SBOA344A July   2019  – September 2022 LMX2694-SEP , SN55HVD233-SEP , SN65C1168E-SEP , TL7700-SEP , TLV1704-SEP , TPS73801-SEP , TPS7H1111-SEP , TPS7H1210-SEP , TPS7H2140-SEP , TPS7H2201-SEP , TPS7H2211-SEP , TPS7H2221-SEP , TPS7H3302-SEP , TPS7H4003-SEP , TPS7H4010-SEP , TPS7H5005-SEP , TPS7H5006-SEP , TPS7H5007-SEP , TPS7H5008-SEP

 

  1.   Abstract
  2.   Trademarks
  3. 1 Radiation Challenges
  4. 2 Temperature Range
  5. 3 Tin Whiskers
  6. 4 Cu Wire Risks
  7. 5 Plastic Outgassing and Moisture Absorption
  8. 6 Harsh Environment Qualification
  9. 7 Multiple Manufacturing Sites
  10. 8 Long Life Cycles
  11. 9 VID - Vendor Item Drawing
  12. 10Conclusions
  13. 11Revision History

3 Tin Whiskers

Many commercial and automotive products now use pure tin (Sn) as the lead finish or as the main constituent of balls in ball grid arrays (BGA) for a low cost, ecologically friendly solution.

There is a risk that the matte Sn plating, now commonly used on COTS and AEC-Q100 PEMs, may grow whiskers under harsh conditions long enough to short between two metal leads. In addition, these whiskers can break off, resulting in electrical shorts in other places in a module. In order to reduce this risk of failure, TI’s Space EP flow opts to not use any pure Sn terminations. Conformal coating is not a complete solution as it only partially retards whisker growth and the whiskers can still grow through coating. Numerous cases of satellite failures have been attributed to Sn whiskers.

TI’s solution is to not use pure Sn terminations. The termination on TI's Space EP products is Sn63Pb37 solder dip, NiPdAu plating or similar finish without matte Sn. For BGAs, TI Space EP products use Sn63Pb37 solder balls.