I'm working with a few BGA chips of a very fine pitch 0.5mm even smaller sometimes. What is the practices for being able to essentially breakout all the connections from these chips? I've just been dead bugging them for now but that's a very time consuming process and it has caused damage to a few of my chips before.
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\$\begingroup\$ I seem to recal one of the FGPA guys I worked with saying that the best (and only propper) way to do it is to have every pin go to a via on a PCB. Don't let the PCB house tent the via, so you can solder tiny probe wires to them when needed. Additionally, if you have silkscreen on both ends (you really should for a prototype board), you can have a grid printed on the back so you can more easily locate the pin you need. At the speeds a lot of these devices operate, you just can't easily add stuff without changing operation - hence you need a proper board and only attach probes where needed. \$\endgroup\$– Joren VaesCommented Sep 16, 2017 at 8:09
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\$\begingroup\$ So you're proposing make a board with through hole vias correct? \$\endgroup\$– E SkalCommented Sep 16, 2017 at 8:19
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\$\begingroup\$ No, just standard vias, but generally you can solder to these if you are a little carefull. If you are working with .5 mm pitch BGA parts, you are going to likely need a via for every pin anyways. \$\endgroup\$– Joren VaesCommented Sep 16, 2017 at 8:20
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\$\begingroup\$ 0.5mm pitch is pretty small. It is actually hard just to figure out how the traces will escape. I suggest you stay away from this unless you have no choice. \$\endgroup\$– user57037Commented Sep 17, 2017 at 3:39
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0.5mm BGA gets expensive: look here page 11.
If you do it properly (as shown in the document) you'll need vias with 0.12mm drill and 0.25mm pad. This is not basic cheap PCB prototyping, it's real high quality manufacturing. You can get 4-layer for $40 these days, but not with these tolerances, this will cost several hundreds.
If you put the solder balls on top of vias the solder will get sucked in, I don't know if it would work.
I'd recommend a BGA prototyping board but couldn't find any in 0.5mm pitch. YMMV. It may very well be cheaper to buy the chip manufacturers' eval board.
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\$\begingroup\$ Thanks for your answer. I have a Dev board for one of the chips I use. Otherwise I just dead bug as mentioned in the original question. Guess I'll just stick to it. \$\endgroup\$– E SkalCommented Sep 16, 2017 at 13:38