unevenly on the wafer?
  4. What is the quantity called that, for each type of defect found by inspection, gives the fraction of chips containing that defect that actually fail electrically?
  5. Which correctly states Little's law, relating work in progress (WIP), throughput and cycle time in a factory?