Information about 0.5mm pitch BGA

[Stevo]

Wow... these things are tiny!

I have a board using a 13x13, 7mm^2 body, 0.5mm pitch bga package. I've done blind and buried via boards before, but never a microvia board. I've played around with a couple designs using microvias, but they weren't quite the same as this design. This board is approximately 1"x2" and has 600 pins.

I've been searching and reading about microvia fabrication and design processes and board stackups. There seems to be a lot regarding 1mm pitch devices, but not 0.5mm bga devices. I have 17 years of layout experience.

Can anyone point me to a book, a website, any other resource, or even your own experience with this technology scale?

Thanks,
Steve

 

[Uky]

.5mm pitch bga

I have made several boards using 0.5 mm pitch BGA's. All of them were made using: Mask>pad (the other way around is also possible = mask defined pad) but this requires extra attention when placing the mask). Plugged micro-via in pad. 3 mill trace width and clearance while inside the BGA package area. As soon as the trace leaves the package area I increased size and clearance (3 mill traces are a pain in the a** for the board makers). BUT, and this is important: It is very important to check with your board maker that he has the capability to produce thes board before you submit the manufacturing file set...