I recently got an email from Practical Components about its new 0.3mm pitch evaluation board and dummy 0.3mm pitch BGA. Now, we’ve been assembling 0.5mm and 0.4mm pitch BGAs for years. Those sizes are kind of not really anything special anymore. We’ve even been putting together PoP (package-on-package) for a couple of years. But we’ve yet to see anything smaller.
Just looking at the numbers, 0.3 may not look all that much smaller than 0.4, but that’s 25% down. Thinking of it in those terms makes it much more intimidating. I haven’t found the pad dimensions yet, but just using rough estimates, a 0.003″ trace would have about 0.0015″ on either side for a between the pads trace. That’s getting pretty dangerous. Likely, you’d have to do every thing with filled and plated-over vias in the pads. (No Open Vias! Not one. Don’t do it.)
I can see a lot of good future use for this size in miniature devices; more processing power in hearing aids and embedded medical devices, for a start. I don’t know how necessary 0.3mm pitch will be for phones. They seem to have stabilized in size and the trend is more toward system in chip than it is toward more shrinking. Regardless, I would expect that in a year, we’ll be seeing mainstream parts in this form factor.
Duane Benson
Go ask Alice
I think she’ll know
How to run your escape routing
With .4mm pitch and less (“.3mm pitch will be a problem” you can take that to the bank) we’re reaching the limit on what we can do with current pcb technologies to design these chips onto boards. We’re moving into .07mm trace/spacing, but!!!! still having to utilize .2mm buried vias, if you’re dealing with low-tiered, cheap product costs customers. As long as you don’t have to via beyond Layer 3, you can get away with uvia technologies, and make it work. Anything beyond layer 3… you’ve reached the limit. As an OEM, you’ll be eating your profits trying to get customer designs corrected. Ka-ching!
Pingback: It (0.3mm) Finally Happened | Hot Wires