Which statement about semiconductor device reliability is generally correct when compared to electromechanical components and typical failure patterns over a product life cycle?
-
Aare less reliable than electromechanical components
-
Busually have a very short MTBF (mean time between failure)
-
Chave a very short infant mortality period
-
DAll of the above
-
ENone of the above
Answer
Correct Answer: have a very short infant mortality period
Explanation
Introduction / Context:This question targets reliability engineering concepts, especially the bath-tub curve for electronic components. It asks which statement aligns with observed failure distributions for semiconductors across early life, useful life, and wear-out phases.
Given Data / Assumptions:
- Semiconductor devices are solid-state with no moving parts.
- Electromechanical devices include relays, switches, and motors that have wear from mechanical motion.
- MTBF represents expected time between failures during the useful life phase.
Concept / Approach:Semiconductors typically show early failures due to latent manufacturing defects. Burn-in screens out weak units, reducing early failure rates. During the long useful life, failure rate is low and MTBF is high. Statements must be checked against this pattern.
Step-by-Step Solution:
1) Compare reliability classes: solid-state parts tend to be more reliable than electromechanical parts.2) Evaluate MTBF: for quality semiconductors, MTBF is high during useful life, not very short.3) Check infant mortality: initial period right after deployment can experience a spike of early failures, which is short if screening is effective.4) Select the statement that matches reality: short infant mortality period is accurate.Verification / Alternative check:Industry practice uses burn-in and accelerated life testing to remove weak units, confirming the brief early failure window, followed by a long low-failure plateau.
Why Other Options Are Wrong:
- are less reliable than electromechanical components: generally false; solid-state devices usually exhibit higher reliability.
- usually have a very short MTBF: false; MTBF is typically long in the useful life phase.
- All of the above: cannot be correct because the first two statements are false.
- None of the above: incorrect because the infant mortality statement is correct.
Common Pitfalls:Assuming constant failure rate across life, confusing MTBF with warranty length, and ignoring screening processes that remove weak devices.
Final Answer:have a very short infant mortality period