PART - In most cases a nonrepairable, throwaway, electrical/electronic
item (e.g., integrated circuit, resistor, capacitor, diode, transistor,
transformer, hybrid, etc.). Some hybrids are repairable.
PART FAMILY - This term is used in calculating part history and failure
rates. A part family is defined as a group of parts that are manufactured on
the same production line which may have different functions but utilize the
same manufacturing techniques and same part technology, i.e. VLSI 1 micron
parts cannot be grouped with VLSI .8 micron parts.
PARTICLE IMPACT NOISE DETECTION (PIND) TEST - An amplified acoustical
test using electromechanical methods for detecting loose particles in
the cavity of an electronic device.
PASSIVATION - The growth of an oxide layer on the surface of a
semiconductor to provide electrical stability by isolating the transistor
surface from electrical and chemical conditions (not to be confused with
PERFORMANCE MONITORING - This terminology is used during the temperature
cycling and refers to the powered on functional monitoring of the equipment
being screened. Performance monitoring should be limited in length, but
still exercise as much of the hardware as possible. When performance
monitoring complex systems, a complete functional test may not be a feasible
alternative due to the testing time required to fully performance monitor
the entire system. If a system test takes a long time, generally over 10
minutes, the screening effectiveness will be reduced and the cost to perform
the screen will be driven up. If feasible, alternatives to long testing may
be used. These include switching parameters tested each cycle until the unit
has exercised all feasible functional operations and a scaled back testing
PRINTED WIRING ASSEMBLY (PWA) - A single printed wiring board containing
a group of interconnected parts which are mounted thereon. Equivalent
terminology is circuit card assembly and printed circuit assembly.
PRINTED WIRING BOARD (PWB) - An unpopulated printed wiring assembly (bare
board), Equivalent terminology is circuit card and printed circuit card.
PRODUCTION LOT - A production lot consists of devices manufactured on the
same production line(s) by means of the same production technique,
materials, controls, and design.
PRODUCTION LOT DATE CODE - A three or four digit number which identifies
the six-week period of time in which an inspection lot was sealed. The first
two digits identify the year (only one if single year). The last two digits
identify the week.
RANDOM VIBRATION STRESS SCREEN - Manufacturing process using vibration
excitation where magnitude and frequency are specified by a probability
REPROCUREMENT - An older electronic system that has not been designed
during Full Scale Development and/or during any of its previous production
procurements to conform with the ESS requirements in this manual.
SPECIFICATION CONTROL DRAWING - A detailed description of the materials,
dimensions, and workmanship for something to be built, installed, or
manufactured. The SCD should contain upgrade screening requirement when
STANDARD MILITARY DRAWING (SMD) - An acquisition document developed under
the SMD Program which controls the parameters and screens of microcircuit
devices not available to the requirements of MIL-M-38510.
SYSTEM - A group of units interconnected or assembled to perform an
overall electronic function.
THERMAL CYCLING STRESS SCREEN - Manufacturing process using thermal
excursions, to expose or surface defects, where a part, PWA, module, unit,
or system is repeatedly driven from a high to low and low to high
temperature limits. The transition between temperature limits is defined in
terms of the temperature rate of change which is expressed in degrees per
UNIT - A group of modules interconnected or assembled to perform a
subfunction within a system.
UPGRADE SCREENED PARTS - Parts which do not meet the minimum quality
levels defined in Section 2.2.1, but
have been subjected to the screening process described in Table 2-l or Table