| yes, the problem is the unleaded alloy itself, soldering alloy used originally in hp dv series is a very hard alloy, and that suffer a lot during thermal cycles during the working of the laptop, day by day, during these thermal cycles crack easily occurs due to the hard nature of the alloy. this happens also because the chip is not cooled properly due to badly designed contact with the cooling pipe.
leaded alloy is much softer, and less sensitve to thermal cycles and it does not crack easily. of course, improving the contact of the chip with the coling pipe will add more reliability too. |