MI L-R-63993A (AR)
3.3 Design and construction. The resistor network shall
consist of a ceramic substrate with conductors, insulating and
resistance patterns applied by a thick film techniques in the
order necessary to meet the requirements of this specification.
The resistance patterns for the trimmable resistors (R2, R4, R7)
shall be on the top side of the substrate and positioned for YAG
laser trimming as specified in detailed drawing. The dc resis-
tance between terminals shall be in accordance with the resistance
table and network schematic of the detailed drawing.
3.3.1 Solderability. Terminal leads shall be free of foreign
material, flash marks, and other irregularities? and conform to
the requirements of the detailed drawing.
3.3.2 Enclosure. Resistor networks shall be encapsulated
sufficiently to withstand the environmental tests specified and
shall not be damaged by standard automatic insertion machine. The
encapsulating material shall be compatible with YAG laser trimming.
3.3.3 Physical dimensions. The physical dimensions of the
resistor network package shall comply with all requirements in
detailed drawing. Package dimension-inspection shall be performed
in accordance with MIL-STD-883, Method 2016.
3.3.4 Terminal leads, terminal and pads. Insertion terminal
leads shall be termed to allow insertion onto printed wiring board
by automatic insertion machines. Terminals shall be mechanically
secured to the substrate by soldering or welding and shall be
electrically bonded to the network terminations. All solder used,
to provide electrical connections, or to secure terminals shall
have a minimum solidus temperature of 182°C (360°F).
Corrosive fluxes shall not be used. There shall be a minimum of
90% of the terminal connection area in electrical contact with the
network terminal pad.
3.4 Electrical characteristics.
3.4.1 Network characteristics. When resistor networks are
subjected to the condition or test specified in Table 1, the per-
cent change in resistance in each resistor element shall not exceed
the value specified in Table I. The examination and test require-
ment method shall be in accordance with MIL-R-83401 for character-
istic M resistor network unless otherwise specified herein.
3.4.2 Maximum voltage. The maximum continuous working voltage
applied to the resistor elements shall be 10 volts dc or 10 volts
rms (root-mean-square, sine-wave).