User manual

ASURO - 9
-
Part II. Electronics
3. Soldering instructions
ASURO has been designed with wired parts (in contrast to the much smaller surface mounted
devices). Fig. 3.1
demonstrates the smallest available package for the ASURO processor IC and
the wired device we have incorporated. The chip inside these devices however is the same!
Although soldering wired devices is much more comfortable and easier, especially untrained
persons have to consider some precautions.
Of course the printed circuit board must be unplugged at any time while soldering.
Switching off is not enough !!
REMOVE batteries
and power supplies!!!
3.1. Tip, solder and temperature
Fig. 3.2
demonstrates
the basics for soldering. The hot spot of the soldering equipment should
reach ca. 360ºC with lead-solder and ca. 390ºC for lead-free solder, while soldering axles may
be done at higher temperatures (420ºC). Electronics are to be soldered with a miniature tip, while
axles must be soldered with a larger tip area.
Use a slightly humid soldering sponge and apply some solder to the hot soldering tip. Shortly
before using soldering equipment, for the  rst time or after a break, old solder must be removed by
wiping off soldering remains from the tip.
Do use solder for electronic work with a diameter of 0.8 or 1 mm.
Fig. 3.1.: Comparison of the largest and smallest case in which the ATmega8L chip is available.