PRO COOL® uses the following yields from TWO COOL® in analysis and reports:
• Equipment
• Parametric
• Defect-Limited (Wafer Fab version only)
PRO COOL® also allows definition of an inspection scrap value. Capacity analysis considers the impact of equipment yield and inspection scrap on the volume of work-in-process. Defect-limited yield and parametric yield losses are not considered in capacity analysis.
Equipment yield losses from TWO COOL® are assumed to exit the process at the tool incurring the equipment yield loss. PRO COOL® assumes that defect and parametric yield losses will be identified at an inspection or test step. The impact of defect and parametric yield losses on work-in-process volume can be reflected in PRO COOL® by setting the appropriate inspection scrap value (See the "Process Step Sequence" dialog box in Chapter 4 of the PRO COOL® User's Guide).
Scrap percentages and costs are calculated in TWO COOL®. The PRO COOL® Inspection Scrap % values must be consistent with the TWO COOL® yields for proper allocation of scrap costs. For example, a PRO COOL® analysis of a three step process with the last step including inspection would compare to the three TWO COOL® parametric yields as shown in the table below.
| TWO COOL® | Parametric Yield | PRO COOL® | Inspection Scrap % |
| Tool Group A | 99% | Step A using Tool A | 0% |
| Tool Group B | 99% | Step B using Tool B | 0% |
| Tool Group C | 99% | Step C using Tool C (Inspection Step) | 3% |
| TWO COOL® Yield | 97% | PRO COOL® Yield | 97% |
Reporting Yield in PRO COOL®
The Management Summary Report shows Line Yield and Composite Yield for the process. Line Yield is defined as follows:
Yield = Ships/Starts
Composite Yield is the product of Equipment Yield, Parametric Yield, and Defect-Limited Yield for each tool group:
YC = (YE x YP x YD)Tool Group
Tool Group yields are presented on several reports:
| | Equipment Yield | Composite Yield | Inspection Scrap |
| Tool Group Report | Yes | Yes | |
| Process Step Report | | Yes | Yes |
| Minimum Cycle Time Report | Yes | Yes | |
| Ships by Process Step Chart | Yes | | Yes |
Composite Yield is reported for information only and is not part of the PRO COOL® cost and capacity analysis.
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