Oh gotcha. When I am tinning I can't tell if it's the right way or if I'm missing something.
Are you using rosin flux or water soluble?
I'm new to the reball process and your thread is helping me deal with the gotchas I'm encountering.
Clean the pcb good before applying the Kapton tape. If you don't it will not stick and will warp during heating. This is bad because it will create heat pockets under the tape that will damage components. I exploded a bank of 6 caps in this manner. When tinning the pads I would use a no clean flux. Water soluble is probably ok as well. Do not use RA flux on the chip. It's too messy and is unnecessarily hard on the pads when cleaning. You may get away with reballing the chip with a water soluble flux. However, DO NOT use water soluble flux to reattach the chip to the pcb. You need a flux that is semi-tacky that will hold it up during the process and help keep the chip in place.
Make sure it's a paste flux for reballing and reattaching.
What are you learning to reball?