Development of Standards for Automation

In implementing automation it is reminded that the industry is faced with frustrations and dissatisfactions for lack of adequate progress in the standardization of the many facets of mechanized assembly--patterns, parts, assembly, inspection. An advance look is given of an R & D document, to be promulgated by the Signal Corps, titled Design Requiremehts for Printed Wiring Electronic Equipment." It is specified that modular units be employed, using printed wiring internally, also integrated through the use of printed wiring, and made adaptable to automation. Etched copper laminate is listed as preferred, line widths and spacings are specified, and the use of epoxy-type conformal coating is required unless the conductors are spaced 4 or 5 times the specified distance. It is presented that the diameter of component-parts leads should be within 0.015" of the mounting hole diameter, with clinching or flaring preferred, eyelets or other auxiliary devices to be avoided whenever possible. and through-plated holes to be paralleled with jumpers. Other advance information shows temperature control at 520°F and 5 seconds, and rosin-base flux in accordance with MIL-F-14256 (Sig C). Modular hole dimensions are tabulated, the essential information being: 0.300" or 0.150" spacing for "in-line" leads; 0.100" or 0.050" for other leads, with the smaller dimensions acceptable for subminiaturization; and additionally, 0.025" permitted only for extreme subminiaturization. Modular dimensioning is described as the cornerstone of the projected overall automation system; through its use the hope is expressed that we can raise our overall volumetric packaging efficiency from 15% to 40 or 50%.