Electronic – Is it possible to hand-solder a BGA without solder balls

bga

In an attempt to fix a short circuit on a BGA package, I ended up making things worse. The BGA is desoldered with some of the balls left on the BGA, some on the PCB, and some gone entirely. I don't have replacement solder balls or a stencil to replace them. Instead of ordering some, waiting and then reballing by hand, I'm considering pulling off all the balls and soldering the pins directly to the pads (preapply some solder to the pads and then use hot air). I haven't been able to find information about this online, so I assume that means it's not a good idea.

What is the benefit of the solder balls? Do they make soldering easier? Is it possible to solder the pins directly to the pcb pads? Between waiting for new solder balls to manually replace on the package (which I've never done before) and attempting to solder the bga directly to the pcb, which is recommended?

It's worth mentioning that another option is to buy another IC, since it's only $20. But I'd prefer to avoid that if possible.


Edit:

Unfortunately hand soldering without solder balls was more difficult than I expected. I tried this several times and was unsuccessful each time. Although I can't be sure about why it didn't work since I can't check the individual connections, the problem seemed to be that I wasn't able to preapply enough solder to the pads and pins since the metal contact area is so small. The height of the applied solder seemed to be consistent enough, so I don't believe that was the issue.

A possible alternative to get more solder would have been to spread solder paste over the pads. However, it's difficult to control the amount of paste with this method and it sounds like it would be asking for a short.

I think I'm just going to order a replacement IC. If the IC were more expensive, I'd probably try to reball by hand first.

Best Answer

Is it possible to do? Sure anything is possible. There are many examples of people hand soldering bga csp or wlp type packages. Some do it as a repair others do it for debugging. Mostly as dead bug style.

Is it practical? No. Depending on the chip the extra length of wire may cause issues especially with high frequency signals. Since you want to solder the chip back in place on the board, the amount of tinning and solder you add to the board and chip is crucial to ensure no shorts no cracks no uneven heating. You are liable to ruin the chip and board that way.