Introduction / Context:
Modern EDA/CAD tools provide rule checking, auto-place hints, and autorouting support, but optimal PCB placement is a multidimensional engineering decision balancing signal integrity, thermal paths, manufacturability, test access, and mechanical constraints.
Given Data / Assumptions:
- The phrase “best possible” implies guaranteed optimality across competing objectives.
- CAD offers design rule checks, constraint managers, and placement aids.
- Engineer retains responsibility for trade-offs and final decisions.
Concept / Approach:
CAD tools assist by enforcing spacing rules, flagging violations, and offering optimization heuristics. However, no general algorithm guarantees a globally optimal placement for all criteria. Human insight is required, especially for high-speed, RF, power integrity, and thermal considerations.
Step-by-Step Solution:
Define constraints: net classes, length matching, keep-outs, thermal zones.Use CAD features to propose placements and check clearances.Iterate with engineering judgment to refine critical component locations (e.g., clocks near receivers, decoupling at pins).Validate with simulation or prototypes for SI/PI and thermal behavior.
Verification / Alternative check:
Compare tool-only placement versus expert-tuned placement on performance metrics; expert guidance typically improves outcomes.
Why Other Options Are Wrong:
Correct: Claims guaranteed optimality that CAD alone does not provide.True only with autorouter enabled / Valid for analog only: Neither condition ensures optimal, since objectives conflict and context matters.
Common Pitfalls:
Overreliance on autorouters without upfront placement discipline.Ignoring thermal relief, return paths, and test points when chasing shortest routes.
Final Answer:
Incorrect
Discussion & Comments