Windchill Risk and Reliability Desktop Help > Windchill Prediction > Part Parameters Required for Predictions > MIL-HDBK-217 Part Parameters > MIL-HBDK-217 Quality Levels > Pi Q Values
Pi Q Values
If the device is screened to custom or intermediate programs, you can enter a Pi Q value directly in Pi Q Value. Additional information on determining Pi Q values from screening programs appears below. You can insert custom quality levels in Prediction Values Library files. For more information, see Prediction Values Library Files.
You may directly enter a value for the quality factor (Pi Q). If the Pi Q value is left at #.#, the value entered for Quality is used to determine the quality factor. For custom and other screening and quality programs, the value of Pi Q can be computed from the following criteria:
Pi Q = 2 + (87 / Sum of Point Valuations of Screenings)
The point valuations are given in the following table. TM refers to the MIL-STD-883 Test Method. When a number sign (#) appears in parentheses after a group number, it means that it is not appropriate for plastic parts. If a tilde (~) appears in parentheses after a point valuation, the point valuation is only assigned if used independent of groups 1, 2, or 3. If a percent sign (%) appears in parentheses after a point valuation, the point valuation is only assigned if used independent of groups 1 or 2.
Group
MIL-STD-883 Screen/Test (Note 3)
Point Valuation
1(#)
TM 1010 (Temperature Cycle, Condition B Minimum) and TM 2001 (Constant Acceleration, Condition B Minimum) and TM 5004 (or 5008 for Hybrids) (Final Electricals at Temp Extremes) and TM 1014 (Seal Test, Condition A, B, or C) and TM 2009 (External Visual)
50
2(#)
TM 1010 (Temperature Cycle, Condition B Minimum) or TM 2001 (Constant Acceleration, Condition B Minimum) TM 5004 (or 5008 for Hybrids) (Final Electricals at Temp Extremes) and TM 1014 (Seal Test, Condition A, B, or C) and TM 2009 (External Visual)
37
3
Pre-Burn in Electricals TM 1015 (Burn-in B-Level/S-Level) and TM 5004 (or 5008 for Hybrids) (Post Burn-in Electricals at Temp Extremes)
30 (B Level) 36 (S Level)
4(#)
TM 2020 Pind (Particle Impact Noise Detection)
11
5
TM 5004 (or 5008 for Hybrids) (Final Electricals at Temp Extremes)
11 (~)
6
TM 2010/17 (Internal Visual)
7
7(#)
TM 1014 (Seal Test, Condition A, B, or C)
7 (%)
8
TM 2012 (Radiography)
7
9
TM 2009 (External Visual)
7 (%)
10
TM 5007/5013 (GaAs) (Wafer Acceptance)
1
11
TM 2023 (Non-Destructive Bond Pull)
1
Sequencing of test within groups 1, 2, and 3 must be followed. Nonhermetic parts should be used only in temperature/humidity controlled environments such as Ground Benign.
Example 1
Manufacturing performs Group 1 test and Class B burn-in:
Pi Q = 2 + (87 / (50 + 30)) = 3.1
Example 2
Manufacturing performs internal visual test, seal test, and final electrical test:
Pi Q = 2 + (87 / (7 + 7 + 11)) = 5.5
For other commercial or unknown screen levels, Pi Q = 10.
MIL-HBDK-217 Quality Levels