Issue:
At 60'C test PCB Fails. Operator did simulation. Use of Heat Gun to heat up the BGA to 60'C while PCB is powered and running. At 60'C BGA fails. When pressed system is back which means that something becomes open. Sent BGA for SEM and found that there are cracks between the Nickel and the Copper layer of the BGA package where the joints are connected (BGA Package PAD).
I was told that it is because of my thermal profile. Visited my profile and had this measured parameters: Dwell Time : 80 - 90 seconds at 183'C Soak Time: 60 secs at 165'C Ramp Rate: 0.8'C per sec. Cooldown Rate: 1.2'C/sec Peak Temp: 223'C
What's your opinion? Is it the package or the SMT assembly process? What could be wrong with the process in Both BGA assembly and SMT process?
thanks and regards, Dreamy
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