Don't try to solder on missing RAM.

It’s technically possible, but the difficulty level is “expert microsoldering with a high chance of bricking your laptop.” Even then, it often doesn’t work.

The problem isn’t just soldering. Yes, you’d need a hot air station, the correct BGA soldering balls, flux, and a steady hand. But RAM chips need to be matched to the memory controller and trained by the BIOS. Laptops with empty pads either had a lower-tier SKU that never received those chips in production, or the board layout is physically missing the necessary resistors, capacitors, and communication traces. You’d need the schematics, a donor board, or the exact chip model and configuration data (resistor straps).

And even if you get them soldered on perfectly, the BIOS might not recognize them. Many laptops lock memory configuration at the factory. One wrong BGA joint? Dead laptop.

There are a few cases where it works—like old ThinkPads with upgradeable RAM modules already socketed, not soldered. But for modern ultrabooks with empty RAM pads? The juice is not worth the squeeze.

If you need more RAM, buy a laptop with the configuration you need from the start, or choose one with soldered RAM that’s already maxed out. This is not a DIY upgrade path.