BGA resoldering - adapters maybe

[sicco]

I have two TDS3000 scopes where the PowerPC CPU is a 352 pins NXP860 CPU was faulty (or I thought it was...) and it was hot-air soldered from the main board. Since then I obtained a few new chips, nicely balled, and I tried to solder those back on. First with a 'manual' Aoyue 968, and later also with an IR6500 rework station. Even got myself an Alibaba re-balling kit. But long story short, none of my attempts were 100% successful. There were always a few pins that were not soldered properly. Or shorts. By now the mainboards have lost some solder pads and tracks. So soldering it back on (without patch wires...) will never succeed anymore.

Now my question: would it not be feasible to get some multi-multi-layer flex PCB with tinned through hole vias for each BGA pin that I can then hand-solder pin by pin, first the BGA chip to the flex PCB, and then the flex PCB to the main board.

Or maybe something with 4 quadrants, and connectors so that I can click-in 4 times for north, east, south west 4x? Only the outer square 4 pin rows have real signals, the inside box is just GND and +3V3 pads. With type type of SMD click on connectors used nowadays in smartphones etc, it should be possible to do 4 pin positions every ball pitch distance?

Anyone offering such 'repair kits'?
What would they be called if they do exist? I mean what search term would I type in to find them?

[tooki]

I’m sure it could be made, I just wouldn’t expect it to work very well. The added parasitics (capacitance and inductance) and trace lengths added could wreak havoc on high-speed signals like memory buses.

[chihaxinh]

You need provide pcb condition picture , see to what pad missing , if pad missing in pcb mainboard, you can remake pad . Hard to rework because CPU and mainboard have large GND zone in center.

Hope you can repair mainboard.
Nam.