BGA on 2 layer PCB

[Howardlong]

Hello, I wont be using breakout board.

I will solderng the BGA on the main board and a complement PCB for power plane emulation, that will be soldered with many wires to stitch the power planes together.

This will also add rigidity.

OK, but if you’re not doing it “properly” from the beginning for adhoc prototyping, I was offering you an alternative.

If you are keen about the importance of the power plane (and I agree that you should be), then I would suggest that trying to fudge it is indeed a false economy as mentioned. A big problem of going off piste in this way is that you’ll almost innevitably spend a lot of time second guessing your workaround rather than concentrating on the project itself.

I agree that the waiting game and costings for four layers is a little frustrating, but in relative terms I’d strongly suggest that in the big scheme of things it’s far less risky and delivers a more reliable result.

The reason I mentioned the breakout solution was that they are designed for prototypes, which is what you’ve said you’re making, and in relative terms they are cheap and available off the shelf. Prototypes don’t have to be neat or elegant from an engineering perspective (cf Jim Williams!). Of course, if your “prototype” is more of a smoke and mirrors marketing thing for a startup or Indiegogo campaign then whether it works or not is of little relevance, and perceptions are everything.

[EEVblog]

BGA on a 2 layer board?
Ha, ha, ha...... good luck with that.

Easy:

https://youtu.be/7AFGcAyK7kE?t=44m21s

[Berni]

If you don't plan to bring out too many pins then its perfectly doable.

Not having a proper ground plane under it might affect things like jitter specs on PLLs, rise times on signals, RF interference produced by the board etc. But a MCU will run perfectly fine

But as people have said 4 layers are not actually that much more expensive in mass production, its just the prototype runs of board that are significantly more expensive. You have to factor in the extra time. If you make10 bucks an hour and you spend an extra 5 hours to get it to fit on 2 layers then you would have likely saved money by paying for 4 layers and saving yourself the work.

[ebastler]

 

Okok
4 layers is what I gonna do.