Wright Williams & Kelly
TECHNICAL ALERT #19
If you do not enter a redo rate or use TWO COOL® for Wafer Fab, the following discussion does not affect your results.
It has been determined that the reduced number of units produced as a result of redo rate are treated the same as parametric limited yield loss. This causes the reduction in units produced to be costed as if the units were produced and then scrapped.
This problem can be corrected by the end user by following the procedure below:
Open Excel and then open Backend1.XLS or Mask1.XLS, go to cell F279 and change the equation to read =((F239*(1-O18))-F240)*O31/7, go to cell A2 and save the file to the exact same name.
Open Excel and then open Backend2.XLS or Mask2.XLS, go to cell F359 and change the equation to read =((F319*(1-O23))-F320)*O36/7, go to cell G359 and change the equation to read =((G319*(1-P23))-G320)*P36/7, go to cell A2 and save the file to the exact same name.
This issue will be corrected in future versions of TWO COOL®.