TABLE OF CONTENTS The lead-free thermal-fatigue solder-joint reliability of high-density packages, such as the 1657CCGA, SMC8, 144BGA, 256PBGA, and 388PBGA, has been determined by temperature cycling tests and statistical analyses. The data acquisition system, failure criterion, and data extraction method have also been presented and discussed. The test data for over 7,000 cycles between 15 20 C and 90 95 C, in a 40 min cycle, have been analysed with certain levels of confidence. Some important results are summarized in the following.
For the 1657CCGA, there were no solder joint failures on all the OSP PCBs with the Sn-Pb solder paste.
The quality (mean life) of the lead-free solder pasted 1657CCGA solder joints on Ni-Au PCBs is better than those on Sn-Cu HASL PCBs with an 83 per cent confidence level.
In 98 out of 100 cases, the mean life of 1657CCGA solder joints with lead-free solder paste on a Ni-Au PCB is better than those on an OSP PCB.
For the lead-free solder pasted 1657CCGA, the solder joint mean life on a Sn-Cu HASL PCB is better than that on an OSP PCB, but with only 66 per cent confidence. This confidence level may not be high enough to make sound decisions.
At 5,000 cycles, the reliability of all of the lead-free solder pasted 1657CCGA solder joints on all of the Sn-Cu HASL, Ni-Au, and OSP PCBs is 90.8 per cent, with a 50 and 76.8 per cent at a 97.5 per cent confidence levels.
For all of the lead-free solder pasted 1657CCGA...
