Small BGA pad size-likelihood of success?

Forum Small BGA pad size-likelihood of success?

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945 1 Feb 24.2020, 22:26:20

Hi guys,
I'm trying to fan out a 36 pin BGA for prototyping. I tried to fan out a 36 pin 0.4mm pitch BGA on the top layer with a random 36 ball BGA I had in my library assuming a 3/3 mil process and it wouldn't work - the pad size was 200 micron as recommended on its datasheet. Makes sense since at 200 micron, assuming an X/X mil process capability yields X = 66.7 micron => 2.7 mil < 3 mil.
I looked up the datasheet for the IGLOO Nano UC36 package; they recommend NSMD, pad diameter of 230 micron with a 330 micron mask, suggesting that the pads are 34% smaller than recommended!
I'm just wondering based on others' experience, how this is likely to go assuming I use 6 mil pads with a 10 mil mask? I'm just prototyping, so trying to keep the NRE cost down.

Thanks in advance for any guidance.
Cheers,