Binning disk drives during manufacturing by evaluating quality metrics prior to a final quality audit
View Patent ↗A method of binning disk drives by evaluating quality metrics prior to a final quality audit is disclosed. A number of disk drives are assembled, and a plurality of quality metrics are generated for each disk drive representing a plurality of operating characteristics. The quality metrics for each disk drive are evaluated for binning the disk drives into a plurality of lots including a first lot and a second lot. A final quality audit (FQA) is performed by executing a number of write and read operations for a plurality of the disk drives in each lot and classifying each disk drive as passing or failing the FQA. If the number of disk drives that fail the FQA out of the first lot falls below a first threshold, the first lot is classified as acceptable for a first tier customer. If the number of disk drives that fail the FQA out of the second lot falls below a second threshold, the second lot is classified as acceptable for a second tier customer.
1. A method of manufacturing disk drives comprising the steps of:
(a) assembling a number of disk drives;
(b) generating a plurality of quality metrics for each disk drive, wherein the quality metrics correspond to a plurality of operating characteristics;
(c) evaluating the quality metrics for each disk drive for binning the disk drives into a plurality of lots including a first lot and a second lot;
(d) performing a final quality audit (FQA) by executing a number of write and read operations for a plurality of the disk drives in each lot and classifying each disk drive as passing or failing the FQA;
(e) if the number of disk drives out of the first lot that fail the FQA falls below a first threshold, classifying the first lot as acceptable for presenting to a first tier customer; and
(f) if the number of disk drives out of the second lot that fail the FQA falls below a second threshold, classifying the second lot as acceptable for presenting to a second tier customer.
2. The method of manufacturing disk drives as recited in claim 1 , wherein the first threshold is less than the second threshold.
3. The method of manufacturing disk drives as recited in claim 2 , wherein if the number of disk drives that fail the FQA out of the first lot falls between the first and second thresholds, classifying the first lot as acceptable for presenting to the second tier customer.
4. The method of manufacturing disk drives as recited in claim 1 , further comprising the step of combining the quality metrics for each disk drive into a composite score representing an overall quality metric for each disk drive, wherein the step of evaluating the quality metrics of each disk drive comprises the step of evaluating the composite score.
5. The method of manufacturing disk drives as recited in claim 4 , wherein the step of evaluating the composite score of each disk drive for binning the disk drives comprises the step of comparing the composite score to a binning threshold.
6. The method of manufacturing disk drives as recited in claim 5 , further comprising the step of selecting the binning threshold relative to the number of disk drives allocated to each lot.
7. The method of manufacturing disk drives as recited in claim 6 , wherein the binning threshold is adapted during the binning operation.