Features of resistors for aerospace applications
Use of lead-containing solder terminals
In general electronic parts, lead-free terminals are the mainstream, but resistors for space applications use lead-containing solder terminals for the following reasons.
Improvement of the reliability by suppressing whisker*
It is known that for Sn and Zn, whiskers grow more prominently in the zero-gravity environment such as outer space than on the ground.
Whiskers have been observed to grow faster in lead-free solders such as Sn for the external electrodes of electronic components and Sn-Ag-Cu used as a joining material. On the other hand, they have been observed to grow slower in Sn-Pb-based lead-containing solders.
Since whiskers can cause short circuits between circuits and poor continuity, it is necessary to use materials that do not easily generate whiskers.