Page 4 - april2020_032720previewaa.indd
P. 4

APRIL 2020       TAP TIMES          -4-          Parts List (QPL) where each device must
                                                                be qualified and certified.


                        Primer (from 3)
                                                                Customer requirements
                                                                Conversion of Customer Requirements is
        RF and Microwave hybrids (also called                   the engineering and quality process that
        multi-chip monolithic microwave                         reviews the customer specification or stan-
        integrated circuit (MMIC) modules, multi-               dard product data sheet and insures the
        chip RF modules) must comply to the                     end product meets all the requirements of
        requirements of MIL-PRF-38534: GENERAL                  MIL-PRF-38534.
        SPECIFICATION FOR HYBRID
        MICROCIRCUITS to supply product to the                  It verifies that the design meets the elec-
        hi-reliability military and space markets.
                                                                trical performance and that the
                                                                process/materials are qualified, the level
                                                                of testing (class level) is correct, and all
        Commercial, off-the-shelf                               required deliverables (data, traveler, etc.)
        The “PRF” in the specification number                   are delineated.
        means it is a performance specification.
        This dates back to a 1994 memo  written
                                                2
        by U.S. Secretary of Defense William
        Perry to use commercial off-the-shelf
        (COTS) components in military systems.



        The Department of Defense (DOD) re-
        sponded by generating performance
        specifications as a way to reduce cost and
        enable the introduction of COTS
        components by not requiring ridged mili-
        tary specifications.


        The end user can now specify the require-
        ments in the “detailed procurement speci-
        fication”. All testing is performed in accor-           Avionics,  military  systems  and  spacecraft  demand  com-
        dance with MIL-STD-883 Test Method and                  ponents  that  can  survive  the  strain    of  severe  environ-
        Procedures as listed:                                   ments, such as the first stage rocket booster of the Arte-
                                                                mis. (NASA)

         1001 to 1999 Environmental tests
         2001 to 2999 Mechanical tests                                   What Does QML control?
         3001 to 4999 Electrical tests (Digital Micro-
            circuits)                                            • Processes and Materials qualified
         5001 to 5999 Test procedures (Linear                   • Design and Manufacturing Process Controlled
            Microcircuits)                                       • Materials verified prior to assembly
                                                                 • 100% Testing on each device (Screening) Group
                                                                 A conformance “Shake and Bake” test)
        Performance specifications                               • Sample Testing (Periodic Inspection) Group B,
        Performance specifications use a qualified                 C, and D)
                                                                 • Quality Management System audited by DLA
        manufacturers/materials list (QML)                        • Radiation levels delineated and Radiation test
        philosophy where each process and mate-                     ing certified.
        rial that is used to build the device is qual-
        ified and certified instead of a Qualified                                                     next page
   1   2   3   4   5   6   7   8   9