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I am working on a board design that is near the limits of the PCB fabricator's capability. It uses 4mil stacked microvias, via in pad, blind and buried vias, 3 mil trace/space, buried capacitance (1mil dielectric), 12 layers, 1mm thickness, controlled impedance, etc. I was wondering if this is standard technology for modern smartphones (iPhone, HTC, Motorola, etc), or are they somehow getting by with looser design rules.

I am just wondering if the industry is making these types of boards by the millions. The reason I'm asking is our customer does not like to use technology on the bleeding edge due to reliability concerns.

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  • \$\begingroup\$ What's more important? Size of the PCB or reliability? If it's reliability I'd ask the PCB fab for the limits that they can achieve 100% of the time... then maybe go smaller when absolutely necessary. \$\endgroup\$ – Spoon Feb 23 '16 at 8:11
  • \$\begingroup\$ We are strictly limited in size. Reliability is a somewhat nebulous criteria, and I just wanted a ball-park type of answer if this technology is main stream or not. \$\endgroup\$ – SDahl Feb 23 '16 at 8:25
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    \$\begingroup\$ Not all PCB manufacturers are created equally, that cheap Chinese supplier might say they can do it but cannot deliver when he needs to. That more expensive supplier might be more honest on what they can deliver reliably. \$\endgroup\$ – Bimpelrekkie Feb 23 '16 at 8:33
  • \$\begingroup\$ Many smartphone SoCs use memory mounted on top of the SoC and that reduces requirements for the pcb significantly as memory does not have be routed on the PCB. Other peripherals are often low pin-count. On other hand smartphone PCBs are often very thin: 8 layers at 0.4mm in 2013: smtnet.com/library/files/upload/… \$\endgroup\$ – Jan Lucas Feb 23 '16 at 9:27
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Yes. In my former position I was part of a team that produced a smartphone. We used all of the techniques you mention except for buried capacitance (unless you're just referring to power/ground planes). We also used 01005 sized components and edge plating for mid-mounted connectors. I would say all of that is pretty standard in the smartphone world.

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