MHS had elaborated a system to guarantee Yield on wafers delivered to the customer even if customer does the probe.
At Product / Process qualification stage:
To determine a representative Yield on a new product / Process, MHS had developed and recommend to apply a 3 yield statically consecutive lots including a lot DOE to validate the robustness. Yield target is defined and commonly agreed with the customer based on these results.
In production:
Depending on the market (industrial, commercial, automotive, military or space) special threshold could be applied.
 Zero Yield thresholds: wafer below 50% of the yield target
Maverick thresholds: wafer below Yield target minus 3sigmas (Nantes).
Additional multiple single site fails would also give maverick results on Swindon on any WAT test.
MHS also proposes to take the leadership, with the customer participation, to any product analysis on reject.
Continuous improvement:
Trough the periodic internal processes review (ISO/TS 16949 approach) and with new customer requirements issued from the customer business review, MHS defines and manages internal action plans to increase mechanical or electrical yield.
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