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Cog·i·ta·tion [koj-i-tey'-shun] – noun: Concerted thought or
reflection; meditation; contemplation.
Kirt [kert] – proper noun: RF Cafe webmaster.
The Next Assembly Line Robot - Antifreeze
Antifreeze now has a new use. Scientists at the University of Minnesota
have discovered a way to exploit the surface tensions properties of
ethylene glycol to cause pairs of components with complementary shapes
to be attracted to each other and self-assemble. In an experiment, hundreds
of LED chips and silicon carriers were mixed in a container of ethylene
glycol, heated, and then shaken to cause the complementary LED/carrier
shapes to mate while in the mixture. The system was then heated to a
temperature that allowed solder dollops in the carriers to melt and
make a connection to the LED die pads. After cooling and rinsing, the
assembled parts were removed and inspected. 600 assemblies were produced
in just two minutes - a 100% yield! A second and final similar step
then assembled the LED/carrier pairs onto a surface-mount package and
yielded 97%. This process is being considered for similar high volume
manufacturing operations that involve parts too small to be efficiently
handled with robotic or human means.