Qualification of the Assembly Process of Flip-Chip BGA Packages ...

Initial Inspection and Electrical Verification
Texas Tech University, Nivetha Shivan, May 2012
The devices from TV1~4 underwent C-SAM analysis and there was no delaminations or
voids that were found. These images could be used as reference images for comparing the
results after pre-conditioning and temperature cycling stress tests to understand what
caused the failure, if any. All devices PASSED electrical test that was done after C-SAM
analysis.
MSL3 Pre-conditioning Results
120 devices per TV were subjected to MSL3 pre-conditioning process according to the
qualification plan. These devices were tested electrically and analyzed using acoustic
microscopy and found to PASS without any electrical failures or anomalies in the CSAM
images.
Temperature Cycling Results
30 devices per TV out of the 120 from the MSL3 lots were subjected to temperature
cycling (JEDEC condition C) for 300 cycles which is the conditional qualification read
point. Following which, they were electrically tested. The devices were then subjected to
200 additional cycles which defines the full qualification read point and another 500
additional cycles which makes the FYI read point. Similarly, 30 devices went through
Pressure cooker tests and were electrically tested at the three read points – 96 hours, 168
hours and 288 hours. Tables 6.6, 6.7 and 6.8 show electrical test results post MSL3, TCT
and PCT.
Table 6.6: Electrical Test Results Post MSL3
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