Defect-Fault Mapping Calculator

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Explanation	Calculator
A conversion matrix maps the defect spectrum (dj) to the fault spectrum (fi). Units on the fault spectrum = fraction of devices under test that are defective due to fault type i. Units on the defect spectrum = fraction of devices under test that are defective due to defect type j. How can we determine Cij? Click here to see.
The defect spectrum is the average number of defects per device under test per defect type.   dj is the number of defects of defect type j in the device under test.  n is the number of elements in the device under test.  dpmj is the defects of defect type j per million elements (ppm). For example: element = wirebond, device = die assembled to a printed wiring board, defect type j = broken wirebond.  Note,
fij is the fraction of all devices under test that are faulty due to fault type i before testing that are related to defect type j. fij = dj Cij  if d2 = 0.2 (20% of all devices under test are defective due to broken wirebond defects (defect type 2); and C12 = 0.7 (70% of all broken wirebond defects appear as open faults (fault type 1).  Then f12 = 0.14, or 14% of all devices under test that are faulty due to open faults can be related to broken wirebond defects. Note,   yield = 1 - fraction of defective devices under test.
Build the entire conversion matrix and use it to determine the fault spectrum.  The sum of the fault spectrum elements (or the defect spectrum elements) is the fraction of defective devices under test. Note, the equality above is only true if defects are "conserved", i.e., every defect is detectable as some type of fault, i.e., the columns of the conversion matrix all sum to 1.0.  yield = 1 - fraction of defective devices under test.
Fault coverage is the fraction of faults detected by a test activity.  Fault coverage is also know as "fault cover", "test coverage", or "test efficiency".  Fault coverage is related to defect coverage by the following equation, dcoverj is the fraction of all devices under test with detected defects of defect type j.  The total defect coverage is given by,